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Sample records for central corneal thickness

  1. Clinical significance of central corneal thickness and comparison of central corneal thickness

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    Özgür Çakıcı

    2014-03-01

    Full Text Available Significance of central corneal thickness has been increasing in ophthalmology practice. It is an important clinical evaluation tool especially prior to refractive surgery and in diagnosis of glaucoma and keratoconus. Refractive surgery is planned according to preoperative central corneal thickness measurements. Besides, in order to determine actual intraocular pressure, central corneal thickness is measured and corrected eye pressure is obtained. Today, devices used in measurement of central corneal thickness do the measurement according to two principles. First and relatively older method is ultrasonic method. Optic method is the second and more recent method. In daily practice, the most commonly used clinical method in measurement of central corneal thickness is ultrasound pachymeter. However, this measurement technique requires contact between cornea and probe and gives thinner measurement results compared to the methods that use optic principle. Recently, several technologic methods based on optics have been put in use; they provide advantages of non-contact technique and objective determination of central corneal thickness. Of these methods, most commonly used include Specular Microscopy, Optical coherence tomography, Laser Doppler Interferometry, Optical low coherence reflectometry pachymetry, Optic based topographic mapping (also called screening section pachymetry and Pentacam. In this article, it was aimed to evaluate importance of central corneal thickness in clinical use and compare measurement methods. J Clin Exp Invest 2014; 5 (1: 153-158

  2. Decreased central corneal thickness in ankylosing spondylitis.

    Science.gov (United States)

    Ortak, Huseyin; Inanır, Ahmet; Demir, Selim; Uysal, Alper; Şahin, Şafak; Sağcan, Mustafa; Önder, Yalçın; Alim, Sait; Demir, Ayşe Kevser

    2014-04-01

    Central corneal thickness and dry eye tests were evaluated in a study population consisting of 68 ankylosing spondylitis patients diagnosed according to the modified New York criteria, and 61 age-matched controls without ankylosing spondylitis. A full ophthalmological evaluation was performed on each subject. All subjects were screened for age, gender, HLA-B27, tear break-up time test, Schirmer test, and duration of disease. Central corneal thickness was measured under topical anesthesia with an ultrasonic pachymeter. The mean central corneal thickness was 537.3 ± 30.6 μm, range 462-600 μm, in ankylosing spondylitis patients, whereas it was 551.7 ± 25.2 μm, range 510-620 μm, in controls (p = 0.005). The Schirmer test result was 7.3 ± 5.9 mm for the ankylosing spondylitis patients and 11.7 ± 5.8 mm for the control group (p = 0.002). Tear break-up time was 7.3 ± 3.2 s for the ankylosing spondylitis patients and 14.0 ± 4.5 s for the control group (p ankylosing spondylitis. In addition, attention must be given to lower dry eye tests in surgical interventions such as photorefractive keratectomy and laser in situ keratomileusis in ankylosing spondylitis patients.

  3. Central Corneal Thickness in Adult Chinese

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The central corneal thickness (CCT) in age 48 years or less of Chinese was characterized and its relationship with gender, age, refraction and intraocular pressure (IOP) was investigated.Right eyes of 1669 participants were included in this study (880 men, 52.7 % and 789 women,47.3 %). Mean age of the samples was 23.8±5.9 years. After the examination of corneal topography and refraction, Goldman applanation tonometry was carried out by one physician. Tonometric values were the mean of three consecutive readings. Subsequently, another physician carried out ultrasonic pachymetry with the DGH 2000 AP ultrasonic pachymeter. Six measuremen ts were made at the center of the cornea of each eye. The mean value was used for analysis. The results showed that mean CCT of male participants was 551.33± 34. 62 μm, 5.79 μm more than that of female participants. Linear regression analyses revealed that CCT was negatively related with age only in female and no association was found between refractive status and CCT. IOP was positively related to CCT, and there was a difference in IOP of 1.5 mmHg (1 mmHg=0. 133 kPa) per 100 μm difference in CCT. Ocular hypertension group was prone to have thicker cornea than average. The results indicated that in adult Chinese CCT tended to decrease with aging in female only. IOP measured by Goldmann tonometry was positively related with CCT so that CCT should be measured along with IOP.

  4. Anatomical characterization of central, apical and minimal corneal thickness

    Institute of Scientific and Technical Information of China (English)

    Federico; Saenz-Frances; Martha; Cecilia; Bermúdez-Vallecilla; Lara; Borrego-Sanz; Luis; Jaez; J; osé; Marìa; Martinez-de-la-Casa; Laura; Morales-Fernandez; Enrique; Santos-Bueso; Julián; Garcia-Sanchez; Julián; Garcia-Feijoo

    2014-01-01

    ·AIM: To anatomically locate the points of minimum corneal thickness and central corneal thickness(pupil center) in relation to the corneal apex.·METHODS: Observational, cross-sectional study, 299 healthy volunteers. Thickness at the corneal apex(AT),minimum corneal thickness(MT) and corneal thickness at the pupil center(PT) were determined using the pentacam. Distances from the corneal apex to MT(MD)and PT(PD) were calculated and their quadrant position(taking the corneal apex as the reference) determined:point of minimum thickness(MC) and point of central thickness(PC) depending on the quadrant position. Two multivariate linear regression models were constructed to examine the influence of age, gender, power of the flattest and steepest corneal axes, position of the flattest axis, corneal volume(determined using the Pentacam)and PT on MD and PD. The effects of these variables on MC and PC were also determined in two multinomial regression models.·RESULTS: MT was located at a mean distance of 0.909 mm from the apex(79.4% in the inferior-temporal quadrant). PT was located at a mean distance of 0.156 mm from the apex. The linear regression model for MD indicated it was significantly influenced by corneal volume(B =-0.024; 95% CI:-0.043 to-0.004). No significant relations were identified in the linear regression model for PD or the multinomial logisticregressions for MC and PC.·CONCLUSION: MT was typically located at the inferiortemporal quadrant of the cornea and its distance to the corneal apex tended to decrease with the increment of corneal volume.

  5. Analysis of the horizontal corneal diameter, central corneal thickness, and axial length in premature infants

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    Ozdemir Ozdemir

    2014-08-01

    Full Text Available Purpose: To determine the horizontal corneal diameter, central corneal thickness, and axial length in premature infants. Methods: Infants with a birth weight of less than 2,500 g or with a gestation period of less than 36 weeks were included in the study. Infants with retinopathy of prematurity (ROP were allocated to Group 1 (n=138, while those without ROP were allocated to Group 2 (n=236. All infants underwent a complete ophthalmologic examination, including corneal diameter measurements, pachymetry, biometry, and fundoscopy. Between-group comparisons of horizontal corneal diameter, central corneal thickness, and axial lengths were performed. Independent sample t-tests were used for statistical analysis. Results: Data was obtained from 374 eyes of 187 infants (102 female, 85 male. The mean gestational age at birth was 30.7 ± 2.7 weeks (range 25-36 weeks, the mean birth weight was 1,514 ± 533.3 g (range 750-1,970 g, and the mean postmenstrual age at examination was 40.0 ± 4.8 weeks. The mean gestational age and the mean birth weight of Group 1 were statistically lower than Group 2 (p0.05. Conclusions: The presence of ROP in premature infants does not alter the horizontal corneal diameter, central corneal thickness, or axial length.

  6. The relationship between central corneal thickness and corneal curvature in adult Nigerians

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    E. Iyamu

    2011-12-01

    Full Text Available Purpose: The aim of this study was to provide average values for central corneal thickness (CCT and corneal curvature (CC and also to determine a regression model for the relationship between CCT and CC in adult Nigerians without glaucoma.Methods: A total of 95 subjects consisting of 56 males and 39 females aged between 20 and 69 years with mean age of 47.1 ± 14.1 years were recruited for the study. Central corneal thickness was measured by ultrasound pachymetry (SW-1000P ultrasound pachymeter, Tianjin Suowei Electronic Technology, China and corneal curvature was measured by keratometry (Bausch & Lomb keratometer H-135A, USA.Results: The average values of 550.1 ± 33.1µm and 43.0 ± 1.1 D were obtained for CCT and CC respectively. CCT significantly correlated with age (p=0.01, and the regression model predicts a decrease of 6.0 µm in CCT per decade. No significant association was found between CC and age (p=0.56. Also, no significant association was found between CCT and CC (p=0.07. Female subjects had significantly steeper corneas than their male counterparts.Conclusion: Central corneal thickness decreases with increasing age. Neither CCT nor age appear to be significantly correlated with corneal curvature. (S Afr Optom 2011 70(1 44-50

  7. Central corneal thickness and intraocular pressure in premature infants.

    Science.gov (United States)

    Sekeroglu, Mehmet Ali; Hekimoglu, Emre; Petricli, İkbal Seza; Karakaya, Jale; Ozcan, Beyza; Yucel, Husniye; Kavurt, Aysen Sumru; Bas, Ahmet Yagmur

    2015-12-01

    To evaluate the central corneal thickness (CCT) and intraocular pressure (IOP) of premature infants and to document correlation of them with gestational age, chronological age, and birth weight of infants. Using a hand-held applanation tonometer and a portable pachymeter, IOP and CCT of 170 premature infants were measured just before initial retinopathy of prematurity screening examination and re-measured 4 weeks after the first visit. The CCT and IOP were positively correlated during the first (r = 0.616, p premature infants with a smaller gestational age were found to be higher (p Premature infants with smaller gestational age have higher CCT and IOP values when compared to older infants. These values tend to become lower 4 weeks after the first examination as infants become older. The CCT and IOP were positively correlated with each other and both were negatively correlated with gestational age, chronological age, and birth weight during first and second visits. PMID:26286757

  8. Effect of fluidics on corneal endothelial cell density, central corneal thickness, and central macular thickness after phacoemulsification with torsional ultrasound

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    Sudeep Das

    2015-01-01

    Full Text Available Aim: To study the relative effects of high and low fluidic parameters on endothelial cell density (ECD, central corneal thickness (CCT, and central macular thickness (CMT after phacoemulsification with torsional ultrasound. Settings and Design: Prospective, randomized clinical trial based on a tertiary eye hospital. Subjects and Methods: The study included 65 patients in each group. Patients were randomized to either the high or the low flow group using a computerized random number table. The study was patient and examiner masked. All patients underwent phacoemulsification with torsional ultrasound. Visual acuity, ECD, CCT, and CMT were measured for all patients preoperatively at 2 weeks and 6 weeks postoperatively. Statistical Analysis Used: The Shapiro–Wilks test was used to assess the normality of the data. Mann–Whitney U-test with the P value set at 0.05 was used to compare the two groups. Results: Cumulative dissipated energy was significantly higher in the low flow group (16.44 ± 9.07 vs. 11.74 ± 6.68; P = 0.002. No statistically significant difference was noted between the two groups in the ECD, CCT, CMT, or corrected distance visual acuity at the end of 6 weeks. Conclusions: No significant difference was noted in the postoperative outcome between high and low flow groups. Parameters can be modified to suit the surgeon's preference, as both high and low flow parameters were found to have comparable postoperative outcomes.

  9. Central Corneal Thickness Measurement by Ultrasound versus Orbscan II

    Science.gov (United States)

    Faramarzi, Amir; Ziai, Hossein

    2008-01-01

    Purpose To compare Orbscan II and ultrasonic pachymetry for measurement of central corneal thickness (CCT) in eyes scheduled for keratorefractive surgery. Methods CCT was measured using Orbscan II (Bausch & Lomb, USA) and then by ultrasonic pachymetry (Tomey SP-3000, Tomey Ltd, Japan) in 100 eyes of 100 patients with no history of ocular surgery scheduled for excimer laser refractive surgery. Results Mean CCT was 544.7±35.5 (range 453–637) μm by ultrasonic pachymetry versus 546.9±41.6 (range 435–648) μm measured by Orbscan II applying an acoustic factor of 0.92 (P=0.14). The standard deviation of measurements was greater with Orbscan pachymetry but the difference was not statistically significant. Conclusion CCT measurements by Orbscan II (applying an acoustic factor) and by ultrasonic pachymetry are not significantly different; however, when CCT readings by Orbscan II are in the lower range, it is advisable to recheck the measurements using ultrasonic pachymetry. PMID:23479527

  10. Central corneal thickness vs Goldman´ tonometry. Study in suspecting patients of Glaucoma.

    OpenAIRE

    Elsa E. Cabeza Martínez; Damaris Peralta Palmero; Elena Triana Gutiérrez

    2010-01-01

    Measuring of the central corneal thickness through ultrasonic pachymetry, in several opportunities can contribute to diagnose glaucoma. The main objective of this research was to determine, the central corneal thickness in suspecting patients of having glaucoma.to check if it makes influence while taking the intraocular pressure with the Tonometer of Goldman, 328 eyes were studied out of the 164 patients who attended the glaucoma provincial appointment as suspecting of suffering from this pat...

  11. Comparison of Central Corneal Thickness Measurements by Ultrasonic Pachymetry and Orbscan II Corneal Topography and Evaluation of Ultrasonic Pachymetry Repeatability

    OpenAIRE

    Semra Tiryaki Demir; Mahmut Odabaşı; Mehmet Ersin Oba; Ayşe Burcu Dirim; Efe Can; Orhan Kara

    2014-01-01

    Objectives: Comparison of central corneal thickness (CCT) measurements by ultrasonic pachymetry and Orbscan II corneal topography and evaluation of ultrasonic pachymetry repeatability for same observer. Materials and Methods: The study included 132, 82, and 80 eyes of 66 patients with primary open-angle glaucoma (POAG), 41 patients with ocular hypertension (OHT), and 40 controls, respectively. All subjects were subjected to routine ophthalmic examination. Orbscan II (Bausch&Lomb) ...

  12. Corneal endothelial cell density and morphology and central corneal thickness in Guangxi Maonan and Han adolescent students of China

    Institute of Scientific and Technical Information of China (English)

    Hao; Liang; Hui-Yi; Zuo; Jin-Mao; Chen; Jie; Cai; Yu-Zhua; Qin; Yu-Ping; Huang; Ying-Ying; Chen; Dong-Yong; Tang; Shao-Jian; Tan

    2015-01-01

    AIM: To investigate the corneal endothelial cell density and morphology and central corneal thickness in the Guangxi Maonan and Han adolescent students of China.METHODS: Noncontact specular microscope(Topcon SP3000 P, Tokyo, Japan) was performed in 133 adolescent students of Maonan nationality(M:F 54:79)and 105 adolescent students of Han nationality(M:F 50:55),5 to 20 y of age, who were randomly selected from 3schools in Huanjiang Maonan Autonomous County of Guangxi Zhuang Autonomous Region of China.Parameters studied included endothelial cell density,mean cell area, coefficient of variation in cell size,percentage hexagonality and central corneal thickness. RESULTS: Endothelial cell density, mean cell area,coefficient of variation in cell size, percentage hexagonality and central corneal thickness in the study population were(2969.50 ±253.93) cells/mm2,(339.23 ±29.44) μm2,(29.96 ±4.07) %,(64.58 ±9.41) % and(523.71 ±32.82) μm in Maonan and(2998.26 ±262.65) cells/mm2,(336.11±30.07) μm2,(29.89±5.03) %,(64.91±11.64) % and(524.39 ±33.15) μm in Han, respectively. No significant differences were observed in endothelial cell density,mean cell area, coefficient of variation in cell size,percentage hexagonality and central corneal thickness between Maonan and Han(P =0.615, 0.659, 0.528, 0.551,0.999). In Maonan and Han, we found age was negatively correlated with endothelial cell density and percentagehexagonality and positively correlated with mean cell area and coefficient of variation in cell size. Negative correlation was also found between central corneal thickness and age in Han, whereas no correlation was found in Maonan. CONCLUSION: There were no differences between Maonan and Han in corneal endothelial cell density and morphology and central corneal thickness. In these two nationalities, there were statistically significant decrease in endothelial cell density and percentage hexagonality with increasing age and statistically significant increase in

  13. Effect of topical dorzolamide on rabbit central corneal thickness

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    Almeida Jr. G.C.

    2006-01-01

    Full Text Available Our objective was to study the effect of dorzolamide on corneal hydration in an 18-week controlled experiment using ultrasonic pachymetry. Twenty-eight male rabbits were divided randomly into four groups. The 7 rabbits in each group received eye drops containing either 2% (w/v dorzolamide or placebo in their right eye, or in their left eye. The 2% dorzolamide rabbits were treated every 8 h. Fellow eyes are defined as eyes which did not receive either dorzolamide or placebo. The study was blind for both the person who applied the drug and the one who performed the pachymetry. The effect of treatments is reported on the basis of the percentage of pachymetric variation compared to the measurement made before drug application. There was no significant difference (P = 0.061 in pachymetric variation between dorzolamide (-4.42 ± 11.71% and placebo (2.48 ± 9.63%. However, there was a significant difference (P = 0.0034 in pachymetric variation between the dorzolamide fellow eyes (-7.56 ± 10.50% and the placebo (-4.42 ± 11.71%. In conclusion, dorzolamide did not increase the corneal thickness in rabbits.

  14. Evaluation of Central Corneal Thickness Measurements by Optical Low Coherence Reflectometry and Contact Ultrasonic Pachymeter

    OpenAIRE

    Kocatürk, Tolga; Erkan, Erol; Çakmak, Harun; Kurt Ömürlü, İmran; Dayanır, Volkan

    2015-01-01

    AbstractObjective: The aim is to compare the central corneal thickness measurements by optical low-coherence reflectometry and contact ultrasonic pachymeter in patients with pseudoexfoliation syndrome, pseudoexfoliation glaucoma, primary open-angle glaucoma as well as healthy subjects.Materials and Methods: We have made a survey of the data of the patients with glaucoma who had been followed for ten years at the Department of Ophthalmology. 148 eyes of 76 patients who had central corneal thic...

  15. Corneal thickness in glaucoma.

    Science.gov (United States)

    De Cevallos, E; Dohlman, C H; Reinhart, W J

    1976-02-01

    The central corneal stromal thickness of patients with open angle glaucoma, secondary glaucoma (the majority aphakic), or a history of unilateral acute angle closure glaucoma were measured and compared with the stromal thickness of a group of normal patients. In open angle glaucoma, there was a small but significant increase in the average stromal thickness. This thickness increase was, in all likelihood, due to an abnormal function of the endothelium in this disease since the level of the intraocular pressure did not seem to be a factor. There was no correlation between stromal thickness and duration of the glaucoma or type of anti-glaucomatous medication. Most cases of secondary glaucome, controlled medically or not, had markedly increased corneal thickness, again, most likely, due to endothelial damage rather than to level of intraocular pressure. After an angle closure attack, permanent damage to the cornea was found to be rare. PMID:1247273

  16. The Influence of Central Corneal Thickness and Corneal Curvature and Axial Length on the Measurement of Intraocular Pressure

    Institute of Scientific and Technical Information of China (English)

    Qing Li; Minru Li; Zhigang Fan; Ningli Wang

    2002-01-01

    Purpose: To examine the influence of central corneal thickness (CCT), corneal curvature (CC), and axial length (AL) on intraocular pressure (IOP).Methods: Eighty-one clinically normal eyes were included in our study. The IOP, CCT, CC, AL were measured using a Goldmann applanation tonometer, optical pachymeter, keratometer and A-scan ultrasound biometer respectively in all subjects.Results: A highly significant positive correlation was identified between IOP and CCT. Linear regression analysis suggests that an increase in CCT of 0. 010 mm is associated with a 4. 946 mmHg increment in IOP. No significant positive correlation was identified between IOP and CC. P values are 0. 724 and 0.414 respectively for vertical and horizontal readings. A paradoxically reversed correlation was present between IOP and axial length.Conclusion: Corneal thickness is a very important confounding factor in the measurement of intraocular pressure, which warrants further attention in our clinical practice.

  17. Central and midperipheral corneal thickness measured with Scheimpflug imaging and optical coherence tomography.

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    Jinhai Huang

    Full Text Available PURPOSE: To compare corneal thickness measurements using Pentacam (Oculus, Germany, Sirius (CSO, Italy, Galilei (Ziemer, Switzerland, and RTVue-100 OCT (Optovue Inc., USA. METHODS: Sixty-six eyes of 66 healthy volunteers were enrolled. Three consecutive measurements were performed with each device. The mean value of the three measurements was used for subsequent analysis. Central corneal thickness (CCT, thinnest corneal thickness (TCT, and midperipheral corneal thickness (MPCT; measured at superior, inferior, nasal, and temporal locations with a distance of 1 mm (CT2mm or 2.5 mm (CT5mm from the corneal apex were analyzed. Differences and agreement between measurements were assessed using the repeated-measures analysis of variance (ANOVA and Bland-Altman analyses, respectively. RESULTS: Statistically significant differences (pSirius>Pentacam>RTVue OCT. For these measurements, agreement between measurements by Sirius and Pentacam was good, whereas Galilei overestimated and RTVue underestimated corneal thickness compared to Sirius and Pentacam. As regards CT5mm measurements, Pentacam provided the largest values, whereas RTVue OCT yielded the smallest values. Agreement of the CT5mm measurements was good between the Pentacam, Sirius, moderate between Galilei and the other two Scheimpflug systems, and poor between the RTVue OCT and the remaining devices. CONCLUSIONS: The Pentacam and Sirius can be used interchangeably for CCT measurements, while the Galilei and RTVue systematically over- and underestimate CCT, respectively. The three Scheimpflug cameras, but not the RTVue, may be used interchangeably for MPCT measurements.

  18. Central Corneal Thickness Measurement by Ultrasound versus Orbscan II

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    Amir Faramarzi

    2008-12-01

    Full Text Available

    PURPOSE: To compare Orbscan II and ultrasonic pachymetry for measurement of central corneal thickness (CCT in eyes scheduled for keratorefractive surgery. METHODS: CCT was measured using Orbscan II (Bausch & Lomb, USA and then by ultrasonic pachymetry (Tomey SP-3000, Tomey Ltd, Japan in 100 eyes of 100 patients with no history of ocular surgery scheduled for excimer laser refractive surgery. RESULTS: Mean CCT was 544.7±35.5 (range 453-637 µm by ultrasonic pachymetry versus 546.9±41.6 (range 435-648 µm measured by Orbscan II applying an acoustic factor of 0.92 (P=0.14. The standard deviation of measurements was greater with Orbscan pachymetry but the difference was not statistically significant. CONCLUSION: CCT measurements by Orbscan II (applying an acoustic factor and by ultrasonic pachymetry are not significantly different; however, when CCT readings by Orbscan II are in the lower range, it is advisable to recheck the measurements using ultrasonic pachymetry.

  1. Comparison of Central Corneal Thickness Measurements by Ultrasonic Pachymetry and Orbscan II Corneal Topography and Evaluation of Ultrasonic Pachymetry Repeatability

    Directory of Open Access Journals (Sweden)

    Semra Tiryaki Demir

    2014-08-01

    Full Text Available Objectives: Comparison of central corneal thickness (CCT measurements by ultrasonic pachymetry and Orbscan II corneal topography and evaluation of ultrasonic pachymetry repeatability for same observer. Materials and Methods: The study included 132, 82, and 80 eyes of 66 patients with primary open-angle glaucoma (POAG, 41 patients with ocular hypertension (OHT, and 40 controls, respectively. All subjects were subjected to routine ophthalmic examination. Orbscan II (Bausch&Lomb corneal topography and ultrasonic pachymetry (Nidek Ultrasonic Pachymetry UP-1000 were used for measurement of CCT. ANOVA (Turkey test was used for variable distribution, paired sample t-test was used for repeated measurements, and the analyses were done by SPSS 20.0. Results: Mean CCT was 558.9±37.2 µm by ultrasonic pachymetry and 553.4±37 µm by corneal topography. There was a significant difference between the two measurements (p0.05. CCT was 555±39.2 µm, 564.3±28.4 µm, and 559.7±41.5 µm by ultrasonic pachymetry in POAG, OHT, and control subjects, respectively; CCT was 550.3±38.3 µm, 558.5±28 µm, and 553.2±42.5 µm by Orbscan II corneal topography in POAG, OHT, and control subjects, respectively. There was a significant linear correlation between Orbscan II corneal topography and ultrasonic pachymetry in CCT measurements (r=0.975, p<0.0001. Repeatability of ultrasonic pachymetry for same observer was (ICC value 0.990. Conclusion: There is a significant correlation between Orbscan II corneal topography and ultrasonic pachymetry in CCT measurements. These two methods of measurements should not be substituted for each other, since ultrasonic pachymetry measures CCT greater than Orbscan II corneal topography. Repeatability of ultrasonic pachymetry for same observer is very high. (Turk J Ophthalmol 2014; 44: 263-7

  2. Repeatability of central corneal thickness measurement with the Pentacam HR system

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    Ruiz Simonato Alonso

    2012-02-01

    Full Text Available PURPOSE: To assess the repeatability of central corneal thickness measurement at the geometrical center (Central Corneal Thickness - CCT given by the Pentacam High Resolution (HR Comprehensive Eye Scanner (Oculus, Wetzlar, Germany over time. METHODS: Prospective, single center, observational study. Two separate CCT measurements were taken by the Pentacam corneal tomography exam (CTm 3 to 12 months apart, and compared. RESULTS: One hundred and sixteen eyes (n=116 of 62 health patients were included in this study. Average CCT in first and last visits was 541.6±37 µm and 543.6±36.9 µm respectively. Mean difference between both measurements was 9.2±6.4 µm, and there was no statistically significant difference in CCT measurement between visits, with good correlation between them (P = 0.057, r² = 0,9209. CONCLUSION: Pentacam (HR CTm gives repeatable CCT measurements over time.

  3. Measurements of central corneal thickness using two immersion ultrasound techniques and optical technique

    International Nuclear Information System (INIS)

    Objective: To compare the accuracy of central corneal thickness measurements using ultrasound biomicroscopy, Orbscan II tomography and an Artemis-2 very high frequency ultrasound scanner. Methods: The prospective study was conducted at Eye World Centre, Riyadh, Saudi Arabia, from September to November 2012. One eye from each of 60 normal subjects was analysed. The central corneal thickness was measured using ultrasound biomicroscopy, Orbscan II tomography and the Artemis-2 very high frequency ultrasound scanner. Results were compared using analysis of variance, repeated-measures analysis of variance and limits of agreement. Results: The mean central corneal thickness was 530.30+-30.75mm, 548.95+-30.33mm and 554.73+-31.97mm for biomicroscopy, tomography and the scanner respectively. The intraobserver repeatability analyses of variance were not significant for the three procedures (p=0.19, 0.23 and 0.41, respectively). A significant difference was noted among the three different methods (p=0.0001). However, comparison among instruments revealed no significant difference between tomography and the scanner (p>0.05), yet significant differences were noted in biomicroscopy vs tomography, and biomicroscopy vs the scanner (p<0.01 and P < 0.001, respectively). The mean differences (and upper/lower limits of agreement) for central corneal thickness measurements were 18.92+-40.71 (60.90/-98.70); 24.7+-13.13 (1.00/-50.40), and -5.8+-38.61 (69.90/-81.40) for biomicroscopy vs tomography, biomicroscopy vs scanner, and tomography vs scanner respectively. Conclusions: The central corneal thickness measurements obtained using Orbscan II tomography and the Artemis-2 very high frequency ultrasound scanner can be used interchangeably. However, Orbscan II tomography and the Artemis-2 scanner measurements cannot be used interchangeably with ultrasound biomicroscopy. (author)

  4. Comparison of Central Corneal Thickness Measurements Obtained with Ultrasonic Pachymetry and Spectral Domain Anterior Segment OCT

    OpenAIRE

    Kirikkaya, Esin Tunca; Akyuz Unsal, Ayşe İpek; Dogramaci, Mahmut

    2014-01-01

    Aim: To compare central corneal thickness (CCT) measurements obtained with Ultrasonic Pachymetry (USP) and Anterior Segment Optical Coherence Tomography (AS-OCT).Methods: Seventy eight eyes of thirty nine volunteers between 40-60 ages were recruited in this study. Best corrected visual acuity (BCVA), intraocular pressure (IOP) measurements, anterior and posterior segment biomicroscopic examinations of all volunteers were performed. CCT measurements were evaluated with Nidek  UP and Zeiss Cirr...

  5. Comparison of Spectral Domain Optical Coherence Tomography and Ultrasonic Pachymetry for Assessment of Central Corneal Thickness

    OpenAIRE

    G. Ertuğrul Mirza

    2014-01-01

    Objectives: The aim of this study was to determine if there is a difference in central corneal thickness (CCT) measurements obtained by Cirrus spectral domain optical coherence tomography (SD-OCT) and ultrasonic pachymetry in healthy individuals. Materials and Methods: The study included 50 healthy consecutively selected individuals without ocular or systemic disease. CCT was first measured using OCT, and then using ultrasonic pachymetry. Results: Mean age of the participants was ...

  6. Assessment of the central corneal thickness and intraocular pressure in premature and full-term newborns

    OpenAIRE

    Muslubas, Isil Bahar Sayman; Oral, Ayse Yesim Aydın; Cabi, Cemalettin; Caliskan, Sinan

    2014-01-01

    Purpose: To assess the central corneal thickness (CCT) and intraocular pressure (IOP) in premature and full-term newborns. Materials and Methods: In this study, we evaluated measurements of CCT and IOP in 45 premature and 45 full-term newborns. IOP was determined with topical anesthesia using a Tono-Pen AVIA, applanation tonometer and a wire lid retractor in premature newborns undergoing screening for retinopathy. Full-term newborns were used as a control group. CCT was determined with a port...

  7. Candidate gene study to investigate the genetic determinants of normal variation in central corneal thickness

    OpenAIRE

    Dimasi, David P.; Kathryn P Burdon; Hewitt, Alex W; Savarirayan, Ravi; Healey, Paul R.; Mitchell, Paul; Mackey, David A.; Craig, Jamie E

    2010-01-01

    Purpose The genetic component underlying variation in central corneal thickness (CCT) in the normal population remains largely unknown. As CCT is an identified risk factor for open-angle glaucoma, understanding the genes involved in CCT determination could improve our understanding of the mechanisms involved in this association. Methods To identify novel CCT genes, we selected eight different candidates based on a range of criteria. These included; aquaporin 1 (AQ1), aquaporin 5 (AQ5), decori...

  8. Relationships between central and peripheral corneal thickness in different degrees of myopia

    Science.gov (United States)

    Ortiz, Sara; Mena, Laura; Rio-San Cristobal, Ana; Martin, Raul

    2013-01-01

    Purpose To analyze the relationship between the central corneal thickness (CCT) and mid-peripheral corneal thickness (PCT) with the degree of myopia [axial length (AL) and spherical equivalent refractive error (SE)]. Methods 175 right myopic eyes from 175 patients were divided according to the degree of SE: group #1 (n = 76, 12.00 D). The CCT and PCT (3 mm from the apex to the superior, inferior, nasal and temporal locations) were measured with the Orbscan-II. Relative peripheral index (RPI) was calculated by dividing the PCT by the CCT. The AL was measured with the IOL Master, and the SE was obtained with subjective refraction. Results AL was 25.18 ± 1.16 mm, 26.59 ± 1.26 mm and 29.45 ± 2.58 mm and SE was −3.31 ± 1.40 D, −8.32 ± 1.64 D and −16.44 ± 4.48 D for groups #1, #2 and #3, respectively. Non-statistically significant differences in central and peripheral corneal thickness were found between groups (P > 0.05 ANOVA). Non-significant relationship was found between central and peripheral corneal thickness with the AL and SE in the three study groups and in the total sample (r  0.05). The RPI values were similar between groups without significant difference between groups (P > 0.05 ANOVA). Linear relationship was found between RPI superior location in group #2 (r = −0.23; P = 0.04) and RPI nasal location in group #3 with the EE (r = 0.41; P = 0.03). Conclusion There are no significant differences among low, moderate and extremely myopic eyes related to the CCT and PCT. Corneal thickness is very similar in myopic eyes with small differences that are not clinically relevant to myopic patient management. PMID:24646900

  9. Central Corneal Thickness Measurements in Nonarteritic Anterior Ischemic Optic Neuropathy Patients: A Controlled Study

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    Haneen Jabaly-Habib

    2014-01-01

    Full Text Available Purpose. To measure central corneal thickness (CCT in patients with history of nonarteritic anterior ischemic optic neuropathy (NAION. Patients and Methods. Patients older than 40 years with a history of NAION (group 1 were prospectively evaluated including full eye examination and central corneal thickness (CCT pachymetry. Patients with a history of intraocular surgery, corneal disease, glaucoma, and contact lens wear were excluded. Measurements were also performed in a gender and age matched control group (group 2. Results. Thirty-one eyes of 31 NAION patients in group 1 were included and 30 eyes of 30 participants in group 2. There were 15 men in group 1 and 9 in group 2 P=0.141, and mean age of the patients was 59±10 years in group 1 versus 61±11 years in group 2 P=0.708. Mean CCT was 539±30 microns in group 1 and 550±33 microns in group 2 P=0.155. Conclusion. Patients with NAION have no special characteristic of CCT in contrast to the crowded optic disc known to be a significant anatomic risk factor for NAION. More studies should be carried out to investigate CCT and other structure related elements in NAION patients.

  10. Importance of Corneal Thickness

    Science.gov (United States)

    ... News About Us Donate In This Section The Importance of Corneal Thickness email Send this article to ... is important because it can mask an accurate reading of eye pressure, causing doctors to treat you ...

  11. Comparison of central corneal thickness measurements with the Galilei dual Scheimpflug analyzer and ultrasound pachymetry

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    Ladi Jeevan

    2010-01-01

    Full Text Available Purpose: To compare corneal pachymetry assessment by the Galilei dual Scheimpflug analyzer with that done by ultrasound (US pachymetry. Materials and Methods: Forty six patients (92 eyes were subjected to corneal pachymetry assessment by Galilei dual Scheimpflug analyzer and US. All the readings were taken by a single operator. Intraoperator repeatability for the Galilei was assessed by taking 10 readings in one eye each of 10 patients. To study the interoperator reproducibility for the Galilei, two observers took a single reading in both the eyes of 25 patients. Results: The mean central corneal thickness (CCT measured by US was 541.83 ± 30.56 μm standard deviation (SD and that measured by Galilei was 541.27 ± 30.07 μm (SD. There was no statistically significant difference between both the methods (P < 0.001. The coefficient of repeatability was 0.43% while the coefficient of reproducibility was 0.377% for the Galilei. Conclusion: Objective, noncontact measurement of the CCT with the Galilei dual Scheimpflug analyzer was convenient, had excellent intraoperator repeatability and interoperator reproducibility, and findings were similar to those obtained with standard US pachymetry.

  12. Comparison of central corneal thickness measurements between anterior chamber-optical coherence tomography and ultrasonic pachymeter

    International Nuclear Information System (INIS)

    Objective: To assess the agreement of central corneal thickness (CCT) measured by anterior chamber-optical coherence tomography (AC-OCT) and ultrasonic pachymeter and provide an objective basis for clinical application of AC-OCT. Methods: CCT of 150 college student volunteers (300 eyes) measured by two devices were obtained. The data was analyzed by paired t test and Pearson correlation analysis. Bland-Altman plot and Mountain plot were used to assess the agreement. Results: The mean CCT values were (530.05 ± 33.611) μm measured by AC-OCT and (543.68 ± 35.088) μm measured by ultrasonic pachymeter. Regression analysis showed a high correlation between the values obtained by both devices (r=0.960, P<0.001). Compared with AC-OCT, ultrasonic pachymeter overestimated the CCT by a mean of 13.62 μm. The two modalities had incomparable results. Conclusion: It is important to be noted in clinical practice that the measurements acquired by these two modalities are not directly interchangeable. However, the CCT measurements by the AC-OCT and ultrasonic pachymeter are highly correlated. AC-OCT is an effective method to observe the changes of the corneal thickness in the long term. (authors)

  13. Comparison of Central Corneal Thickness and Retinal Nerve Fiber Layer Thickness and Ganglion Cell Complex in Patients with Ocular Hypertension

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    Gamze Mumcu Taşlı

    2013-12-01

    Full Text Available Purpose: To evaluate the correlation of retinal nerve fiber layer thickness (RNFLT with ganglion cell complex and central corneal thickness (CCT measurements in patients with ocular hypertension and healthy subjects. Material and Method: Seventy-six eyes of 38 patients with ocular hypertension and 76 eyes of 38 healthy subjects were included in this study. Both groups were stratified by CCT into 579 µm (p0.05. In the control group, there was no significant correlation between CCT and RNFLT (average, superior average, inferior average measurements (p>0.05. There was no significant correlation between CCT and average, superior average, inferior average ganglion cell complex in both groups. Discussion: Ocular hypertension patients with CCT <550 µm may represent patients who have very early undetected glaucoma. This may in part explain the higher risk of these patients for progression to glaucoma. (Turk J Ophthalmol 2013; 43: 385-90

  14. The Association of Central corneal thickness with Intra-ocular Pressure and Refractive Error in a Nigerian Population

    OpenAIRE

    Eghosasere Iyamu; Misan Memeh

    2008-01-01

    The purpose of this study was to determine the variation of central corneal thickness (CCT) with intraocular pressure (IOP) and spherical equivalent refractive error. A total of thirty-nine (N=39) subjects within 20-75 years with mean age 45.2 ± 15.4 years were used for this study. The central corneal thickness was assessed with the Corneo-Gage plus ultrasonic Pachymeter, the IOP with slit-lamp mounted Goldmann applanation tonometer and refractive status by Protec 2000 autorefractor, phoropte...

  15. Central corneal thickness and intraocular pressure in the Cameroonian nonglaucomatous population

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    André Omgbwa Eballe

    2010-07-01

    Full Text Available André Omgbwa Eballe1, Godefroy Koki2, Augustin Ellong2, Didier Owono2, Emilienne Epée2, Lucienne Assumpta Bella2, Côme Ebana Mvogo1, Jeanne Mayouego Kouam21Faculty of Medicine and Pharmaceuticals Sciences, University of Douala; 2Faculty of Medicine and Biomedical Sciences, University of Yaoundé, CameroonAim: We performed a prospective, analytical study from 01 January to 31 March 2009 in the Ophthalmology Unit of the Gyneco-Obstetric and Pediatric Hospital of Yaounde, aiming to determine the profile of central corneal thickness (CCT in the Cameroonian nonglaucomatous black population and its relationship with intraocular pressure (IOP.Results and discussion: Four hundred and eighty-five patients (970 eyes meeting our ­inclusion criteria were selected for this study. The average CCT was 529.29 ± 35.9 µm in the right eye (95% confidence interval [CI]: 526.09–532.49, 528.19 ± 35.9 µm in the left eye (95% CI: 524.99–531.40 and 528.74 ± 35.89 µm in both eyes (95% CI: 526.48–531.00, range 440 to 670 µm. The average IOP was 13.01 ± 2.97 mmHg in both eyes (95% CI: 12.82–13.19. A rise in CCT by 100 µm was followed by an increase in IOP of about 2.8 mmHg (95% CI: 2.3–3.6 for both eyes taken together. Linear regression analysis showed that corneal thickness was negatively correlated with age and IOP was positively related with age.Conclusion: CCT in the Cameroonian nonglaucomatous black population was found to be lower compared with CCT values in Caucasian and Asian populations. On the basis of reference values ranging between 527 and 560 µm, an adjustment of IOP values by a correction factor is required for many Cameroonian patients. This will improve the diagnosis and follow-up of glaucoma by helping to detect true ocular hypertension.Keywords: central corneal thickness, intraocular pressure, Cameroon

  16. Central corneal thickness in black Cameroonian ocular hypertensive and glaucomatous subjects

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    Christelle Domngang Noche

    2010-11-01

    Full Text Available Christelle Domngang Noche1, André Omgbwa Eballe2, Assumpta Lucienne Bella31Innel Medical Center, 2Faculty of Medicine, University of Douala, 3Faculty of Medicine and Biomedical Sciences, University of Yaoundé, CameroonPurpose: To evaluate central corneal thickness (CCT in a black Cameroonian population of ocular hypertensive and glaucomatous subjects.Material and methods: This was a prospective study undertaken with an ultrasonic pachymeter from January 2009 to December 2009 in an eye clinic (INNEL Medical center in Yaoundé, Cameroon.Results: One hundred subjects (200 eyes were enrolled in the study. Sixty subjects were glaucomatous (primary open angle glaucoma, POAG group, and 40 ocular hypertensive (OHT group. The mean age of the sample was 52.60 ± 12.23 years. For the whole sample, CCT was 534.71 ± 37.95 µm in the right eye and 533.61 ± 37.67 µm in the left eye, with no statistically significant difference between the 2 eyes (P = 0.446. CCT in the POAG group was 526.30 ± 37.34 µm in the right eye and 524.90 ± 35.92 µm in the left eye. CCT in the OHT group was 547.32 ± 35.71 µm in the right eye and 546.67 ± 36.85 µm in the left eye. There was a statistically significant difference between CCT of the 2 groups (right eye: P = 0.013; left eye: P = 0.007.Conclusion: Mean CCT of ocular hypertensive subjects was thicker than CCT of glaucomatous ones in our Cameroonian sample. However, in both ocular hypertensive or glaucomatous patients, CCT of black Cameroonians is thinner than that reported in other studies in Caucasian populations.Keywords: central corneal thickness, ocular hypertension, glaucoma, black Cameroonian

  17. The Influence of Type-1 Diabetes Mellitus on Central Corneal Thickness in Children

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    Pınar Yüksekkaya

    2014-12-01

    Full Text Available Objectives: To evaluate the central corneal thickness (CCT in children with diabetes mellitus (DM, to compare the results with those of age- and sex-matched healthy subjects, and to assess the presence of any relationship between the disease-variable parameters and CCT. Materials and Methods: This prospective, cross-sectional study included 138 eyes of 138 subjects. The CCT was measured by ultrasonic pachymetry in 66 children with type-1 DM and in 72 healthy subjects. The effects of the duration of DM, current hemoglobin A1c levels (HbA1c, and fasting blood glucose (FBG levels on CCT were also evaluated. Results: The demographic characteristics of the study and control groups were similar (p>0.05. The average CCT was greater in the study (555.2±38.6 µm than in the control group (547.7±31.5 µm, but the difference was not statistically significant (independent t-test, p=0.211. CCT was also not significantly different in children with diabetes >5 years’ duration (554.6±39.3 µm compared to diabetes ≤5 years’ duration (555.6±38.6 µm (p>0.05, and there was no significant correlation between the CCT- and the DM-related parameters in the study group (p>0.05. Conclusion: Our findings indicate that DM does not affect the corneal thickness in adolescents. We also did not find any significant correlation between disease-related variables and the CCT. (Turk J Ophthalmol 2014; 44: 445-8

  18. Long-term change in central corneal thickness from a glaucoma perspective

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    Nikhil S Choudhari

    2013-01-01

    Full Text Available Aim: To investigate the longitudinal change in central corneal thickness (CCT over 3 years in patients with glaucoma. Materials and Methods: The Chennai Glaucoma Follow-up Study, an offshoot of the Chennai Glaucoma Study, was designed to evaluate the progression of glaucoma. A cohort of participants in the Chennai Glaucoma Study that were suffering from glaucoma or were at a higher risk for glaucoma underwent comprehensive ophthalmic evaluation at the base hospital at 6-month intervals during the years 2004 to 2007. The CCT (average of 10 readings was measured between 11 am and 1 pm on any given day using an ultrasonic pachymeter. Patients with a history of ocular surgery, corneal disease and usage of topical carbonic anhydrase inhibitor were excluded. No patient was a contact lens wearer. Results: One hundred and ninety-six patients (84 male, 112 female met the inclusion criteria. We analyzed data from the right eye. The mean age of the patients was 59.97 ± 9.06 years. Fifty-nine (30.1% of the patients were diabetic. The mean change in CCT (CCT at first patient visit - CCT at last patient visit was 3.46 ± 7.63 μm. The mean change in CCT was 0.75 μm per year (R 2 = 0.00. Age, gender, intraocular pressure at the first patient visit and diabetic status had no significant influence on the magnitude of change in CCT. Conclusion: A carefully obtained CCT reading by a trained examiner need not be repeated for at least 3 years as long as the ocular and systemic factors known to affect the measurement of CCT are constant.

  19. Corneal thickness and endothelial density before and after cataract surgery

    OpenAIRE

    Ventura, A.; Walti, R; Bohnke, M

    2001-01-01

    BACKGROUND/AIMS—Deturgescence of the corneal stroma is controlled by the pumping action of the endothelial layer and can be monitored by measurement of central corneal thickness (pachymetry). Loss or damage of endothelial cells leads to an increase in corneal thickness, which may ultimately induce corneal decompensation and loss of vision. Little is known about the effect of moderate reductions in endothelial cell number on the thickness of the corneal stroma. This study aimed to investigate ...

  20. Comparison of Spectral Domain Optical Coherence Tomography and Ultrasonic Pachymetry for Assessment of Central Corneal Thickness

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    G. Ertuğrul Mirza

    2014-08-01

    Full Text Available Objectives: The aim of this study was to determine if there is a difference in central corneal thickness (CCT measurements obtained by Cirrus spectral domain optical coherence tomography (SD-OCT and ultrasonic pachymetry in healthy individuals. Materials and Methods: The study included 50 healthy consecutively selected individuals without ocular or systemic disease. CCT was first measured using OCT, and then using ultrasonic pachymetry. Results: Mean age of the participants was 31.44 years. Mean CCT measured using SD-OCT was 531.78 µm versus 535.15 µm by ultrasonic pachymetry. Mean CCT measurement obtained by Cirrus SD-OCT showed statistically significant difference by approximately 3.37 µm than the one obtained by ultrasonic pachymetry (t-test, p<0.05; however, Bland-Altman analysis proved that there was high concordance between the measurements. Conclusion: CCT measurements obtained by Cirrus SD-OCT were very similar to those obtained by ultrasonic pachymetry, and as such we think that Cirrus SD-OCT can be used in our present ophthalmology practice to measure OCT. (Turk J Ophthalmol 2014; 44: 259-62

  1. Central corneal thickness and anterior chamber depth measurement by Sirius® Scheimpflug tomography and ultrasound

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    Jorge J

    2013-02-01

    Full Text Available J Jorge,1 JL Rosado,2 JA Díaz-Rey,1 JM González-Méijome11Clinical and Experimental Optometry Research Laboratory, Center of Physics (Optometry, School of Sciences, University of Minho, Braga, 2Opticlinic, Lisboa, PortugalBackground: The purpose of this study was to compare the accuracy of the new Sirius® Scheimpflug anterior segment examination device for measurement of central corneal thickness (CCT and anterior chamber depth (ACD with that of CCT measurements obtained by ultrasound pachymetry and ACD measurements obtained by ultrasound biometry, respectively.Methods: CCT and ACD was measured in 50 right eyes from 50 healthy subjects using a Sirius Scheimpflug camera, SP100 ultrasound pachymetry, and US800 ultrasound biometry.Results: CCT measured with the Sirius was 546 ± 39 µm and 541 ± 35 µm with SP100 ultrasound pachymetry (P = 0.003. The difference was statistically significant (mean difference 4.68 ± 10.5 µm; limits of agreement −15.8 to 25.20 µm. ACD measured with the Sirius was 2.96 ± 0.3 mm compared with 3.36 ± 0.29 mm using US800 ultrasound biometry (P < 0.001. The difference was statistically significant (mean difference −0.40 ± 0.16 mm; limits of agreement −0.72 to 0.07 mm. When the ACD values obtained using ultrasound biometry were corrected according to the values for CCT measured by ultrasound, the agreement increased significantly between both technologies for ACD measurements (mean difference 0.15 ± 0.16 mm; limits of agreement −0.16 to 0.45 mm.Conclusion: CCT and ACD measured by Sirius and ultrasound methods showing good agreement between repeated measurements obtained in the same subjects (repeatability with either instrument. However, CCT and ACD values, even after correcting ultrasound ACD by subtracting the CCT value obtained with either technology should not be used interchangeably.Keywords: Scheimpflug corneal tomography, ultrasound biometry, ultrasound pachymetry, limits of agreement

  2. Age-related changes in central corneal thickness in normal eyes among the adult Lithuanian population

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    Galgauskas S

    2014-07-01

    Full Text Available Saulius Galgauskas,1 Grazina Juodkaite,1 Janina Tutkuviene2 1Center of Eye Diseases, 2Faculty of Medicine, Department of Anatomy, Histology and Anthropology, Vilnius University, Vilnius, Lithuania Background: The purpose of this study was to estimate mean central corneal thickness (CCT and determine whether there are any correlations between CCT, age, and sex in the adult ­Lithuanian population.Methods: A total of 1,650 Caucasians of Lithuanian origin (aged 18–89 years comprising 688 (41.7% men and 962 (58.3% women were examined. Subjects were stratified by age into seven groups. CCT was measured using ultrasonic pachymetry. Correlations between CCT, age, and sex were sought.Results: Mean (± standard deviation CCT for both eyes was 544.6±30.5 µm. Mean CCT was 545.2±30.5 µm in the left eye and 544.6±30.5 µm in the right eye, and was 545.0±25.6 µm in men and 544.4±33.5 µm in women. Mean CCT was 550.8±35.7 µm in subjects aged 18–29 years, 557.5±27.6 µm in those aged 30–39 years, 551.3±31.4 µm in those aged 50–59 years, 544.0±31.4 µm in those aged 50–59 years, 544.2±31.6 µm in those aged 60–79 years, 535.1±27.8 µm in those aged 70–79 years, and 530.1±16.8 µm in those aged 80–89 years. No statistically significant difference in CCT was found between the sexes (P>0.05. However, there was a significant difference in subjects aged 18–29 years; men had higher CCT than women (P<0.05. A statistically significant negative correlation was found between CCT and age (r=−0.263, P<0.05 that was stronger in men (r=−0.406, P<0.05 than in women (r=−0.118, P<0.05. Conclusion: The mean CCT in adult Lithuanians was 544.6±30.5 µm, of the left eye 545.2±30.5 µm and of the right – 544.6±30.5 µm. CCT of the right eye was equal to the CCT of both eyes. Mean CCT was 545.0±25.6 µm in men and 544.4±33.5 µm in women. Young men tended to have higher CCT than women. CCT decreases over the

  3. Ocular biometry and central corneal thickness in children: a hospital-based study

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    Adem Gul

    2014-06-01

    Full Text Available Objetivo: Investigar a distribuição do comprimento axial, profundidade da câmara anterior, espessura do cristalino, profundidade da câmara vítrea e espessura corneal central em crianças em diferentes faixas etárias. Métodos: Foram estudados 364 olhos de 182 crianças entre 1 e 12 anos de idade. O comprimento axial, a profundidade da câmara anterior , a espessura do cristalino e a profundidade da câmara vítrea foram medidos por biometria ultrassônica. A espessura corneal central foi medida por paquimetria ultrassônica em todas as crianças. Resultados: A idade média foi de 6,54 ± 3,42 anos. O comprimento axial foi 20,95 mm no grupo de 1-2 anos de idade e 22,95 mm no grupo de 11-12 anos de idade. A espessura corneal central foi 556 µm no grupo de 1-2 anos de idade e 555 µm no grupo de 11-12 anos de idade. A profundidade da câmara anterior média e profundidade da câmara vítrea aumentou com a idade (3,06 mm a 3,44 mm de profundidade da câmara anterior, 13,75 mm a 15,99 mm de profundidade da câmara vítrea e da espessura do cristalino diminuiu com o aumento da idade (3,67 mm a 3,51 mm. Conclusões: Em nosso estudo, os valores do comprimento axial aumentou com a idade e atingiu os níveis adultos aos 9-10 anos de idade. A espessura do cristalino diminuiu gradualmente até os 12 anos de idade. As medições de espessura corneal central não seguiu um algoritmo linear.

  4. Comparison of Measurement of Central Corneal Thickness with Spectral Domain Optical Coherence Tomography and Standard Ultrasonic Pachymeter in Premature Infants

    OpenAIRE

    Emre Hekimoglu; Muhammet Kazım Erol; Devrim Toslak; Deniz Turgut Coban; Berna Doğan; Ozgur Yucel

    2015-01-01

    Purpose. To evaluate the repeatability of measurement of central corneal thickness (CCT) by spectral domain optical coherence (SD-OCT) in premature infants and compare it to CCT measurement by ultrasonic pachymetry (USP). Methods. Three CCT measurements of the left eyes of 50 premature infants were obtained by SD-OCT using the iVue system. 10 CCT measurements of each 28 left eyes of 28 infants were obtained by USP using the Pacscan 300P system. Bland-Altman plots were developed and the limit ...

  5. Changes on the corneal thickness and curvature after orthokeratology

    Science.gov (United States)

    Mitsui, Iwane; Yamada, Yoshiya

    2004-07-01

    To evaluate the corneal thickness and curvature changes after Orthokeratology contact lens wear, using the ORBSCAN II corneal topography system, corneal thickness and corneal curvature were measured on one hundred and twenty eyes of sixty patients before and after wearing the custom rigid gas permeable contact lenses for Orthokeratology. The contact lenses were specially designed for each eye. The subjects wore the orthokeratology lenses for approximately Four hours with their eyes closed. The corneal thickness of the subjects was increased on fifty-five eyes at not only the peripheral zone but also the center of the cornea. The average increase of central and peripheral corneal thickness was 18 micrometer and 22micrometer, respectively. The mean anterior curvature of corneal surface changed 1.25D. The mean posterior curvature of corneal endothelium side changed 0.75D.

  6. Distribution of Central Corneal Thickness and its Association with Ocular Parameters in a Large Central European Cohort: The Gutenberg Health Study

    OpenAIRE

    Hoffmann, Esther M; Lamparter, Julia; Mirshahi, Alireza; Elflein, Heike; Hoehn, René; Wolfram, Christian; Lorenz, Katrin; Adler, Max; Wild, Philipp S.; Schulz, Andreas; Mathes, Barbara; Blettner, Maria; Pfeiffer, Norbert

    2013-01-01

    Main objective To evaluate the distribution of central corneal thickness (CCT) in a large German cohort and to analyse its relationship with intraocular pressure and further ocular factors. Design Population-based, prospective, cohort study. Methods The Gutenberg Health Study (GHS) cohort included 4,698 eligible enrollees of 5,000 subjects (age range 35–74 years) who participated in the survey from 2007 to 2008. All participants underwent an ophthalmological examination including slitlamp bio...

  7. Central Corneal Thickness in Highly Myopic Eyes: Inter-device Agreement of Ultrasonic Pachymetry, Pentacam and Orbscan II Before and After Photorefractive Keratectomy

    OpenAIRE

    Nader Nassiri; Kourosh Sheibani; Sare Safi; Saman Nassiri; Alireza Ziaei; Farnaz Haji; Shiva Mehravaran; Nariman Nassiri

    2014-01-01

    Purpose: To determine inter-device agreement for central corneal thickness (CCT) measurement among ultrasound pachymetry, rotating Scheimpflug imaging (Pentacam, Oculus, Wetzlar, Germany), and scanning slit corneal topography (Orbscan II, Bausch & Lomb, Rochester, NY, USA) in highly myopic eyes before and after photorefractive keratectomy (PRK). Methods: This prospective comparative study included 61 eyes of 32 patients with high myopia who underwent PRK. Six month postoperative CCT value...

  8. Measurement of central corneal thickness by ultrasonic pachymeter and oculus pentacam in patients with well-controlled glaucoma: hospital-based comparative study

    OpenAIRE

    Rashid RF; Farhood QK

    2016-01-01

    Riyam Faihan Rashid, Qasim K Farhood Department of Ophthalmology, College of Medicine, University of Babylon, Babylon, Iraq Background: The measurement of central corneal thickness (CCT) plays an important role in the diagnosis and treatment of glaucoma and many corneal diseases.Objective of the study: To compare the measurement of CCT by ultrasonic pachymeter with that measured by oculus pentacam in both normal subjects and patients with well-controlled glaucoma.Patients and methods: In 17...

  9. Diurnal variations in human corneal thickness.

    OpenAIRE

    Harper, C L; Boulton, M. E.; Bennett, D.; Marcyniuk, B; Jarvis-Evans, J H; Tullo, A. B.; Ridgway, A E

    1996-01-01

    AIM: To elucidate the diurnal variation in human corneal thickness over a 48 hour period. METHOD: Changes in central corneal thickness were monitored in eight healthy subjects (four male, four female) aged between 10 and 63 years using an ultrasonic pachymeter. Measurements were made over a 48 hour period-immediately before sleep, immediately upon waking and at 15, 30, 45 minutes, 1, 1.5, 2, 2.5, 3 hours, and at 2 hour intervals thereafter throughout the remainder of each day. RESULTS: The me...

  10. Comparison of central corneal thickness measurements using optical low-coherence reflectometry, Fourier domain optical coherence tomography, and Scheimpflug camera

    Directory of Open Access Journals (Sweden)

    Saban Gonul

    2014-12-01

    Full Text Available Purpose: To compare the results of central corneal thickness (CCT measurements obtained using optical low-coherence reflectometry (OLCR, Fourier domain optical coherence tomography (FD-OCT, and a Scheimpflug camera (SC, combined with Placido corneal topography. Methods: A total of 25 healthy subjects were enrolled in the present study, and one eye of each subject was included. A detailed ophthalmic examination was performed in all cases following CCT measurements with OLCR, FD-OCT, and SC. The results were compared using an ANOVA test. Bland-Altman analysis was used to demonstrate agreement between methods. Intra-examiner repeatability was assessed by using intraclass correlation coefficients (ICCs. Results: Statistically significant differences were observed between the results of the CCT measurements obtained using the three different devices (p=0.009. Significant correlations were found between OLCR and FD-OCT (r=0.97; p0.98. Conclusion: Although the results of CCT measurements obtained from these three devices were highly correlated with one another and the mean differences between instruments were comparable with the reported diurnal CCT fluctuation, the measurements are not directly interchangeable in clinical practice because of the wide LOA values.

  11. Corneal thickness and I.O.P. changes in rhegmatogenous retinal detachment

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    Azad Raj

    1990-01-01

    Full Text Available Twenty patients with Rhegmatogenous retinal detachment were subjected to applanation tonometry and Corneal Thickness measurement to ascertain (i the change in central & peripheral corneal thickness and (ii effect of Intra Ocular Pressure on these corneal changes. Twenty age and sex matched controls also underwent similar investigation. It was observed that both the mean Intra Ocular Pressure and the corneal thickness (both Peripheral Corneal Thickness and Central Corneal Thickness] of the affected eye showed statistically significant reduction (P 0.001 when compared to Intra Ocular Pressure and Corneal Thickness changes of fellow-eyes and eyes of control subjects. In addition to these even the fellow eyes which had normal Intra Ocular Pressure, showed statistically low Central Corneal Thickness measurement, when compared with controls. In view of the above observation and reduction in Corneal Thickness measurement, the present study indicates generalised corneal changes in Rhegmatogenous retinal detachment unrelated to intraocular pressure.

  12. Corneal endothelial morphology and central thickness in patients with type II diabetes mellitus

    DEFF Research Database (Denmark)

    Storr-Paulsen, Allan; Singh, Amardeep; Jeppesen, Helene;

    2014-01-01

    PURPOSE: To investigate corneal endothelial cell density and morphology in type II diabetic and non-diabetic patients and to relate potential differences to the glycaemic status. METHODS: A prospective clinical study including 107 patients with type II diabetes and 128 non-diabetic patients. Samp...

  13. Comparing acromegalic patients to healthy controls with respect to intraocular pressure, central corneal thickness, and optic disc topography findings

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    Emine Sen

    2014-01-01

    Full Text Available Aims: The aim was to compare the intraocular pressure (IOP, central corneal thickness (CCT, and optic disc topography findings of biochemically controlled acromegalic patients and the control group and to evaluate the effect of the duration of acromegaly and serum growth hormone and insulin-like growth factor-1 (IGF-1 levels on these ocular parameters. Materials and Methods: IOP measurement with Goldmann applanation tonometry, CCT measurement with ultrasonic pachymetry, and topographic analysis with Heidelberg retinal tomograph III were performed on 35 biochemically controlled acromegalic patients and 36 age- and gender-matched controls. Results: Mean IOP and CCT were 14.7 ± 2.9 mmHg and 559.5 ± 44.9 μm in the acromegaly patients and 13.0 ± 1.6 mmHg and 547.1 ± 26.7 μm in controls (P = 0.006 and P = 0.15, respectively. A significant moderate correlation was found between the duration of acromegaly and CCT (r = 0.391 and IOP (r = 0.367. Mean retinal nerve fiber layer (RNFL thickness was significantly lower in the acromegalic patients (0.25 ± 0.05 mm as compared to controls (0.31 ± 0.09 mm (P = 0.01. A significant moderate correlation was detected between IGF-1 level and disc area (r = 0.362, cup area (r = 0.389 and cup volume (r = 0.491. Conclusion: Biochemically controlled acromegalic patients showed significantly higher CCT and IOP levels and lower RNFL thickness compared to healthy controls and the duration of disease was correlated with CCT and IOP levels.

  14. Decreased keratocyte density and central corneal thickness in primary open-angle glaucoma patients undergoing treatment with topical prostaglandin analogues

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    Sibel Kocabeyoglu

    2015-01-01

    Full Text Available Purpose: To evaluate whether prostaglandin (PG analogue use is associated with alterations in keratocyte density and central corneal thickness (CCT in subjects with primary open-angle glaucoma (POAG. Materials and Methods: Thirty-five POAG patients treated with PG analogues for >2 years and 35 control subjects without glaucoma were included in this cross-sectional study. All subjects were underwent CCT measurements using ultrasound pachymetry. Keratocyte densities of each stromal layer were determined by in vivo confocal microscopy. Student′s t-test and Chi-square test were used for statistical evaluations. Correlations between keratocyte densities and CCT were analyzed using Pearson′s correlation analysis. Results: Keratocyte densities in each stromal layer were significantly lower in glaucoma patients receiving PG analogues as compared to those of controls (P < 0.001. The mean CCT was also lower in glaucoma patients (515.2 ± 18.8 μ than control subjects (549.6 ± 21.1 μ, P < 0.001. A positive correlation between keratocyte densities in each stromal layer and CCT was observed in POAG patients. Conclusions: Long-term administration of topical PG analogues may adversely influence keratocyte densities and CCT. Further prospective studies are required clarify the relationship between PG analogues and their effects on the cornea.

  15. Evaluation of the Endothelial Cell Density and the Central Corneal Thickness in Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma

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    Bożydar T. Tomaszewski

    2014-01-01

    Full Text Available Purpose. Evaluation of central corneal thickness (CCT and endothelial cell density (ECD in patients with senile cataract and coexisting pseudoexfoliation (PEX syndrome with glaucoma (PEXG and without glaucoma using specular microscopy. Participants and Methods. The study included 122 patients (217 eyes. In this group of patients we identified 133 eyes with PEX syndrome (65 with glaucoma, 68 without glaucoma and 84 eyes without PEX syndrome. ECD and CCT were measured in each eye by specular microscopy. Results. ECD in eyes with PEX syndrome without glaucoma (2297 ± 359 cell/mm2 and in eyes with PEXG (2241 ± 363 cell/mm2 was lower than in the control group (2503 ± 262 cell/mm2 (P<0.001. CCT in eyes with PEXG (508.2 ± 32.6 μm was thinner than in eyes with PEX syndrome without glaucoma (529.7 ± 30.3 μm and control group (527.7 ± 29.4 μm (P<0.001. Conclusions. This research shows that in eyes with PEX syndrome, both with and without glaucoma, ECD was statistically significantly lower than in the control group. In patients with PEXG, CCT was statistically significantly thinner than in the PEX syndrome and control group.

  16. Association of CHRDL1 mutations and variants with X-linked megalocornea, Neuhauser syndrome and central corneal thickness.

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    Alice E Davidson

    Full Text Available We describe novel CHRDL1 mutations in ten families with X-linked megalocornea (MGC1. Our mutation-positive cohort enabled us to establish ultrasonography as a reliable clinical diagnostic tool to distinguish between MGC1 and primary congenital glaucoma (PCG. Megalocornea is also a feature of Neuhäuser or megalocornea-mental retardation (MMR syndrome, a rare condition of unknown etiology. In a male patient diagnosed with MMR, we performed targeted and whole exome sequencing (WES and identified a novel missense mutation in CHRDL1 that accounts for his MGC1 phenotype but not his non-ocular features. This finding suggests that MMR syndrome, in some cases, may be di- or multigenic. MGC1 patients have reduced central corneal thickness (CCT; however no X-linked loci have been associated with CCT, possibly because the majority of genome-wide association studies (GWAS overlook the X-chromosome. We therefore explored whether variants on the X-chromosome are associated with CCT. We found rs149956316, in intron 6 of CHRDL1, to be the most significantly associated single nucleotide polymorphism (SNP (p = 6.81×10(-6 on the X-chromosome. However, this association was not replicated in a smaller subset of whole genome sequenced samples. This study highlights the importance of including X-chromosome SNP data in GWAS to identify potential loci associated with quantitative traits or disease risk.

  17. Comparison of Measurement of Central Corneal Thickness with Spectral Domain Optical Coherence Tomography and Standard Ultrasonic Pachymeter in Premature Infants

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    Emre Hekimoglu

    2015-01-01

    Full Text Available Purpose. To evaluate the repeatability of measurement of central corneal thickness (CCT by spectral domain optical coherence (SD-OCT in premature infants and compare it to CCT measurement by ultrasonic pachymetry (USP. Methods. Three CCT measurements of the left eyes of 50 premature infants were obtained by SD-OCT using the iVue system. 10 CCT measurements of each 28 left eyes of 28 infants were obtained by USP using the Pacscan 300P system. Bland-Altman plots were developed and the limit of agreement (LoA was determined to compare the mean of the SD-OCT and USP measurements. Results. No statistically significant difference was found among the 3 CCT measurements by SD-OCT. Both USP and SD-OCT have been performed for only left eyes of 28 of the 50 babies. Those results have been compared with each other. A statistically significant difference was found between the mean CCT measurements by SD-OCT and USP (p<0.05. The LoA between the SD-OCT and USP measurements ranged from 11.4 to −64.1. Conclusions. CCT can be measured using the iVue SD-OCT system with a high level of repeatability. Although measurement of CCT by SD-OCT and USP is highly correlated, the 2 systems cannot be used interchangeably in premature infants.

  18. The Path to Open-Angle Glaucoma Gene Discovery: Endophenotypic Status of Intraocular Pressure, Cup-to-Disc Ratio, and Central Corneal Thickness

    OpenAIRE

    Charlesworth, Jac; Kramer, Patricia L.; Dyer, Tom; Diego, Victor; Samples, John R.; Craig, Jamie E; Mackey, David A.; Hewitt, Alex W; Blangero, John; Wirtz, Mary K.

    2010-01-01

    The primary open-angle glaucoma (POAG) risk factors intraocular pressure, vertical cup-to-disc ratio, and central corneal thickness are shown to be highly heritable in 22 large POAG families from Australia and the Northwest Pacific region of the United States. Furthermore, bivariate genetic analysis reveals that both intraocular pressure and vertical cup-to-disc ratio represent potentially useful endophenotypes for the genetic dissection of POAG risk.

  19. Differences in Central Corneal Thickness between Spectral Domain-Optical Coherence Tomography and Ultrasound Pachymetry in Patients with Dry Eye Disease

    OpenAIRE

    Celebi, Ali Riza Cenk; Mirza, G. Ertugrul

    2016-01-01

    Purpose. To compare central corneal thickness (CCT) values via Spectral Domain-Optical Coherence Tomography (SD-OCT) and ultrasonic pachymetry in patients with severe dry eye disease (DED) to determine the level of agreement between these 2 methods. Methods. The paired samples t-test was used to compare CCT values in severe DED patients. Matching analysis between methods was performed using intraclass correlation coefficient (ICC). Intrasession reliability of the measurement methods was calcu...

  20. Comparison of Central Corneal Thickness Measurements by Ultrasonic Pachymetry, Orbscan II, and SP3000P in Eyes with Glaucoma or Glaucoma Suspect

    OpenAIRE

    Mei-Ching Teng; Ing-Chou Lai; Tsung-Ho Ou

    2012-01-01

    Background: Intraocular pressure (IOP) measurements are affected by the central cornea thickness (CCT). The conventional method for CCT measurement is ultrasonic pachymetry. However, noncontact procedures lower the risk of infection and corneal damage. In this study, we compared the CCT measured by Orbscan II, SP3000P, and ultrasonic pachymetry in patients with glaucoma or glaucoma suspect.Methods: The CCT of 208 eyes (46 eyes with glaucoma suspect, 42 with primary angle-closure glaucoma, and...

  1. Distribution of central corneal thickness and its association with ocular parameters in a large central European cohort: the Gutenberg health study.

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    Esther M Hoffmann

    Full Text Available MAIN OBJECTIVE: To evaluate the distribution of central corneal thickness (CCT in a large German cohort and to analyse its relationship with intraocular pressure and further ocular factors. DESIGN: Population-based, prospective, cohort study. METHODS: The Gutenberg Health Study (GHS cohort included 4,698 eligible enrollees of 5,000 subjects (age range 35-74 years who participated in the survey from 2007 to 2008. All participants underwent an ophthalmological examination including slitlamp biomicroscopy, intraocular pressure measurement, central corneal thickness measurement, fundus examination, and were given a questionnaire regarding glaucoma history. Furthermore, all subjects underwent fundus photography and visual field testing using frequency doubling perimetry. RESULTS: Mean CCT was 557.3 ± 34.3 µm (male and 551.6±35.2 µm in female subjects (Mean CCT from right and left eyes. Younger male participants (35-44 years presented slightly thicker CCT than those older. We noted a significant CCT difference of 4 µm between right and left eyes, but a high correlation between eyes (Wilcoxon test for related samples: p<0.0001. Univariable linear regression stratified by gender showed that IOP was correlated with CCT (p<0.0001. A 10 µm increase in CCT led to an increase in IOP between 0.35-0.38 mm Hg, depending on the eye and gender. Multivariable linear regression analysis revealed correlations between gender, spherical equivalent (right eyes, and CCT (p<.0001 and p=0.03, respectively. CONCLUSIONS: We observed positive correlations between CCT and IOP and gender. CCT was not correlated with age, contact lens wear, positive family history for glaucoma, lens status, or iris colour.

  2. Comparing two acromegalic patients with respect to central corneal thickness, intraocular pressure, and tear insulin-like growth factor levels before and after treatment

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    Kan Emrah

    2015-01-01

    Full Text Available The aim of the study was to compare the central corneal thickness (CCT, intraocular pressure (IOP, and tear insulin-like growth factor-1 (IGF-1 levels of 2 patients with acromegaly before and after the surgical treatment of the disease. CCTs, IOP levels, and tear IGF-1 values showed a decrease after the treatment in 2 patients. As we found higher CCT, IOP, and tear IGF-1 levels in the active phase of the disease in two acromegaly patients, detailed information about the activity of the disease may be important before the examination of these patients.

  3. Comparison of central corneal thickness measured with Orbscan-Ⅱ, Pentacam and ultrasonic pachymetry%Orbscan-Ⅱ、Pentacam及超声测厚仪角膜厚度测量值的比较

    Institute of Scientific and Technical Information of China (English)

    王霁雪; 吴荒; 杨隆艳; 郑雅娟

    2010-01-01

    Objective To assess the reliability of Orbscan-Ⅱ , Pentacam and ultrasonic pachymetry (US) for central corneal thickness (CCT) measurements. Methods Central corneal thick- ness was measured using Orbscan-Ⅱ, Pentacam and ultrasonic pachymetry in 159 preoperative cases (318 eyes). Patients were further divided into three groups according to corneal thickness (0.05).结论 三种方法用于测量准分子激光角膜手术前近视患者的角膜中央厚度时虽然存在一定差异,但总体上无统计学意义,具有很好的协同性,但相互间还不能完全替代.

  4. Repeatability and Reproducibility of Measurements Using a NT-530P Noncontact Tono/Pachymeter and Correlation of Central Corneal Thickness with Intraocular Pressure

    Science.gov (United States)

    Kamiya, Kazutaka; Fujiwara, Kazuko; Shimizu, Kimiya

    2013-01-01

    Purpose. To investigate the repeatability and reproducibility of intraocular pressure (IOP) and central corneal thickness (CCT) measurements using a noncontact tono/pachymeter (NT-530P) and to assess the correlation of CCT with IOP. Methods. Forty-six eyes of healthy volunteers were measured by two examiners. Three consecutive measurements per eye were performed. Repeatability was assessed using the coefficient of variation, and reproducibility was assessed using Bland-Altman plots. Linear correlations were used to determine agreement between CCT and noncorrected IOP and CCT and corrected IOP, which was calculated using a formula built into the NT-530P. Results. The coefficient of variation for IOP was 6.4% and for CCT was 0.4%. The 95% limits of agreement between examiners were −0.17 ± 1.42 mmHg (range: −2.95 to 2.61 mmHg) for IOP, −0.93 ± 4.37 μm (range: −9.50 to 7.64 μm) for CCT. The corrected IOP was significantly higher than the noncorrected IOP (P = 0.010.3). The noncorrected IOP significantly correlated with CCT (r = −0.4883, P = 0.0006). The corrected IOP showed no significant correlation with CCT (r = −0.0285, P = 0.8509). Conclusions. NT-530P offered repeatability and reproducibility in both IOP and CCT measurements. The corrected IOP calculated using the NT-530P was independent of the CCT, suggesting that this IOP may be less influenced by the central corneal thickness. PMID:24222904

  5. Repeatability and Reproducibility of Measurements Using a NT-530P Noncontact Tono/Pachymeter and Correlation of Central Corneal Thickness with Intraocular Pressure

    Directory of Open Access Journals (Sweden)

    Fusako Fujimura

    2013-01-01

    Full Text Available Purpose. To investigate the repeatability and reproducibility of intraocular pressure (IOP and central corneal thickness (CCT measurements using a noncontact tono/pachymeter (NT-530P and to assess the correlation of CCT with IOP. Methods. Forty-six eyes of healthy volunteers were measured by two examiners. Three consecutive measurements per eye were performed. Repeatability was assessed using the coefficient of variation, and reproducibility was assessed using Bland-Altman plots. Linear correlations were used to determine agreement between CCT and noncorrected IOP and CCT and corrected IOP, which was calculated using a formula built into the NT-530P. Results. The coefficient of variation for IOP was 6.4% and for CCT was 0.4%. The 95% limits of agreement between examiners were −0.17±1.42 mmHg (range: −2.95 to 2.61 mmHg for IOP, −0.93±4.37 μm (range: −9.50 to 7.64 μm for CCT. The corrected IOP was significantly higher than the noncorrected IOP (P=0.010.3. The noncorrected IOP significantly correlated with CCT (r=−0.4883, P=0.0006. The corrected IOP showed no significant correlation with CCT (r=−0.0285, P=0.8509. Conclusions. NT-530P offered repeatability and reproducibility in both IOP and CCT measurements. The corrected IOP calculated using the NT-530P was independent of the CCT, suggesting that this IOP may be less influenced by the central corneal thickness.

  6. Short-term variation of central corneal thickness and axial anterior chamber depth of healthy eyes using Scheimpflug photography via the Oculus Pentacam*

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    S. D. Mathebula

    2009-12-01

    Full Text Available The purpose of this study was to investigate short-term variation and intra-subject repeatabil-ity of  human central corneal thickness (CCT and axial anterior chamber depth (AACD measure-ments obtained using the Oculus Pentacam. Forty consecutive images of the right eye of the anteriorsegment of 10 young and healthy individuals were measured with the Pentacam. Measurements of CCT and AACD were ob-tained from these images and means, standard deviations,variances and repeatability of the measurements were investigated. Both parameters (CCTand AACD showed small variation with good orexcellent repeatability for all eyes. The inter-subject or overall means and standard deviations for CCT and AACD of the 10 right eyes were 0.555 ±0.05 millimeters (or 555 ± 50 microns and 3.206± 0.04 millimeters, respectively. The individual or intra-subject averages for samples of CCT and AACD measurements are also provided in this paper. Univariate normality of the data was explored with Kolmogorov-Smirnov, Lilliefors and ShapiroWilks tests and we found that generally the data was normally distributed although there were some exceptions. Based on the results of this study, the Oculus Pentacam appears to provide repeatable and reliable measures for both CCT and AACD in young,normal eyes. Further research is, however, needed to determine short-term variation and repeatability of CCT and AACD with the Pentacam in more com-plicated eyes with, say, corneal scarring or ectasia or where refractive surgery may be an issue.

  7. Central Corneal Thickness in Highly Myopic Eyes: Inter-device Agreement of Ultrasonic Pachymetry, Pentacam and Orbscan II Before and After Photorefractive Keratectomy

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    Nader Nassiri

    2014-01-01

    Full Text Available Purpose: To determine inter-device agreement for central corneal thickness (CCT measurement among ultrasound pachymetry, rotating Scheimpflug imaging (Pentacam, Oculus, Wetzlar, Germany, and scanning slit corneal topography (Orbscan II, Bausch & Lomb, Rochester, NY, USA in highly myopic eyes before and after photorefractive keratectomy (PRK. Methods: This prospective comparative study included 61 eyes of 32 patients with high myopia who underwent PRK. Six month postoperative CCT values were compared to preoperative values in 27 patients (51 eyes who completed the follow up period. To determine the level of agreement, Pentacam and Orbscan II readings were compared to ultrasonic pachymetry measurements as the gold standard method. Results: Mean CCT measurements with ultrasound, Pentacam, and Orbscan II before PRK were 557μm, 556μm, and 564μm, respectively; and 451μm, 447μm, and 438μm 6 months after surgery in the same order. Preoperatively, the 95% limits of agreement (LoA with ultrasound measurements were -20μm to 17μm for Pentacam and -21μm to 33μm for Orbscan II. Six months postoperatively, the 95% LoA were -30μm to 23μm for Pentacam and -69μm to 43μm for Orbscan II. Conclusion: Preoperatively, CCT measurements were higher with Orbscan II as compared to ultrasound. Postoperatively, both Pentacam and Orbscan II measurements were lower than those obtained with ultrasound, but Pentacam had better agreement. The use of ultrasound, as the gold standard method, or Pentacam both appear to be preferable over Orbscan II among patients with high myopia.

  8. Measurement of central corneal thickness by ultrasonic pachymeter and oculus pentacam in patients with well-controlled glaucoma: hospital-based comparative study

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    Rashid RF

    2016-03-01

    Full Text Available Riyam Faihan Rashid, Qasim K Farhood Department of Ophthalmology, College of Medicine, University of Babylon, Babylon, Iraq Background: The measurement of central corneal thickness (CCT plays an important role in the diagnosis and treatment of glaucoma and many corneal diseases.Objective of the study: To compare the measurement of CCT by ultrasonic pachymeter with that measured by oculus pentacam in both normal subjects and patients with well-controlled glaucoma.Patients and methods: In 173 eyes of both controls and patients with open-angle glaucoma (normal intraocular pressure attending Ibn Al Haitham Teaching Eye Hospital, CCT was measured by oculus pentacam and then by ultrasound pachymeter at the same morning by the same technicians.Results: The results showed no significant difference in CCT readings measured by the two devices in both glaucoma and control groups (glaucoma group: 547.29±49.32 µm with pentacam vs 547.66±45.24 µm with ultrasound pachymeter; control group: 551.02±36.28 µm with pentacam vs 541.25±34.96 µm with ultrasound pachymeter. P-values were >0.05 in both groups (statistically not significant.Conclusion and recommendation: Ultrasonic pachymeter and oculus pentacam can be used interchangeably in measuring CCT, and we recommend a nontouch method (in this study, pentacam Scheimpflug camera for measuring CCT during assessment of patients with glaucoma or any ocular disease or surgery. Keywords: CCT, open-angle glaucoma, ultrasound pachymeter, Scheimpflug camera

  9. Correlação entre a espessura corneana central e o comprimento axial ocular nos portadores de glaucoma e em olhos normais Correlation between central corneal thickness and axial length in patients with glaucoma and normal eyes

    Directory of Open Access Journals (Sweden)

    Paula Resende Aquino de Assis Pereira Mello

    2009-08-01

    Full Text Available OBJETIVO: Correlacionar a espessura corneana central com o comprimento axial ocular nos portadores de glaucoma primário de ângulo aberto, com glaucoma primário de fechamento angular e indivíduos com olhos normais. MÉTODOS: A amostra foi constituída de 94 olhos de 94 pacientes, divididos em três grupos compostos por 33 olhos de 33 pacientes portadores de glaucoma primário de ângulo aberto, 30 olhos de 30 pacientes com glaucoma primário de fechamento angular e 31 olhos normais de 31 indivíduos. A espessura corneana e o comprimento axial do olho foram obtidos pela paquimetria ultrassônica e ecobiometria, respectivamente. RESULTADOS: A média da espessura corneana central foi de 535,1 mm no glaucoma primário de fechamento angular; 520,6 mm no glaucoma primário de ângulo aberto e 519,2 mm nos olhos normais (p=0,18. A média do comprimento axial do globo ocular nos portadores de glaucoma primário de fechamento angular foi de 22,16 mm e nos grupos com glaucoma primário de ângulo aberto e olhos normais foram de 22,68 mm e 22,64 mm, respectivamente (p=0,13. Não houve correlação significativa entre a espessura corneana central e comprimento axial do globo ocular nos grupos com glaucoma primário de fechamento angular (r=-0,085; p=0,65, glaucoma primário de ângulo aberto (r=-0,070; p=0,69 e olhos normais (r=-0,120; p=0,52. CONCLUSÃO: Os resultados deste trabalho sugerem não haver correlação entre a espessura corneana central e o comprimento axial do globo ocular nos portadores de glaucoma e indivíduos com olhos normais.PURPOSE: To evaluate and to correlate the central corneal thickness with the ocular axial length in patients with primary open-angle glaucoma, primary angle-closure glaucoma and individuals with normal eyes. METHODS: The sample was composed of 94 patients' eyes, divided into three groups constituted of 33 eyes of 33 primary open-angle glaucoma patients, 30 eyes of 30 primary angle-closure glaucoma patients and 31

  10. Differences in Central Corneal Thickness between Spectral Domain-Optical Coherence Tomography and Ultrasound Pachymetry in Patients with Dry Eye Disease

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    Ali Riza Cenk Celebi

    2016-01-01

    Full Text Available Purpose. To compare central corneal thickness (CCT values via Spectral Domain-Optical Coherence Tomography (SD-OCT and ultrasonic pachymetry in patients with severe dry eye disease (DED to determine the level of agreement between these 2 methods. Methods. The paired samples t-test was used to compare CCT values in severe DED patients. Matching analysis between methods was performed using intraclass correlation coefficient (ICC. Intrasession reliability of the measurement methods was calculated via the concordance correlation coefficient (CCC, variation equivalent, and Pearson’s correlation coefficient. The Bland-Altman procedure was used to graphically represent the differences between CCT values. Results. The study included 56 eyes of 24 female and 4 male patients. Mean age of the patients was 50.9±11.3 years. Mean CCT via Cirrus SD-OCT was 523.82±30.98 μm versus 530.050±31.85 μm via ultrasonic pachymetry (paired samples t-test, P<0.001. The Bland-Altman plot showed good agreement between the examiners. The ICC for repeatability was 0.974. The CCC between the 2 methods’ CCT values was 0.973. The variation equivalent was 0.976 and Pearson’s correlation coefficient was 99.3%, which also indicated high correlation between the 2 methods’ measurements. Conclusions. The present findings show that in patients with severe DED Cirrus SD-OCT provides reliable intraobserver CCT values.

  11. Differences in Central Corneal Thickness between Spectral Domain-Optical Coherence Tomography and Ultrasound Pachymetry in Patients with Dry Eye Disease.

    Science.gov (United States)

    Celebi, Ali Riza Cenk; Mirza, G Ertugrul

    2016-01-01

    Purpose. To compare central corneal thickness (CCT) values via Spectral Domain-Optical Coherence Tomography (SD-OCT) and ultrasonic pachymetry in patients with severe dry eye disease (DED) to determine the level of agreement between these 2 methods. Methods. The paired samples t-test was used to compare CCT values in severe DED patients. Matching analysis between methods was performed using intraclass correlation coefficient (ICC). Intrasession reliability of the measurement methods was calculated via the concordance correlation coefficient (CCC), variation equivalent, and Pearson's correlation coefficient. The Bland-Altman procedure was used to graphically represent the differences between CCT values. Results. The study included 56 eyes of 24 female and 4 male patients. Mean age of the patients was 50.9 ± 11.3 years. Mean CCT via Cirrus SD-OCT was 523.82 ± 30.98 μm versus 530.050 ± 31.85 μm via ultrasonic pachymetry (paired samples t-test, P variation equivalent was 0.976 and Pearson's correlation coefficient was 99.3%, which also indicated high correlation between the 2 methods' measurements. Conclusions. The present findings show that in patients with severe DED Cirrus SD-OCT provides reliable intraobserver CCT values. PMID:27375899

  12. Evaluation of corneal thickness and topography in normal eyes using the Orbscan corneal topography system

    OpenAIRE

    Liu, Z.; HUANG, A; Pflugfelder, S.

    1999-01-01

    AIMS—To map the thickness, elevation (anterior and posterior corneal surface), and axial curvature of the cornea in normal eyes with the Orbscan corneal topography system.
METHODS—94 eyes of 51 normal subjects were investigated using the Orbscan corneal topography system. The anterior and posterior corneal elevation maps were classified into regular ridge, irregular ridge, incomplete ridge, island, and unclassified patterns, and the axial power maps were grouped into round, oval, symmetric bo...

  13. Comparison between a New Optical Biometry Device and an Anterior Segment Optical Coherence Tomographer for Measuring Central Corneal Thickness and Anterior Chamber Depth

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    Jinhai Huang

    2016-01-01

    Full Text Available Purpose. To compare between a new optical biometer (AL-Scan, Nidek Co., Aichi, Japan and an anterior segment optical coherence tomographer (Visante AS-OCT, Carl Zeiss Meditec, Dublin, USA for measuring central corneal thickness (CCT, anterior chamber depth (ACD, and aqueous depth (AD. Methods. Sixty-three eyes of 63 normal subjects were examined with AL-Scan and Visante AS-OCT in this prospective study. One eye per subject was measured three times with both devices to record their CCT, ACD, and AD. All procedures were performed by the same operator. Agreement between the two devices was assessed using paired t-tests, Bland-Altman plots, and 95% limits of agreement (LoA. Results. The mean CCT, ACD, and AD measured by AL-Scan were 538.59±27.37 μm, 3.70±0.30 mm, and 3.16±0.30 mm, respectively. The mean values obtained by the Visante OCT were 536.14±26.61 μm for CCT, 3.71±0.29 mm for ACD, and 3.17±0.29 mm for AD. The mean CCT by the AL-Scan was higher than that obtained by the Visante AS-OCT (difference = 2.45±6.07 μm, P<0.05. The differences in ACD and AD measurements were not statistically significant. The 95% LoA of CCT, ACD, and AD were between −9.44 and 14.35 μm, −0.15 and 0.12 mm, and −0.15 and 0.12 mm, respectively. Conclusions. Since these two devices were comparable for measuring CCT, ACD, and AD, their results can be interchangeably used in the clinic.

  14. Comparison between a New Optical Biometry Device and an Anterior Segment Optical Coherence Tomographer for Measuring Central Corneal Thickness and Anterior Chamber Depth.

    Science.gov (United States)

    Huang, Jinhai; Lu, Weicong; Savini, Giacomo; Chen, Hao; Wang, Chengfang; Yu, Xinxin; Bao, Fangjun; Wang, Qinmei

    2016-01-01

    Purpose. To compare between a new optical biometer (AL-Scan, Nidek Co., Aichi, Japan) and an anterior segment optical coherence tomographer (Visante AS-OCT, Carl Zeiss Meditec, Dublin, USA) for measuring central corneal thickness (CCT), anterior chamber depth (ACD), and aqueous depth (AD). Methods. Sixty-three eyes of 63 normal subjects were examined with AL-Scan and Visante AS-OCT in this prospective study. One eye per subject was measured three times with both devices to record their CCT, ACD, and AD. All procedures were performed by the same operator. Agreement between the two devices was assessed using paired t-tests, Bland-Altman plots, and 95% limits of agreement (LoA). Results. The mean CCT, ACD, and AD measured by AL-Scan were 538.59 ± 27.37 μm, 3.70 ± 0.30 mm, and 3.16 ± 0.30 mm, respectively. The mean values obtained by the Visante OCT were 536.14 ± 26.61 μm for CCT, 3.71 ± 0.29 mm for ACD, and 3.17 ± 0.29 mm for AD. The mean CCT by the AL-Scan was higher than that obtained by the Visante AS-OCT (difference = 2.45 ± 6.07 μm, P LoA of CCT, ACD, and AD were between -9.44 and 14.35 μm, -0.15 and 0.12 mm, and -0.15 and 0.12 mm, respectively. Conclusions. Since these two devices were comparable for measuring CCT, ACD, and AD, their results can be interchangeably used in the clinic. PMID:27403339

  15. Effect of compound tropicamide eye drop on measurement of central corneal thickness%复方托吡卡胺对中央角膜厚度测量的影响

    Institute of Scientific and Technical Information of China (English)

    曾原; 李懿

    2015-01-01

    目的:评价复方托吡卡胺眼液对中央角膜厚度测量的影响及影响持续的时间。方法选择拟行激光角膜屈光手术的近视眼患者120例240眼,分别于点眼前和点眼后1,4 h 用 OrbscanⅡ眼前节检查系统和非接触反射显微镜SP-2000P测量角膜厚度。结果以OrbscanⅡ测量复方托吡卡胺点眼前、点眼后1 h、点眼后4 h中央角膜厚度(CCT)分别为(545±27),(559±31),(544±26)μm;以SP-2000P测量分别为(508±26),(521±29),(506±24)μm。复方托吡卡胺点眼后1 h与点眼前与相比,2种仪器测量CCT均增加( P<0.01);复方托吡卡胺点眼后4 h 与点眼后1 h 相比,2种仪器测量 CCT 均下降( P <0.01);复方托吡卡胺点眼后4 h与点眼前相比,CCT均无变化。结论复方托吡卡胺点眼1 h后使CCT增加;复方托吡卡胺对CCT影响在点眼4 h后消除。准分子激光屈光手术术前检查中,CCT的测量应在复方托吡卡胺点眼前或者点眼后4h进行。%Objective To evaluate the effect of compound tropicamide eye drops on the measurement of central corneal thickness and to investi-gate the duration of the effect.Methods In this trial, 240 eyes of 120 myopic patients undergoing corneal laser refractive surgery were selected, and central corneal thicknesses were measured before treatment and 1 , 4 h after administration of compound tropicamide eye drops using OrbscanⅡ anterior segment analysis system and SP -2000P non -contact specular microscope, respectively.Results The central corneal thick-ness was (545 ±27),(559 ±31) and (544 ±26) μm before and 1 and 4 h after administration, measured with Orbscan Ⅱ anterior segment analysis system, whereas being ( 508 ± 26 ) , ( 521 ±29 ) and (506 ±24) μm measured with SP -2000P non -contact specular microscope.The central corneal thickness measured with both OrbscanⅡsystem and SP-2000 P microscope increased 1 h after

  16. Partial-thickness corneal tissue restoration after a chemical burn

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    Galan A

    2016-04-01

    Full Text Available Alessandro Galan, Anton Giulio Catania, Giuseppe Lo Giudice San Paolo Ophthalmic Center, San Antonio Hospital, Padova, Italy Purpose: We describe a case of full-thickness corneal restoration after an acute corneal burn with an acid agent. Methods: A 32-year-old male reported painful discomfort, redness, photophobia, and a decrease in visual acuity in the left eye after a unilateral burn with an acid agent. Slit-lamp examination revealed massive corneal melting involving necrotic sequestrum of the entire corneal surface. Surgical approach was carried out in order to preserve residual ocular tissues. Results: Extensive corneal–conjunctival layer curettage of the necrotic tissue was performed showing perfectly clear undamaged deep lamellar corneal layers. The patient underwent multilayered amniotic membrane transplantation and total capsular–conjunctival flap in order to preserve ocular tissue from further melting or corneal perforation. A complete and spontaneous “restitutio ad integrum” of the corneal layers was shown during the follow-up. The cornea was perfectly clear with restored normal anatomical architecture. Conclusion: In this case, a spontaneous full-thickness corneal tissue restoration occurred after an acute chemical burn. Studies about the mechanisms whereby different cells interact and replicate within the stroma may unveil the biology behind corneal regeneration and transparency. Keywords: amniotic membrane, chemical burn, corneal healing

  17. A comparative study of central corneal thickness (CCT and intraocular pressure (IOP in University of KwaZulu-Natal students of Black and Indian ethnicity*

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    Z. Sardiwalla

    2012-12-01

    Full Text Available Thisstudy compared central corneal thickness (CCT and intraocular pressure (IOP of Black and Indian students from the University of Kwa-Zulu-Natal. Two hundred (100 Black and 100 Indi-an participants of both genders aged 18-25 years (mean and standard deviation; 20.1±1.6 years participated in this study. CCT and IOP were measured for the right eye of each participant using a Tono-Pachymeter (NT530P and a Goldmann applanation tonometer (GAT respectively. Data was analyzed with descriptive, t-test and Pearson’s cor-relation statistics. In the total sample (N = 200, the mean CCT value was 519.5 ± 38.6 μm and CCT was higher in the Indians (526.5 ± 37.2 µm than in the Blacks (512.4 ± 38.9 µm (p = 0.01.  Also, it was higher in the females (522.3 µm than in males (516.7 µm, but the difference was insignificant (p = 0.07. The mean CCT was higher in the Indian males (520.1 µm than in the Black males (513.2 µm, but the difference was insignificant (p=0.39.  However, it was significantly higher in the Indian females (533 µm than in the Black females (511.6 µm (p = 0.003. In the total sample, the mean IOP was 14.6 mmHg and IOP was greater in Indiansthan Blacks (mean = 15.3 ± 2.9 mmHg and 13.8 ± 2.6 mmHg respectively (p = 0.01. Also, the mean IOP (N = 200 value was slightly higher in the females (14.7 mmHg than in males (14.5 mmHg (p = 0.51. The mean IOP was higher in the Indian males (15.0 mmHg than in the Black males (14.0 mmHg (p = 0.07 and the mean IOP value was higher in the Indian females (15.7 mmHg than in the Black females (13.6 mmHg (p < 0.001. The higher mean IOP value in the Indian than Black participants was attributed to the higher mean CCT values. A positive, but inconsistent association between CCT and IOP was found in this study, the coefficient in the total sample (r = 0.382, p = 0.000, in the Blacks (r = 0.196, p = 0.05 and in Indians (r = 0.498, p = 0.000. A national population study comparing CCT and IOP in the various

  18. Evaluation of corneal thickness alterations during menstrual cycle in productive age women

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    Negar Amiri Ghahfarokhi

    2015-01-01

    Full Text Available Purpose: To determine the change in corneal thickness through different phases of menstrual cycle in women who are in their productive age. Materials and Methods: Fifty healthy women with normal past medical history were enrolled in this prospective study. Central corneal thickness was measured with ultrasound pachymeter three times during a menstrual cycle: Beginning of the cycle (days 1-3, ovulation time, and at the end of cycle (days 27-32. We confirmed ovulation time with determining a peak in luteinizing hormone in urine. To avoid the diurnal variation of the corneal thickness which is well recognized, we checked all our subjects at 10 in the morning. Results: In days 1 to 3 of menstruation, mean corneal thickness was 541.40±11.36 and 540.82±11.70 microns for left and right eyes respectively. At ovulation time the mean thickness changed to 556.50±7.11 and 555.98±7.26 microns for left and right eyes respectively, and at the end of the cycle, the corneal thickness turned in to 536.38±12.83 and 535.48±13.08 microns for left and right eyes respectively. The difference of corneal thickness was statistically significant relating to the different stages of menstrual cycle. Conclusion: The thickest cornea during the menstruation cycle is achieved at the ovulation time and the thinnest at the end of the cycle and this should be taken in to account whilst plan to do a corneal refractive surgery.

  19. Estudo da correlação entre pressão intra-ocular e espessura corneana central (projeto glaucoma Intraocular pressure vs central corneal thickness:a comparative study (glaucoma project

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    Kenji Sakata

    2000-10-01

    Full Text Available Objetivos: Avaliar a distribuição da espessura corneana central (ECC e sua relação com a pressão intra-ocular (PIO em um grupo de pacientes e demonstrar a utilidade da paquimetria para avaliar a PIO em casos selecionados. Métodos: A espessura corneana central foi determinada em 167 pacientes com mais de 40 anos de idade (319 olhos por meio de paquimetria ultra-sônica. A pressão intra-ocular foi medida com tonômetro de aplanação de Goldmann. Resultados: A ECC média dos 319 olhos foi 0,5173 + 0,0377 mm, sendo o valor máximo 0,656 mm e o mínimo 0,430 mm. A PIO média foi 16,44 + 3,88 mmHg, a pressão máxima 30 mmHg e a pressão mínima 8 mmHg. Foi observada uma regressão linear de 0,13677 nas variáveis analisadas (p=0,0145, não havendo diferença entre sexo e idade. Dividiu-se as observações em dois grupos: grupo I -- PIO £ 21 mmHg -- com 285 olhos que apresentaram uma ECC média de 0,517 + 0,0376; e o grupo II -- PIO > 21 mmHg -- com 34 olhos que apresentaram uma ECC média de 0,519 + 0,0393. Conclusão: Observou-se uma regressão linear entre PIO e ECC, ou seja, quanto maior a ECC maior será a PIO. Demonstrou-se a utilidade da paquimetria corneana na avaliação da PIO daqueles pacientes em que esta estava falsamente aumentada ou diminuída na tonometria de aplanação, direcionando a terapêutica a pacientes realmente portadores de glaucoma.Purpose: To evaluate the distribution of the central corneal thickness (CCT and its relationship with the intraocular pressure (IOP in a group of patients and to demonstrate the usefulness of the pachymeter to evaluate IOP in selected cases. Methods: The central cornea thickness of 167 patients over 40 years old (319 eyes was determined using ultrasonic pachymetry. The intraocular pressure was measured by the "Goldmann" applanation tonometer.Results: The CCT average of the 319 eyes was 0.5173 + 0.0377mm, the maximum value being 0.656mm and the minimum value 0.430mm. The IOP average was

  20. Correlation between Corneal Thickness and Degree of Myopic Refractory Error

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    A Mortazavi

    2005-01-01

    Full Text Available Background: corneal thickness is an important factor in refractive surgeries such as Radial Keratotomy (RK, Photo Refractive Keratotomy (PRK and Laser Insitu Keratomileusis (LASIK. This study evaluated the correlation between this factor and the degree of myopic refractory error. Methods: In this cross-sectional study, 224 myopic eyes (112 patients which had undergone LASIK operation were assessed. These patients had referred to Aban Eye Clinic, Isfahan, Iran, during August and September 2002. Corneal thickness was measured by ORB SCAN Topoghraphy, and cycloplegic refraction was performed with autorefratometery and retinoscopy. Suspected keratoconus cases and hyperopic patients were excluded. Results: The patients' age was 27.2 ± 1.36 in men (N = 35 and 30.13 ± 1.04 in women (N = 77. Mean value of myopic refractory error in male patients was 5.1 ± 0.24D and in female patients was 3.8 ± 0.36D. Mean of corneal thickness was 540 ± 5.25 µM and 530 ± 5.88 µM in male and female patients respectively. There was no correlation between the degree of myopia and corneal thickness in any of the patients. Also in this research, no relations between the age and myopia were found. Right eye (P > 0.5, r = 0.124 Left eye (P > 0.5, r = 0.104. Conclusion: Based on our findings, corneal thickness and myopic refectory error do not seem to have any relations. (r = 0.039, p = 0.684. Keywords: Corneal Thickness, Cornea, Myopia, LASIK, Refractory Error

  1. Comparação entre as medidas da espessura central corneana usando a paquimetria óptica e a ultra-sônica Comparison between the measurements of central corneal thickness using optic and ultrasonic pachymeters

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    Aline Leonel Maimone

    2007-10-01

    Full Text Available OBJETIVOS: Comparar a medida da espessura corneana central (ECC obtida pelo paquímetro óptico Haag-Streit e a paquimetria ultrassônica DGH 500 (PachetteTM. MÉTODOS: Foram avaliados, 200 olhos de 100 pacientes utilizando-se o paquímetro óptico (PO e o ultrassônico (PU. As medidas foram realizadas na área central da córnea, respeitando a área dos 3 mm, em pacientes com córneas normais, em olhos hipermétropes, emétropes e míopes, excluindo doenças oculares, usuários de lentes de contato ou submetidos às cirurgias. RESULTADOS: A média geral da ECC medida pelo PO foi 603,8± 32,6µm, e 568,2±40,5 µm pelo PU. As comparações entre as medidas dos dois aparelhos foram realizadas ao nível de 5% de significância e a diferença entre os dois aparelhos foi 35,7±26,4 µm (p=0,0000, indicando diferença significativa entre os métodos utilizados. Não houve diferença estatística entre olhos hipermétropes, emétropes e míopes usando o PU. CONCLUSÃO: A medida da ECC é superestimada pelo PO quando comparada com o PU.PURPOSE: To compare measurements of central corneal thickness obtained using a Haag-Streit optic pachymeter and a DGH 500 (Pachette Ttm ultrasonic pachymeter in normal patients. METHODS: An evaluation was made of 200 eyes of 100 patients using Optic (PO and Ultrasonic (PU pachymeters. Measurements were made in the area of the central cornea (ECC respecting the 3.0 mm territory, in patients with normal corneas of hypermetropic, emetropic and myopic eyes. Patients with ocular diseases, ocular surgeries, and contact lens wearers, were excluded. A statistical analysis was performed using a Paired Student's t test to compare measurements between instruments at the 5% level of significance. RESULTS: The mean thickness of the ECC measured by the PO was 603.8±32.6µm and by the PU, 568.2±40.5µm. The difference between the two instruments was 35.7±26.4µm. Applying the t test with p = <5%, the difference was significant. We

  2. Biomechanical corneal changes induced by different flap thickness created by femtosecond laser

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    Fabricio W. Medeiros

    2011-01-01

    Full Text Available OBJECTIVE: To evaluate the impact of the creation of corneal flaps at different thicknesses on the biomechanical properties of swine corneas. METHOD: Twelve swine eyes were obtained to form two groups: 100 μm flap thickness and 300 μm flap thickness. Each eye was submitted to the following examinations: raster topography to investigate corneal curvature alterations, ocular response analyzer to investigate corneal hysteresis change, optical coherence tomography to measure central corneal and flap thickness and sonic wave propagation velocity as a measure of stiffness, before and immediately after flap creation. After flap amputation, surface wave velocity measurements were repeated. RESULTS: Measured flap thicknesses were statistically different for thin and thick flap groups, with an average of 108.5 + 6.9 and 307.8 + 11.5 μm respectively. Hysteresis and corneal resistance factor did not change significantly after flap creation in the thin flap group. With thicker flaps, both parameters decreased significantly from 8.0 +1.0 to 5.1 +1.5 mmHg and from 8.2 + 1.6 to 4.1 +2.5 mmHg respectively. Simulated keratometry values increased in the thick flap group (from 39.5 + 1 D to 45.9+1.2 D after flap creation but not in the thin flap group (from 40.6 + 0.6 D to 41.4+ 1.0 D. Regarding surface wave velocity analysis, the surgical procedures induced statistically lower results in some positions. CONCLUSION: In the experimental conditions established by this model, thicker flaps presented a greater biomechanical impact on the cornea.

  3. Comparison of Central Corneal Thickness Measured by AC-OCT and OCT%AC-OCT与OCT测量中央角膜厚度的比较

    Institute of Scientific and Technical Information of China (English)

    曾阳发; 刘杏; 蔡小于; 黄晶晶; 郑小萍; 李媚; 王涛; 毛真

    2007-01-01

    [目的]探讨眼前段光学相干断层扫描仪(AC-OCT)测量中央角膜厚度(CCT),并与光学相干断层扫描仪(OCT)进行比较.[方法]分别用OCT和AC-OCT的高分辨单线扫描程序(High Resolution Corneal)、角膜地形图程序(Pachymerry Map)测量30例(30只眼)正常受试者的CCT.采用配对t检验对之进行比较;用相关分析方法分析两种仪器测量值之间的相关性;随机选择1只眼分别用两种OCT仪依次重复测量CCT 10次,采用变异系数作为评判标准,比较测量的可重复性.[结果]OCT测量的CCT平均值为526.0(s=29.4)μm;AC-OCT角膜地形图程序测量的中央2 mm区域最小值、最大值和平均值的均值分别是512.6(s=31.7)μm,522.0(s=32..3)μm和515.0(s=31.7)μm,高分辨单线扫描程序测得的CCT值为518.9(s=31.1)μm;OCT测量的CCT值比AC-OCT的各测量值分别大13.3(s=5.9)μm(P=0.000);3.9(s=6.3)μm(P=0.002);11.0(s=5.9)μm(P=0.000);7.0(s=6.4)μm(P=0.000).OCTCCT与AC-OCT各CCT值有很好的相关性(rOCT-AC-OCT Min=0.987,rOCT-AC-OCT Max=0.987,rOCT-AC-OCT Mean=0.988,rOCT-AC-OCT Flap=0.986,P均=0.000).OCT测量CCT值10次的变异系数为0.67%.AC-OCT角膜地形图中央2 mm区域中的最小值、最大值和平均值以及高分辨单线扫描程序测量值的变异系数分别为0.23%,0.48%,0.20%和0.37%.[结论]OCT测量的CCT值比AC-OCT的各CCT值大,两种OCT的测量值相关性较好;AC-OCT测量CCT的可重复性稍好于OCT.

  4. Assessment of Corneal Epithelial Thickness in Asymmetric Keratoconic Eyes and Normal Eyes Using Fourier Domain Optical Coherence Tomography

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    S. Catalan

    2016-01-01

    Full Text Available Purpose. To compare the characteristics of asymmetric keratoconic eyes and normal eyes by Fourier domain optical coherence tomography (OCT corneal mapping. Methods. Retrospective corneal and epithelial thickness OCT data for 74 patients were compared in three groups of eyes: keratoconic (n=22 and normal fellow eyes (n=22 in patients with asymmetric keratoconus and normal eyes (n=104 in healthy subjects. Areas under the curve (AUC of receiver operator characteristic (ROC curves for each variable were compared across groups to indicate their discrimination capacity. Results. Three variables were found to differ significantly between fellow eyes and normal eyes (all p<0.05: minimum corneal thickness, thinnest corneal point, and central corneal thickness. These variables combined showed a high discrimination power to differentiate fellow eyes from normal eyes indicated by an AUC of 0.840 (95% CI: 0.762–0.918. Conclusions. Our findings indicate that topographically normal fellow eyes in patients with very asymmetric keratoconus differ from the eyes of healthy individuals in terms of their corneal epithelial and pachymetry maps. This type of information could be useful for an early diagnosis of keratoconus in topographically normal eyes.

  5. The measurement of corneal thickness from center to limbus in vivo in C57BL/6 and BALB/c mice using two-photon imaging.

    Science.gov (United States)

    Zhang, Hongmin; Wang, Liya; Xie, Yanting; Liu, Susu; Deng, Xianming; He, Siyu; Chen, Guoming; Liu, Hui; Yang, Biao; Zhang, Junjie; Sun, Shengtao; Li, Xiaohua; Li, Zhijie

    2013-10-01

    The mouse corneal thickness is very important for research into the fields of eye disease. However, the in vivo corneal thickness for the entire cornea from the pupil to the limbus was not determined. We measured in vivo corneal layer thicknesses in different corneal areas, from the central cornea to the limbus, in the widely used inbred C57BL/6 and BALB/c mouse strains using two-photon (2 PH) imaging. Eight corneas of the C57BL/6 or BALB/c were scanned using a 2 PH laser scanning fluorescence microscopy system. A total of 14 thicknesses of the different corneal layers, from different corneal regions, were measured using image processing software. In both C57BL/6 and BALB/c mice, the thickness of the corneal layers was inhomogeneous in different areas of the cornea, and all of the layers had their minimum thickness at the limbus. In C57BL/6 mice, the thickness of the corneal layers gradually increased from the central to the paracentral cornea, peaked at the fifth measurement point in the paracentral area, and decreased from this point to the limbus. In BALB/c mice, the thickness of the entire cornea and corneal epithelium had its maximum at the central cornea and gradually decreased from the central cornea to the peripheral cornea and to the limbus. The thickness of the corneal stroma and endothelium had its maximum at the fourth measurement point in the paracentral cornea and gradually decreased from the paracentral cornea to the limbus. The ratio of epithelial thickness to the total corneal thickness gradually decreased from the central cornea to the limbus in both C57BL/6 and BALB/c mice. The minimum ratio was observed at the fourteenth measurement point in both C57BL/6 and BALB/c mice. The ratio of stromal and endothelial to the total corneal thickness gradually increased from the central cornea to the limbus in both C57BL/6 and BALB/c mice. The maximum ratio was observed at the fourteenth measurement point in C57BL/6 mice. The ratio at the first eight

  6. Hypobaric Hypoxia: Effects on Intraocular Pressure and Corneal Thickness

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    Marcella Nebbioso

    2014-01-01

    Full Text Available Objective. The purpose of this study focused on understanding the mechanisms underlying ocular hydrodynamics and the changes which occur in the eyes of subjects exposed to hypobaric hypoxia (HH to permit the achievement of more detailed knowledge in glaucomatous disease. Methods. Twenty male subjects, aged 32±5 years, attending the Italian Air Force, were enrolled for this study. The research derived from hypobaric chamber, using helmet and mask supplied to jet pilotes connected to oxygen cylinder and equipped with a preset automatic mixer. Results. The baseline values of intraocular pressure (IOP, recorded at T1, showed a mean of 16±2.23 mmHg, while climbing up to 18,000 feet the mean value was 13.7±4.17 mmHg, recorded at T2. The last assessment was performed returning to sea level (T4 where the mean IOP value was 12.8±2.57 mmHg, with a significant change (P<0.05 compared to T1. Pachymetry values related to corneal thickness in conditions of hypobarism revealed a statistically significant increase (P<0.05. Conclusions. The data collected in this research seem to confirm the increasing outflow of aqueous humor (AH in the trabecular meshwork (TM under conditions of HH.

  7. Comparison of central corneal thickness measured by AS-OCT, Pentacam and A-mode ultrasound%前节OCT、Pentacam及A超测量中央角膜厚度的比较

    Institute of Scientific and Technical Information of China (English)

    方一明; 王世明; 李晓霞; 林淑贤; 叶翠芬; 陈阿娜

    2013-01-01

    Objective To compare the difference of central corneal thickness (CCT) measured by anterior segment optical coherence tomography(AS-OCT),Pentacam and A-mode ultrasound.Methods AS-OCT,Pentacam and A-mode ultrasound were used to measure the CCT on 102 myopic cases (204 eyes) undergoing laser in situ keratomileusis (LASIK),and then compared the results.Resulls AS-OCT and Pentacam had better repeatability in measurement of CCT than A-mode ultrasound.The value of CCT measured by AS-OCT,Pentacam and A-mode ultrasound were (532-± 30)μm,(539 ±31)μm and (537 ±29)μm.There was a significant linear correlation in CCT measured by three measurements (P < 0.05).The regression equation of three measurements were CCT Pentacam =0.934 CCT AS-OCT +39.789,CCT Pentacam =0.875 CCT A-mode +70.194 and CCT AS-OCT =0.913 CCT Amode + 40.962.The CCT measured by AS-OCT was obvious lower than that measured by Pentacam and A-mode ultrasound,there were statistical differences (P < 0.05).Conclusions AS-OCT,Pentacam and A-mode ultrasound have different advantage of three measurements on clinical using,these instruments should not be used interchangeably for CCT measurement.%目的 比较前节OCT、Pentacam和A超测量中央角膜厚度(CCT)的差异.方法 选择近视患者102例(204眼),行角膜屈光手术前分别用前节OCT (AS-OCT) 、Pentacam和A超测量CCT,并进行统计分析.结果 前节OCT和Pentacam测量CCT的重复性高于A超;三者测得的CCT分别为(532±30) ìm、(539±31) μm和(537±29)μm;三者测量CCT均具有显著相关性(P<0.05);三者的回归方程分别为CCT Pentacam=0.934 CCT前节OCT+ 39.789、CCT Pentacam=0.875 CCT A超+70.194和CCT前节OCT=0.913 CCT A超+40.962.前节OCT测量角膜厚度的结果小于Pentacam与A超(P<0.05).结论 前节OCT、Pentacam和A超在测量角膜厚度方面各有优势,不能简单替代.

  8. Difference in normal corneal thickness and curvature between Mongolian and Han nationalities

    Institute of Scientific and Technical Information of China (English)

    Hai-Xia; Zhao; Li; Zhang; Wen-Ying; Guan

    2015-01-01

    AIM: To investigate the differences in central corneal thickness(CCT) and curvature in myopic patients with different genders between Mongolian and Han nationalities in the Inner Mongolia region.METHODS: Patients with myopia, among whom 122cases(244 eyes) were Mongolian and 150 cases(300eyes) were Han, were selected. Pentacam was used to measure the corneal curvature, whereas CCT was determined by Pentacam, Orbscan and ultrasound pachymetry.RESULTS: Comparisons of the curvature of men and women in Mongolia showed a significant difference(P <0.05) by comparing of the CCT values measured by three methods in Han and Mongolian in Inner Mongolia, we can draw a conclusion that the CCT values measured by Pentacam are less than the values by Orbscan and ultrasound pachymetry, and there are statistically significant difference in CCT measurement among the instruments except between the Orbscan and ultrasound pachymetry. The CCT values of Mongolians are more than Han people, and the analysis exhibited statistical significance. The CCT values measured by Orbscan in Mongolia of women are more than men, the difference showed statistical significance.CONCLUSION: Corneal curvature in Mongolian females was significantly higher than that in males. However, no significant difference was observed among Han males and females. The CCT values of Mongolian females were higher than those of males. The normal CCT values measured by Pentacam in Mongolian myopic patients were smaller than those obtained by Orbscan or ultrasound. The normal CCT values of Mongolian patients with myopia were higher than those reported for domestic people.

  9. A review of corneal diameter, curvature and thickness values and influencing factors*

    Directory of Open Access Journals (Sweden)

    K. P. Mashige

    2013-12-01

    Full Text Available The cornea is an important ocular structure involved in the mediation of visual perception. It is the principal refractive surface of the eye and vision can be significantly affected by relatively small changes in its structure and parameters. Measurement of corneal parameters is important in the diagnosis and management of ocular diseasessuch as keratoconus and glaucoma, and also in the fitting of contact lenses or with refractive surgery such as Laser-Assisted in situ Keratomileusis(LASIK and photorefractive keratectomy (PRK. The human corneal diameter, anterior curvature and centre thickness as well as factors influencing them are reviewed in this article. This review will be useful to eye care professionals who routinely measure these parameters when fitting contact lenses and assessing, diagnosing as well as managing corneal and other ocular conditions. (S Afr Optom 2013 72(4 185-194

  10. Relationship between Corneal Thickness,Corneal Curva-ture,and Intraocular Pressure before and after Laser Treat-ment for Simple Myopia

    Institute of Scientific and Technical Information of China (English)

    Ahmad MA; Edrees MH; Jafarzadehpur E

    2014-01-01

    Purpose:To determine the relationship of central corneal thickness (CCT), curvature (CC), and intraocular pressure (IOP) as determinative factors for corneal biomechanics and in refractive surgery. Methods:.The study investigated 48 eyes from subjects who visited the Excimer Laser Surgery Clinic at the Department of Ophthalmology. The refractive error, IOP, CCT, and CC were measured in all participants. After 3 months, all exami-nations were repeated. Results:.Linear regression demonstrated a significant positive relationship between pre- and postoperative CCT,.CC,.and IOP values..The IOP showed a significant correlation with CCT (P=0.033) for pre-PRK, but no significant relationship was seen post-PRK. The CCT also correlated significantly with CC both pre-and post-PRK (P<0.05). Conclusion:.The IOP was significantly correlated with CCT before PRK, but its behavior differed after surgery. Nearly the same correlation was seen between CCT and CC before and after the PRK;.nevertheless,.IOP measurements should be calculated or estimated more precisely after PRK based on CCT corrections.

  11. The Influence of Soft Contact Lens Materials on the Central, Para-Central and Peripheral Corneal Endothelium

    OpenAIRE

    Lloyd McKernan, Aoife; Simo Mannion, Luisa; O'Dwyer, Veronica

    2015-01-01

    Title: The influence of soft contact lens materials on the central, para-central and peripheral corneal endothelium prior to and following two weeks cessation of soft contact lens wear. Purpose: To examine the influence of a variety of soft contact lens (SCL) materials on the central, para-central and peripheral corneal endothelium measurements, prior to and following two weeks cessation of SCL wear. Methods: Endothelial measurements were taken using the CEM-530 (Nidek, Japan) specular ...

  12. Research and analysis on corneal endothelial cell morphology and corneal thickness in patients with diabetics%糖尿病患者角膜内皮细胞形态学和角膜厚度研究分析

    Institute of Scientific and Technical Information of China (English)

    徐武平; 魏春惠; 顾榴丽

    2014-01-01

    AIM: To assess the impact of diabetes on corneal endothelial cells through the quantitative analysis of corneal endothelial cell morphology for patients with diabetics. METHODS: The corneal thickness and endothelial cell morphology of 360 eyes of 299 cases were detected using full automatic corneal endothelial cell analyzer. The normal control group included 175 eyes of 148 cases, and there were 185 eyes of 151 cases for the patients with diabetes, 110 eyes of 92 cases for the non-proliferating phase group and 75 eyes of 59 cases for the proliferating phase group. The average density of central corneal endothelial cells, proportion of hexagonal cells, coefficient of variation and corneal thickness were compared among groups, and then the statistical analysis was conducted. RESULTS: Compared with the cornea of the normal group, in the diabetes group, the coefficient of variation of corneal endothelial cells and central corneal thickness increased, while the average density of central corneal endothelial cells and proportion of hexagonal cells decreased, showing a significant difference (P0. 05). CONCLUSION: Compared with the cornea of normal control group, in the diabetes group, the corneal endothelial cells show abnormal morphology, which aggravates with the severity of lesions, especially for the significant changes in the coefficient of variation and the proportion of hexagonal cells. As a result, the corneal resistance to damage in patients with diabetes will decrease.%目的:通过对糖尿病患者进行角膜内皮细胞形态学定量分析,评估糖尿病对角膜内皮细胞的影响。  方法:应用全自动角膜内皮细胞分析仪对299例360眼进行角膜厚度及内皮细胞形态检测。正常对照组148例175眼,糖尿病患者151例185眼,其中非增殖期组患者92例110眼,增殖期组59例75眼。比较各组患者的中央角膜内皮细胞平均密度、六边形细胞比例、变异系数及角膜厚度,并进行统

  13. Corneal thickness changes during corneal collagen cross-linking with UV-A irradiation and hypo-osmolar riboflavin in thin corneas

    Directory of Open Access Journals (Sweden)

    Belquiz Amaral Nassaralla

    2013-06-01

    Full Text Available PURPOSE: To evaluate the thinnest corneal thickness changes during and after corneal collagen cross-linking treatment with ultraviolet-A irradiation, using hypo-osmolar riboflavin solution in thin corneas. METHODS: Eighteen eyes of 18 patients were included in this study. After epithelium removal, iso-osmolar 0.1% riboflavin solution was instilled to the cornea every 3 minutes for 30 minutes. Hypo-osmolar 0.1% riboflavin solution was then applied every 20 seconds for 5 minutes or until the thinnest corneal thickness reached 400 µm. Ultraviolet-A irradiation was performed for 30 minutes. During irradiation, iso-osmolar 0.1% riboflavin drops were applied every 5 minutes. Ultrasound pachymetry was performed at approximately the thinnest point of the cornea preoperatively, after epithelial removal, after iso-osmolar riboflavin instillation, after hypo-osmolar riboflavin instillation, after ultraviolet-A irradiation, and at 1, 6 and 12 months after treatment. RESULTS: Mean preoperative thinnest corneal thickness was 380 ± 11 µm. After epithelial removal it decreased to 341 ± 11 µm, and after 30 minutes of iso-osmolar 0.1% riboflavin drops, to 330 ± 7.6 µm. After hypo-osmolar 0.1% riboflavin drops, mean thinnest corneal thickness increased to 418 ± 11 µm. After UVA irradiation, it was 384 ± 10 µm. At 1, 6 and 12 months after treatment, it was 372 ± 10 µm, 381 ± 12.7, and 379 ± 15 µm, respectively. No intraoperative, early postoperative, or late postoperative complications were noted. CONCLUSIONS: Hypo-osmolar 0.1% riboflavin solution seems to be effective for swelling thin corneas. The swelling effect is transient and short acting. Corneal thickness should be monitored throughout the procedure. Larger sample sizes and longer follow-up are required in order to make meaningful conclusions regarding safety.

  14. Limbal stem cells: Central concepts of corneal epithelial homeostasis

    Institute of Scientific and Technical Information of China (English)

    Jinny; J; Yoon; Salim; Ismail; Trevor; Sherwin

    2014-01-01

    A strong cohort of evidence exists that supports the localisation of corneal stem cells at the limbus. The distinguishing characteristics of limbal cells as stem cells include slow cycling properties, high proliferative potential when required, clonogenicity, absence of differentiation marker expression coupled with positive expression of progenitor markers, multipotency, centripetal migration, requirement for a distinct niche environment and the ability of transplanted limbal cells to regenerate the entire corneal epithelium. The existence of limbal stem cells supports the prevailing theory of corneal homeostasis, known as the XYZ hypothesis where X represents proliferation and stratification of limbal basal cells, Y centripetal migration of basal cells and Z desquamation of superficial cells. To maintain the mass of cornea, the sum of X and Y must equal Z and very elegant cell tracking experiments provide strong evidence in support of this theory. However, several recent stud-ies have suggested the existence of oligopotent stem cells capable of corneal maintenance outside of the limbus. This review presents a summary of data which led to the current concepts of corneal epithelial homeostasis and discusses areas of controversy surrounding the existence of a secondary stem cell reservoir on the corneal surface

  15. 前节OCT与超声角膜测厚仪在角膜内皮移植术后测量中央角膜厚度的比较%Comparison of central corneal thickness measurements between anterior segment optical coherence tomography and ultrasonic pachymeter after DSAEK

    Institute of Scientific and Technical Information of China (English)

    李炳震; 彭荣梅; 任婧; 刘峰; 吴玲玲; 洪晶

    2011-01-01

    Objective To assess the agreement of central corneal thickness ( CCT) measured by anterior segment-optical tomography (AS-OCT) and ultrasonic pachymeter after Descemet's Stripping with Automated Endothelium Keratoplasty (DSAEK) and provide objective basis for clinical application of AS-OCT. Methods Forty-one eyes of 38 patients after Descemet's Stripping with Automated Endothelium Keratoplasty (DSAEK) underwent CCT measurement by AS-OCT and ultrasonic pachymeter.The data was analyzed by paired-t test and Pearson correlation analysis. Bland-Altman plot was used to assess the agreement.Results The mean CCT values were(728.73±1 38.39)μ m measured by AS-OCT and (718.56+131.37)μ m measured by ultrasonic pachymeter,and there was no significant difference between the two methods. Regression analysis showed a high correlation between the values obtained by both devices (r =0.916, P<0.01). AS-OCT and ultrasonic pachymeter showed a less a-greernent in CCT measurement after DSAEK. Conclusions After DSAEK, there is a reasonable agreement between two techniques, AS-OCT and ultrasonic pachymeter of CCT measurements. Considering the special advantages, AS-OCT is an effective method to observe the changes of the corneal thickness in the long term.%目的 比较角膜内皮移植(DSAEK)术后后眼前节相干光断层扫描(AS-OCT)与超声角膜测厚仪测量的中央角膜厚度(CCT),评估两种方法的一致性,为AS-OCT的临床应用提供客观依据.方法 分别应用AS-OCT与超声角膜测厚仪测量DSAEK后患者38例(41只眼)的CCT,对两种方法所得的测量值进行配对t检验及Pearson相关分析,并采用Bland-Altman plot进行一致性评价.结果 AS-OCT与超声角膜测厚仪测量CCT的平均值分别为(728.73±138.39)μm和(718.56±131.37)μm;两组数据差异无统计学意义(t=-1.170;P=0.249).通过Pearson相关性分析,这两种方法的测量值成正相关(r=0.916,P <0.01).AS-OCT与超声角膜测厚测量

  16. Central Corneal Thickness Measurement by Ultrasound versus Orbscan II

    OpenAIRE

    Amir Faramarzi; Hossein Ziai

    2008-01-01

  1. AS-OCT与A超测量中央角膜厚度与前房深度的比较%Comparison of central corneal thickness and anterior chamber depth measurements using the Anterior Segment Optical Coherence Tomography and A-scan ultrasonography

    Institute of Scientific and Technical Information of China (English)

    曾阳发; 李彬彬; 黄国富; 李月桃; 何明光

    2009-01-01

    目的 探讨眼前段光学相干断层扫描技术(anteriorsegment optical coherence tomography,AS-OCT)和A型超声波生物测量技术(A超)测量,中央角膜厚度(central corneal thickness,CCT)和前房深度(anterior chamber depth,ACD)的异同.方法 分别采用AS-OCT和A超测量33名(54只眼)正常人的CCT和ACD,分别采用配对t检验、Pearson相关和Bland-Altman方法,分析两种仪器的测量值的差异、相关性和一致性.结果 A超与AS-OCT的CCT值分别为(524.41±23.24)μm、(513.37±22.71)μm,之间的差异有统计学意义(t=15.906,P=0.000),差值均数为(11.04±5.10)μm.两种仪器的CCT值正相关(r=0.976,P=0.000).95%LoA(95% Limts of Agreement)为(-21.03,-1.04)μm,95%LoA的区间范围为19.99μm,为A超CCT平均值的3.81%.A超与AS-OCT的ACD值分别为(2.89±0.29)mm、(3.18±0.26)mm,之间的差异有统计学意义(f=-12.052,P=0.000),差值的均数为(-0.29±0.17)mm.两种仪器的ACD值相关(r=0.803,P=0.000).95%LoA为(-0.63,-0.06)mm,95%LoA的区间范围为0.57mm,为A超ACD平均值的19.72%.结论 AS-OCT的CCT值和ACD值与A超的测量值相关.与A超相比,AS-OCT的CCT测量值更小,而ACD值更大.两种仪器测量CCT的一致性比ACD高.%Objective To assess central corneal thickness(CCT)and anterior chamber depth (ACD) measurements with anterior segment optical coherence tomography (AS-OCT)comparing with A-scan ultrasonography (A-scan US).Methods 54 eyes of 33 normal subjects were enrolled in the study.CCT and ACD were measured using AS-OCT and A-scan US.The measurements of two instruments were analyzed using paired t test,Pearson correlation and Bland-Altman plot,respectively.Results The CCT of AS-OCT and A-scan US were 524.41± 23.24 microm and 513.37± 22.7 microm,respectively.The CCT values measured by A-scan US were significantly greater than AS-OCT, paired difference was 11.04± 5.10 microm (t =15.906, P =0.000).There were a significantly correlation between CCTs value of two instruments (r =0

  2. Repeatability and interobserver reproducibility of Artemis-2 high-frequency ultrasound in determination of human corneal thickness

    Directory of Open Access Journals (Sweden)

    Ogbuehi KC

    2012-05-01

    Full Text Available Kelechi C Ogbuehi, Uchechukwu L OsuagwuOutpatient Clinic, Department of Optometry, King Saud University, Riyadh, Kingdom of Saudi ArabiaBackground: The purpose of this study was to assess the repeatability and limits of agreement of corneal thickness values measured by a high-frequency ultrasound (Artemis-2, hand-held ultrasound pachymeter (DGH-500 and a specular microscope (SP-3000P.Methods: Central corneal thickness (CCT was analyzed in this prospective randomized study that included 32 patients (18 men and 14 women aged 21–24 years. Measurements were obtained in two sessions, one week apart, by two examiners with three devices in a randomized order. Nine measurements were taken (three with each device on one randomly selected eye of each patient in each measurement session. The coefficient of repeatability and interobserver reproducibility for the values of each method were calculated. The limits of agreement between techniques were also evaluated.Results: There were no significant differences in CCT values between sessions for each of the three devices (P > 0.05. The repeatability coefficients for the Artemis-2 (±8 µm/±9 µm were superior to those of the SP-3000P (±9 µm/±11 µm and DGH 500 (±12 µm/±12 µm in session 1/session 2 respectively, while the interobserver reproducibility index (differences between session 1 and session 2 was superior for the SP-3000P (±17 µm with respect to DHG-500 (±29 µm and the Artemis-2 (±31 µm. In session 1 and session 2, the limits of agreement between the techniques were 35 µm to -31 µm and 34 to -20 µm, respectively, for DGH-500 versus Artemis-2, 73 µm to 3 µm and 60 µm to 9 µm for Artemis-2 versus SP-3000P, and 58 µm to 22 µm and 72 µm to 10 µm for DGH-500 versus SP-3000P comparisons. The DGH-500 and Artemis-2 gave similar values (P > 0.05 in both sessions, but both (Artemis-2 and DGH-500 values were significantly greater than that of the SP-3000P (P < 0.05 in both sessions

  3. Factors Affecting Corneal Hysteresis in Taiwanese Adults

    Institute of Scientific and Technical Information of China (English)

    Jia-Kang Wang; Tzu-Lun Huang; Pei-Yuan Su; Pei-Yao Chang

    2015-01-01

    Purpose: To investigate the correlation of various corneal hysteresis (CH) factors in Chinese adults. Methods: From January 2009 to November 2011, the healthy right eyes of a total of 292 adults were recruited into the study. Goldmann-correlated intraocular pressure (IOPG) and CH were measured using an ocular response analyzer (ORA). Central corneal thickness was measured using the ORA’s in-tegrated handheld ultrasonic pachymeter. The IOLMaster was used to obtain the ocular biometric measurements including axial length, anterior chamber depth, and keratometric values. The Pearson correlation coefficient was used to test correla-tions between CH and quantitative factors. The chi-square test was used to detect differences in categorical values. Results: Longer axial length (P=0.0001), lower IOPG (P=0.03), older age(P=0.003),and thinner central corneal thick-ness (P=0.0001) were significantly associated with lower CH. The anterior chamber depth (P=0.34), gender (P=0.23), and corneal curvature (P=0.18) had no relationship to CH. Conclusion:Various factors including axial length, intraocular pressure, age, and central corneal thickness can affect measure-ment of corneal biomechanical properties in Chinese adults. But the anterior chamber depth, gender, and corneal curvature were irrelevant to CH.

  4. Espessura corneana mensurada pelo paquímetro ultra-sônico e pelo microscópio especular Topcon SP-2000P em gatos Corneal thickness measured by ultrasound pachymeter and by Topcon SP-2000P specular microscope Topcon SP-2000P in cats

    Directory of Open Access Journals (Sweden)

    J.J.T. Ranzani

    2008-04-01

    Full Text Available Avaliou-se a espessura corneana central de 13 gatos normais com microscópio especular de não-contato Topcon SP-2000P e paquímetro ultra-sônico. Foi observado aumento da espessura corneana mensurada pelo paquímetro ultra-sônico comparado ao microscópio especular.The central corneal thickness of 13 normal cats was evaluated by a Topcon SP-2000P noncontact specular microscope and by an ultrasonic pachymetry was evaluated. An increase on the corneal thickness measured by ultrasonic pachymetry as compared to the specular microscope was observed.

  5. Central corneal thickness in children with type 1 diabetes mellitus and the effect of metabolic control on corneal thickness

    Directory of Open Access Journals (Sweden)

    Emine Cinici

    2015-09-01

    Result: CCT is increased in the patients compared to the control group even before diabetes mellitus (DM has developed a retinopathy. A relation of this increase with period of diabetes, HbA1C level and hypoglycemia attack number could not be detected. [Arch Clin Exp Surg 2015; 4(3.000: 148-152

  6. Production of Hypoxia-induced Corneal Edema in Aged Eyes

    Institute of Scientific and Technical Information of China (English)

    Alan K. Cheung; Andrew W. Siu; Digby W. Cheung; Edwin C. Mo

    2004-01-01

    Purpose:Corneal thickness assessment is a common clinical procedure applied in corneal and contact lens care. This study aims to investigate the effect of age on hypoxiainduced corneal swelling.Methods:Eighteen male subjects were equally divided into the younger [(23.7±0.8) and older [(74.4±2.5) years old]groups.Each subject wore a thick soft contact lens (uniform thickness of 0.3 mm) on the left cornea. With the contact lens in place, the baseline central corneal thickness was measured using a specially designed photo-pachometer. The lens was then patched behind the closed eyelids, producing an extremely hypoxic stress to the cornea. The change in central corneal thickness was monitored every 20 minutes with momentary disruptions to the hypoxic stress over the next 2 hours. The increase in thickness was taken as an index of corneal edema. The rate of change in corneal thickness, as derived from a non-linear mathematical model, was compared between groups. Results:The corneal thickness of both age groups increased significantly with time (P<0.000 1 ). The mean corneal swelling constant for the older subjects was 16.5 × 10-3 (S.E.M. = 2.65 × 10-3) and the value for the younger subjects was 46.5 × 10-3 (S.E.M. = 3.25× 10-3). The difference was statistically significant (P < 0.000 1 ).Conclusion:Aging cornea has a slower hypoxia-induced edema response compared with the younger group. Whether it is caused by a decreased corneal lactate production or an increased resistance to physical expansion deserves further investigation. Eye Science2004;20:1-5.

  7. Corneal topography

    DEFF Research Database (Denmark)

    Andersen, J.; Koch-Jensen, P.; Østerby, Ole

    1993-01-01

    The central corneal zone is depicted on keratoscope photographs using a small target aperture and a large object distance. Information on the peripheral area is included by employing a hemispherical target with a dense circular and radial pattern. On a 16 mm (R = 8 mm) reference steel sphere...

  8. One-year Outcomes of Pachymetry and Epithelium Thicknesses after Accelerated (45 mW/cm2) Transepithelial Corneal Collagen Cross-linking for Keratoconus Patients

    Science.gov (United States)

    Zhang, Xiaoyu; Sun, Ling; Chen, Yingjun; Li, Meiyan; Tian, Mi; Zhou, Xingtao

    2016-01-01

    The thickness of corneal pachymetry and the epithelium after accelerated (45 mW/cm2) transepithelial corneal collagen cross-linking (CXL) for keratoconus were assessed in this prospective case series study. Twenty-eight patients were treated for keratoconus. The mean Kmax was 56.18 ± 7.90. The thinnest point, as assessed by optical coherence tomography (OCT), was 443.18 ± 39.75 μm. Accelerated transepithelial CXL was performed, and corrected distance visual acuity (CDVA), corneal topography, and OCT were recorded at 1 week postoperatively as well as at 1, 3, 6, and 12 months. The surgery was uneventful in all eyes. Postoperative epithelial edema was observed and faded in 3 days. The postoperative Kmax was 54.56 ± 8.81, 55.78 ± 8.11, 56.37 ± 8.71, 55.80 ± 7.92, and 55.47 ± 8.24 at 1 week, 1 month, 3 months, 6 months, and 12 months, respectively (all, P > 0.05). The thinnest postoperative corneal point, 439.04 ± 44.99 μm, was observed at 12 months (P = 0.109). The epithelial thickness decreased during the first postoperative week then showed a gradual recovery. Postoperative pachymetry thickness showed no significant changes for up to 12 months. Postoperative epithelial thickness decreased temporarily, then stabilized at month 12. Accelerated transepithelial CXL was shown to be effective and safe for the treatment of keratoconus. PMID:27597655

  9. One-year Outcomes of Pachymetry and Epithelium Thicknesses after Accelerated (45 mW/cm(2)) Transepithelial Corneal Collagen Cross-linking for Keratoconus Patients.

    Science.gov (United States)

    Zhang, Xiaoyu; Sun, Ling; Chen, Yingjun; Li, Meiyan; Tian, Mi; Zhou, Xingtao

    2016-01-01

    The thickness of corneal pachymetry and the epithelium after accelerated (45 mW/cm(2)) transepithelial corneal collagen cross-linking (CXL) for keratoconus were assessed in this prospective case series study. Twenty-eight patients were treated for keratoconus. The mean Kmax was 56.18 ± 7.90. The thinnest point, as assessed by optical coherence tomography (OCT), was 443.18 ± 39.75 μm. Accelerated transepithelial CXL was performed, and corrected distance visual acuity (CDVA), corneal topography, and OCT were recorded at 1 week postoperatively as well as at 1, 3, 6, and 12 months. The surgery was uneventful in all eyes. Postoperative epithelial edema was observed and faded in 3 days. The postoperative Kmax was 54.56 ± 8.81, 55.78 ± 8.11, 56.37 ± 8.71, 55.80 ± 7.92, and 55.47 ± 8.24 at 1 week, 1 month, 3 months, 6 months, and 12 months, respectively (all, P > 0.05). The thinnest postoperative corneal point, 439.04 ± 44.99 μm, was observed at 12 months (P = 0.109). The epithelial thickness decreased during the first postoperative week then showed a gradual recovery. Postoperative pachymetry thickness showed no significant changes for up to 12 months. Postoperative epithelial thickness decreased temporarily, then stabilized at month 12. Accelerated transepithelial CXL was shown to be effective and safe for the treatment of keratoconus. PMID:27597655

  10. Surgical compensation of presbyopia with corneal inlays.

    Science.gov (United States)

    Konstantopoulos, Aris; Mehta, Jodhbir S

    2015-05-01

    Presbyopia, the physiological change in near vision that develops with ageing, gradually affects individuals older than 40 years and is a growing cause of visual disability due to ageing demographics of the global population. The routine use of computers and 'smartphones', combined with the affluence of the 'baby boomers' generation has set high standards for near vision correction. Corneal inlays are a relatively new treatment modality that is effective at compensating for presbyopia. The dimensions of these devices vary from 2 to 3.8 mm in diameter and 5 to 32 μm in thickness. They are implanted in the anterior corneal stroma of the non-dominant eye, most commonly, in a femtosecond laser created corneal pocket. They improve near vision by increasing the depth of focus, creating a hyper-prolate region of increased central cornea power or providing a refractive add power. This article reviews the literature on the efficacy and safety of corneal inlays. PMID:25652889

  11. Surgical compensation of presbyopia with corneal inlays.

    Science.gov (United States)

    Konstantopoulos, Aris; Mehta, Jodhbir S

    2015-05-01

    Presbyopia, the physiological change in near vision that develops with ageing, gradually affects individuals older than 40 years and is a growing cause of visual disability due to ageing demographics of the global population. The routine use of computers and 'smartphones', combined with the affluence of the 'baby boomers' generation has set high standards for near vision correction. Corneal inlays are a relatively new treatment modality that is effective at compensating for presbyopia. The dimensions of these devices vary from 2 to 3.8 mm in diameter and 5 to 32 μm in thickness. They are implanted in the anterior corneal stroma of the non-dominant eye, most commonly, in a femtosecond laser created corneal pocket. They improve near vision by increasing the depth of focus, creating a hyper-prolate region of increased central cornea power or providing a refractive add power. This article reviews the literature on the efficacy and safety of corneal inlays.

  12. Crustal-thickness variations in the central Andes

    Science.gov (United States)

    Beck, Susan L.; Zandt, George; Myers, Stephen C.; Wallace, Terry C.; Silver, Paul G.; Drake, Lawrence

    1996-05-01

    We estimated the crustal thickness along an east-west transect across the Andes at lat 20°S and along a north-south transect along the eastern edge of the Altiplano from data recorded on two arrays of portable broadband seismic stations (BANJO and SEDA). Waveforms of deep regional events in the downgoing Nazca slab and teleseismic earthquakes were processed to isolate the P-to-S converted phases from the Moho in order to compute the crustal thickness. We found crustal-thickness variations of nearly 40 km across the Andes. Maximum crustal thicknesses of 70 74 km under the Western Cordillera and the Eastern Cordillera thin to 32 38 km 200 km east of the Andes in the Chaco Plain. The central Altiplano at 20°S has crustal thicknesses of 60 to 65 km. The crust also appears to thicken from north (16°S, 55 60 km) to south (20°S, 70 74 km) along the Eastern Cordillera. The Subandean zone crust has intermediate thicknesses of 43 to 47 km. Crustal-thickness predictions for the Andes based on Airy-type isostatic behavior show remarkable overall correlation with observed crustal thickness in the regions of high elevation. In contrast, at the boundary between the Eastern Cordillera and the Subandean zone and in the Chaco Plain, the crust is thinner than predicted, suggesting that the crust in these regions is supported in part by the flexural rigidity of a strong lithosphere. With additional constraints, we conclude that the observation of Airy-type isostasy is consistent with thickening associated with compressional shortening of a weak lithosphere squeezed between the stronger lithosphere of the subducting Nazca plate and the cratonic lithosphere of the Brazilian craton.

  13. Recovery of Corneal Endothelial Cells from Periphery after Injury.

    Directory of Open Access Journals (Sweden)

    Sang Ouk Choi

    Full Text Available Wound healing of the endothelium occurs through cell enlargement and migration. However, the peripheral corneal endothelium may act as a cell resource for the recovery of corneal endothelium in endothelial injury.To investigate the recovery process of corneal endothelial cells (CECs from corneal endothelial injury.Three patients with unilateral chemical eye injuries, and 15 rabbit eyes with corneal endothelial chemical injuries were studied. Slit lamp examination, specular microscopy, and ultrasound pachymetry were performed immediately after chemical injury and 1, 3, 6, and 9 months later. The anterior chambers of eyes from New Zealand white rabbits were injected with 0.1 mL of 0.05 N NaOH for 10 min (NaOH group. Corneal edema was evaluated at day 1, 7, and 14. Vital staining was performed using alizarin red and trypan blue.Specular microscopy did not reveal any corneal endothelial cells immediately after injury. Corneal edema subsided from the periphery to the center, CEC density increased, and central corneal thickness decreased over time. In the animal study, corneal edema was greater in the NaOH group compared to the control at both day 1 and day 7. At day 1, no CECs were detected at the center and periphery of the corneas in the NaOH group. Two weeks after injury, small, hexagonal CECs were detected in peripheral cornea, while CECs in mid-periphery were large and non-hexagonal.CECs migrated from the periphery to the center of the cornea after endothelial injury. The peripheral corneal endothelium may act as a cell resource for the recovery of corneal endothelium.

  14. Evaluation of Corneal Topography and Biomechanical Parameters after Use of Systemic Isotretinoin in Acne Vulgaris

    Directory of Open Access Journals (Sweden)

    Yusuf Yildirim

    2014-01-01

    Full Text Available Purpose. We report the effect of isotretinoin on corneal topography, corneal thickness, and biomechanical parameters in patients with acne vulgaris. Method. Fifty-four eyes of 54 patients who received oral isotretinoin for treatment of acne vulgaris were evaluated. All patients underwent a corneal topographical evaluation with a Scheimpflug camera combined with Placido-disk (Sirius, ultrasonic pachymetry measurements, and corneal biomechanical evaluation with an ocular response analyzer at baseline, in the 1st, 3rd, and 6th months of treatment, and 6 months after isotretinoin discontinuation. Results. The thinnest corneal thickness measured with Sirius differed significantly in the 1st, 3rd, and 6th months compared with the baseline measurement; there was no significant change in ultrasonic central corneal thickness measurements and biomechanical parameters (corneal hysteresis and corneal resistance factor throughout the study. Average simulated keratometry and surface asymmetry index increased significantly only in the first month of treatment according to the baseline. All changes disappeared 6 months after the end of treatment. Conclusion. Basal tear secretion and corneal morphologic properties were significantly influenced during the systemic isotretinoin treatment and the changes were reversible after discontinuation. No statistical important biomechanical differences were found to be induced by isotretinoin.

  15. The influence of corneal astigmatism on retinal nerve fiber layer thickness and optic nerve head parameter measurements by spectral-domain optical coherence tomography

    OpenAIRE

    Liu Lin; Zou Jun; Huang Hui; Yang Jian-guo; Chen Shao-rong

    2012-01-01

    Abstract Background To evaluate the influence of corneal astigmatism (CA) on retinal nerve fiber layer (RNFL) thickness and optic nerve head(ONH) parameters measured with spectral-domain optical coherence tomography (OCT) in high myopes patients before refractive surgery. Methods Seventy eyes of 35 consecutive refractive surgery candidates were included in this study. The mean age of the subjects was 26.42 ± 6.95 years, the average CA was −1.17 diopters (D; SD 0.64; range −0.2 to-3.3D), All s...

  16. 超高分辨率OCT角膜上皮厚度自动测量的重复性研究%Study of repeatability of corneal epithelium thickness profiles automatically measured by ultra -high resolution OCT system

    Institute of Scientific and Technical Information of China (English)

    徐肃仲; 叶欣杰; 许哲; 杨纯; 沈梅晓

    2013-01-01

    目的:研究基于自动分层算法的超高分辨率谱域 OCT ( UHR-OCT)用于角膜上皮厚度测量的重复性。  方法:使用自行搭建的UHR-OCT系统采集18例健康受试者(年龄23.2±0.9岁)左眼的图像,应用一种基于轴向梯度信息和最短路径的分层算法对得到的SD-OCT图像进行边界探测获取角膜上皮厚度。  结果:自动与手动的上皮分层的位置有很好的相关性(P>0.05,配对t检验)。自动算法获取的6 mm范围平均上皮厚度为52.1±2.1μm,范围从50.3±1.8μm 到53.2±2.4μm,与手动分层之间的角膜上皮厚度差异为0.4±0.3μm。UHR-OCT自动算法重复测量上皮厚度的组内相关系数ICC和可重复性系数CoR分别为0.90±0.05,1.44±0.01μm。  结论:对于超高分辨率OCT,自动分层方法在角膜上皮厚度测量中有着很好的准确性和可重复性。%AIM:To assess the repeatability of thickness profiles of corneal epithelium produced by aautomatic hierarchic algorithm that was applied to images obtained by a custom-built ultra-high resolution OCT ( UHR-OCT ) system. METHODS:Eighteen left eyes of 18 subjects (23.2±0.9) years;mean age±standard deviation) were imaged twice on non-consecutive days by a custom-built ultra-high resolution OCT ( UHR -OCT ) system. A hierarchic algorithm based on the axial gradient information and a shortest path search was developed to measure the corneal epithelial thickness profiles from the SD-OCT images. RESULTS: There was good correlation between theautomatic and manual hierarchy positions of the epithelium ( p >0.05, paired t -test ). The average epithelial thickness of the 6mm central corneal region determined by the automatic hierarchic algorithm was 52.1±2.1μm, ranging from 50.3 ±1.8μm to 53.2 ±2.4μm along the horizontal meridian. The epithelial thickness differences between automatic and manual hierarchy by the UHR-OCT systems were 0.4 ±0

  17. Comparison of corneal thickness measurements with the Sirius and Ultrasound Pachymetry%新型三维眼前节分析仪Sirius与A型超声测厚仪测角膜厚度比较分析

    Institute of Scientific and Technical Information of China (English)

    杨凤; 黄锦海; 徐真; 成拾明; 王勤美

    2013-01-01

    目的 探讨新型Scheimpflug/Placido三维眼前节分析仪Sirius测量健康人群角膜厚度的可重复性,以及与A型超声角膜测厚仪测量结果的一致性.方法 前瞻性研究.选取36名志愿者右眼作为研究对象,由同一检查者依次使用Sirius系统和A超进行测量.将Sirius系统获得的中央角膜厚度(Central corneal thickness,CCT)和最薄点角膜厚度(Thinnest corneal thickness,TCT)分别与A超角膜测厚仪测量结果进行比较,采用配对t检验分析差异性;Pearson相关分析相关性;Bland-Altman分析一致性.结果 Sirius系统测得的CCT、TCT和超声测厚仪结果的均值分别为(533.06±34.21)μm、(526.25±34.21) μm和(525.94±34.51) μm.CCT和TCT的变异系数均小于0.6%,Cronbach Alpha系数、组内相关系数均大于0.99,Sirius系统测得的CCT、TCT具有很高的重复性.CCT与超声角膜厚度差异有统计学意义(P<0.05);TCT与超声角膜厚度差异无统计学意义(P>0.05);两仪器具有显著的相关性,CCT和TCT与超声角膜厚度的相关系数r分别为0.984和0.987 (P <0.05).CCT和TCT与超声角膜厚度具有较好的一致性,95%的一致性界限分别为(-5.2 μm,19.4 μm)和(-10.9 μm,11.5 μm).结论 Sirius系统获得的中央角膜厚度、最薄点角膜厚度具有很好的重复性,与A型超声测厚仪具有高度的相关性和一致性,在临床工作中,可以考虑相互替代.%Objective To assess the repeatability of corneal thickness measurements in healthy eyes obtained with a new Scheimpflug/Placid imaging system (Sirius,CSO Inc.) and the agreement of the measurements with those obtained by Ultrasound Pachymetry (UP).Methods In this prospective study,corneal thickness was measured in 36 subjects (36 eyes) by a single operator.Three consecutive scans were acquired for each eye.The central comeal thickness (CCT) and thinnest comeal thickness (TCT) of the Sirius were compared to UP,respectively.Data were compared using paired

  18. Changes in corneal sensitivity following cross-linking for progressive early-stage keratoconus

    Directory of Open Access Journals (Sweden)

    Anelise de Medeiros Lago

    2014-04-01

    Full Text Available Purpose: To evaluate changes in corneal sensitivity following corneal cross-linking (CXL in patients with progressive earlier stage keratoconus. Methods: Thirty-eight eyes of 19 patients (11 women, 8 men were included in a prospective, nonrandomized clinical study. The mean patient age was 22 years (range, 18-26 years. Inclusion criteria were early stage bilateral progressive keratoconus, a transparent cornea, and a thickness of ≥440 µm in the thinnest area of the cornea. Using the Cochet-Bonnet esthesiometer, central corneal sensitivity was measured before surgery, 7 days after surgery, and once a month thereafter until recovery of baseline preoperative levels. Central corneal sensitivity >40 mm was considered normal. Results: Corneal sensitivity gradually returned to preoperative levels in all treated eyes. The mean central corneal sensitivity was 52.2, 24.0, 38.2, 42.5, 50.0, and 52.5 mm before surgery, 7 days after surgery, and at 1, 2, 3, and 4 months after surgery, respectively. Normal levels of corneal sensation, but not baseline (preoperative levels, were observed 2 months after surgery. The preoperative levels were observed 3 months after surgery. Conclusions: Our results suggest that central corneal sensitivity can be decreased for as long as 3 months after CXL for progressive earlier stage keratoconus.

  19. LASIK术中角膜刀与角膜瓣厚度关系的临床研究%Clinical Study of the Correlation between Microkeratome and Corneal Flap Thickness in LASIK Surgery

    Institute of Scientific and Technical Information of China (English)

    唐静晓; 王彬; 董竟

    2009-01-01

    目的:通过对角膜瓣厚度的临床观察,找出角膜刀与角膜瓣厚度的相关因素,从而确保手术的安全性.方法:对在我院行LASIK治疗的患者进行术后追踪观察3~6个月,分为90刀组和110刀组,通过统计学处理找出90刀及110刀制作角膜瓣的厚度值.结果:90刀组的角膜瓣厚度值为(116.55±12.36)μm,110刀为(138.37±12.48)μm.结论:LASIK术中角膜瓣的厚度在理论上是固定的,但在临床实践中发现角膜瓣的厚度与理论值存在较大偏差,故提醒我们设计角膜切削深度时一定要结合本单位设备情况及术者的经验找出自己的角膜瓣厚度值,从而确保手术的安全性.%Objective: By clinical observation of corneal flap thickness, find out the relevant factors of the correlation between microkeratome and corneal flap thickness, so as to ensure the safety of surgery. Method: Patients in my hospital for LASIK treatment with follow-up after 3 to 6 months, the knife is divided into 90 groups and 110 groups through statistical analysis to find out the value of the thickness of the corneal flap that 90 and 110 knife make. Results: Corneal flap thickness value of the group of 90 knife is (116.55±12.36μm), 110 knife is (138.37±12.48 μm). Conclusion: In LASIK surgery in theory the corneal flap thickness is fixed, but in clinical practice we found that the thickness of the corneal flap exist large deviations with the theoretical value, which it reminds us that the design of corneal cutting depth must combine our unit equipment situation and experience of person to find out own corneal flap thickness value, so as to ensure the safety of surgery.

  20. Changes in corneal structure with continuous wear of High-Dk Soft contact lenses : a pilot study

    OpenAIRE

    González-Méijome, José Manuel; González-Pérez, Javier; Cerviño, Alejandro; Yebra-Pimentel Vilar, Eva; Parafita, Manuel A.

    2003-01-01

    Despite numerous studies that have considered the effects of extended wear of high-Dk soft contact lenses on ocular physiology, little attention has been paid to the impact of such lenses on central or peripheral corneal thickness and curvature. The present study aims to report the time course of changes in corneal thickness and curvature that accompanies the 30-night continuous wear of new silicone hydrogel soft contact lenses in a neophyte population in a longitudinal study. Methods. Six...

  1. Evaluation of Corneal Deformation Analyzed with Scheimpflug Based Device in Healthy Eyes and Diseased Ones

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    Michele Lanza

    2014-01-01

    Full Text Available This study was designed to evaluate the correlation between corneal biomechanical and morphological data in healthy eyes, eyes that underwent myopic photorefractive keratectomy (PRK, keratoconus affected eyes, and keratoconus affected eyes that underwent corneal collagen crosslinking (CCC. Complete clinical eye examination of all eyes was followed by tomographic (Pentacam, Oculus, Wetzlar, Germany and biomechanical (Corvis ST, Oculus, Wetzlar, Germany evaluation. Differences among Corvis ST (CST parameters in the different groups have been performed. Linear regression between central corneal thickness (CCT, intraocular pressure (IOP, and anterior corneal curvature measured with Sim’K (KM, versus corneal deformation parameters measured with Corvis ST in the different groups, has been run using SPSS software version 18.0. We evaluated 64 healthy eyes of 64 patients with a mean refractive error of -0.65±1.68 D (measured as spherical equivalent, 17 eyes of 17 patients that underwent myopic PRK for a mean refractive defect of -4.91±2.05 D (measured as spherical equivalent, 16 eyes of 16 patients affected by keratconus (stage 2-3 of Amsler Classification, and 13 eyes of 13 patients affected by keratoconus that underwent CCC. Our data suggest that corneal curvature would have a greater influence on corneal deformation than CCT; in fact KM values are more strongly associated with more CST parameters both about corneal change in shape and both about the corneal ability to come back at original shape.

  2. Corneal Laceration

    Medline Plus

    Full Text Available ... eye or something striking the eye with significant force, like a metallic hand tool. A corneal laceration is deeper than a corneal abrasion , cutting ... with Industry Medical Disclaimer Privacy Policy Terms of Service For ...

  3. Corneal tissue water content mapping with THz imaging: preliminary clinical results (Conference Presentation)

    Science.gov (United States)

    Sung, Shijun; Bajwa, Neha; Deng, Sophie X.; Taylor, Zachary; Grundfest, Warren

    2016-03-01

    Well-regulated corneal water content is critical for ocular health and function and can be adversely affected by a number of diseases and injuries. Current clinical practice limits detection of unhealthy corneal water content levels to central corneal thickness measurements performed by ultrasound or optical coherence tomography. Trends revealing increasing or decreasing corneal thickness are fair indicators of corneal water content by individual measurements are highly inaccurate due to the poorly understood relationship between corneal thickness and natural physiologic variation. Recently the utility of THz imaging to accuarately measure corneal water content has been explored on with rabbit models. Preliminary experiments revealed that contact with dielectric windows confounded imaging data and made it nearly impossible to deconvolve thickness variations due to contact from thickness variations due to water content variation. A follow up study with a new optical design allowed the acquisition of rabbit data and the results suggest that the observed, time varying contrast was due entirely to the water dynamics of the cornea. This paper presents the first ever in vivo images of human cornea. Five volunteers with healthy cornea were recruited and their eyes were imaged three times over the course of a few minutes with our novel imaging system. Noticeable changes in corneal reflectivity were observed and attributed to the drying of the tear film. The results suggest that clinically compatible, non-contact corneal imaging is feasible and indicate that signal acquired from non-contact imaging of the cornea is a complicated coupling of stromal water content and tear film.

  4. Corneal Laceration

    Medline Plus

    Full Text Available ... Health Find an Ophthalmologist Academy Store Eye Health A-Z Symptoms Glasses & Contacts Tips & Prevention News Ask an Ophthalmologist Español Eye Health / Eye Health A-Z Corneal Laceration Sections What Is Corneal Laceration? Corneal ...

  5. Corneal Epithelial Remodeling and Its Effect on Corneal Asphericity after Transepithelial Photorefractive Keratectomy for Myopia.

    Science.gov (United States)

    Hou, Jie; Wang, Yan; Lei, Yulin; Zheng, Xiuyun; Zhang, Ying

    2016-01-01

    Purpose. To evaluate the changes in epithelial thickness profile following transepithelial photorefractive keratectomy (T-PRK) for myopia and to investigate the effect of epithelial remodeling on corneal asphericity. Methods. Forty-four patients (44 right eyes) who underwent T-PRK were retrospectively evaluated. Epithelial thickness was measured using spectral-domain optical coherence tomography at different corneal zones (central, 2 mm; paracentral, 2-5 mm; and mid-peripheral, 5-6 mm) preoperatively and at 1 week and 1, 3, and 6 months postoperatively. The correlation between the changes in corneal epithelial thickness (ΔCET) and postoperative Q-value changes (ΔQ) was analyzed 6 months postoperatively. Results. Epithelial thickness at 6 months showed a negative meniscus-like lenticular pattern with less central thickening, which increased progressively toward the mid-periphery (3.69 ± 4.2, 5.19 ± 3.8, and 6.23 ± 3.9 μm at the center, paracenter, and mid-periphery, resp., P myopia. PMID:27672447

  6. The influence of corneal astigmatism on retinal nerve fiber layer thickness and optic nerve head parameter measurements by spectral-domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Liu Lin

    2012-05-01

    Full Text Available Abstract Background To evaluate the influence of corneal astigmatism (CA on retinal nerve fiber layer (RNFL thickness and optic nerve head(ONH parameters measured with spectral-domain optical coherence tomography (OCT in high myopes patients before refractive surgery. Methods Seventy eyes of 35 consecutive refractive surgery candidates were included in this study. The mean age of the subjects was 26.42 ± 6.95 years, the average CA was −1.17 diopters (D; SD 0.64; range −0.2 to-3.3D, All subjects in this study were WTR CA. 34 eyes were in the normal CA group with a mean CA was −0.67 ± 0.28D, 36 eyes were in the high CA group with an average CA of −1.65 ± 0.49D. All subjects underwent ophthalmic examination and imaging with the Cirrus HD OCT. Results No significant difference was noted in the average cup-to-disk ratio, vertical cup-to-disk ratio and cup volume (all P values > 0.05. Compared with the normal CA group, the high CA group had a larger disc area and rim area, thinner RNFL thickness in the temporal quadrant, and the superotemporal and inferotemporal peaks were farther to the temporal horizon (All P values P values > 0.05. Conclusions The degree of with-the-rule CA should be considered when interpreting ONH parameters and peripapillary RNFL thickness measured by the Cirrus HD OCT. Virtual slides The virtual slide(s for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1148475676881895

  7. Application of corneal tomography before keratorefractive procedure for laser vision correction.

    Science.gov (United States)

    Luz, Allan; Lopes, Bernardo; Salomão, Marcela; Ambrósio, Renato

    2016-05-01

    Ectasia after refractive surgery represents a major concern among refractive surgeons. Corneal abnormalities and preexisting corneal ectasia are the most important risk factors. Corneal topography and central corneal thickness are the factors traditionally screening for in refractive surgery candidates. Study of the anterior surface by Placido topography allows for identification of keratoconus before biomicroscopy. However, this is insufficient for the evaluation of pre-operative refractive surgery. There are cases of ectasia after laser in situ keratomilusis (LASIK) without identifiable risk factors such that there is a need to go beyond the corneal surface. A key requirement is quantifying susceptibility to corneal biomechanical instability and progression to ectasia. Tomographic indices derived from elevation maps and pachymetry spatial variation produce a Belin Ambrosio display final D index (BAD-D index), which has shown better results compared to surface curvature indices for detecting very mild forms of ectasia. A logistic regression formula, integrating age, residual stromal bed, and BAD-D (Ectasia Susceptibility Score, ESS) resulted in a significant improvement in accuracy, leading to 100% sensitivity and 94% specificity for detecting susceptible cases. A comprehensive corneal structural analysis based on corneal segmental tomography can detect susceptible corneas, which increases safety for refractive surgery patients.

  8. Role of Optical Coherence Tomography on Corneal Surface Laser Ablation

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    Bruna V. Ventura

    2012-01-01

    Full Text Available This paper focuses on reviewing the roles of optical coherence tomography (OCT on corneal surface laser ablation procedures. OCT is an optical imaging modality that uses low-coherence interferometry to provide noninvasive cross-sectional imaging of tissue microstructure in vivo. There are two types of OCTs, each with transverse and axial spatial resolutions of a few micrometers: the time-domain and the fourier-domain OCTs. Both have been increasingly used by refractive surgeons and have specific advantages. Which of the current imaging instruments is a better choice depends on the specific application. In laser in situ keratomileusis (LASIK and in excimer laser phototherapeutic keratectomy (PTK, OCT can be used to assess corneal characteristics and guide treatment decisions. OCT accurately measures central corneal thickness, evaluates the regularity of LASIK flaps, and quantifies flap and residual stromal bed thickness. When evaluating the ablation depth accuracy by subtracting preoperative from postoperative measurements, OCT pachymetry correlates well with laser ablation settings. In addition, OCT can be used to provide precise information on the morphology and depth of corneal pathologic abnormalities, such as corneal degenerations, dystrophies, and opacities, correlating with histopathologic findings.

  9. Comparison of Corneal Topographical and Biomechanical Properties in Cases with Atopic Dermatitis and Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Yusuf Yıldırım

    2013-06-01

    Full Text Available Pur po se: To compare the topographic, biomechanical, and thickness properties of corneas of patients with atopic dermatitis (AD and of healthy individuals. Ma te ri al and Met hod: In this prospective, cross-sectional, and comparative study, 28 healthy individuals (control group and 28 patients with AD (study group were enrolled. Corneal topographical measurements using Scheimpflug camera with a Placido disc topographer (Sirius, corneal biomechanical properties using Ocular Response Analyzer (ORA, and central corneal thickness (CCT using ultrasonic pachymeter were obtained for each participant. Re sults: Topographic parameters were not significantly different between both groups (p>0.05. Corneal hysteresis (CH and corneal resistance factor (CRF were found same in both groups. CCT measured with ultrasonic pachymeter was significantly lower in patients with AD compared to health controls (p<0.05. Dis cus si on: No significant difference was found between patients with AD and age-matched healthy individuals regarding the corneal topographic findings and corneal biomechanical parameters. CCT was found to be lower in cases with AD than in healthy controls. (Turk J Ophthalmol 2013; 43: 140-4

  10. [Influence of corneal transparency on the quality of topographies].

    Science.gov (United States)

    Franko Zeitz, P; Kohlhaas, M

    2012-12-01

    Corneal topographs that measure the anterior and posterior corneal surface with optical methods need a clear cornea for precise measurements. Opacities cause artifacts in the corneal thickness (with measurements usually being too thin) and corneal curvatures. This is important to know as certain pathologies may repeatedly cause similar artifacts. This is highly relevant after a corneal cross-linking, Lasek or PRK, as these procedures cause typical artifacts that can easily be misinterpreted. PMID:23258670

  11. Corneal amyloidosis associated with keratoconus.

    Science.gov (United States)

    Stern, G A; Knapp, A; Hood, C I

    1988-01-01

    Nodular, gray-white, central corneal opacities which extended from the subepithelial zone through the anterior four fifths of the stroma developed in a 50-year-old man with a longstanding history of hard contact lens wear for keratoconus. Results of histopathologic analysis of the corneal button obtained at the time of penetrating keratoplasty disclosed that the opacities were composed of amyloid. Corneal amyloidosis is rarely found in association with keratoconus. Although there were some similarities in the pattern of amyloid deposition to that seen in primary familial amyloidosis of the cornea, the authors believe that their patient is more likely to have had a secondary amyloidosis. Corneal amyloidosis should be considered in keratoconus patients with development of unusual forms of central corneal opacification. PMID:3278260

  12. SURGICAL OUTCOME OF TRIPLE PROCEDURE AS PENETRATING KERATOPLASTY WITH EXTRACAPSULAR CATARACT EXTRACTION WITH POSTERIOR CHAMBER INTRAOCULAR LENS IMPLANTATION IN PATIENTS WITH BOTH CENTRAL CORNEAL OPACITY AND ADVANCED CATARACT AT RURAL SET UP

    OpenAIRE

    Shubhangi Nigwekar, Kishor Badhe, Neeta Misra, Surekha Bangal

    2015-01-01

    Purpose: To study the surgical outcome of triple procedure as penetrating keratoplasty (PKP) with conventional extra capsular cataract extraction (ECCE) with posterior chamber intraocular lens (PCIOL) implantation in patients with both central corneal opacity and advanced cataract at rural set up. Introduction: When corneal opacity and cataract present together then well-established and effective triple procedure is indicated. Prognosis for a clear graft is good in triple, as graft endothe...

  13. 青少年近视眼患者配戴角膜塑形镜七年的角膜厚度和内皮观察%Corneal thickness and endothelial observation for youth myopia patients fitted with ortho-k lens for seven years

    Institute of Scientific and Technical Information of China (English)

    郭曦; 谢培英

    2014-01-01

    种安全的治疗方法.%Objective To observe the changes of the corneal thickness and ednothelial cell for youth myopia patients fitted with long-term orthokeratology (Ortho-K,OK).Methods Retrospective case series study.During 2000 to 2005,30 patients with OK lens wearing more than seven years in the Bei Yi Optometry & Ophthalmology Center had been chose in this study,and all the right eye of each person was selected for retrospective case statistics (30 eyes).the measure instruments,including A scan pachymeter and endothelium microscope,were used to the long-term continuous supervise,which involved the central and para-peripheral corneal thickness,corneal endothelium and corneal conjunctival complications rate.Then the 30 patients were divided into two groups:the moderate-low myopia group is less than-4.00 D with 12 patients (24 eyes),and the high myopia group is more than-5.00 D with 10 patients (20 eyes).And the difference between two groups was involved in this research.The one-way analysis of variance was used to compare before,after six months,after one year,after three years,after five years and after seven years OK lens wearing for the patients.And the variance analysis was used to compare between moderate-low and high myopia groups.Results Corneal thickness analysis during these seven years:the average central corneal thickness before and after seven-years wearing are (549.45 ± 33.72) and (538.97 ± 34.28) μm,respectively,and the central corneal thickness had no significant changes (F =1.749,P =0.076) ; The corneal thickness of nasal,superior,temporal and inferior also had no significant changes (P > 0.05).The average corneal endothelial cell densities before and after seven-years wearing are (3188.53 ± 272.25) and (3186.64 ± 278.69) num/mm2,respectively,and the corneal endothelial cell density had no significant changes during seven years wearing (F =2.204,P =0.088).The average hexagonal cell ratio before and after seven-years wearing are 66.18% ± 6.42% and 64.65% ± 8.03

  14. Corneal Laceration

    Science.gov (United States)

    ... drugs. These drugs thin the blood and may increase bleeding. After you have finished protecting the eye, see a physician immediately. Next Corneal Laceration Symptoms Related Ask an Ophthalmologist Answers I lost sight from a corneal scar as a child. Now that I’m older, ...

  15. Comparison of Fourier-Domain and Time-Domain Optical Coherence Tomography in the Measurement of Thinnest Corneal Thickness in Keratoconus

    Directory of Open Access Journals (Sweden)

    Chunxiao Wang

    2015-01-01

    Full Text Available Objective. To compare fourier-domain optical coherence tomography (FD-OCT and time-domain OCT (TD-OCT in the determination of thinnest corneal thickness (TCT. Methods. This study included 55 keratoconus patients and 50 healthy volunteers. The RTVue-OCT (FD-OCT and Visante-OCT (TD-OCT were used for the measurement of the TCT. Three consecutive scans were performed. The comparison and agreement between the two modalities were analyzed by paired t-test, the Pearson correlation, intraclass correlation coefficient (ICC, and Bland-Altman plots. intraobserver repeatability was analyzed by the intraobserver within-subject standard deviation (S(w, coefficient of variation (CV(w, and ICC. Results. The TCT value of normal corneas was higher by RTVue-OCT (530.4 ± 19.7 μm than Visante-OCT (521.5 ± 18.3 μm (p<0.001. For keratoconus eyes, the TCT was 425.0 ± 58.2 μm and 424.4 ± 55.7 μm (difference being 0.6 ± 10.2 μm, p=0.604. Strong correlation (r = 0.938∼0.985 (ICC = 0.915–0.984 was observed between the two OCTs, and each OCT exhibited excellent repeatability in determining the TCT in all subjects (ICC = 0.984–0.994. Conclusions. The values of TCT obtained from RTVue-OCT and Visante-OCT were highly correlated; however, the two values were different. Both OCT instruments exhibited good intraobserver reliability. The existence of systematic differences suggested that the two instruments cannot be used interchangeably.

  16. In Vivo Corneal Biomechanical Properties with Corneal Visualization Scheimpflug Technology in Chinese Population

    Directory of Open Access Journals (Sweden)

    Ying Wu

    2016-01-01

    Full Text Available Purpose. To determine the repeatability of recalculated corneal visualization Scheimpflug technology (CorVis ST parameters and to study the variation of biomechanical properties and their association with demographic and ocular characteristics. Methods. A total of 783 healthy subjects were included in this study. Comprehensive ophthalmological examinations were conducted. The repeatability of the recalculated biomechanical parameters with 90 subjects was assessed by the coefficient of variation (CV and intraclass correlation coefficient (ICC. Univariate and multivariate linear regression models were used to identify demographic and ocular factors. Results. The repeatability of the central corneal thickness (CCT, deformation amplitude (DA, and first/second applanation time (A1/A2-time exhibited excellent repeatability (CV% ≤ 3.312% and ICC ≥ 0.929 for all measurements. The velocity in/out (Vin/out, highest concavity- (HC- radius, peak distance (PD, and DA showed a normal distribution. Univariate linear regression showed a statistically significant correlation between Vin, Vout, DA, PD, and HC-radius and IOP, CCT, and corneal volume, respectively. Multivariate analysis showed that IOP and CCT were negatively correlated with Vin, DA, and PD, while there was a positive correlation between Vout and HC-radius. Conclusion. The ICCs of the recalculated parameters, CCT, DA, A1-time, and A2-time, exhibited excellent repeatability. IOP, CCT, and corneal volume significantly influenced the biomechanical properties of the eye.

  17. In Vivo Corneal Biomechanical Properties with Corneal Visualization Scheimpflug Technology in Chinese Population.

    Science.gov (United States)

    Wu, Ying; Tian, Lei; Huang, Yi-Fei

    2016-01-01

    Purpose. To determine the repeatability of recalculated corneal visualization Scheimpflug technology (CorVis ST) parameters and to study the variation of biomechanical properties and their association with demographic and ocular characteristics. Methods. A total of 783 healthy subjects were included in this study. Comprehensive ophthalmological examinations were conducted. The repeatability of the recalculated biomechanical parameters with 90 subjects was assessed by the coefficient of variation (CV) and intraclass correlation coefficient (ICC). Univariate and multivariate linear regression models were used to identify demographic and ocular factors. Results. The repeatability of the central corneal thickness (CCT), deformation amplitude (DA), and first/second applanation time (A1/A2-time) exhibited excellent repeatability (CV% ≤ 3.312% and ICC ≥ 0.929 for all measurements). The velocity in/out (V in/out), highest concavity- (HC-) radius, peak distance (PD), and DA showed a normal distribution. Univariate linear regression showed a statistically significant correlation between V in, V out, DA, PD, and HC-radius and IOP, CCT, and corneal volume, respectively. Multivariate analysis showed that IOP and CCT were negatively correlated with V in, DA, and PD, while there was a positive correlation between V out and HC-radius. Conclusion. The ICCs of the recalculated parameters, CCT, DA, A1-time, and A2-time, exhibited excellent repeatability. IOP, CCT, and corneal volume significantly influenced the biomechanical properties of the eye. PMID:27493965

  18. Corneal Epithelial Remodeling and Its Effect on Corneal Asphericity after Transepithelial Photorefractive Keratectomy for Myopia

    Directory of Open Access Journals (Sweden)

    Jie Hou

    2016-01-01

    Full Text Available Purpose. To evaluate the changes in epithelial thickness profile following transepithelial photorefractive keratectomy (T-PRK for myopia and to investigate the effect of epithelial remodeling on corneal asphericity. Methods. Forty-four patients (44 right eyes who underwent T-PRK were retrospectively evaluated. Epithelial thickness was measured using spectral-domain optical coherence tomography at different corneal zones (central, 2 mm; paracentral, 2–5 mm; and mid-peripheral, 5-6 mm preoperatively and at 1 week and 1, 3, and 6 months postoperatively. The correlation between the changes in corneal epithelial thickness (ΔCET and postoperative Q-value changes (ΔQ was analyzed 6 months postoperatively. Results. Epithelial thickness at 6 months showed a negative meniscus-like lenticular pattern with less central thickening, which increased progressively toward the mid-periphery (3.69±4.2, 5.19±3.8, and 6.23±3.9 μm at the center, paracenter, and mid-periphery, resp., P<0.01. A significant positive relationship was observed between epithelial thickening and ΔQ 6 months postoperatively (r=0.438, 0.580, and 0.504, resp., P<0.01. Conclusions. Significant epithelial thickening was observed after T-PRK and showed a lenticular change with more thickening mid-peripherally, resulting in increased oblateness postoperatively. Epithelial remodeling may modify the epithelial thickness profile after surface ablation refractive surgery for myopia.

  19. Corneal Laceration

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    Full Text Available ... about eye health and preserving your vision. Privacy Policy Related Corneal Collagen Cross-linking Approved to Treat ... Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of Service For Advertisers For Media Ophthalmology ...

  20. Corneal Laceration

    Medline Plus

    Full Text Available ... itself. A corneal laceration is a very serious injury and requires immediate medical attention to avoid severe ... 27, 2015 Dark Spot in Vision After Blunt Trauma Dec 21, 2014 Pain a Year After Eyelid ...

  1. Corneal transplant

    Science.gov (United States)

    ... clear outer lens on the front of the eye. A corneal transplant is surgery to replace the cornea with tissue ... years. Rejection can sometimes be controlled with steroid eye drops. Other ... are: Bleeding Cataracts Infection of the eye Glaucoma ( ...

  2. Sunitinib inhibits inflammatory corneal lymphangiogenesis.

    OpenAIRE

    Detry, Benoît; Blacher, Silvia; Erpicum, Charlotte; Paupert, Jenny; Maertens, Ludovic; Maillard, Catherine; Munaut, Carine; Sounni, Nor Eddine; Lambert, Vincent; Foidart, Jean-Michel; Rakic, Jean-Marie; Cataldo, Didier; Noël, Agnès

    2013-01-01

    PURPOSE: To evaluate the antilymphangiogenic potential of multi-target tyrosine kinase inhibitor sunitinib in corneal neovascularization (NV). METHODS: Inflammatory corneal NV was induced by thermal cauterization applied in the central cornea of mice, to which sunitinib malate was daily administered by gavage or not. At days 6, 11, or 17 post cauterization, lymphatic and blood vessels, as well as inflammatory cells were immunostained and quantified in whole-mounted corneas. RT-PCRs were perfo...

  3. Therapeutic efficiency of tissue-engineered human corneal endothelium transplants on rabbit primary corneal endotheliopathy

    Institute of Scientific and Technical Information of China (English)

    Ting-jun FAN; Jun ZHAO; Xiu-zhong HU; Xi-ya MA; Wen-bo ZHANG; Chao-zhong YANG

    2011-01-01

    To evaluate the therapeutic efficiency of tissue-engineered human corneal endothelia (TE-HCEs) on rabbit primary corneal endotheliopathy (PCEP), TE-HCEs reconstructed with monoclonal human corneal endothelial cells (mcHCECs) and modified denuded amniotic membranes (mdAMs) were transplanted into PCEP models of New Zealand white rabbits using penetrating keratoplasty. The TE-HCEs were examined using diverse techniques including slit-lamp biomicroscopy observation and pachymeter and tonometer measurements in vivo, and fluorescent microscopy, alizarin red staining, paraffin sectioning, scanning and transmission electron microscopy observations in vitro. The corneas of transplanted eyes maintained transparency for as long as 200 d without obvious edema or immune rejection. The corneal thickness of transplanted eyes decreased gradually after transplanting, reaching almost the thickness of normal eyes after 156 d, while the TE-HCE non-transplanted eyes were turbid and showed obvious corneal edema. The polygonal corneal endothelial cells in the transplanted area originated from the TE-HCE transplant. An intact monolayer corneal endothelium had been reconstructed with the morphology, cell density and structure similar to those of normal rabbit corneal endothelium. In conclusion, the transplanted TE-HCE can reconstruct the integrality of corneal endothelium and restore corneal transparency and thickness in PCEP rabbits. The TE-HCE functions normally as an endothelial barrier and pump and promises to be an equivalent of HCE for clinical therapy of human PCEP.

  4. Choroidal thickness following extrafoveal photodynamic treatment with verteporfin in patients with central serous chorioretinopathy

    DEFF Research Database (Denmark)

    Pryds, Anders; Larsen, Michael

    2012-01-01

    Purpose: To evaluate the effect of verteporfin photodynamic treatment (PDT) on choroidal thickness in patients with central serous chorioretinopathy (CSC). Methods: Choroidal thickness was measured with enhanced depth imaging- optical coherence tomography (EDI-OCT) before and after verteporfin PDT...... (full-dose verteporfin, half-light dose) in 16 eyes in 16 patients with serous detachment of the fovea secondary to extrafoveal angiographic fluorescein leakage. Treatment was confined to the area of leakage, whereas choroidal thickness before and after treatment was assessed over a larger area...... of the fundus using OCT. Results: Complete resolution of the serous detachment was seen in all 16 eyes within 1 month of extrafoveal PDT, while choroidal thickness in the area where PDT was applied decreased from 407 µm [mean; 95% confidence interval (CI(95) ) 356-458 µm] to 349 µm (mean; CI(95) 300-399 µm; p...

  5. Full-Thickness Retinochoroidal Incision in the Management of Central Retinal Vein Occlusion

    Directory of Open Access Journals (Sweden)

    San-Ni Chen

    2015-01-01

    Full Text Available Purpose. To evaluate the clinical outcomes in patients with central retinal vein occlusion (CRVO treated with full-thickness retinochoroidal incisions and to compare whether there is difference in treatment response in ischemic and nonischemic CRVO. Methods. Retrospective study of patients of CRVO receiving full-thickness retinochoroidal incisions in Changhua Christian Hospital. Fluorescein angiography (FA, slit-lamp biomicroscopy, indirect funduscopy, best corrected visual acuity, and central macular thickness (CMT measured by optical coherence tomography were performed pre- and postoperatively. Patients were divided into an ischemic and nonischemic group according to the findings of FA. Patients were followed up for at least 1 year. Results. Twenty-eight eyes (14 ischemic and 14 nonischemic CRVO were included. Functional retinochoroidal venous anastomosis (RCVA was achieved in 48 of the 65 retinochoroidal incisions (73.8%. Central macular thickness (CMT and retinal hemorrhage decreased significantly after the surgery. Significant visual gain was observed postoperatively in the nonischemic group, but not in the ischemic group. Postoperative complications included vitreous hemorrhage (17.8%, neovascular glaucoma (7.1%, and preretinal fibrovasular membrane (10.7%, all of which were in the ischemic group. Conclusions. RCVA formation induced by retinochoroidal incisions could improve venous flow, and decrease CMT and retinal hemorrhage. However, only eyes with nonischemic CRVO showed visual improvement.

  6. Corneal Transplantation

    DEFF Research Database (Denmark)

    Hjortdal, Jesper Østergaard

    with less risk of rejection episodes. Besides covering updated chapters on penetrating keratoplasty, and anterior and posterior lamellar procedures, this textbook also gives a thorough overview of the history of corneal transplantation and a detailed presentation of the microstructural components...... of the cornea essential to keratoplasty procedures. Corneal banking has changed over recent years as graft preparation for anterior and posterior lamellar keratoplasty now often is performed within the bank. Chapters have been devoted to description of graft registries, which are an indispensable source...

  7. Analysis of low-energy and high-frequency femtosecond laser for the construction of deep anterior donor corneal lamellae

    Directory of Open Access Journals (Sweden)

    Gustavo Victor

    2014-04-01

    Full Text Available Purpose: To evaluate the efficacy and reliability of a low-energy femtosecond laser with a high repetition rate for construction of deep anterior donor corneal lamellae. Methods: This was a prospective laboratory investigation. Twenty-five human corneal buttons were femtosecond laser cut to create thick anterior lamellae (diameter, 10mm; thickness, 500µm. The laser cuts were made using an LDV® femtosecond laser in a Ziemer® anterior chamber. To obtain a better edge, the lamellae were trephined with an 8mm trephine (Katena®. The central corneal thickness and the anterior lamellae were measured using a Mitutoyo® thickness gauge with an accuracy of 0.001mm. Results: The central thickness of the 25 corneas ranged from 500 to 705µm (mean, 584 ± 51µm. The thickness of the anterior lamellae ranged from 420 to 480µm (mean, 455 ± 12.7µm. The anterior lamellae diameters were 7.90 ± 0.1mm, and all laser cuts were round. The lamellar interfaces appeared regular by surgical microscopy. There were no cases of inter-lamellar adhesion. Conclusion: The LDV® femtosecond laser appears to be a safe and reliable instrument for cutting deep anterior lamellae from donor corneoscleral buttons. Minimal variation in donor lamellar depth with the laser will be useful for creating donor corneal tissue for deeper anterior lamellar keratoplasty or endothelial keratoplasty surgery or both from a single donor cornea.

  8. The Long-Term Effects of Silicone Hydrogel Contact Lens Wear on Corneal Morphology

    OpenAIRE

    Yelda Yıldız; Canan Gürdal; Özge Saraç; Şenay Aşık Nacaroğlu; Tamer Takmaz; İzzet Can

    2012-01-01

    Pur po se: To evaluate the effects of silicone hydrogel contact lenses (SHCL) on central corneal thickness (CCT), corneal endothelial cell morphology, and tear functions. Ma te ri al and Met hod: Fifty-five eyes of 28 SHCL wearers (Group 1) and 52 eyes of 26 healthy subjects (Group 2) were included in this study’. According to their contact lens wearing time, the contact lens wearing subjects were divided into 2 groups: Group 1a - wearing time less than 1 year and Group 1b - weari...

  9. Cortical thickness difference across the central sulcus visualized in the presence of vasogenic edema

    Energy Technology Data Exchange (ETDEWEB)

    Togao, Osamu [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582 (Japan)], E-mail: togao@dr.hosp.kyushu-u.ac.jp; Yoshiura, Takashi; Mihara, Futoshi; Noguchi, Tomoyuki; Hiwatashi, Akio; Yamashita, Koji; Yoshitake, Tadamasa; Honda, Hiroshi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582 (Japan)

    2008-05-15

    Purpose: To confirm the cortical thickness difference across the central sulcus (CS) visualized in the presence of vasogenic edema on MRI. Materials and methods: T2-weighted images of 70 cerebral hemispheres showing vasogenic edema infiltrating into subcortical white matter around the CS were studied retrospectively. Two neuroradiologists measured the cortical thickness of the anterior and posterior banks of the CS, precentral sulci (PrCS), and postcentral sulci (PoCS). Additionally, we compared the cortical thickness of the anterior and posterior banks of each sulcus visually using a grading scale. Results: On T2-weighted images, the cerebral cortex was highlighted by a high signal-intensity vasogenic edema in the adjacent white matter, and its thickness was readily measurable. The unique cortical thickness difference between the anterior and posterior banks of the CS were confirmed with measurements of 2.67 and 1.48 mm (p < 0.0001). The cortical measurements across other cerebral sulci were 2.04 and 1.95 mm (NS) for the PrCS, and 1.67 and 1.77 mm (NS) for the PoCS. The cortical thickness ratios were 1.86 for the CS, 1.05 for the PrCS, and 0.96 for the PoCS. On visual evaluation, the anterior bank of the CS was thicker than the posterior bank in 93% (65/70). For the PrCS and PoCS, the thickness of the anterior and posterior banks appeared to be equal in over 70% of the patients. Conclusion: A prominent cortical thickness difference across the CS in the presence of vasogenic edema was confirmed. This finding is considered to facilitate the identification of the CS in patients with brain tumors.

  10. Corneal Laceration

    Medline Plus

    Full Text Available ... Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Corneal Laceration ... without Eye Protection Jun 19, 2014 Leer en Español: ¿Qué Es una Laceración de la Córnea? Find ...

  11. Changes in Corneal Biomechanical Properties after Long-Term Topical Prostaglandin Therapy.

    Directory of Open Access Journals (Sweden)

    Na Wu

    Full Text Available To compare corneal biomechanical properties, measured by a newly developed tonometer (Corneal Visualization Scheimpflug Technology, Corvis ST, in untreated primary open angle glaucoma (POAG patients, POAG patients with long-term topical prostaglandin analog (PGA therapy and in normal controls. Further is to investigate the potential effects of PGA on corneal biomechanics.In this case-control study, 35 consecutive medication naïve eyes with POAG, 34 POAG eyes with at least 2 years treatment by PGA and 19 normal eyes were included. Intraocular pressure (IOP, central corneal thickness (CCT and corneal biomechanical parameters, including deformation amplitude (DA, applanation time (AT1 and AT2, applanation length (AL1 and AL2, applanation velocity (AV1 and AV2, and peak distance and radius were measured using Corvis ST. Axial length and corneal curvature were measured with partial coherence interferometry (IOLMaster, Zeiss, Germany. General linear model analysis was performed to investigate the corneal biomechanical property changes among the normal controls, newly diagnosed POAG patients and POAG patients with long-term PGA treatment, and among the subgroups of different types of PGA treatment, including bimatoprost, latanoprost and travoprost. Furthermore, pairwise comparisons using Bonferroni correction for least squares means were employed.AT1 (p<0.0001, AV1 (p<0.0001, AT2 (p = 0.0001, AV2 (p<0.0001 and DA (p = 0.0004 in newly diagnosed glaucoma patients were significantly different from those in normal subjects and in patients underwent at least 2 years topical PGA therapy after adjusting for age and gender. After adjusting for age, gender, IOP, CCT, axial length and corneal curvature, a significant difference was detected for DA between glaucoma patients without PGA treatment and patients with long-term PGA therapy (p = 0.0387. Furthermore, there were no statistical significant differences in all of the corneal biomechanical parameters among

  12. Optovue iVue OCT测量角膜厚度的可重复性及其与Pentacam、Visante OCT的一致性研究%Repeatability of corneal thickness measurement with Optovue iVue OCT and a comparative study with Pentacam and Visante OCT

    Institute of Scientific and Technical Information of China (English)

    苏小连; 吴文静; 王雁

    2015-01-01

    Background Measurement of corneal thickness is of great significance for the design of refractive surgery and the diagnosis of eye diseases,measuring equipments and technology develop rapidly in recent years.Optovue iVue OCT is a new frequency-domain optical coherence tomography (OCT),to compare its results with those of Pentacam and Visante OCT is helpful to objectively assess the clinical value of Optovue iVue OCT.Objective This study was to investigate the repeatability of corneal thickness measurement with Optovue iVue OCT and the comparatbility with Pentacam three-dimensional anterior segment analysis diagnostic system and Visante OCT.In addition,this study attempted to analyze the distribution of average corneal thickness in each quadrant by Optovue iVue OCT.Methods The corneal thicknesses of the corneal thinnest point,the central point and 3:00,6:00,9:00,12:00 zones 1 mm away from the center of the cornea were measured in 45 right eyes of 45 subjects with myopia using Optovue iVue OCT,Pentacam and Visante OCT in Tianjin Eye Hospital.Interclass correlation coefficient (ICC) was used to analyze the repeatability of measurement by Optovue iVue OCT.The agreements between Optovue iVue OCT and Pentacam or Visante OCT were evaluated by Bland-Altman test.The corneal area of 1.0-2.5 mm away from the center was divided into eight quadrants and the average corneal thickness of each quadrant was measured and analysis with Optovue iVue OCT.Results No significant difference was found in corneal thickness values for 3 times by Optovue iVue OCT (P=0.546).The ICC by Optovue iVue OCT was 99.92%,99.99%,99.96%,99.99%,99.99% and 99.97% at the corneal thinnest point,the central point and 3:00,6:00,9:00,12:00 zones respectively.There were significant differences among the 3 kinds of methods (P =0.000,0.001,0.000,0.003,0.002,0.000).The measured values of Optovue iVue OCT were significantly lower mean 24.20 μm than those of Pentacam (P=0.000,0

  13. Repeatability of corneal parameters with Pentacam after laser in situ keratomileusis

    Directory of Open Access Journals (Sweden)

    Jain Rajeev

    2007-01-01

    Full Text Available Aim: To investigate the coefficient of repeatability (CR for corneal parameters evaluated with Pentacam after laser in situ keratomileusis (LASIK in myopic eyes. Design and Setting: Prospective, non-interventional, non-comparative study in an institutional setup. Materials and Methods: Forty eyes of 40 consecutive subjects who had undergone LASIK for myopia were assessed with the Scheimpflug system (Pentacam 70700: Oculus, Wetzlar Germany. The mean of five consecutive measurements of all the corneal parameters was recorded and CR was calculated as standard deviation of the difference from the mean of these repeat measurements divided by the mean response. The statistical significance of the CR was calculated for these parameters at 5% significance level. Results: The best CR was observed for the periphery of the anterior corneal curvature (0.18% and the least for the horizontal meridian of the posterior corneal curvature (1.29%. Despite being significantly different ( P < 0.001, both the measurements were highly repeatable in post-LASIK eyes. The central, apical and minimal corneal thickness had a CR of 1%, 0.78% and 0.77% respectively. These were equally repeatable ( P >0.323. The CR of the mean radius of curvature of the anterior cornea (0.29% was significantly better ( P < 0.001 than the posterior corneal curvature (0.57%. Conclusion: The CR for the post-LASIK cornea with Pentacam was the best for the anterior corneal curvature. Significantly, Pentacam has a high degree of repeatability for the posterior corneal curvature, which has a potential for early detection of keratectasia in these eyes. Post-LASIK pachymetry with Pentacam also showed excellent repeatability.

  14. Day to day clinically relevant corneal elevation, thickness, and curvature parameters using the orbscan II scanning slit topographer and the pentacam scheimpflug imaging device

    Directory of Open Access Journals (Sweden)

    Hashemi Hassan

    2010-01-01

    Full Text Available The introduction of different techniques and computerized devices into clinical ophthalmology has significantly improved our knowledge of the eyes, optics, and eye conditions. Today, corneal topography is performed with a wide range of devices that implement a variety of techniques. Advance computerized analysis systems provide us with simple and quick evaluation procedures, yet the sophisticated data and clinical information that is generated can only be interpreted with adequate knowledge of the system itself as well as the accepted normal ranges of various properties assessed with these systems. Two computerized topography systems that are in common use are the Orbscan (Bausch and Lomb Inc., Rochester, NY, USA and the Pentacam (Oculus GmBH, Wetzlar, Germany. The Orbscan is a slit-scanning device and the Pentacam is Scheimpflug imaging device. In this review, we present a brief description of both technologies, the techniques implemented in each device and the acquisition process with each. This will be followed by a list of corneal parameters that need to be assessed in screening patients for refractive surgery. We will discuss how these parameters are displayed, how each parameter may serve as clinic criteria, and how data should be interpreted. We will also try to provide evidence regarding the accuracy of different measurements, and the comparability of the two devices.

  15. Corneal Regeneration by Deep Anterior Lamellar Keratoplasty (DALK Using Decellularized Corneal Matrix.

    Directory of Open Access Journals (Sweden)

    Yoshihide Hashimoto

    Full Text Available The purpose of this study is to demonstrate the feasibility of DALK using a decellularized corneal matrix obtained by HHP methodology. Porcine corneas were hydrostatically pressurized at 980 MPa at 10°C for 10 minutes to destroy the cells, followed by washing with EGM-2 medium to remove the cell debris. The HHP-treated corneas were stained with H-E to assess the efficacy of decellularization. The decellularized corneal matrix of 300 μm thickness and 6.0 mm diameter was transplanted onto a 6.0 mm diameter keratectomy wound. The time course of regeneration on the decellularized corneal matrix was evaluated by haze grading score, fluorescein staining, and immunohistochemistry. H-E staining revealed that no cell nuclei were observed in the decellularized corneal matrix. The decellularized corneal matrices were opaque immediately after transplantation, but became completely transparent after 4 months. Fluorescein staining revealed that initial migration of epithelial cells over the grafts was slow, taking 3 months to completely cover the implant. Histological sections revealed that the implanted decellularized corneal matrix was completely integrated with the receptive rabbit cornea, and keratocytes infiltrated into the decellularized corneal matrix 6 months after transplantation. No inflammatory cells such as macrophages, or neovascularization, were observed during the implantation period. The decellularized corneal matrix improved corneal transparency, and remodelled the graft after being transplanted, demonstrating that the matrix obtained by HHP was a useful graft for corneal tissue regeneration.

  16. On the correlation between minimum thickness and central deflection during small punch test

    Science.gov (United States)

    Kumar, Pradeep; Chattopadhyay, J.; Dutta, B. K.

    2016-07-01

    Present paper deals with a detailed study on the correlation between minimum thickness (t/t0) and central deflection (δ/t0). Such data are obtained during the deformation of a small punch test of miniaturized specimen. Finite element studies have been carried out to investigate the effect of various parameters which are expected to influence this correlation. The parameters under consideration are material hardening, material yield stress, coefficient of friction and initial thickness of the specimen. It is shown that the correlation remains unaffected with respect to change in material parameters. Similarly, the coefficient of friction beyond 0.2 also does not affect the correlation. However, change in thickness has significant effect on the correlation. A modification has been suggested in the existing correlation to consider the influence of thickness change. The modified correlation is then used to calculate fracture toughness using the experimental results quoted in the literature. It is shown that the modified correlation improves the fracture toughness prediction considerably.

  17. Contours of Corcoran Clay Thickness in feet by Page (1986) for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the thickness of the Corcoran Clay Member of the Tulare Formation. The complex hydrologic system of the Central Valley is simulated...

  18. Corneal laceration caused by river crab

    Directory of Open Access Journals (Sweden)

    Vinuthinee N

    2015-01-01

    Full Text Available Naidu Vinuthinee,1,2 Anuar Azreen-Redzal,1 Jaafar Juanarita,1 Embong Zunaina2 1Department of Ophthalmology, Hospital Sultanah Bahiyah, Alor Setar, 2Department of Ophthalmology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia Abstract: A 5-year-old boy presented with right eye pain associated with tearing and photophobia of 1-day duration. He gave a history of playing with a river crab when suddenly the crab clamped his fingers. He attempted to fling the crab off, but the crab flew and hit his right eye. Ocular examination revealed a right eye corneal ulcer with clumps of fibrin located beneath the corneal ulcer and 1.6 mm level of hypopyon. At presentation, the Seidel test was negative, with a deep anterior chamber. Culture from the corneal scrapping specimen grew Citrobacter diversus and Proteus vulgaris, and the boy was treated with topical gentamicin and ceftazidime eyedrops. Fibrin clumps beneath the corneal ulcer subsequently dislodged, and revealed a full-thickness corneal laceration wound with a positive Seidel test and shallow anterior chamber. The patient underwent emergency corneal toileting and suturing. Postoperatively, he was treated with oral ciprofloxacin 250 mg 12-hourly for 1 week, topical gentamicin, ceftazidime, and dexamethasone eyedrops for 4 weeks. Right eye vision improved to 6/9 and 6/6 with pinhole at the 2-week follow-up following corneal suture removal. Keywords: corneal ulcer, pediatric trauma, ocular injury

  19. Three-dimensional LASIK flap thickness variability: topographic central, paracentral and peripheral assessment, in flaps created by a mechanical microkeratome (M2 and two different femtosecond lasers (FS60 and FS200

    Directory of Open Access Journals (Sweden)

    Kanellopoulos AJ

    2013-04-01

    Full Text Available A John Kanellopoulos,1,2 George Asimellis1 1Laservision.gr Institute, Athens, Greece; 2NYU Medical School, New York, USA Purpose: To evaluate programmed versus achieved laser-assisted in situ keratomileusis (LASIK flap central thickness and investigate topographic flap thickness variability, as well as the effect of potential epithelial remodeling interference on flap thickness variability. Patients and methods: Flap thickness was investigated in 110 eyes that had had bilateral myopic LASIK several years ago (average 4.5 ± 2.7 years; range 2–7 years. Three age-matched study groups were formed, based on the method of primary flap creation: Group A (flaps made by the Moria Surgical M2 microkeratome [Antony, France], Group B (flaps made by the Abbott Medical Optics IntraLase™ FS60 femtosecond laser [Santa Ana, CA, USA], and Group C (flaps made by the Alcon WaveLight® FS200 femtosecond laser [Fort Worth, TX, USA]. Whole-cornea topographic maps of flap and epithelial thickness were obtained by scanning high-frequency ultrasound biomicroscopy. On each eye, topographic flap and epithelial thickness variability was computed by the standard deviation of thickness corresponding to 21 equally spaced points over the entire corneal area imaged. Results: The average central flap thickness for each group was 138.33 ± 12.38 µm (mean ± standard deviation in Group A, 128.46 ± 5.72 µm in Group B, and 122.00 ± 5.64 µm in Group C. Topographic flap thickness variability was 9.73 ± 4.93 µm for Group A, 8.48 ± 4.23 µm for Group B, and 4.84 ± 1.88 µm for Group C. The smaller topographic flap thickness variability of Group C (FS200 was statistically significant compared with that of Group A (M2 (P = 0.004, indicating improved topographic flap thickness consistency – that is, improved precision – over the entire flap area affected. Conclusions: The two femtosecond lasers produced a smaller flap thickness and reduced variability than the mechanical

  20. Overnight corneal swelling with high and low powered silicone hydrogel lenses☆

    Science.gov (United States)

    Moezzi, Amir M.; Fonn, Desmond; Varikooty, Jalaiah; Simpson, Trefford L.

    2014-01-01

    Purpose To compare central corneal swelling after eight hours of sleep in eyes wearing four different silicone hydrogel lenses with three different powers. Methods Twenty-nine neophyte subjects wore lotrafilcon A (Dk, 140), balafilcon A (Dk, 91), galyfilcon A (Dk, 60) and senofilcon A (Dk, 103) lenses in powers −3.00, −10.00 and +6.00 D on separate nights, in random order, and on one eye only. The contra-lateral eye (no lens) served as the control. Central corneal thickness was measured using a digital optical pachometer before lens insertion and immediately after lens removal on waking. Results For the +6.00 D and −10.00 D, lotrafilcon A induced the least swelling and galyfilcon A the most. The +6.00 D power, averaged across lens materials, induced significantly greater central swelling than the −10.00 and −3.00 D (Re-ANOVA, p < 0.001), (7.7 ± 2.9% vs. 6.8 ± 2.8% and 6.5 ± 2.5% respectively) but there was no difference between −10.00 and −3.00 D. Averaged for power, lotrafilcon A induced the least (6.2 ± 2.8%) and galyfilcon A the most (7.6 ± 3.0%) swelling at the center (Re-ANOVA, p < 0.001). Central corneal swelling with +6.00 D was significantly greater than −10.00 D lens power despite similar levels of average lens transmissibility of these two lens powers. Conclusions The differences in corneal swelling of the lens wearing eyes are consistent with the differences in oxygen transmission of the silicone hydrogel lenses. In silicone hydrogel lenses central corneal swelling is mainly driven by central lens oxygen transmissibility. PMID:25649637

  1. Riboflavin for corneal cross-linking.

    Science.gov (United States)

    O'Brart, D P S

    2016-06-01

    Corneal collagen cross-linking (CXL) with riboflavin and ultraviolet A (UVA) radiation is the first therapeutic modality that appears to arrest the progression of keratoconus and other corneal ectasias. Riboflavin is central to the process, acting as a photosensitizer for the production of oxygen singlets and riboflavin triplets. These free radicals drive the CXL process within the proteins of the corneal stroma, altering its biomechanical properties. Riboflavin also absorbs the majority of the UVA radiation, which is potentially cytotoxic and mutagenic, within the anterior stroma, preventing damage to internal ocular structures, such as the corneal endothelium, lens and retina. Clinical studies report cessation of ectatic progression in over 90% of cases and the majority document significant improvements in visual, keratometric and topographic parameters. Clinical follow-up is limited to 5-10 years, but suggests sustained stability and enhancement in corneal shape. Sight-threatening complications are rare. The optimal stromal riboflavin dosage for CXL is as yet undetermined. PMID:27458610

  2. Thickness of Knox Group overburden on Central Chestnut Ridge, Oak Ridge Reservation

    International Nuclear Information System (INIS)

    The thickness of residual soil overlying the Knox Group along Central Chestnut Ridge was estimated by a conventional seismic refraction survey. The purpose of this survey was to identify sites on the Department of Energy's Oak Ridge Reservation where ample overburden exists above the water table for the shallow land burial of low-level radioactive waste. The results of the survey suggest that the upper slopes of the higher ridges in the area have a minimum of 16 to 26 m (52 to 85 ft) of overburden and that the crests of these ridges may have more than 30 m (100 ft). Therefore, it is unlikely that sound bedrock would be encountered during trench excavation [maximum of 10 m (32 ft)] along Central Chestnut Ridge. Also, the relatively low seismic wave velocities measured in the overburden suggest that the water table is generally deep. On the basis of these preliminary results, Central Chestnut Ridge appears to be suitable for further site characterization for the shallow land burial of low-level radioactive waste. 3 references, 5 figures, 1 table

  3. Evaluation of corneal biomechanical properties following penetrating keratoplasty using ocular response analyzer

    Directory of Open Access Journals (Sweden)

    Vanathi Murugesan

    2014-01-01

    Full Text Available Purpose: To evaluate corneal biomechanical properties in eyes that has undergone penetrating keratoplasty (PK. Materials and Methods: Retrospective observational study in a tertiary care centre. Data recorded included ocular response analyzer (ORA values of normal and post-keratoplasty eyes [corneal hysteresis (CH, corneal resistance factor (CRF, Goldmann-correlated intraocular pressure (IOPg, and cornea-compensated intraocular pressure (IOPcc], corneal topography, and central corneal thickness (CCT. Wilcoxon signed rank test was used to analyze the difference in ORA parameter between post-PK eyes and normal eyes. Correlation between parameters was evaluated with Spearman′s rho correlation. Results: The ORA study of 100 eyes of 50 normal subjects and 54 post-keratoplasty eyes of 51 patients showed CH of 8.340 ± 1.85 and 9.923 ± 1.558, CRF of 8.846 ± 2.39 and 9.577 ± 1.631 in post-PK eyes and normal eyes, respectively. CH and CRF did not correlate with post-keratoplasty astigmatism (P = 0.311 and 0.276, respectively while a significant correlation was observed with IOPg (P = 0.004 and IOPcc (P < 0.001. Conclusion: Biomechanical profiles were significantly decreased in post-keratoplasty eyes with significant correlation with higher IOP as compared with that in normal eyes.

  4. The molecular genetics of the corneal dystrophies--current status.

    Science.gov (United States)

    Klintworth, Gordon K

    2003-05-01

    The pertinent literature on inherited corneal diseases is reviewed in terms of the chromosomal localization and identification of the responsible genes. Disorders affecting the cornea have been mapped to human chromosome 1 (central crystalline corneal dystrophy, familial subepithelial corneal amyloidosis, early onset Fuchs dystrophy, posterior polymorphous corneal dystrophy), chromosome 4 (Bietti marginal crystalline dystrophy), chromosome 5 (lattice dystrophy types 1 and IIIA, granular corneal dystrophy types 1, 2 and 3, Thiel-Behnke corneal dystrophy), chromosome 9 (lattice dystrophy type II), chromosome 10 (Thiel-Behnke corneal dystrophy), chromosome 12 (Meesmann dystrophy), chromosome 16 (macular corneal dystrophy, fish eye disease, LCAT disease, tyrosinemia type II), chromosome 17 (Meesmann dystrophy, Stocker-Holt dystrophy), chromosome 20 (congenital hereditary endothelial corneal dystrophy types I and II, posterior polymorphous corneal dystrophy), chromosome 21 (autosomal dominant keratoconus) and the X chromosome (cornea verticillata, cornea farinata, deep filiform corneal dystrophy, keratosis follicularis spinulosa decalvans, Lisch corneal dystrophy). Mutations in nine genes (ARSC1, CHST6, COL8A2, GLA, GSN, KRT3, KRT12, M1S1and TGFBI [BIGH3]) account for some of the corneal diseases and three of them are associated with amyloid deposition in the cornea (GSN, M1S1, TGFBI) including most of the lattice corneal dystrophies (LCDs) [LCD types I, IA, II, IIIA, IIIB, IV, V, VI and VII] recognized by their lattice pattern of linear opacities. Genetic studies on inherited diseases affecting the cornea have provided insight into some of these disorders at a basic molecular level and it has become recognized that distinct clinicopathologic phenotypes can result from specific mutations in a particular gene, as well as some different mutations in the same gene. A molecular genetic understanding of inherited corneal diseases is leading to a better appreciation of the

  5. The thick-bedded tail of turbidite thickness distribution as a proxy for flow confinement: Examples from tertiary basins of central and northern Apennines (Italy)

    Science.gov (United States)

    Marini, Mattia; Felletti, Fabrizio; Milli, Salvatore; Patacci, Marco

    2016-07-01

    This study reviews the thickness statistics of non-channelized turbidites from four tertiary basins of Central-Northern Apennines (Italy), where bed geometry and sedimentary character have been previously assessed. Though very different in terms of size and, arguably, character of feeder system, these basins share a common stratigraphic evolution consisting in transition from an early ponded to a late unconfined setting of deposition. Based on comparison of thickness subsets from diverse locations and stratigraphic heights within the studied turbidite fills, this paper seeks to answer the following questions: i) how data collection procedures and field operational constraints (e.g. measure location, outcrop quality, use of thicknesses data from single vs. multiple correlative sections, stratigraphic thickness of the study interval) can affect statistics of sample data? ii) how depositional controls of confined vs. unconfined turbidite basins can result in different thickness-frequency distributions?; and iii) is there in thickness statistics a 'flow confinement' signature which can be used to distinguish between confined and unconfined turbidites? Results suggest that: i) best practices of data collection are crucial to a meaningful interpretation of sample data statistics, especially in presence of stratigraphic and spatial trends of turbidite bed thickness; ii) a systematic bias against cm-thick Tcd Bouma sequence turbidites exists in sample data, which can result in the low-end tail of empirical thickness-frequency distributions to depart significantly from the actual distribution of turbidite thickness; and iii) thickness statistics of beds starting with a basal Ta/Tb Bouma division bear a coherent relationship to the transition from ponded to unconfined depositional settings, consisting in reduction of variance and mean and, consequently, parameters, or even type, of best fit model distribution. This research highlights the role of flow stripping, sediment by

  6. Clinical Observation of Transepithelial Corneal Collagen Cross-linking by Iontophoresis of Riboflavin in Treatment of Keratoconus

    Institute of Scientific and Technical Information of China (English)

    Na Li; Zhengjun Fan; Xiujun Peng; Xu Pang; Chunyu Tian

    2014-01-01

    Purpose: To evaluate the efficacy and safety of transepithelial collagen cross-linking by iontophoretic delivery of riboflavin in treatment of progressive keratoconus.Methods:.Eleven patients (15 eyes) with progressive kerato-conus were enrolled. After 0.1% riboflavin-distilled water so-lution was deliveried via transepithelial iontophpresis for 5 min with 1 mA current, and ultraviolet radiation (370 nm,.3 mW /cm2) was performed at a 1.5 cm distance for 30 min. The fol-low up were 6 months in all eyes. The uncorrected visual acu-ity, corrected visual acuity,endothelial cell counting, corneal thickness,.intraocular pressure, corneal curvature, corneal to-pography,.OCT and corneal opacity before and 6-month after surgery were analyzed.Results: At 6 month postoperatively, mean uncorrected visual acuity and corrected visual acuity changed from 0.36 to 0.30 and from 0.42 to 0.57 without statistical significance..The mean value of each index of corneal curvature declined with-out statistical significance.Kmax value dereased from 60.91 to 59.91, and the astigmatism declined from 3.86 to 3.19. Cen-tral corneal thickness decreased from 460.93 μm to 455.40μm,.and thinnest corneal thickness declined from 450.87 μm to 440.60 μm with no statistical significance..Intraocular pres-sure was significantly elevated from 10.85 mmHg to 12.62 mmHg. Endothelial cell count did not change significantly. No corneal haze occurred. Mean depth of corneal demarcation line was 288.46 μm at 1 month postoperatively..Conclusion:.Transepithelial corneal collagen cross-linking by iontophoresis is effective and safe in the treatment of progres-sive keratoconus, and yields stable clinical outcomes during 6-month follow up..However,.long-term follow up is urgently required. (Eye Science 2014; 29:160-164)

  7. Thickness variation of Simpson group in south-central Oklahoma and its tectonic significance

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Q.T.; Crump, J. (ARCO Oil and Gas Co., Plano, TX (USA))

    1989-08-01

    The Middle Ordovician Simpson Group in the Southern Oklahoma aulacogen is composed of interbedded sandstone, limestone, and shale. Several pulses of subsidence controlled the deposition of these sediments. Simpson Group thickness variations, based on an isopach map and corresponding regional cross sections, define the presence of two distinct depositional basins flanked on their northern sides by a stable cratonic shelf. The anomalous thickness of Simpson sediments within these basins is related to syndepositional subsidence along zones of weakness initiated during the rifting stage of aulacogen development. The larger basin covers the western part of south-central Oklahoma. The northern flank of this basin illustrates a zone of rapid thickening of sediments. The updip portion of the northern flank is the northernmost limit of the Southern Oklahoma aulacogen. The depocenter of the larger basin is positioned in the Ardmore basin. Paleostress studies using calcite twin lamellae along the southeastern portion of the Sulfur fault within the smaller basin reveal an east-west compression followed by north-south compression. Surface folds formed by the east-west compression are highly faulted and overturned, whereas the folds formed by the north-south compression are open, slightly asymmetric, with rounded hinges and limbs. Similar east-west-trending structures in the subsurface could be a favorable target for hydrocarbon exploration. In general, these basins are genetically related but are separated by a large Precambrian basement block (Tishomingo Granite).

  8. Corneal thickness and daily curve of intraocular pressure in suspected and glaucomatous patients Espessura corneana e curva diária de pressão intra-ocular em pacientes suspeitos e glaucomatosos

    Directory of Open Access Journals (Sweden)

    Sebastião Cronemberger

    2005-04-01

    Full Text Available PURPOSE: To evaluate in suspected and glaucomatous patients the correlation between central corneal thickness (CCT and intraocular pressure (IOP, measured during the daily curve of intraocular pressure (DCPo, including CCT and IOP measurements in bed at 6 am. The ocular axial length was also compared. METHODS: 114 eyes from 73 patients, 30 eyes suspected of glaucoma (group I and 84 eyes with chronic open-angle glaucoma (group II were prospectively studied. Both groups were subjected to DCPo with measurements of IOP at 9 am, 12 pm, 6 pm, 10:30 pm and on the next day at 6 am in bed and in darkness before the patient gets up. Using the ultrasonic DGH 5100® device, CCT measurements were performed at 9 am, 6 pm, 10:30 pm and the next day at 6 am in bed before the patient gets up. The ocular axial length was also measured. RESULTS: In the total sample and, separately in each group, the mean IOP was more elevated in bed at 6 am. There were no significant CCT changes during the day within each group or between both groups. No statistically significant difference was found between the mean ocular axial length of both groups. CONCLUSIONS: In suspected and glaucomatous patients, there were no statistically significant CCT variations during the day; therefore, only one CCT measurement is sufficient. Also, there was no statistically significant difference between ocular axial length of both groups.OBJETIVO: Verificar em pacientes suspeitos de glaucoma e glaucomatosos se existe correlação entre a espessura corneana central (ECC e a pressão intra-ocular (Po, medidos durante a curva diária de pressão intra-ocular (CDPo, incluindo-se as medidas da ECC e da Po às 6:00 horas da manhã no leito. Avaliar também comparativamente o diâmetro axial ântero-posterior (Diâm. axial em ambos os grupos. MÉTODOS: 114 olhos de 73 pacientes selecionados no Serviço de Glaucoma do Hospital São Geraldo, foram divididos em dois grupos: grupo I - pacientes suspeitos de

  9. Reduced corneal swelling and deswelling response in the iridocorneal endothelial syndrome

    NARCIS (Netherlands)

    M.T.P. Odenthal; C.P. Nieuwendaal; H.W. Venema; J. Oosting; H.J. Volker-Dieben; A. Kijlstra

    2006-01-01

    Purpose. Despite severe abnormalities of the corneal endothelium in the iridocorneal endothelial (ICE) syndrome, the cornea can remain clear and maintain its normal thickness for years before corneal decompensation occurs. The aim of this study is to analyze this discrepancy by studying corneal hydr

  10. Knockdown of NBCe1 In Vivo Compromises the Corneal Endothelial Pump

    OpenAIRE

    Liu, Cailing; Cheng, Qiang; Nguyen, Tracy; Bonanno, Joseph A

    2010-01-01

    Sodium bicarbonate cotransporter (NBC) expression was reduced in corneal endothelium by lentiviral delivery of shRNA. Corneal thickness in these eyes showed greater sensitivity to the topical carbonic anhydrase inhibitor brinzolamide, indicating that NBC works in conjunction with carbonic anhydrases as a component of the corneal endothelial pump.

  11. Crustal thickness in central Europe from single-station seismic noise autocorrelation analysis

    Science.gov (United States)

    Becker, Gesa; Knapmeyer-Endrun, Brigitte

    2016-04-01

    The InSight mission to Mars will place a single three-component seismometer on the planet's surface, requiring the application of single-station methods. In addition, seismicity on Mars is likely less abundant than on Earth, making it important to also use the available seismic noise. For these reasons different approaches of seismic noise autocorrelation have been tested with broadband three-component datasets from 12 stations across central Europe. These stations cover varying Moho depths of ca. 25-50 km depth. With the help of the autocorrelations, reflected body waves are extracted in order to estimate the crustal thickness at each station. This is of special relevance for Mars, where average crustal thickness is uncertain by a factor of two. The different approaches used are waterlevel normalized autocorrelation, with and without application of a short-term and long-term average filter to the spectrum of the data prior to autocorrelation, and phase autocorrelation. These approaches are compared and analyzed. Estimates for the Moho depths are made from the lag times of the reflected P-waves and compared to available Moho depth values at the stations. Due to the availability of three-component data these estimates can be cross-validated and in some cases not only P-wave reflections, but also possible S-wave and multiple reflections can be identified. The estimates compare well with the general trend of Moho depth expected for these stations. The consistency of results is further investigated by comparing different stations of the GERES array (aperture 2 km), which also allows to examine results for closely located broad-band and short-period stations side by side.

  12. A brief history of corneal transplantation: From ancient to modern

    Directory of Open Access Journals (Sweden)

    Alexandra X Crawford

    2013-01-01

    corticosteroids. Recent developments, including the replacement of selected corneal layers rather than full-thickness keratoplasty, have the potential to improve or transform corneal transplant surgery in the future.

  13. Mantle transition zone thickness in the Central South-American Subduction Zone

    Science.gov (United States)

    Braunmiller, Jochen; van der Lee, Suzan; Doermann, Lindsey

    We used receiver functions to determine lateral variations in mantle transition zone thickness and sharpness of the 410- and 660-km discontinuities in the presence of subducting lithosphere. The mantle beneath the central Andes of South America provides an ideal study site owing to its long-lived subduction history and the availability of broadband seismic data from the dense BANJO/SEDA temporary networks and the permanent station LPAZ. For LPAZ, we analyzed 26 earthquakes between 1993-2003 and stacked the depth-migrated receiver functions. For temporary stations operating for only about one year (1994-1995), station stacks were not robust. We thus stacked receiver functions for close-by stations forming five groups that span the subduction zone from west to east, each containing 12 to 25 events. We found signal significant at the 2σ level for several station groups from P to S conversions that originate near 520- and 850-900 km depth, but most prominently from the 410- and 660-km discontinuities. For the latter, the P to S converted signal is clear in stacks for western groups and LPAZ, lack of coherent signal for two eastern groups is possibly due to incoherent stacking and does not necessitate the absence of converted energy. The thickness of the mantle transition zone increases progressively from a near-normal 255 km at the Pacific coast to about 295 km beneath station LPAZ in the Eastern Cordillera. Beneath LPAZ, the 410-km discontinuity appears elevated by nearly 40 km, thus thickening the transition zone. We compared signal amplitudes from receiver function stacks calculated at different low-pass frequencies to study frequency dependence and possibly associated discontinuity sharpness of the P to S converted signals. We found that both the 410- and 660-km discontinuities exhibit amplitude increase with decreasing frequency. Synthetic receiver function calculations for discontinuity topography mimicking observed topography show that the observed steep

  14. Corneal melanosis successfully treated using topical mitomycin-C and alcohol corneal epitheliectomy: a 3-year follow-up case report

    Directory of Open Access Journals (Sweden)

    Mehmet Balcı

    2015-08-01

    Full Text Available ABSTRACTWe report a case of primary acquired corneal melanosis without atypia associated with corneal haze in a patient with a history of limbal malignant melanoma and the effect of mitomycin-C. A 75-year-old woman with a history of limbal malignant melanoma presented with loss of vision in right eye. Corneal examination showed a patchy melanotic pigmentation with a central haze. Topical mitomycin-C improved visual acuity and corneal haze. However, the pigmented lesions persisted, and they were removed with alcohol corneal epitheliectomy. Histopathological examination demonstrated primary acquired melanosis without atypia. The lesions were successfully removed, and there were no recurrences during the follow-up period of 36 months. The association of conjunctival and corneal melanosis without atypia is a rare condition. In addition, co-existence of central corneal haze and melanosis may decrease visual acuity. Topical mitomycin-C and alcohol corneal epitheliectomy can be useful treatments in this condition.

  15. Posterior Corneal Elevation after Small Incision Lenticule Extraction for Moderate and High Myopia.

    Directory of Open Access Journals (Sweden)

    Yu Zhao

    Full Text Available To investigate the changes of posterior corneal elevation after small incision lenticule extraction (SMILE for moderate and high myopia.In this prospective study, fifty consecutive eyes of thirty patients (10 male, 20 female who underwent SMILE for myopia and myopic astigmatism were included. Eyes were divided in two groups based on the preoperative spherical equivalent refraction: high myopia group (32 eyes, range -6.25D to -10.00D and moderate myopia group (18 eyes, range -3.00D to -6.00D. Posterior corneal surfaces were measured by a Scheimpflug camera (Pentacam, Oculus Germany preoperatively and 1 month, 3 months, 6 months and 12 months postoperatively. Posterior central elevation (PCE and posterior mean elevation (PME at 17 predetermined points in the central-4mm area above the best-fit sphere were analyzed.No significant difference in the amount of posterior corneal elevation changes in the high myopia group was noted over time (P = 0.23 and P = 0.94 for PCE and PME, respectively. Similarly, the changes in the moderate myopia group before and after SMILE were not significant either (P = 0.34 and P = 0.40 for PCE and PME. A statistically significant correlation was found between the residual bed thickness and the shift of the PCE in the high myopia group at 12 months postoperatively (r = 0.53, P = 0.01.The results of this study suggest that the posterior corneal surface remain stable within one year after SMILE for both moderate and high myopia. The changes of PCE correlate to the residual bed thickness for high myopia. Long-term changes of posterior corneal surface need further investigation.

  16. Clinical and Topographical Corneal Changes after Keraring Implantation in Keratoconus Patients

    Directory of Open Access Journals (Sweden)

    Mirzaei Mohamad

    2015-01-01

    Full Text Available Introduction: Keratoconus is a progressive, non-inflammatory, bilateral, ecstatic disease of the cornea that is characterized by corneal steepening which progresses to irregular conical shape, with subsequent irregular astigmatism and decreased visual acuity. In early stages of disease, spectacles or RGP lenses are the main treatment. At advanced stages, when these treatment options fail to correct visual acuity, surgical procedures such as penetrating keratoplasty or lamellar keratoplasty are required.METHODS: Keraring segments were placed in 30 eyes of 21 keratoconus patients. The mean follow-up time was 6.2 months. All patients underwent a complete ocular examination and corneal topography which was obtained by Pentacam (Oculus Pentacam®, USA. Improvement in uncorrected visual acuity (UCVA, best spectacle corrected visual acuity, refraction and topographic changes including keratometry, maximum anterior and posterior elevation, central corneal thickness and thinnest point thickness and location were evaluated.RESULTS: No intraoperative or postoperative complications occurred in any of the patients. ICRS implantation significantly improved UCVA (P=0.005 and BSCVA (P=0.000. Mean Spherical equivalent significantly reduced from -6.66±3.52 to -4.42±3.20 (p=0.000. A clinically significant reduction in mean keratometry (p=0.000, Max Ant Elevation (P=0.024 and Max Post Elevation (P=0.002 were recorded. No clinically significant changes in central corneal thickness, thinnest point thickness and thinnest point location were observed.Conclusion: With mean follow-up of 6.2 months, Keraring segments implantation caused significant clinical improvement in UCVA, BCVA Refractive Error and Keratometric findings of the most keratoconic patients. Keywords: keratoconus; ICRS; Keraring

  17. The Continental Distillery: Building Thick Continental Crust in the Central Andes (Invited)

    Science.gov (United States)

    Wagner, L. S.; Beck, S. L.; Zandt, G.; Long, M. D.; Tavera, H.; Minaya, E.; Biryol, C. B.; Bishop, B.; Eakin, C. M.; Franca, G.; Knezevic Antonijevic, S.; Kumar, A.; Ryan, J. C.; Scire, A. C.; Ward, K. M.; Young, B. E.

    2013-12-01

    The formation of stable continental crust and the associated development and destruction of mantle lithospheric roots is central to our understanding of plate tectonics, both at its inception and as an ongoing process today. Subduction zones play an important role in the creation and refinement of continental crust, and also serve as a possible mechanism for the removal of residual mantle material. The central Andes provide an intriguing laboratory for the study of these processes. Up to 400 km wide, 1500 km long, and with an average elevation of 4 km, the Altiplano Plateau is the largest orogen on earth associated with an ocean-continent subduction zone. This is much larger than adjacent 'normal' sections of the Andes, raising the question of why this portion of South American crust became so much more substantial than surrounding areas. Over the past several years, new seismic data have made it possible for us to develop a more complete picture of the lithospheric and asthenospheric processes involved in the development of the Altiplano Plateau and the adjacent narrower orogen further to the north. The 'Central Andean Uplift and the Geodynamics of High Topography' (CAUGHT) comprises in part a broadband deployment of 50 stations across the northern flank of the Altiplano Plateau in southern Peru and northern Bolivia. The adjacent 'PerU Lithosphere and Slab Experiment' (PULSE) includes 40 broadband stations that cover the region directly north of the CAUGHT deployment, encompassing the northern edge of the Altiplano, the transition to 'normal' width orogen, and the transition in slab geometry from normal to flat from south to north across the study area. Uplift of the Altiplano Plateau is likely due to some combination shortening, isostasy due to lithospheric destruction or changes in crustal density, magmatic addition to the crust, and/or flow within the thickened crust. Our studies indicate pervasive low velocities across the Altiplano consistent with a

  18. First Identification of a Triple Corneal Dystrophy Association: Keratoconus, Epithelial Basement Membrane Corneal Dystrophy and Fuchs' Endothelial Corneal Dystrophy

    Directory of Open Access Journals (Sweden)

    Cosimo Mazzotta

    2014-09-01

    Full Text Available Purpose: To report the observation of a triple corneal dystrophy association consisting of keratoconus (KC, epithelial basement membrane corneal dystrophy (EBMCD and Fuchs' endothelial corneal dystrophy (FECD. Methods: A 55-year-old male patient was referred to our cornea service for blurred vision and recurrent foreign body sensation. He reported bilateral recurrent corneal erosions with diurnal visual fluctuations. He underwent corneal biomicroscopy, Scheimpflug tomography, in vivo HRT confocal laser scanning microscopy and genetic testing for TGFBI and ZEB1 mutations using direct DNA sequencing. Results: Biomicroscopic examination revealed the presence of subepithelial central and paracentral corneal opacities. The endothelium showed a bilateral flecked appearance, and the posterior corneal curvature suggested a possible concomitant ectatic disorder. Corneal tomography confirmed the presence of a stage II KC in both eyes. In vivo confocal laser scanning microscopy revealed a concomitant bilateral EBMCD with hyperreflective deposits in basal epithelial cells, subbasal Bowman's layer microfolds and ridges with truncated subbasal nerves as pseudodendritic elements. Stromal analysis revealed honeycomb edematous areas, and the endothelium showed a strawberry surface configuration typical of FECD. The genetic analysis resulted negative for TGFBI mutations and positive for a heterozygous mutation in exon 7 of the gene ZEB1. Conclusion: This is the first case reported in the literature in which KC, EBMCD and FECD are present in the same patient and associated with ZEB1 gene mutation. The triple association was previously established by means of morphological analysis of the cornea using corneal Scheimpflug tomography and in vivo HRT II confocal laser scanning microscopy.

  19. The Effect of Contact Lens Usage on Corneal Biomechanical Parameters in Keratoconus Patients

    Directory of Open Access Journals (Sweden)

    Ali Bülent Çankaya

    2012-05-01

    Full Text Available Pur po se: To determine and compare the corneal biomechanical properties in keratoconus patients using rigid gas permeable contact lenses and keratoconus patients who do not use contact lenses. Ma te ri al and Met hod: The study consisted of 70 healthy controls (Group A, 27 ketatoconus subjects who do not use contact lens (Group B and 36 rigid gas permeable contact lens using keratoconic patients (Group C. Corneal viscoelastic parameters were measured with an Ocular response analyzer (ORA. Central corneal thickness was measured with an ultrasonic pachymeter. The differences in ORA parameters between the groups were compared. Re sults: The mean corneal hysteresis (CH in Groups A, B, and C were 10.3±1.5 mm Hg, 7.8±1.4 mm Hg, and 7.4±1.2 mm Hg, respectively. The differences in mean CH between Group A and the other two groups were statistically significant (p<0.01 for both comparisons, but no statistically significant difference was found between groups B and C in terms of mean CH (p=0.61. The mean corneal resistance factor (CRF was 10.7±1.9 in Group A compared with 6.6±1.6 in Group B and 6.1±1.5 in Group C. The differences in mean CRF between Group A and the other two groups were statistically significant (p<0.01 for both comparisons. There was no significant difference in CRF between the keratoconus eyes with or without rigid gas permeable contact lens usage (p=0.57. Dis cus si on: Our results suggest that ORA-generated parameters may be different in subjects with keratoconus. Corneal biomechanical parameters did not demonstrate a clear trend of change with rigid gas permeable contact lens usage. (Turk J Ophthalmol 2012; 42: 197-201

  20. Human corneal epithelial subpopulations

    DEFF Research Database (Denmark)

    Søndergaard, Chris Bath

    2013-01-01

    and cytomorphometry. Limbal epithelial cells expanded in 2% O2 exhibited slow growth, low fraction of cells in S/G2 , high CFE, high expression of stem cell markers ABCG2 and p63α, and low fraction of differentiation marker CK3 resembling a LESC phenotype. The effect of hypoxia to maintain LESCs in culture...... was not dependent on the system used for propagation (Bath et al. 2013a). Laser capture microdissection was used to isolate cellular subpopulations in situ from the spatially defined differentiation pathway in human corneal epithelium according to an optimized protocol for maintenance of expression profiles...... bioinformatics. The location of primitive cells in BLCs, migratory and activated cells in SLCs and differentiated cells in paracentral/central cornea was evident from mapping of significantly upregulated genes in each compartment to the gene ontology (GO). Interestingly, many GO terms in BLCs were also involved...

  1. Ocular histopathological changes after eyeball enucleation induced by corneal trauma

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To observe the ocular histopathological changes aftereyeball enucleation induced by corneal trauma.Methods: Light microscopic examination was done on 117 eyeball specimens enucleated after corneal trauma (18 with corneal fissure and 99 with corneal perforating trauma).Results: Acute, subacute or chronic inflammatory changes, and fibrous membrane formation were observed in well-closed corneal wounds, whereas inflammation, atrophy and scar were observed in the focal tissues. But at the late period, secondary glaucoma, retinal detachment, endophthalmitis and eyeball atrophy resulted in blindness. Corneal fistula was observed in those with inadequate cure of wounds caused by ingrowth of corneal epithelium, embedment of iris and vitreous body, and large area of centrally located tissue deficiency of the corneal. A high incidence of endophthalmitis was noted due to the presence of corneal fistula. Severe inflammation was observed in the anterior segmental tissues with fibrous infiltration in the anterior chamber, which might result in rapid destruction of the eyeballs.Conclusions: Ocular pathology varies with the difference of the position, form, size and closing conditions of the corneal laceration after trauma.

  2. Goldmann applanation tonometry compared with corneal-compensated intraocular pressure in the evaluation of primary open-angle Glaucoma

    Directory of Open Access Journals (Sweden)

    Ehrlich Joshua R

    2012-09-01

    Full Text Available Abstract Background To better understand the role of corneal properties and intraocular pressure (IOP in the evaluation of primary open-angle glaucoma (POAG; and to determine the feasibility of identifying glaucomatous optic neuropathy (GON using IOP corrected and uncorrected for corneal biomechanics. Methods Records from 1,875 eyes of consecutively evaluated new patients were reviewed. Eyes were excluded if central corneal thickness (CCT or Ocular Response Analyzer (ORA measurements were unavailable. Presence or absence of GON was determined based on morphology of the optic disc, rim and retinal nerve fiber layer at the time of clinical examination, fundus photography and Heidelberg Retinal Tomography. Goldmann-applanation tonometry (GAT in the untreated state was recorded and Goldmann-correlated (IOPg and corneal-compensated IOP (IOPcc were obtained using the ORA. Glaucomatous eyes were classified as normal or high-tension (NTG, HTG using the conventional cutoff of 21 mm Hg. One eligible eye was randomly selected from each patient for inclusion. Results A total of 357 normal, 155 HTG and 102 NTG eyes were included. Among NTG eyes, IOPcc was greater than GAT (19.8 and 14.4 mm Hg; p  Conclusions IOPcc may account for measurement error induced by corneal biomechanics. Compared to GAT, IOPcc may be a superior test in the evaluation of glaucoma but is unlikely to represent an effective diagnostic test.

  3. SURGICAL OUTCOME OF TRIPLE PROCEDURE AS PENETRATING KERATOPLASTY WITH EXTRACAPSULAR CATARACT EXTRACTION WITH POSTERIOR CHAMBER INTRAOCULAR LENS IMPLANTATION IN PATIENTS WITH BOTH CENTRAL CORNEAL OPACITY AND ADVANCED CATARACT AT RURAL SET UP

    Directory of Open Access Journals (Sweden)

    Shubhangi Nigwekar, Kishor Badhe, Neeta Misra, Surekha Bangal

    2015-10-01

    Full Text Available Purpose: To study the surgical outcome of triple procedure as penetrating keratoplasty (PKP with conventional extra capsular cataract extraction (ECCE with posterior chamber intraocular lens (PCIOL implantation in patients with both central corneal opacity and advanced cataract at rural set up. Introduction: When corneal opacity and cataract present together then well-established and effective triple procedure is indicated. Prognosis for a clear graft is good in triple, as graft endothelium does not touch the hard nucleus which may occur in two steps or sequential surgery. It provides faster visual rehabilitation. Being single step procedure it reduces patient’s hospital stay, postoperative care and follows up visits. Methodology: In this hospital based observational , three years longitudinal study, we studied the surgical outcome of relatively rare one step triple procedure as PKP with conventional ECCE with PCIOL implantation in sulcus or in bag, in patients with both central corneal opacity and advanced cataract at rural set up. The outcome measures included graft clarity on slit lamp, postoperative unaided visual acuity with Snellen’s chart and the occurrence of postoperative complications after taking IEC permission and informed written consent in local language from study patients. Results: Out of 13 study patients mean age was 61.15yrs (Range50-80yrs. Follow up range was 9-34 months. At final follow up 9 patients (69.23% had clear grafts and 61.52% patients gained visual acuity >6/24. Graft failure was the most common post operative complication in 30.76% followed by Posterior capsular opacification (PCO in 15.38% patients which was treated well with YAG laser capsulotomy. Conclusion: Triple procedure gives good results in respect to graft clarity, unaided vision, and faster rehabilitation.

  4. The Long-Term Effects of Silicone Hydrogel Contact Lens Wear on Corneal Morphology

    Directory of Open Access Journals (Sweden)

    Yelda Yıldız

    2012-03-01

    Full Text Available Pur po se: To evaluate the effects of silicone hydrogel contact lenses (SHCL on central corneal thickness (CCT, corneal endothelial cell morphology, and tear functions. Ma te ri al and Met hod: Fifty-five eyes of 28 SHCL wearers (Group 1 and 52 eyes of 26 healthy subjects (Group 2 were included in this study’. According to their contact lens wearing time, the contact lens wearing subjects were divided into 2 groups: Group 1a - wearing time less than 1 year and Group 1b - wearing time more than 1 year. CCT, epithelial thickness, corneal endothelial cell morphology, ocular surface disease index score (OSDI, and tear break-up time (TBUT were evaluated. Re sults: In Group 1 and Group 2, the mean CCT was 561.85±39.98 µm and 537.25±27.12 µm, respectively (p: 0.001.The epithelial thickness was 50.38±5.41 µm and 55.64±5.32 µm, respectively (p: 0.001. In Group 1a and Group1 b, the mean CCT was 573.39±33.86 µm and 546.96±42.98 µm (p: 0.014 and the epithelial thickness was 49.51±4.78 µm and 51.50±6.04 µm (p>0.05, respectively. In Group 1, the percentage of endothelial cells larger than 700µ was low, while the percentage of endothelial cells between 200 and 400µ was high (p<0,05. Dis cus si on: With SHCL wear, the corneal morphology is more affected in the short-term period. During long-term contact lens wear, the cornea enters an adaptation period and shows near-normal morphology. Tear functions are not affected by short- or long-term SHCL wear. (Turk J Ophthalmol 2012; 42: 91-6

  5. Corneal mucus plaques.

    Science.gov (United States)

    Fraunfelder, F T; Wright, P; Tripathi, R C

    1977-02-01

    Corneal mucus plaques adhered to the anterior corneal surface in 17 of 67 advanced cases of keratoconjunctivitis sicca. The plaques were translucent to opaque and varied in size and shape, from multiple isolated islands to bizarre patterns involving more than half the corneal surface. Ultrastructurally, they consisted of mucus mixed with desquamated degenerating epithelial cells and proteinaceous and lipoidal material. The condition may be symptomatic but can be controlled and prevented in most cases by topical ocular application of 10% acetylcysteine.

  6. Estimated Thickness of Quaternary Sediment in the Wood River Valley aquifer system, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is the estimated thickness of Quaternary sediment of the Wood River Valley aquifer system. This isopach map was constructed by subtracting the...

  7. Interannual variability of summer sea ice thickness in the Siberian and central Arctic under different atmospheric circulation regimes

    Science.gov (United States)

    Haas, Christian; Eicken, Hajo

    2001-03-01

    Extensive drill hole and electromagnetic induction measurements of sea ice thickness in the Siberian and central Arctic Seas in the summers of 1993, 1995, and 1996 reveal significant interannual variability. In the Laptev Sea, minimum and maximum modal first-year ice thicknesses amounted to 1.25 and 1.85 m in 1995 and 1996, respectively. Ice thickness correlates with ice extent, which reached a record minimum in August 1995 and was well above average in 1996. These differences are explained by the strength and location of a summer cyclonic atmospheric circulation pattern affecting both ice advection and surface melt. From drifting buoys deployed in 1995 and satellite radar backscatter data, first- and second-year ice regimes are delineated. Differences in first-year ice backscatter coefficients between 1993, 1995, and 1996 are explained by differences in level ice surface roughness. The Lagrangian evolution of ice thickness between 1995 and 1996 is studied. While the shape of the thickness distribution does not change significantly, the mean (modal) ice thickness of the ice field increases from 1.80 m (1.25 m) in 1995 to 2.86 m (2.25 m) in 1996. The thickness distribution of second-year ice in 1996 closely agrees with that of level multiyear ice downstream in the Transpolar Drift obtained in 1991. In 1996, mean level ice thickness increases at 0.23 and 0.16 m deg-1 with latitude in the Kara and Laptev Sea sectors of the Arctic Ocean, respectively.

  8. Inverse Cutting of Posterior Lamellar Corneal Grafts by a Femtosecond Laser

    DEFF Research Database (Denmark)

    Hjortdal, Jesper; Nielsen, Esben; Vestergaard, Anders;

    2012-01-01

    Inverse Cutting of Posterior Lamellar Corneal Grafts by a Femtosecond Laser Jesper Hjortdal*, Esben Nielsen, Anders Vestergaard and Anders Søndergaard Department of Ophthalmology, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, Denmark Abstract: Purpose: Posterior lamellar grafting...... of the cornea has become the preferred technique for treatment of corneal endothelial dysfunction. Posterior lamellar grafts are usually cut by a micro-keratome or a femto-second laser after the epithelial side of the donor cornea has been applanated. This approach often results in variable central graft......: A CZM 500 kHz Visumax femto-second laser was used. Organ cultured donor grafts were mounted in an artifical anterior chamber with the endothelial side up and out. Posterior grafts of 7.8 mm diameter and 130 micron thickness were prepared by femto-second laser cutting. A standard DSAEK procedure...

  9. Characterization of Corneal Indentation Hysteresis.

    Science.gov (United States)

    Ko, Match W L; Dongming Wei; Leung, Christopher K S

    2015-01-01

    Corneal indentation is adapted for the design and development of a characterization method for corneal hysteresis behavior - Corneal Indentation Hysteresis (CIH). Fourteen porcine eyes were tested using the corneal indentation method. The CIH measured in enucleated porcine eyes showed indentation rate and intraocular pressure (IOP) dependences. The CIH increased with indentation rate at lower IOP ( 25 mmHg). The CIH was linear proportional to the IOP within an individual eye. The CIH was positively correlated with the IOP, corneal in-plane tensile stress and corneal tangent modulus (E). A new method based on corneal indentation for the measurement of Corneal Indentation Hysteresis in vivo is developed. To our knowledge, this is the first study to introduce the corneal indentation hysteresis and correlate the corneal indentation hysteresis and corneal tangent modulus.

  10. Riboflavin-ultraviolet a corneal cross-linking for keratoconus

    Directory of Open Access Journals (Sweden)

    El-Raggal Tamer

    2009-01-01

    Full Text Available Purpose: To evaluate the safety, efficacy of riboflavin-ultraviolet A irradiation (UVA corneal cross-linking and present refractive changes induced by the treatment in cases of keratoconus. Materials and Methods: The study includes 15 eyes of 9 patients with keratoconus with an average keratometric (K reading less than 54 D and minimal corneal thickness greater than 420 microns. The corneal epithelium was removed manually within the central 8.5 mm diameter area and the cornea was soaked with riboflavin eye drops (0.1% in 20% dextran t-500 for 30 minutes followed by exposure to UVA radiation (365 nm, 3 mW/cm 2 for 30 minutes. During the follow-up period, uncorrected visual acuity (UCVA, best spectacle-corrected visual acuity (BSCVA, manifest refraction, slit lamp examination and topographic changes were recorded at the first week, first month, 3 and 6 months. Results: There was statistically significant improvement of UCVA from a preoperative mean of 0.11 ± 0.07 (range 0.05-0.3 to a postoperative mean of 0.15 ± 0.06 (range 0.1-0.3 (P < 0.05. None of the eyes lost lines of preoperative UCVA but 1 eye lost 1 line of preoperative BSCVA. The preoperative mean K of 49.97 ± 2.81 D (range 47.20-51.75 changed to 48.34 ± 2.64 D (range 45.75-50.40. This decrease in K readings was statistically significant (P < 0.05. All eyes developed minimal faint stromal haze that cleared in 14 eyes within 1 month. In only 1 eye, this resulted in a very faint corneal scar. Other sight threatening complications were not encountered in this series. Progression of the original disease was not seen in any of the treated eyes within 6 months of follow-up. Conclusion: Riboflavin-UVA corneal cross-linking is a safe and promising method for keratoconus. Larger studies with longer follow up are recommended.

  11. Corneal heat scar caused by photodynamic therapy performed through an implanted corneal inlay.

    Science.gov (United States)

    Mita, Mariko; Kanamori, Tomomi; Tomita, Minoru

    2013-11-01

    A 60-year-old man had a combination of laser in situ keratomileusis and Kamra corneal inlay implantation to correct presbyopia. Although the outcome was favorable postoperatively, central serous chorioretinopathy was observed in the left eye along with a decrease in the uncorrected (UDVA) and corrected (CDVA) distance visual acuities and the corrected near visual acuity (CNVA). Photodynamic therapy (PDT) was later performed in a university hospital. After PDT, the patient experienced a decline in the visual acuity and came to our clinic a month after the PDT. Degeneration and a scar were observed at the location of the inlay due to the heat and burning. Flattening of the corneal topography was also observed where the corneal scar was located, along with a significant decrease in CDVA in the left eye. Prior to any surgery in which the corneal inlay is an impediment, surgeons should take advantage of the reversibility of the Kamra inlay by explanting the inlay.

  12. Corneal reconstruction by stem cells and bioengineering

    Directory of Open Access Journals (Sweden)

    Arjamaa O

    2012-09-01

    Full Text Available Olli ArjamaaDepartment of Biology, University of Turku, Turku, FinlandAbstract: Almost 300 million people are visually impaired worldwide due to various eye diseases such as cataracts, glaucoma, age-related macular degeneration, diabetic retinopathy, and corneal diseases. Notably, ten million people are blind because of severe ocular surface diseases and the majority of cases occur in developing countries. Blinding ocular surface diseases have, however, become treatable by grafting of surface layers, or by full-thickness transplantation of the cornea. As the demand for human corneal tissue for surface reconstruction and transplantation far exceeds the supply, methods are being developed to supplement tissue donation. Xenotransplantation of the cornea or cells from genetically modified pigs may become one of the solutions. Transplantation of limbal stem cells within tissue biopsies, to restore the transparency of the cornea is another remarkable method, which has shown its potential in several clinical studies. The combination of stem cell technology and engineering of biocompatible tissue equivalent, still at preclinical stage, has shown us how synthetic corneal tissue is able to guide cultured corneal stromal stem cells of human origin, to become native-like stroma, the most important layer of the cornea. These findings give hope for a large-quantity production of biomaterial for corneal reconstruction. As such, clinical ophthalmologists should become more familiar with the methods of laboratory science.Keywords: eye, grafting, keratoplasty, xenotransplantation, cell reservoir, biocompatible tissue equivalent

  13. Comparison of Corneal Endothelial Changes After a Single-Dose Injection of Bevacizumab or Ranibizumab

    Directory of Open Access Journals (Sweden)

    Fatih Horozoğlu

    2013-12-01

    Full Text Available Purpose: To compare the corneal endothelial changes after injection of a single-dose intravitreal bevacizumab or intravitreal ranibizumab. Material and Method: In this retrospective study, we evaluated 27 eyes of 27 patients with either diabetic macular edema or senile macular degeneration, who underwent 1.25 mg/0.05 ml intravitreal bevacizumab or 0.5 mg/0.05 ml ranibizumab injection. None of the patients had corneal pathology. Fourteen eyes of 14 patients received intravitreal ranibizumab, other 13 eyes of 13 patients received intravitreal bevacizumab. We evaluated preoperative and postoperative 1st week and 1st month visual acuity, corneal endothelial count at mm2, intraocular pressure, and pachymetry results. For statistical analysis, Mann-Whitney U and Wilcoxon tests were used. Results: Mean age of the patients was 69.3±12.5 (44-85 year. Average corneal endothelial cell count for bevacizumab and ranibizumab was preoperatively 2358.1±487 and 2348.9±598, postoperative 1. week 2360.8±474.1 and 2398.3±585.6, postoperative 1. month 2315.1±465 and 2407.4±585.6, respectively. Preoperative and postoperative corneal endothelial cell counts were not statistically significantly different in both groups (respectively, 1. week p=0.953 and p=0.59; 1. month p=0.26 and p=0.555. Average central macular thickness for bevacizumab and ranibizumab was preoperatively 527.3±36.9 and 544.1±55.5 µm, postoperative 1. week 529.2±49.9 and 543.5±51.8 µm, postoperative 1. month 530.3±55 and 543.9±46.6 µm, respectively. Preoperative and postoperative central macular thickness values for both groups were not statistically significantly different (respectively, 1. week P=0.515 and P=0.838; 1. month P=0.678 and P=0.444. Discussion: Injection of a single dose of 1.25 mg/0.05 ml bevacizumab or 0.5 mg/0.05 ml ranibizumab does not affect the corneal endothelial cell count at 1. week and 1. month. (Turk J Ophthalmol 2013; 43: 391-4

  14. Construction of a Corneal Stromal Equivalent with SMILE-Derived Lenticules and Fibrin Glue.

    Science.gov (United States)

    Yin, Houfa; Qiu, Peijin; Wu, Fang; Zhang, Wei; Teng, Wenqi; Qin, Zhenwei; Li, Chao; Zhou, Jiaojie; Fang, Zhi; Tang, Qiaomei; Fu, Qiuli; Ma, Jian; Yang, Yabo

    2016-01-01

    The scarcity of corneal tissue to treat deep corneal defects and corneal perforations remains a challenge. Currently, small incision lenticule extraction (SMILE)-derived lenticules appear to be a promising alternative for the treatment of these conditions. However, the thickness and toughness of a single piece of lenticule are limited. To overcome these limitations, we constructed a corneal stromal equivalent with SMILE-derived lenticules and fibrin glue. In vitro cell culture revealed that the corneal stromal equivalent could provide a suitable scaffold for the survival and proliferation of corneal epithelial cells, which formed a continuous pluristratified epithelium with the expression of characteristic markers. Finally, anterior lamellar keratoplasty in rabbits demonstrated that the corneal stromal equivalent with decellularized lenticules and fibrin glue could repair the anterior region of the stroma, leading to re-epithelialization and recovery of both transparency and ultrastructural organization. Corneal neovascularization, graft degradation, and corneal rejection were not observed within 3 months. Taken together, the corneal stromal equivalent with SMILE-derived lenticules and fibrin glue appears to be a safe and effective alternative for the repair of damage to the anterior cornea, which may provide new avenues in the treatment of deep corneal defects or corneal perforations. PMID:27651001

  15. Current status of corneal xenotransplantation.

    Science.gov (United States)

    Kim, Mee Kum; Hara, Hidetaka

    2015-11-01

    Corneal allo-transplantation is a well-established technique to treat corneal blindness. However, the limited availability of human donors demands the exploration of alternative treatments such as corneal xenotransplantation (e.g., pigs as donors) and bioengineered corneas. Since the first attempt of corneal xenotransplantation using a donor pig cornea in 1844, great advances have been made in the development of genetically-engineered pigs, effective immunosuppressive protocols and the establishment of guidelines for the conduction of clinical trials. We highlight immunological and physio-anatomical barriers of corneal xenotransplantation, recent progress of corneal xenotransplantation in non-human-primates studies, and regulatory guidelines to conduct clinical trials for corneal xenotransplantation.

  16. Corneal blindness and xenotransplantation.

    Science.gov (United States)

    Lamm, Vladimir; Hara, Hidetaka; Mammen, Alex; Dhaliwal, Deepinder; Cooper, David K C

    2014-01-01

    Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world's blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies between parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty, and endothelial keratoplasty (EK). Indications for corneal transplantation vary between countries, with Fuchs' dystrophy being the leading indication in the USA and keratoconus in Australia. With the exception of the USA, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, for example stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future.

  17. Validez y reproducibilidad de la ecografía convencional de alta resolución en la estimación del espesor corneal central, profundidad de la cámara anterior y ángulo iridocorneal

    OpenAIRE

    Gómez Herrera, Juan Jesús

    2015-01-01

    En el campo de las técnicas de diagnóstico basadas en imágenes, tanto en atención primaria como especializada, uno de los pilares de la colaboración con el programa de la Organización Mundial de la Salud Visión 2020 es el desarrollo y aplicación de técnicas que evalúen los factores cuya detección y/o corrección permitan prevenir la aparición de glaucoma. Entre estos factores se encuentran la evaluación del ángulo iridocorneal y la estimación tanto del espesor corneal central como de la profun...

  18. Quantitative proteomic analysis of mice corneal tissues reveals angiogenesis-related proteins involved in corneal neovascularization.

    Science.gov (United States)

    Shen, Minqian; Tao, Yimin; Feng, Yifan; Liu, Xing; Yuan, Fei; Zhou, Hu

    2016-07-01

    Corneal neovascularization (CNV) was induced in Balb/c mice by alkali burns in the central area of the cornea with a diameter of 2.5mm. After fourteen days, the cornea from one eye was collected for histological staining for CNV examination, while the cornea from the other eye of the same mouse was harvested for proteomic analysis. The label-free quantitative proteomic approach was applied to analyze five normal corneal tissues (normal group mice n=5) and five corresponding neovascularized corneal tissues (model group mice n=5). A total of 2124 proteins were identified, and 1682 proteins were quantified from these corneal tissues. Among these quantified proteins, 290 proteins were significantly changed between normal and alkali burned corneal tissues. Of these significantly changed proteins, 35 were reported or predicted as angiogenesis-related proteins. Then, these 35 proteins were analyzed using Ingenuity Pathway Analysis Software, resulting in 26 proteins enriched and connected to each other in the protein-protein interaction network, such as Lcn-2, αB-crystallin and Serpinf1 (PEDF). These three significantly changed proteins were selected for further Western blotting validation. Consistent with the quantitative proteomic results, Western blotting showed that Lcn-2 and αB-crystallin were significantly up-regulated in CNV model, while PEDF was down-regulated. This study provided increased understanding of angiogenesis-related proteins involved in corneal vascular development, which will be useful in the ophthalmic clinic of specifically target angiogenesis.

  19. Carotid intima-media thickness and apolipoproteins in patients of ischemic stroke in a rural hospital setting in central India: A cross-sectional study

    OpenAIRE

    Jyoti Jain; Tejal Lathia; Om Prakash Gupta; Vishakha Jain

    2012-01-01

    Context: Carotid intima-media thickness (CIMT) and apolipoproteins have been found as a risk factor for ischemic stroke . Objective: The objective was to study the carotid intima-media thickness, apolipoproteins, and their relation in patients of ischemic stroke in central rural India. Settings and Design: A cross-sectional study was performed in a rural hospital in central India. Materials and Methods: In all patients of ischemic stroke proven by computerized tomography (CT), CIMT, apolipopr...

  20. Trifluoperazine: corneal endothelial phototoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Hull, D.S.; Csukas, S.; Green, K. (Medical Coll. of Georgia, Augusta (USA))

    1983-10-01

    Trifluoperazine is used for the treatment of psychiatric disorders. Perfusion of corneal endothelial cells with trifluoperazine-HC1 concurrent with exposure to long wavelength ultraviolet light resulted in a corneal swelling rate greater than that found in perfused corneas not exposed to ultraviolet light. Exposure of endothelial cells to 25 W incandescent light during perfusion with trifluoperazine-HC1 did not result in a higher corneal swelling rate compared to those perfused in the dark. The increased corneal swelling rate could be produced by pre-exposure of the trifluoperazine-HC1 perfusing solution to ultraviolet light suggesting the production of toxic photoproducts during exposure of trifluoperazine-HC1 to ultraviolet light. Perfusion of corneal endothelial cells with non-ultraviolet illuminated trifluoperazine-HC1 had no effect on endothelial cell membranes or ultrastructure. This is in contrast to cells perfused with trifluoperazine-HC1 that had been exposed to ultraviolet light in which there was an alteration of mitochondria and a loss of cytoplasmic homogeneity. The data imply that the trifluoperazine-HC1 photoproduct had an adverse effect on cellular transport mechanisms. The study also further demonstrates the value of the corneal endothelial cell model for identifying the physiological and anatomical changes occuring in photo-induced toxic reactions.

  1. KERATOCONUS AND EPI-OFF CORNEAL CROSS-LINKING BY RIBOFLAVIN-ULTRAVIOLET TYPE A: INDICATIONS AND RATIONAL OF EMPLOYMENT

    Directory of Open Access Journals (Sweden)

    A. Caporossi

    2010-11-01

    Full Text Available Keratoconus is the most common dystrophic corneal ectasia, characterized by the presence of irregular astigmatism associated with a reduction of corneal thickness. It is the leading cause of corneal transplant in Italy and Europe. Recently a new therapeutic opportunity is offered by Riboflavin + UV A Corneal Cross-linking, first introduced in Italy in 2004 by Professor Aldo Caporossi at the Department of Ophthalmology of Siena. This treatment requires early diagnosis to prevent corneal ectatic modifications related to pathology. The modern treatment of keratoconus is directed into three "directories": 1 prevention of its progression; 2 reduction of the related refractive defect and induced corneal aberrations; 3 replacement of ectatic corneal in advanced phase not subjected to conservative approach and HRGP lens intolerance. Riboflavin + UV A Collagen Cross-linking is mostly indicated in patients between 10 and 26 years old with progressive keratoconus (stage 1 and 2 with strict adherence to the recommended inclusion thickness (thinnest point > 400 microns.

  2. Association of CHRDL1 mutations and variants with X-linked megalocornea, Neuhäuser syndrome and central corneal thickness

    DEFF Research Database (Denmark)

    Davidson, Alice E; Cheong, Sek-Shir; Hysi, Pirro G;

    2014-01-01

    We describe novel CHRDL1 mutations in ten families with X-linked megalocornea (MGC1). Our mutation-positive cohort enabled us to establish ultrasonography as a reliable clinical diagnostic tool to distinguish between MGC1 and primary congenital glaucoma (PCG). Megalocornea is also a feature of Ne...

  3. Correlating corneal arcus with atherosclerosis in familial hypercholesterolemia

    Directory of Open Access Journals (Sweden)

    Zech Loren A

    2008-03-01

    Full Text Available Abstract Background A relationship between corneal arcus and atherosclerosis has long been suspected but is controversial. The homozygous familial hypercholesterolemia patients in this study present a unique opportunity to assess this issue. They have both advanced atherosclerosis and corneal arcus. Methods This is a cross-sectional study of 17 patients homozygous for familial hypercholesterolemia presenting to the Clinical Center of the National Institutes of Health. Plasma lipoproteins, circumferential extent of arcus, thoracic aorta and coronary calcific atherosclerosis score, and Achilles tendon width were measured at the National Institutes of Health. Results Patients with corneal arcus had higher scores for calcific atherosclerosis (mean 2865 compared to 412, cholesterol-year score (mean 11830 mg-yr/dl compared to 5707 mg-yr/dl, and Achilles tendon width (mean 2.54 cm compared to 1.41 cm than those without. Corneal arcus and Achilles tendon width were strongly correlated and predictive of each other. Although corneal arcus was correlated with calcific atherosclerosis (r = 0.67; p = 0.004, it was not as highly correlated as was the Achilles tendon width (r = 0.855; p Conclusion Corneal arcus reflects widespread tissue lipid deposition and is correlated with both calcific atherosclerosis and xanthomatosis in these patients. Patients with more severe arcus tend to have more severe calcific atherosclerosis. Corneal arcus is not as good an indicator of calcific atherosclerosis as Achilles tendon thickness, but its presence suggests increased atherosclerosis in these hypercholesterolemic patients.

  4. Influence of corneal collagen crosslinking with riboflavin and ultraviolet-a irradiation on excimer laser surgery.

    NARCIS (Netherlands)

    Kampik, D.; Ralla, B.; Keller, S.; Hirschberg, M.; Friedl, P.H.A.; Geerling, G.

    2010-01-01

    PURPOSE: Riboflavin/ultraviolet A (UVA) cross-linking (CXL) of corneal collagen is a novel method of stabilizing corneal mechanical properties and preventing progression of keratectasias. This study was conducted to investigate whether CXL influences ablation rate, flap thickness, and refractive res

  5. 2型糖尿病患者角膜厚度和内皮细胞形态学的初步研究%Central corneal thickness and corneal endothelium morphology in type 2 diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    余玲; 谢汉平; 孟晓红; 余延基

    2003-01-01

    目的研究2型糖尿病患者角膜厚度和内皮细胞形态学的变化.方法采用角膜测厚仪和非接触式角膜内皮镜对60例(60眼)2型糖尿病患者及60例(60眼)健康志愿者的角膜厚度及内皮细胞形态进行比较研究;并采用逐步回归分析方法研究全身因素对角膜内皮细胞密度及角膜厚度的影响.结果糖尿病患者较正常人角膜内皮细胞密度降低,细胞面积变异系数增加,差异有显著性(P<0.05).角膜厚度两组间差异无显著性.增殖性糖尿病视网膜病变患者较单纯性糖尿病视网膜病变患者角膜内皮细胞密度显著降低(P<0.05).糖尿病患者血浆糖化血红蛋白水平与角膜内皮细胞密度负相关(r= -0.761,P<0.01).无一全身因素与角膜厚度相关.结论糖尿病患者角膜内皮细胞形态结构异常,且随糖尿病视网膜病变的加重而加重.糖尿病患者在内眼手术及眼外伤手术时应特别注意保护角膜内皮,防止角膜内皮功能失代偿.

  6. Ice thickness, volume and subglacial topography of Urumqi Glacier No. 1, Tianshan mountains, central Asia, by ground penetrating radar survey

    Indian Academy of Sciences (India)

    Puyu Wang; Zhongqin Li; Shuang Jin; Ping Zhou; Hongbing Yao; Wenbin Wang

    2014-04-01

    The results of radar survey for three times are presented, aiming to determine ice thickness, volume and subglacial topography of Urumqi Glacier No. 1, Tianshan Mountains, central Asia. Results show that the distribution of ice is more in the center and lesser at both ends of the glacier. The bedrock is quite regular with altitudes decreasing towards the ice front, showing the U-shaped subglacial valley. By comparison, typical ice thinning along the centerline of the East Branch of the glacier was 10–18 m for the period 1981–2006, reaching a maximum of ∼30 m at the terminus. The corresponding ice volume was 10296.2 × 104 m3, 8797.9 × 104 m3 and 8115.0 × 104 m3 in 1981, 2001 and 2006, respectively. It has decreased by 21.2% during the past 25 years, which is the direct result of glacier thinning. In the same period, the ice thickness, area and terminus decreased by 12.2%, 10.3%, and 3.6%, respectively. These changes are responses to the regional climatic warming, which show a dramatic increase of 0.6°C (10 a)−1 during the period 1981–2006.

  7. Corneal endothelium after deep anterior lamellar keratoplasty and penetrating keratoplasty for keratoconus: A four-year comparative study

    Directory of Open Access Journals (Sweden)

    Anil Kubaloglu

    2012-01-01

    Full Text Available Purpose: To compare the status of corneal endothelium and central corneal thickness within the first four postoperative years after deep anterior lamellar keratoplasty (DALK and penetrating keratoplasty (PK in patients with keratoconus. Materials and Methods: Thirty-nine eyes (Group A which had PK and 44 eyes (Group B which had DALK for the treatment of keratoconus were included in this retrospective study. The endothelial cell density (ECD, the mean endothelial cell area and the coefficient of variation of cell area were assessed with a non-contact specular microscope, and the central corneal thickness (CCT was measured with an ultrasound pachymeter. Results: Mean ECD loss rate at two years was 36.24% in Group A and 18.12% in Group B (P<0.001. Mean ECD loss rate at four years was 47.82% in Group A and 21.62% in Group B (P<0.001. Mean annual ECD loss rate was calculated 14.12% per year in Group A and 5.78% per year in Group B. In the PK group, increase in mean CCT was 15.60% in two years and 15.03% in four years, while in the DALK group, mean CCT increased by 8.05% in two years and 9.31% in four years. Conclusions: As the majority of ectatic disorders such as keratoconus occur in young people, long-term endothelial cell survival following treatment with keratoplasty is essential for the long-term visual ability. Our finding that corneal endothelial cell loss in the DALK group occurs at a slower rate than in the PK group suggests DALK as a safer alternative to PK in these selected patients.

  8. Isolation of bovine corneal keratan sulfate and its growth factor and morphogen binding

    OpenAIRE

    Weyers, Amanda; Yang, Bo; Solakyildirim, Kemal; Yee, Vienna; Li, Lingyun; Zhang, Fuming; Linhardt, Robert

    2013-01-01

    Keratan sulfate (KS) is an important glycosaminoglycan that is found in cartilage, reproductive, and neural tissues. Corneal KS glycosaminoglycan is found N-linked to lumican, keratocan, and mimecan proteoglycans and has been widely studied by investigators interested in corneal development and diseases. Recently, the availability of corneal KS has become severely limited due to restricted the shipment of bovine central nervous system by-products across international borders in efforts to pre...

  9. Fuchs endothelial corneal dystrophy: clinical characteristics of surgical and nonsurgical patients

    Directory of Open Access Journals (Sweden)

    Goldberg RA

    2014-09-01

    Full Text Available Roger A Goldberg,1,2 Sabri Raza,1 Eric Walford,1 William J Feuer,1 Jeffrey L Goldberg1,3 1Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA; 2Tufts-New England Eye Center/Ophthalmic Consultants of Boston, Boston, MA, USA; 3Shiley Eye Center, University of California San Diego, San Diego, CA, USA Purpose: To review the patient and clinical characteristics of patients with Fuchs endothelial corneal dystrophy (FECD. Methods: Review of records for every patient who presented to the Bascom Palmer Eye Institute between 2003 and 2009 whose visit was coded for endothelial corneal dystrophy (International Classification of Diseases, Ninth Revision [ICD9] 371.57, bullous keratopathy (ICD9 371.23, or who underwent a corneal surgery with or without cataract extraction. Demographic, clinical, and ancillary testing data were collected from the time of presentation, diagnosis, and follow-up, and the use, timing, and type of surgical interventions was documented, with 6-month and final visual acuities recorded. Results: A total of 2,370 charts were included in this study, of which 966 patients had a diagnosis of FECD. Of these, 197 patients (21% received a corneal transplantation procedure. The surgery most often performed was penetrating keratoplasty with or without cataract extraction (66%, followed by endothelial keratoplasty with or without cataract extraction (34%. The risk factors for surgery include worse visual acuity at presentation (20/60 Snellen visual acuity in surgical patients versus 20/40 Snellen visual acuity in nonsurgical patients, P<0.001, greater average central corneal thickness (635 µm versus 592 µm, P<0.001, loss of visual acuity over time (two lines lost versus zero lines lost, P<0.001, increasing age (P<0.001, and male sex (P=0.008. Over half of patients (52% did not receive surgery despite poor vision. Conclusion: During this time period, FECD did not have a consistent pattern for management or treatment, and despite

  10. An Association between Corneal Inflammation and Corneal Lymphangiogenesis after Keratoplasty

    Institute of Scientific and Technical Information of China (English)

    Weihua Li; Wencong Wang; Shiqi Ling

    2014-01-01

    Purpose:To examine the relationship between corneal in-flammation and corneal lymphangiogenesis after keratoplasty. Methods:.Rat corneal lymphangiogenesis was examined by lymphatic vessel endothelial receptor (LYVE-1) immunohis-tochemistry and whole mount immunofluorescence at 1, 3, 7, 10, and 14 days after corneal transplantation. Corneal inflam-mation was evaluated by inflammation index (IF) grading and NF-κB immunohistochemistry at the same time points. The association between lymphatic vessel counting (LVC) and the IF scores was then examined. Results:.LYVE-1 positive lymphatic vessels occurred in the corneal stroma on day 3,.developed throughout days 7 and 10,.and peaked in number at day 14 after keratoplasty. Corneal inflammation was strong on day 3, and then resolved gradually,.but increased again from days 7 to 14 after the transplantation..LVC was strongly and positively correlated with IF after keratoplasty(r=0.41;P<0.05). However, changes in IF scores and LVC were not parallel. Conclusion:.A close,.but not parallel,.relationship was found between corneal lymphangiogenesis and corneal inflammation after corneal transplantation.

  11. Isolation of bovine corneal keratan sulfate and its growth factor and morphogen binding.

    Science.gov (United States)

    Weyers, Amanda; Yang, Bo; Solakyildirim, Kemal; Yee, Vienna; Li, Lingyun; Zhang, Fuming; Linhardt, Robert J

    2013-05-01

    Keratan sulfate (KS) is an important glycosaminoglycan that is found in cartilage, reproductive tissues, and neural tissues. Corneal KS glycosaminoglycan is found N-linked to lumican, keratocan and mimecan proteoglycans, and has been widely studied by investigators interested in corneal development and diseases. Recently, the availability of corneal KS has become severely limited, owing to restrictions on the shipment of bovine central nervous system byproducts across international borders in an effort to prevent additional cases of mad cow disease. We report a simple method for the purification of multi-milligram quantities of bovine corneal KS, and characterize its structural properties. We also examined its protein-binding properties, and discovered that corneal KS bound with high affinity to fibroblast growth factor-2 and sonic hedgehog, a growth factor and a morphogen involved in corneal development and healing. PMID:23402351

  12. Weekly periodicities of aerosol optical thickness over Central Europe – evidence of an anthropogenic direct aerosol effect

    Directory of Open Access Journals (Sweden)

    B. Vogel

    2007-08-01

    Full Text Available Statistical analyses of data from 14 ground-based sun photometer stations all over Central Europe are presented. All stations are part of the Aerosol Robotic Network (AERONET, and only data of the highest data quality level 2.0 had been applied. The averages by weekday of aerosol optical thickness (AOT at a wavelength of 440 nm of 12 of the 14 stations show a weekly periodicity with lowest values on Sunday and Monday, but greatest values from Wednesday until Saturday, that is significant at least on a 90% level. The stations in Germany and in Greater Paris show weekly cycles with ranges of about 20% on average. In Northern Italy and Switzerland this range is about 10% on average. The corresponding weekly cycle of anthropogenic gaseous and particulate emissions leads us to the conclusion of the anthropogenic origin of the weekly AOT cycle. Since these AOT patterns are derived from the reduction of the direct sun radiation by the columnar atmospheric aerosol, this result represents strong evidence for an anthropogenic direct aerosol effect on shortwave radiation. Furthermore, this study makes a first contribution to the understanding and explanation of recently observed weekly periodicities in meteorological variables as temperature in Germany.

  13. Comparative Study of Anterior Eye Segment Measurements with Spectral Swept-Source and Time-Domain Optical Coherence Tomography in Eyes with Corneal Dystrophies

    Directory of Open Access Journals (Sweden)

    Anna K. Nowinska

    2015-01-01

    Full Text Available Purpose. To compare anterior eye segment measurements and morphology obtained with two optical coherence tomography systems (TD OCT, SS OCT in eyes with corneal dystrophies (CDs. Methods. Fifty healthy volunteers (50 eyes and 54 patients (96 eyes diagnosed with CD (epithelial basement membrane dystrophy, EBMD = 12 eyes; Thiel-Behnke CD = 6 eyes; lattice CD TGFBI type = 15 eyes; granular CD type 1 = 7 eyes, granular CD type 2 = 2 eyes; macular CD = 23 eyes; and Fuchs endothelial CD = 31 eyes were recruited for the study. Automated and manual central corneal thickness (aCCT, mCCT, anterior chamber depth (ACD, and nasal and temporal trabecular iris angle (nTIA, tTIA were measured and compared with Bland-Altman plots. Results. Good agreement between the TD and SS OCT measurements was demonstrated for mCCT and aCCT in normal individuals and for mCCT in the CDs group. The ACD, nTIA, and tTIA measurements differed significantly in both groups. TBCD, LCD, and FECD caused increased CCT. MCD caused significant corneal thinning. FECD affected all analyzed parameters. Conclusions. Better agreement between SS OCT and TD OCT measurements was demonstrated in normal individuals compared to the CDs group. OCT provides comprehensive corneal deposits analysis and demonstrates the association of CD with CCT, ACD, and TIA measurements.

  14. Genetics of corneal endothelial dystrophies

    Indian Academy of Sciences (India)

    Chitra Kannabiran

    2009-12-01

    The corneal endothelium maintains the level of hydration in the cornea. Dysfunction of the endothelium results in excess accumulation of water in the corneal stroma, leading to swelling of the stroma and loss of transparency. There are four different corneal endothelial dystrophies that are hereditary, progressive, non-inflammatory disorders involving dysfunction of the corneal endothelium. Each of the endothelial dystrophies is genetically heterogeneous with different modes of transmission and/or different genes involved in each subtype. Genes responsible for disease have been identified for only a subset of corneal endothelial dystrophies. Knowledge of genes involved and their function in the corneal endothelium can aid understanding the pathogenesis of the disorder as well as reveal pathways that are important for normal functioning of the endothelium.

  15. Comparison of aspheric keratectomy excimer laser subepithelial keratomileusis (LASEK)and aspheric laser in situ keratomileusis(LASIK) for different thickness corneal%非球面切削LASEK和LASIK治疗不同厚度角膜的高度近视

    Institute of Scientific and Technical Information of China (English)

    朱云喜; 金敏; 王小园; 高宗银; 杨为中; 朱远军

    2010-01-01

    目的 探讨角膜波前像差联合Q值优化的非球面切削准分子激光上皮下角膜切削术(LASEK)与角膜波前像差联合Q值优化的非球面切削准分子激光原位角膜磨镶术(LASIK),分别治疗角膜薄(500μm)的高度近视的临床疗效比较.方法 选取角膜厚度薄的高度近视患者行LASEK治疗25例(42只眼),角膜厚的高度近视患者38例(65只眼),比较术前视力、年龄、角膜厚度、切削厚度、剩余角膜厚度、等效球镜度、球差、慧差、总阶像差,术后2周,4周,3月,6月的视力,比较术后6月两组视力、等效球镜度、球差、慧差、总阶像差、HAZE等级.结果 两种手术方式术后6月内的视力,术后6月的等效球镜度、球差、慧差、总阶像差均无统计学意义,治疗高度近视具有相同均具有很高的安全性、有效性及可预测性且两组具有相同的临床疗效.结论 非球面切削的LASEK治疗角膜薄的高度近视与非球面切削的LASIK治疗角膜厚的高度近视具有相同的临床疗效.%Objective To compare the clinical curative effect of corneal wavefront-guided combining Q-value guided aspheric keratctomy excimer LASEK for high myopia of thin cornea (500μm). Methods Of selected 25 high myopia of thin cornea (42 eyes), and 38 high myopia of thick cornea (65 eyes), compared the preoperative uncorrected visual acuity (UCVA), age, corneal thickness, atherectomy thickness,remnant thickness, spherical equivalent (SE), Coma-like RMS (root of mean square), spherical-like RMS,RMSg (root of mean square of general aberration) with postoperative UCVA of 2, 4 weeks, 1 month, 3, 6 months SE, Coma-like RMS, spherical-like RMS, RMSg, Level of Haze. Results There were no statistically significant differences between two groups 6 months aiter operation in UCVA, spherical equivalent (SE),Coma-like RIMS, spherical-like RMS and RMSg. Both groups showed high safety, efficacy, predictability and the same clinical curative effect

  16. Contact Lens Related Corneal Ulcer

    OpenAIRE

    Loh, KY; P Agarwal

    2010-01-01

    A corneal ulcer caused by infection is one of the major causes of blindness worldwide. One of the recent health concerns is the increasing incidence of corneal ulcers associated with contact lens user especially if the users fail to follow specific instruction in using their contact lenses. Risk factors associated with increased risk of contact lens related corneal ulcers are: overnight wear, long duration of continuous wear, lower socio-economic classes, smoking, dry eye and poor hygiene. Th...

  17. A Case of Solitary Nonvascularized Corneal Epithelial Dysplasia

    Directory of Open Access Journals (Sweden)

    Tomoya Morii

    2016-01-01

    Full Text Available Background. Epithelial dysplasia is categorized as conjunctival/corneal intraepithelial neoplasia which is a precancerous lesion. The lesion is usually developed at the limbal region and grows towards central cornea in association with neovascularization into the lesion. Here, we report a case of isolated nonvascularized corneal epithelial dysplasia surrounded by normal corneal epithelium with immune histochemical finding of ocular surface tissues cytokeratins, for example, keratin 13 and keratin 12. Case Presentation. A 76-year-old man consulted us for visual disturbance with localized opacification of the corneal epithelium in his left eye. His visual acuity was 20/20 and 20/200 in his right and left eye, respectively. Slit lamp examination showed a whitish plaque-like lesion at the center of his left corneal epithelium. No vascular invasion to the lesion was found. The lesion was surgically removed and subjected to histopathological examination and diagnosed as epithelial dysplasia. Amyloidosis was excluded by direct fast scarlet 4BS (DFS staining. Immunohistochemistry showed that the dysplastic epithelial cells express keratin 13 and vimentin, but not keratin 12, indicating that the neoplastic epithelial cells lacked corneal-type epithelium differentiation. Conclusions. The lesion was diagnosed as nonvascularized epithelial dysplasia of ocular surface. Etiology of the lesion is not known.

  18. A Case of Solitary Nonvascularized Corneal Epithelial Dysplasia

    Science.gov (United States)

    Morii, Tomoya; Sumioka, Takayoshi; Izutani-Kitano, Ai; Takada, Yukihisa; Okada, Yuka; Kao, Winston W.-Y.; Saika, Shizuya

    2016-01-01

    Background. Epithelial dysplasia is categorized as conjunctival/corneal intraepithelial neoplasia which is a precancerous lesion. The lesion is usually developed at the limbal region and grows towards central cornea in association with neovascularization into the lesion. Here, we report a case of isolated nonvascularized corneal epithelial dysplasia surrounded by normal corneal epithelium with immune histochemical finding of ocular surface tissues cytokeratins, for example, keratin 13 and keratin 12. Case Presentation. A 76-year-old man consulted us for visual disturbance with localized opacification of the corneal epithelium in his left eye. His visual acuity was 20/20 and 20/200 in his right and left eye, respectively. Slit lamp examination showed a whitish plaque-like lesion at the center of his left corneal epithelium. No vascular invasion to the lesion was found. The lesion was surgically removed and subjected to histopathological examination and diagnosed as epithelial dysplasia. Amyloidosis was excluded by direct fast scarlet 4BS (DFS) staining. Immunohistochemistry showed that the dysplastic epithelial cells express keratin 13 and vimentin, but not keratin 12, indicating that the neoplastic epithelial cells lacked corneal-type epithelium differentiation. Conclusions. The lesion was diagnosed as nonvascularized epithelial dysplasia of ocular surface. Etiology of the lesion is not known. PMID:27042371

  19. Corneal lesion as the initial manifestation of tyrosinemia type II.

    Science.gov (United States)

    Tsai, Chun-Pin; Lin, Pei-Yu; Lee, Ni-Chung; Niu, Dau-Ming; Lee, Shui-Mei; Hsu, Wen-Ming

    2006-06-01

    Tyrosinemia type II (Richner-Hanhart syndrome) is a rare autosomal recessive disease with deficiency of tyrosine aminotransferase and subsequently increasing level of serum tyrosine. We report the case of a 2-year-old girl who was referred due to bilateral corneal lesions. Slit-lamp examination showed small granular white deposits arranged in a dendritic pattern in the superficial central cornea of both eyes. Physical examination revealed painful, non-pruritic, hyperkeratotic plaques on the soles, palms and fingertips. Mental evaluation demonstrated developmental delay for her age. Blood examination revealed serum tyrosine level to be 1868 microM (normal range, 30-110 microM), which decreased to 838 microM with 2-month diet on tyrosine and phenylalanine restriction. The corneal and skin lesions resolved completely. However, the corneal deposits recurred a month later as her mother failed to strictly control the diet because the little girl was losing weight and activity. With specific formula and adjusted diet regimen, the corneal lesions decreased again. Corneal pseudodendritic deposits may be the initial manifestation in patients with tyrosinemia type II. Early diagnosis and intervention with diet control are crucial for preventing permanent visual and developmental deficits. Corneal deposits can be one of the parameters in monitoring the efficacy of diet control.

  20. Bilateral acute corneal calcification.

    Science.gov (United States)

    Freddo, T F; Leibowitz, H M

    1985-04-01

    A 38-year-old man with brittle, juvenile onset diabetes mellitus and bilateral severe dry eyes with recurrent corneal ulcers developed atypical band-shaped calcifications of both corneas during a 24-hour period. Serum calcium, phosphate, and carbon dioxide levels all were within normal limits. The patient was mildly uremic but was not in renal failure. When EDTA chelation failed to clear the deposits, partial keratectomies were performed in both eyes and the specimens were examined by light and electron microscopy, including energy dispersive x-ray analysis. Microscopic studies revealed an atypical calcific keratopathy which involved neither Bowman's layer nor the most superficial stromal lamellae. The deposits were confined to deeper lamellae in the anterior stroma and by electron microscopy were composed of extracellular crystalline aggregates. Energy dispersive x-ray analysis of these aggregates confirmed the presence of calcium and phosphate. Corneal dessication appeared to be a major contributing factor in the rapid formation of these deposits.

  1. Geophysical Investigations on Malta (Central Mediterranean) using Ambient Noise: Assessing Array Performance and Influence of a Thick Low Velocity Layer.

    Science.gov (United States)

    Farrugia, D.; Paolucci, E.; D'Amico, S.; Galea, P. M.

    2014-12-01

    The use of microtremors to obtain shear wave velocity (Vs) profiles of the subsurface is becoming a widespread approach due to its various advantages. Noise measurements were carried out at four sites on Malta (Central Mediterranean). Array techniques were first tested in an area where a ≈45 m layer of soft Blue Clay (BC) overlies the harder limestone. Three array configurations (two arrays of 17 geophones in an L-shape and circle respectively and one 42 geophone array in an L-shape) were tested and processed using the f-k and two SPAC techniques: Modified and Extended SPAC. No significant difference was observed in the dispersion curve from the two short arrays despite having different shapes. However, a significant variation was observed between the dispersion curve from the long and short arrays in the low frequency part. A joint inversion, using two direct search methods, of the dispersion and the H/V curve was then used to obtain the Vs profile for the site, with most of the profiles being in agreement both in terms of velocity and depth. A study was also conducted at three other sites on Malta where hard Upper Coralline Limestone (UCL) overlies the soft BC creating a velocity inversion in the soil profile. The shape of the effective dispersion curves obtained using ESAC show both an inverse dispersive trend and normal dispersion. This shape is tentatively explained in terms of the presence of higher mode Rayleigh waves. A Genetic Algorithm approach was then used to jointly invert the H/V and Rayleigh wave dispersion curve. It was observed that the BC velocity was higher when overlain by a large thickness of UCL. This could be linked to the effective pressure caused by the hard UCL, making the BC more compact, and having a higher velocity. The theoretical implications of a prominent low-velocity layer on site amplification and the interpretation of ambient noise data are investigated and discussed.

  2. Advances in corneal cell therapy.

    Science.gov (United States)

    Fuest, Matthias; Yam, Gary Hin-Fai; Peh, Gary Swee-Lim; Mehta, Jodhbir S

    2016-09-01

    Corneal integrity is essential for visual function. Transplantation remains the most common treatment option for advanced corneal diseases. A global donor material shortage requires a search for alternative treatments. Different stem cell populations have been induced to express corneal cell characteristics in vitro and in animal models. Yet before their application to humans, scientific and ethical issues need to be solved. The in vitro propagation and implantation of primary corneal cells has been rapidly evolving with clinical practices of limbal epithelium transplantation and a clinical trial for endothelial cells in progress, implying cultivated ocular cells as a promising option for the future. This review reports on the latest developments in primary ocular cell and stem cell research for corneal therapy. PMID:27498943

  3. Comparison of central corneal edema and visual recovery between liquefaction and conventional phacoemulsification in soft cataracts Comparação do edema de córnea central e da recuperação visual após facoemulsificação por liquefação e convencional em cataratas moles

    Directory of Open Access Journals (Sweden)

    Celso Takashi Nakano

    2009-02-01

    Full Text Available PURPOSE: The aim of the present study is to assess central corneal edema and visual recovery after cataract surgery performed according to two technologies: conventional ultrasonic and liquefaction (Aqualase®. METHODS:This is a prospective contralateral study in wich 20 patients with comparable preoperative conditions were submitted to cataract surgery were evaluated. Preoperative assessment involved complete ophthalmological examination and the study included patients with bilateral cataracts up to grade 2, according to the Lens Opacity Classification System II. The same cristaline fracture technique was used in all cases, and surgical procedures were performed by the same experienced surgeon, using two technologies: liquefaction or conventional phacoemulsification. Postoperative central corneal edema was measured by corneal optical pachymetry (Orbscan II® on the 1st, 3rd, 7th and 10th postoperative days. RESULTS:None of the 20 patients submitted to surgery was lost during the postoperative follow-up or excluded from the analysis. On the first postoperative, the visual acuity average was 0.031 logMAR in the Aqualase® group and 0.043 logMAR in the conventional surgery group. No statistical difference was detected in the assessment of visual acuity throughout the postoperative period. Central corneal pachymetry varied from 543.93 + 34.69 preoperatively to 545.08 ± 25.67 on the last day of follow-up in the Aqualase® group, and from 543.13 + 30.62 to 536.08 + 34.89 in the conventional technique group, without statistical significance. CONCLUSION:This study suggests that both techniques are equally effective for surgery on lenses with grade I or II cataract, and that they provide similar results in terms of visual recovery and central corneal edema.OBJETIVO: Avaliar o edema corneano central e a recuperação visual após cirurgia de catarata realizada através de duas tecnologias: ultrassônica convencional e liquefação (Aqualase®. M

  4. Corneal Transplant Infection due to Alternaria alternata: A Case Report

    Directory of Open Access Journals (Sweden)

    Vasileios Konidaris

    2013-01-01

    Full Text Available Purpose. To report a case of Alternaria alternata keratitis in a patient with a corneal transplant in her right eye due to bullous pseudophakic keratopathy. Methods. A 66-year-old female underwent a full-thickness keratoplasty in her right eye due to bullous pseudophakic keratopathy. Three weeks after keratoplasty, epithelial edema and a stromal opacity with an infiltrate and development of peripheral corneal opacities appeared. The diagnosis of Alternaria alternata keratitis was made. Results. The patient underwent a second keratoplasty, due to the corneal melting as a result of the fungal infection. She was also given combined antifungal treatment locally and systematically. Conclusion. Corneal transplantation alone would not have been sufficient to keep the fungus in the anterior portion of the eye. Combined antifungal treatment, locally and systematically, was important in attempting to prevent the further spread of the fungus to the interior of the eye. To our knowledge, the case presented here is only the second one in the literature concerning a keratomycosis due to Alternaria alternata corneal transplant infection.

  5. Concise Review: An Update on the Culture of Human Corneal Endothelial Cells for Transplantation.

    Science.gov (United States)

    Parekh, Mohit; Ferrari, Stefano; Sheridan, Carl; Kaye, Stephen; Ahmad, Sajjad

    2016-02-01

    The cornea forms the front window of the eye, enabling the transmission of light to the retina through a crystalline lens. Many disorders of the cornea lead to partial or total blindness, and therefore corneal transplantation becomes mandatory. Recently, selective corneal layer (as opposed to full thickness) transplantation has become popular because this leads to earlier rehabilitation and visual outcomes. Corneal endothelial disorders are a common cause of corneal disease and transplantation. Corneal endothelial transplantation is successful but limited worldwide because of lower donor corneal supply. Alternatives to corneal tissue for endothelial transplantation therefore require immediate attention. The field of human corneal endothelial culture for transplantation is rapidly emerging as a possible viable option. This manuscript provides an update regarding these developments. Significance: The cornea is the front clear window of the eye. It needs to be kept transparent for normal vision. It is formed of various layers of which the posterior layer (the endothelium) is responsible for the transparency of the cornea because it allows the transport of ions and solutes to and from the other layers of the cornea. Corneal blindness that results from the corneal endothelial dysfunction can be treated using healthy donor tissues. There is a huge demand for human donor corneas but limited supply, and therefore there is a need to identify alternatives that would reduce this demand. Research is underway to understand the isolation techniques for corneal endothelial cells, culturing these cells in the laboratory, and finding possible options to transplant these cells in the patients. This review article is an update on the recent developments in this field. PMID:26702128

  6. Corneal Cross-Linking (with a Partial Deepithelization) in Keratoconus with Five Years of Follow-Up

    Science.gov (United States)

    Galvis, Virgilio; Tello, Alejandro; Carreño, Néstor I.; Ortiz, Alvaro I.; Barrera, Rodrigo; Rodriguez, Carlos Julián; Ochoa, Miguel E.

    2016-01-01

    We performed a retrospective interventional case series including 80 eyes of 48 patients with keratoconus (KC) who were treated with modified corneal cross-linking (CXL) for KC (with a partial deepithelization in a pattern of stripes). The average follow-up was 5.8 years (with a minimum of 5 years). At the last follow-up visit, compared with preoperative values, there were no significant changes in spherical equivalent, average keratometry, corneal thickness, corneal hysteresis, or corneal resistance factor. The distance-corrected visual acuity was 20/39 preoperatively and 20/36 postoperatively (P = 0.3). The endothelial cell count decreased by 4.7% (P < 0.005). These findings suggest that this modified corneal CXL technique is a safe and effective alternative to halt the progression of KC up to five years after the procedure. However, some concerns remain as to whether this technique can affect in some degree the corneal endothelial cells. PMID:27199574

  7. AUTOMATED VIDEO IMAGE MORPHOMETRY OF THE CORNEAL ENDOTHELIUM

    NARCIS (Netherlands)

    SIERTSEMA, JV; LANDESZ, M; VANDENBROM, H; VANRIJ, G

    1993-01-01

    The central corneal endothelium of 13 eyes in 13 subjects was visualized with a non-contact specular microscope. This report describes the computer-assisted morphometric analysis of enhanced digitized images, using a direct input by means of a frame grabber. The output consisted of mean cell area, c

  8. Keratoconus and Normal-Tension Glaucoma: A Study of the Possible Association with Abnormal Biomechanical Properties as Measured by Corneal Hysteresis (An AOS Thesis)

    Science.gov (United States)

    Cohen, Elisabeth J.

    2009-01-01

    Purpose: To test the hypothesis that keratoconus and pellucid patients who have glaucoma or are suspected of having glaucoma have lower corneal hysteresis (CH) and/or corneal resistance factor (CRF) measurements compared to controls. Methods: A prospective study at a tertiary eye center of keratoconus and pellucid patients with glaucoma or suspected of having glaucoma, and age-matched keratoconus and pellucid controls, was performed. After informed consent was obtained, corneal topography, ocular response analyzer measurements, pachymetry, intraocular pressure, A-scan measurements, Humphrey visual fields (VFs), and disc photos were done. Analyses compared cases to controls on primary (CH and CRF) and secondary variables. Disc photos and VFs were rated in a masked fashion. Results: The mean CH (8.2, SD=1.6, vs 8.3, SD=1.5) and CRF (7.3, SD=2.0, vs 6.9, SD=2.1) were low and did not differ significantly between 20 study patients (29 eyes) and 40 control patients (61 eyes), respectively. CH had a negative, significant correlation with maximum corneal curvature by topography (P < .002) and positive, significant correlation with central corneal thickness (P < .003). The mean cup-disc ratio was larger among cases than controls (0.54, SD=0.20, vs 0.38, SD=0.20; P = .003). VFs were suggestive of glaucoma more often among the study eyes than controls (11 of 29, 37.9%, vs 8 of 60, 13.3%; P =.019). Conclusions: CH was low in study and control patients and was correlated with severity of keratoconus/pellucid, but not with glaucoma/suspected glaucoma or control status. Evidence of glaucoma was more common in study eyes than controls, but was present in both. PMID:20126503

  9. LIM Homeobox Domain 2 Is Required for Corneal Epithelial Homeostasis.

    Science.gov (United States)

    Sartaj, Rachel; Chee, Ru-ik; Yang, Jing; Wan, Pengxia; Liu, Aihong; Guaiquil, Victor; Fuchs, Elaine; Rosenblatt, Mark I

    2016-02-01

    The cornea requires constant epithelial renewal to maintain clarity for appropriate vision. A subset of stem cells residing at the limbus is primarily responsible for maintaining corneal epithelium homeostasis. Trauma and disease may lead to stem cell deficiency and therapeutic targeting to replenish the stemness capacity has been stalled by the lack of reliable corneal epithelial stem cell markers. Here we identified the location of Lhx2 in mice (mLhx2) cornea and conjunctival tissue using an Lhx2eGFP reporter model and in human tissues (hLHX2). Lhx2 localized to the basal cells of central cornea, the conjunctiva and the entire limbal epithelium in humans and mice. To ascribe a functional role we generated Lhx2 conditional knockout (cKO) mice and the phenotypic effects in corneas were analyzed by slit lamp microscopy, in cell-based assays and in a model of corneal epithelium debridement. Immunodetection on corneal sections were used to visualize conjunctivalization, a sign of limbal barrier failure. Lhx2cKO mice produced reduced body hair and spontaneous epithelial defects in the cornea that included neovascularization, perforation with formation of scar tissue and opacification. Cell based assays showed that Lhx2cKO derived corneal epithelial cells have a significantly lower capacity to form colonies over time and delayed wound-healing recovery when compared to wildtype cells. Repeated corneal epithelial wounding resulted in decreased re-epithelialization and multiple cornea lesions in Lhx2cKO mice compared to normal recovery seen in wildtype mice. We conclude that Lhx2 is required for maintenance of the corneal epithelial cell compartment and the limbal barrier. PMID:26661907

  10. Restoration of the rabbit corneal surface after total epithelial debridement and complete limbal excision

    Directory of Open Access Journals (Sweden)

    S.J. Faria-e-Sousa

    2012-05-01

    Full Text Available How is the corneal epithelium restored when all of it plus the limbus have been eliminated? This investigation explored the possibility that this may be achieved through the conjunctival epithelium. The corneal epithelium of the right eye of 12 rabbits (Oryctolagus cuniculus was totally scraped followed by surgical excision of the limbus plus 1.0-1.5 mm of the adjacent conjunctiva. Antibiotics and corticosteroids were applied for 1 week after surgery. Histological and immunohistochemical techniques were used to monitor the events taking place on the eye surface 2 weeks and 1, 3 and 6 months thereafter. Initially, the corneal surface was covered by conjunctival-like epithelium. After 1 month and more prominently at 3 and 6 months an epithelium displaying the morphological features of the cornea and reacting with the AE5 antibody was covering the central region. It is likely that the corneal epithelium originated from undifferentiated cells of the conjunctiva interacting with the corneal stroma.

  11. Femtosecond laser-assisted keratoplasty in a child with corneal opacity:case report

    Directory of Open Access Journals (Sweden)

    E. Yu. Markova

    2014-01-01

    Full Text Available Corneal opacities are the fourth cause of blindness world-wide. Over the past two centuries, various corneal transplantation (i.e., keratoplasty methods have been developed and improved. Nowadays, femtolaserssisted keratoplasty is one of most promising techniques. Femtosecond laser have several advantages that provide additional surgical benefits. Among them, no thermal injury, the ability to cut deeply on a single plane and to perform various corneal profiles should be mentioned. In children, corneal disorders are of special importance while femtosecondassisted keraatoplasty case reports are rare. Here, we describe femtosecond laserssisted penetrating keratoplasty in a girl with a rough central corneal opacity.

  12. Spontaneous corneal perforation in an eye with Peters' anomaly

    Directory of Open Access Journals (Sweden)

    Kim M

    2013-07-01

    Full Text Available Moosang Kim, Seung-Chan Lee, Seung-Jun Lee Department of Ophthalmology, School of Medicine, Kangwon National University, Chuncheon, South Korea Abstract: A premature female infant underwent her first ophthalmologic examination at the age of 4 weeks. The initial examination of the baby was requested for evaluation of a ‘white spot’ on the surface of her right eye. She had been hospitalized in the neonatal intensive care unit because of systemic abnormalities, such as a right clavicle fracture and microcephaly. Slit-lamp examination of the right eye showed a central corneal opacity, corneal thinning, and an iridocorneal adhesion. The lens and fundus of the right eye could not be observed. We observed no pathologic findings in the left eye. The baby's parents were informed of the high risk for spontaneous corneal perforation without external pressure. At 42 days of age, an ophthalmologic examination of the infant was again requested for evaluation of ‘tears’ from her right eye 3 hours previously. Examination revealed corneal perforation, iris protrusion, and a flat anterior chamber. We performed emergent conjunctival flap surgery. Three months following surgery, the patient's right eye was successfully preserved with no sign of inflammation or leakage. Keywords: conjunctival flap, corneal perforation, Peters' anomaly

  13. Management of advanced corneal ectasias.

    Science.gov (United States)

    Maharana, Prafulla K; Dubey, Aditi; Jhanji, Vishal; Sharma, Namrata; Das, Sujata; Vajpayee, Rasik B

    2016-01-01

    Corneal ectasias include a group of disorders characterised by progressive thinning, bulging and distortion of the cornea. Keratoconus is the most common disease in this group. Other manifestations include pellucid marginal degeneration, Terrien's marginal degeneration, keratoglobus and ectasias following surgery. Advanced ectasias usually present with loss of vision due to high irregular astigmatism. Management of these disorders is difficult due to the peripheral location of ectasia and associated severe corneal thinning. Newer contact lenses such as scleral lenses are helpful in a selected group of patients. A majority of these cases requires surgical intervention. This review provides an update on the current treatment modalities available for management of advanced corneal ectasias. PMID:26294106

  14. Changes in the micromorphology of the corneal subbasal nerve plexus in patients after plaque brachytherapy

    International Nuclear Information System (INIS)

    To quantify the development of radiation neuropathy in corneal subbasal nerve plexus (SNP) after plaque brachytherapy, and the subsequent regeneration of SNP micromorphology and corneal sensation. Nine eyes of 9 melanoma patients (ciliary body: 3, iris: 2, conjunctiva: 4) underwent brachytherapy (ruthenium-106 plaque, dose to tumour base: 523 ± 231 Gy). SNP micromorphology was assessed by in-vivo confocal microscopy. Using software developed in–house, pre-irradiation findings were compared with those obtained after 3 days, 1, 4 and 7 months, and related to radiation dose and corneal sensation. After 3 days nerve fibres were absent from the applicator zone and central cornea, and corneal sensation was abolished. The earliest regenerating fibres were seen at the one-month follow-up. By 4 months SNP structures had increased to one-third of pre-treatment status (based on nerve fibre density and nerve fibre count), and corneal sensation had returned to approximately two-thirds of pre-irradiation values. Regeneration of SNP and corneal sensation was nearly complete 7 months after plaque brachytherapy. The evaluation of SNP micromorphology and corneal sensation is a reliable and clinically useful method for assessing neuropathy after plaque brachytherapy. Radiation-induced neuropathy of corneal nerves develops quickly and is partly reversible within 7 months. The clinical impact of radiation-induced SNP damage is moderate

  15. [Transplantation of corneal endothelial cells].

    Science.gov (United States)

    Amano, Shiro

    2002-12-01

    Though conventional corneal transplantation has achieved great success, it still has several drawbacks including limited availability of donor corneas, recurrent allograft rejection, and subsequent graft failure in certain cases. Reconstructing clinically usable corneas by applying the technology of regenerative medicine can offer a solution to these problems, as well as making corneal transplantation a non-emergency surgery and enabling the usage of banked corneal cells. In the present study, we focused on corneal endothelium that is critical for corneal transparency and investigated the reconstruction of cornea utilizing cultured human corneal endothelial cells (HCECs). We succeeded in steadily culturing HCECs by using culture dishes pre-coated with extracellular matrix produced by calf corneal endothelial cells and culture media that contained basic fibroblast growth factor and fetal bovine serum. We performed the following analysis utilizing these cultured HCECs. The older the donor was, the more frequently large senescent cells appeared in the passaged HCECs. The telomeres of HCECs were measured as terminal restriction fragments (TRF) by Southern blotting. HCECs, in vivo from donors in their seventies had a long TRFs of over 12 kilobases. Passaging shortened the TRFs but there was no difference in TRFs among donors of various ages. These results indicated that shortening of telomere length is not related to senescence of HCECs. We investigated the role of advanced glycation end products (AGEs) in the senescence of in vivo HCECs. The results indicated that AGE-protein in the aqueous humor is endocytosed into HCECs via AGE receptors expressed on the surface of HCECs and damages HCECs by producing reactive oxygen species and inducing apoptosis, suggesting that AGEs, at least partly, cause the senescence of HECEs. HCECs were cultured using adult human serum instead of bovine serum to get rid of bovine material that can be infected with prions. Primary and passage

  16. Cornea stress test--evaluation of corneal endothelial function in vivo by contact lens induced stress

    Directory of Open Access Journals (Sweden)

    Saini Jagjit

    1997-01-01

    Full Text Available Reliable and valid assessment of corneal endothelial function is a critical input for diagnosing, prognosticating and monitoring progression of disorders affecting corneal endothelium. In 123 eyes, corneal endothelial function was assessed employing data from the corneal hydration recovery dynamics. Serial pachometric readings were recorded on Haag-Striet pachometer with Mishima-Hedbys modification before and after two hours of thick soft contact lens wear. Percentage Recovery Per Hour (PRPH was derived from raw data as an index of endothelial function. Assessed PRPH in pseudophakic corneal oedema and Fuchs′ endothelial dystrophy eyes (35.9 +/- 9.8% was significantly lower than normal controls (61.9 +/- 10.5%. On employing receiver operation characteristics curve analysis the tested results demonstrated high sensitivity (87% and specificity (92% for detection of low endothelial function at PRPH cut off of 47.5%. Using this PRPH cut off, 80% of Fuchs′ endothelial dystrophy and 93.3% of pseudophakic corneal oedema eyes could be demonstrated to have low endothelial function. A total of 66.7% of diabetic eyes also demonstrated PRPH of lower than 47.5%. Clear corneal grafts demonstrated PRPH values of 24.6% to 73.0%. Of 6 corneal grafts that demonstrated initial PRPH of lower than 47.5%, 4 failed within 4 to 6 months. Our data demonstrated high sensitivity and specificity of this corneal stress test. PRPH index was useful in quantifying endothelial function in clinical disorders including diabetes mellitus. The index PRPH was demonstrated to be useful in monitoring and prognosticating outcome of corneal grafts.

  17. Cell therapy of congenital corneal diseases with umbilical mesenchymal stem cells: lumican null mice.

    Directory of Open Access Journals (Sweden)

    Hongshan Liu

    Full Text Available BACKGROUND: Keratoplasty is the most effective treatment for corneal blindness, but suboptimal medical conditions and lack of qualified medical personnel and donated cornea often prevent the performance of corneal transplantation in developing countries. Our study aims to develop alternative treatment regimens for congenital corneal diseases of genetic mutation. METHODOLOGY/PRINCIPAL FINDINGS: Human mesenchymal stem cells isolated from neonatal umbilical cords were transplanted to treat thin and cloudy corneas of lumican null mice. Transplantation of umbilical mesenchymal stem cells significantly improved corneal transparency and increased stromal thickness of lumican null mice, but human umbilical hematopoietic stem cells failed to do the same. Further studies revealed that collagen lamellae were re-organized in corneal stroma of lumican null mice after mesenchymal stem cell transplantation. Transplanted umbilical mesenchymal stem cells survived in the mouse corneal stroma for more than 3 months with little or no graft rejection. In addition, these cells assumed a keratocyte phenotype, e.g., dendritic morphology, quiescence, expression of keratocyte unique keratan sulfated keratocan and lumican, and CD34. Moreover, umbilical mesenchymal stem cell transplantation improved host keratocyte functions, which was verified by enhanced expression of keratocan and aldehyde dehydrogenase class 3A1 in lumican null mice. CONCLUSIONS/SIGNIFICANCE: Umbilical mesenchymal stem cell transplantation is a promising treatment for congenital corneal diseases involving keratocyte dysfunction. Unlike donated corneas, umbilical mesenchymal stem cells are easily isolated, expanded, stored, and can be quickly recovered from liquid nitrogen when a patient is in urgent need.

  18. Intrastromal keratoplasy with segment implantation in combination with corneal collagen cross-linking

    Directory of Open Access Journals (Sweden)

    Z.I. Moroz

    2013-03-01

    Full Text Available ABSTRACT Purpose. To evaluate the efficacy of intrastromal keratoplasy with intra-corneal ring segment (ICRS implantation in combination with corneal collagen cross-linking in the treatment of early and advanced keratoconus. Material and methods. In the study 183 eyes with keratoconus were included: 87 eyes (47.5% with the stage II and 96 eyes (32.5% with stage III. The ICRS were implanted as a first step of treatment in 98 cases (53.5%, cross-linking was performed 3 months later. In 85 cases (46.4% the CXL was performed as a first step followed by the ICRS implantation after 3 months. Results. Patients were examined 3, 6, 24 months after surgery. Best functional results were obtained after the ICRS implantation: UCVA and BCVA increased by 3-5 lines, mean keratometry readings decreased by 3.5-4D, the average spherical equivalent decreased by 3.2-2.75D, astigmatism decreased by 2.6-3.9D. After the subsequent CXL procedure, there was a slight improvement of the obtained results. The results obtained in the groups І and II differed insignificantly and were almost identical. At 24 months after surgery some deterioration of functional results was detected in 23.1-26.7% of cases. In the rest of the cases, the obtained effect remained stable. Conclusions. 1. Intra-corneal ring segments implantation and cross-linking are aimed to halt a keratoconus progression and have been successfully used to treat the disease of initial and far-advanced stages. 2. The combination of both methods gives better functional results regardless of which method is performed as a first step. 3. The choice of method to be performed as a first step of treatment depends on the central pachymetry and corneal thickness in a 5-7mm zone of ectasia. 4. Interval between the first and the second step of treatment has to be 3 months or more.

  19. Image-guided modified deep anterior lamellar keratoplasty (DALK) corneal transplant using intraoperative optical coherence tomography

    Science.gov (United States)

    Tao, Yuankai K.; LaBarbera, Michael; Ehlers, Justis P.; Srivastava, Sunil K.; Dupps, William J.

    2015-03-01

    Deep anterior lamellar keratoplasty (DALK) is an alternative to full-thickness corneal transplant and has advantages including the absence of allograft rejection; shortened duration of topical corticosteroid treatment and reduced associated risk of glaucoma, cataract, or infection; and enables use of grafts with poor endothelial quality. DALK begins by performing a trephination of approximately 80% stromal thickness, as measured by pachymetry. After removal of the anterior stoma, a needle is inserted into the residual stroma to inject air or viscoelastic to dissect Descemet's membrane. These procedures are inherently difficult and intraoperative rates of Descemet's membrane perforation between 4-39% have been reported. Optical coherence tomography (OCT) provides high-resolution images of tissue microstructures in the cornea, including Descemet's membrane, and allows quantitation of corneal layer thicknesses. Here, we use crosssectional intraoperative OCT (iOCT) measurements of corneal thickness during surgery and a novel micrometeradjustable biopsy punch to precision-cut the stroma down to Descemet's membrane. Our prototype cutting tool allows us to establish a dissection plane at the corneal endothelium interface, mitigates variability in cut-depths as a result of tremor, reduces procedure complexity, and reduces complication rates. iOCT-guided modified DALK procedures were performed on 47 cadaveric porcine eyes by non-experts and achieved a perforation rate of ~5% with a mean corneal dissection time care.

  20. Reconstruction of Rabbit Corneal Layer Composed of Corneal Fibroblasts and Corneal Epithelium on the Lyophilized Amniotic Membrane

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Many researchers have employed the cryopreserved amniotic membrane(CAM) and corneal epithelial cells in the treatment of a severely damaged burned cornea, with corneal epithelial cells cultured on an amniotic membrane (AM). The lyophilized amniotic membrane (LAM) has a higher graft take and a longer shelf life; it is easier to store and safer because of gamma irradiation. Two Teflon rings(Ahn's supporter) were made for culturing the cells on the LAM, and were then used to support the LAM. To reconstruct a corneal layer composed of corneal fibroblasts and epithelium, the corneal fibroblasts were first cultivated on the stromal side of LAM for five days, followed by epithelial cells culture on the epithelial side, by using the air-liquid interface culture. The reconstructed corneal layer composed of corneal fibroblasts and corneal epithelial cells has a much healthier basal layer of corneal epithelium than the reconstructed corneal epithelium, which was got by using only corneal epithelial cells, and resembles the epithelium of normal corneas, without the horny layer. Thus, the reconstruction of the corneal layer by using a LAM is considered to be a good in vitro model, not only for its application in toxicological test kits, but also for transplantation in patients with a severely damaged cornea.

  1. Proteins of the corneal stroma: importance in visual function.

    Science.gov (United States)

    Xuan, Meng; Wang, Shurong; Liu, Xin; He, Yuxi; Li, Ying; Zhang, Yan

    2016-04-01

    The human cornea, consisting of five layers, is the transparent tissue that refracts and transmits light to the lens and retina, providing about two thirds of the refractive power of the eye. The stroma layer comprises nearly 90 % of the thickness of the cornea and thus plays a pivotal role in normal visual function. The bulk of this layer is constituted by proteins in the extracellular martrix secreted by the corneal epithelial, stroma, and endothelial cells. Clinical research has shown that corneal stroma diseases are common and involve conditions such as infections, injuries, and genetic defects, which cause severe visual disturbances or even blindness. To improve our understanding of the basic molecular mechanisms involved in the physiological and pathological activities of the corneal stroma, its proteins have been brought into the limelight to determine their crucial and irreplaceable roles. The data presented in a previous study have demonstrated the presence of 1679 proteins in the stroma, and this data set has subsequently been perfected by utilizing a highly sensitive isobaric peptide-labeling approach. According to their manifestations, these proteins can be classified as a gel-like organic material composed of proteoglycans, enzymes, and hemocyanin-binding proteins and a network of filaments composed of collagen, elastin, keratin, vimentin, and interconnected filaments comprising fibronectin and laminin. The aim of this review is to describe some corneal stroma proteins by highlighting their major functions and valuable applications in ophthalmologic research toward the better characterization and treatment of eye diseases.

  2. Traumatic corneal endothelial rings from homemade explosives.

    Science.gov (United States)

    Ng, Soo Khai; Rudkin, Adam K; Galanopoulos, Anna

    2013-08-01

    Traumatic corneal endothelial rings are remarkably rare ocular findings that may result from blast injury. We present a unique case of bilateral traumatic corneal endothelial rings secondary to blast injury from homemade explosives. PMID:23474743

  3. Corneal biomechanics: a review.

    Science.gov (United States)

    Piñero, David P; Alcón, Natividad

    2015-03-01

    Biomechanics is often defined as 'mechanics applied to biology'. Due to the variety and complexity of the behaviour of biological structures and materials, biomechanics is better defined as the development, extension and application of mechanics for a better understanding of physiology and physiopathology and consequently for a better diagnosis and treatment of disease and injury. Different methods for the characterisation of corneal biomechanics are reviewed in detail, including those that are currently commercially available (Ocular Response Analyzer and CorVis ST). The clinical applicability of the parameters provided by these devices are discussed, especially in the fields of glaucoma, detection of ectatic disorders and orthokeratology. Likewise, other methods are also reviewed, such as Brillouin microscopy or dynamic optical coherence tomography and others with potential application to clinical practice but not validated for in vivo measurements, such as ultrasonic elastography. Advantages and disadvantages of all these techniques are described. Finally, the concept of biomechanical modelling is revised as well as the requirements for developing biomechanical models, with special emphasis on finite element modelling. PMID:25470213

  4. Comparison of corneal measurements in keratoconic eyes using rotating Scheimpflug camera and scanning-slit topography

    Institute of Scientific and Technical Information of China (English)

    Mohammad; Naderan; Saeed; Shoar; Morteza; Naderan; Mohammad; Amin; Kamaleddin; Mohammad; Taher; Rajabi

    2015-01-01

    AIM: To compare the anterior segment measurements obtained by rotating Scheimpflug camera(Pentacam) and Scanning-slit topography(Orbscan IIz) in keratoconic eyes.METHODS: A total of 121 patients, 71 males(58.7%)and 50 females(41.3%)(214 eyes) with the diagnosis of keratoconus(KC) were enrolled in this study. Following diagnosis of KC by slit-lamp biomicroscopic examination, central corneal thickness(CCT), thinnest corneal thickness(TCT), anterior chamber depth(ACD),and pupil diameter(PD) were measured by a single examiner using successive instrumentation by Pentacam and Orbscan.RESULTS: There was no significant difference between the two instruments for the measurement of CCT and TCT. In contrast, scanning-slit topography measured ACD(3.46±0.40 mm vs 3.38±0.33 mm, P =0.019) and PD(4.97 ±1.26 mm vs 4.08 ±1.19 mm, P <0.001) significantly larger than rotating Scheimpflug camera.The two devices made similar measurements for CCT(95% CI:-2.94 to5.06, P =0.602). However, the mean difference for TCT was-6.28(95% CI:-10.51 to-2.06, P =0.004) showing a thinner measurement by Orbscan than by Pentacam. In terms of the ACD, the mean difference was 0.08 mm(95%CI: 0.04 to 0.12, P <0.001) with Orbscan giving a slightly larger value than Pentacam. Similarly, Orbscan measurement for PD was longer than Pentacam(95% CI:0.68 to 1.08, P <0.001).CONCLUSION: A good agreement was found between Pentacam and Orbscan concerning CCT measurement while comparing scanning-slit topography and rotatingScheimpflug camera there was an underestimation for TCT and overestimation for ACD and PD.

  5. Management of pediatric corneal limbal dermoids.

    Science.gov (United States)

    Pirouzian, Amir

    2013-01-01

    This paper reviews the data in the published literature (PubMed from 1937 to 2011) concerning the medical and surgical management of pediatric limbal dermoids. Current standard medical treatment for grade I pediatric limbal dermoids (ie, with superficial corneal involvment) is initially conservative. In stages II (ie, affecting the full thickness of the cornea with/without endothelial involvement) and III (ie, involvement of entire cornea and anterior chamber), a combination of excision, lamellar keratoplasty, and amniotic membrane and limbal stem cell tranplantation are advocated. Combinations of these approaches seem to yield better and more stable long-term ocular surface cosmesis and fewer complications in comparison with traditional methods of excision and lamellar keratoplasty. Management of amblyopia (i.e. occlusion treatment, chemical penalization with/without spectacle wear, etc) must continue after surgical excision to yield optimal results when or if the surgery is done at a younger age. PMID:23576860

  6. Adipose-derived mesenchymal stem cell administration does not improve corneal graft survival outcome.

    Directory of Open Access Journals (Sweden)

    Sherezade Fuentes-Julián

    Full Text Available The effect of local and systemic injections of mesenchymal stem cells derived from adipose tissue (AD-MSC into rabbit models of corneal allograft rejection with either normal-risk or high-risk vascularized corneal beds was investigated. The models we present in this study are more similar to human corneal transplants than previously reported murine models. Our aim was to prevent transplant rejection and increase the length of graft survival. In the normal-risk transplant model, in contrast to our expectations, the injection of AD-MSC into the graft junction during surgery resulted in the induction of increased signs of inflammation such as corneal edema with increased thickness, and a higher level of infiltration of leukocytes. This process led to a lower survival of the graft compared with the sham-treated corneal transplants. In the high-risk transplant model, in which immune ocular privilege was undermined by the induction of neovascularization prior to graft surgery, we found the use of systemic rabbit AD-MSCs prior to surgery, during surgery, and at various time points after surgery resulted in a shorter survival of the graft compared with the non-treated corneal grafts. Based on our results, local or systemic treatment with AD-MSCs to prevent corneal rejection in rabbit corneal models at normal or high risk of rejection does not increase survival but rather can increase inflammation and neovascularization and break the innate ocular immune privilege. This result can be partially explained by the immunomarkers, lack of immunosuppressive ability and immunophenotypical secretion molecules characterization of AD-MSC used in this study. Parameters including the risk of rejection, the inflammatory/vascularization environment, the cell source, the time of injection, the immunosuppression, the number of cells, and the mode of delivery must be established before translating the possible benefits of the use of MSCs in corneal transplants to clinical

  7. Adipose-derived mesenchymal stem cell administration does not improve corneal graft survival outcome.

    Science.gov (United States)

    Fuentes-Julián, Sherezade; Arnalich-Montiel, Francisco; Jaumandreu, Laia; Leal, Marina; Casado, Alfonso; García-Tuñon, Ignacio; Hernández-Jiménez, Enrique; López-Collazo, Eduardo; De Miguel, Maria P

    2015-01-01

    The effect of local and systemic injections of mesenchymal stem cells derived from adipose tissue (AD-MSC) into rabbit models of corneal allograft rejection with either normal-risk or high-risk vascularized corneal beds was investigated. The models we present in this study are more similar to human corneal transplants than previously reported murine models. Our aim was to prevent transplant rejection and increase the length of graft survival. In the normal-risk transplant model, in contrast to our expectations, the injection of AD-MSC into the graft junction during surgery resulted in the induction of increased signs of inflammation such as corneal edema with increased thickness, and a higher level of infiltration of leukocytes. This process led to a lower survival of the graft compared with the sham-treated corneal transplants. In the high-risk transplant model, in which immune ocular privilege was undermined by the induction of neovascularization prior to graft surgery, we found the use of systemic rabbit AD-MSCs prior to surgery, during surgery, and at various time points after surgery resulted in a shorter survival of the graft compared with the non-treated corneal grafts. Based on our results, local or systemic treatment with AD-MSCs to prevent corneal rejection in rabbit corneal models at normal or high risk of rejection does not increase survival but rather can increase inflammation and neovascularization and break the innate ocular immune privilege. This result can be partially explained by the immunomarkers, lack of immunosuppressive ability and immunophenotypical secretion molecules characterization of AD-MSC used in this study. Parameters including the risk of rejection, the inflammatory/vascularization environment, the cell source, the time of injection, the immunosuppression, the number of cells, and the mode of delivery must be established before translating the possible benefits of the use of MSCs in corneal transplants to clinical practice. PMID

  8. Bilateral Keratectasia 34 Years after Corneal Transplant

    Directory of Open Access Journals (Sweden)

    Xavier Valldeperas

    2010-07-01

    Full Text Available We report the clinical findings of a patient with severe bilateral keratectasia 34 years after a penetrating keratoplasty (PK in both eyes. An otherwise healthy 67-year-old man complained of deterioration of the eyesight in both eyes over the last 6 months. The patient was diagnosed with bilateral keratoconus at the age of 32 years, and he underwent a bilateral PK. At presentation, visual acuity was 20/200 in the right eye and light perception in the left eye. A Pentacam pachymetric map revealed a central pachymetry of 720 µm in the right eye and of 710 µm in the left eye, as well as an average paracentral pachymetry of 436 and 270 µm in the 9-mm zone in the right and the left eye, respectively. Corneal topography revealed bilateral irregular and asymmetric bowing with generalized steepening and high corneal power. We describe a case of bilateral keratectasia 34 years after PK in a patient who was originally diagnosed with bilateral keratoconus.

  9. Acute corneal hydrops in keratoconus

    Directory of Open Access Journals (Sweden)

    Prafulla K Maharana

    2013-01-01

    Full Text Available Acute corneal hydrops is a condition characterized by stromal edema due to leakage of aqueous through a tear in descemet membrane. The patient presents with sudden onset decrease in vision, photophobia, and pain. Corneal thinning and ectasias combined with trivial trauma to the eye mostly by eye rubbing is considered as the underlying cause. With conservative approach self-resolution takes around 2 to 3 months. Surgical intervention is required in cases of non-resolution of corneal edema to avoid complications and for early visual rehabilitation. Intracameral injection of air or gas such as perflouropropane is the most common surgical procedure done. Recent investigative modality such as anterior segment optical coherence tomography is an extremely useful tool for diagnosis, surgical planning, and postoperative follow up. Resolution of hydrops may improve the contact lens tolerance and visual acuity but most cases require keratoplasty for visual rehabilitation.

  10. 近视屈光度数与角膜屈光力和非球面系数的相关性%Preliminary study of the correlation between refractive error and corneal refractive power, corneal asphericity in myopic eye

    Institute of Scientific and Technical Information of China (English)

    韩启超; 冯梅艳

    2014-01-01

    目的:对不同近视屈光状态下人眼角膜总屈光力、后表面屈光力、眼轴、角膜非球面参数 Q 值、中央角膜厚度(central cornea thickness, CCT)及眼压进行测量,并探讨近视度数与上述相关参数的关系。  方法:近视患者138例138眼(所有患者选择右眼进行分析),根据综合验光仪测量的近视度数,患者分为三组:低度近视组(-1.00D~-3.00D),中度近视组(-3.25D~-6.00D),高度近视组(>-6.00D)。各眼使用Pentacam眼前节分析仪(德国,Oculus公司)进行检测,获得角膜总屈光力和后表面屈光力以及Q值,使用非接触式眼压测量仪(日本Canon公司)测量眼压,使用 A 超测量仪(美国Tomey公司AL-3000)测量中央角膜厚度(CCT)和眼轴长度。数据采用Pearson相关性分析、单因素方差分析进行处理。  结果:近视度数与眼轴呈负相关(r=-0.682, P  结论:角膜屈光力在近视发展过程中有正视化作用,Q值与近视度数及眼压的相关关系对指导角膜屈光手术有临床意义。%AIM: To investigate the correlation between myopic refractive error and relative factors, including the corneal refractive power, posterior refractive power, axial length, corneal asphericity coefficient Q value, central cornea thickness ( CCT) and intraocular pressure ( IOP) . METHODS: According to the degree of myopia measured by subjective refraction, 138 myopia patients were divided into three subgroups:mild group (-1. 00D--3. 00D), moderate group (-3. 25D--6. 00D), high group (>6. 00D). The Pentacam anterior segment tomographer (Germany, Oculus Company) was used to measure the corneal refractive power, posterior refractive power, and corneal asphericity in the right eye. IOP, CCT and axial length were measured by a non-contact tonometer and A-scan ultrasonic, respectively. The data was analyzed with a Pearson correlation analysis and one-way ANOVA. RESULTS: The myopic refractive error was negatively correlated with

  11. Collagens and proteoglycans of the corneal extracellular matrix

    Directory of Open Access Journals (Sweden)

    Y.M. Michelacci

    2003-08-01

    Full Text Available The cornea is a curved and transparent structure that provides the initial focusing of a light image into the eye. It consists of a central stroma that constitutes 90% of the corneal depth, covered anteriorly with epithelium and posteriorly with endothelium. Its transparency is the result of the regular spacing of collagen fibers with remarkably uniform diameter and interfibrillar space. Corneal collagen is composed of heterotypic fibrils consisting of type I and type V collagen molecules. The cornea also contains unusually high amounts of type VI collagen, which form microfibrillar structures, FACIT collagens (XII and XIV, and other nonfibrillar collagens (XIII and XVIII. FACIT collagens and other molecules, such as leucine-rich repeat proteoglycans, play important roles in modifying the structure and function of collagen fibrils.Proteoglycans are macromolecules composed of a protein core with covalently linked glycosaminoglycan side chains. Four leucine-rich repeat proteoglycans are present in the extracellular matrix of corneal stroma: decorin, lumican, mimecan and keratocan. The first is a dermatan sulfate proteoglycan, and the other three are keratan sulfate proteoglycans. Experimental evidence indicates that the keratan sulfate proteoglycans are involved in the regulation of collagen fibril diameter, and dermatan sulfate proteoglycan participates in the control of interfibrillar spacing and in the lamellar adhesion properties of corneal collagens. Heparan sulfate proteoglycans are minor components of the cornea, and are synthesized mainly by epithelial cells. The effect of injuries on proteoglycan synthesis is discussed.

  12. Progress in corneal wound healing.

    Science.gov (United States)

    Ljubimov, Alexander V; Saghizadeh, Mehrnoosh

    2015-11-01

    Corneal wound healing is a complex process involving cell death, migration, proliferation, differentiation, and extracellular matrix remodeling. Many similarities are observed in the healing processes of corneal epithelial, stromal and endothelial cells, as well as cell-specific differences. Corneal epithelial healing largely depends on limbal stem cells and remodeling of the basement membrane. During stromal healing, keratocytes get transformed to motile and contractile myofibroblasts largely due to activation of transforming growth factor-β (TGF-β) system. Endothelial cells heal mostly by migration and spreading, with cell proliferation playing a secondary role. In the last decade, many aspects of wound healing process in different parts of the cornea have been elucidated, and some new therapeutic approaches have emerged. The concept of limbal stem cells received rigorous experimental corroboration, with new markers uncovered and new treatment options including gene and microRNA therapy tested in experimental systems. Transplantation of limbal stem cell-enriched cultures for efficient re-epithelialization in stem cell deficiency and corneal injuries has become reality in clinical setting. Mediators and course of events during stromal healing have been detailed, and new treatment regimens including gene (decorin) and stem cell therapy for excessive healing have been designed. This is a very important advance given the popularity of various refractive surgeries entailing stromal wound healing. Successful surgical ways of replacing the diseased endothelium have been clinically tested, and new approaches to accelerate endothelial healing and suppress endothelial-mesenchymal transformation have been proposed including Rho kinase (ROCK) inhibitor eye drops and gene therapy to activate TGF-β inhibitor SMAD7. Promising new technologies with potential for corneal wound healing manipulation including microRNA, induced pluripotent stem cells to generate corneal

  13. Progress in corneal wound healing.

    Science.gov (United States)

    Ljubimov, Alexander V; Saghizadeh, Mehrnoosh

    2015-11-01

    Corneal wound healing is a complex process involving cell death, migration, proliferation, differentiation, and extracellular matrix remodeling. Many similarities are observed in the healing processes of corneal epithelial, stromal and endothelial cells, as well as cell-specific differences. Corneal epithelial healing largely depends on limbal stem cells and remodeling of the basement membrane. During stromal healing, keratocytes get transformed to motile and contractile myofibroblasts largely due to activation of transforming growth factor-β (TGF-β) system. Endothelial cells heal mostly by migration and spreading, with cell proliferation playing a secondary role. In the last decade, many aspects of wound healing process in different parts of the cornea have been elucidated, and some new therapeutic approaches have emerged. The concept of limbal stem cells received rigorous experimental corroboration, with new markers uncovered and new treatment options including gene and microRNA therapy tested in experimental systems. Transplantation of limbal stem cell-enriched cultures for efficient re-epithelialization in stem cell deficiency and corneal injuries has become reality in clinical setting. Mediators and course of events during stromal healing have been detailed, and new treatment regimens including gene (decorin) and stem cell therapy for excessive healing have been designed. This is a very important advance given the popularity of various refractive surgeries entailing stromal wound healing. Successful surgical ways of replacing the diseased endothelium have been clinically tested, and new approaches to accelerate endothelial healing and suppress endothelial-mesenchymal transformation have been proposed including Rho kinase (ROCK) inhibitor eye drops and gene therapy to activate TGF-β inhibitor SMAD7. Promising new technologies with potential for corneal wound healing manipulation including microRNA, induced pluripotent stem cells to generate corneal

  14. Get It through Your Thick Head: Emerging Principles in Neuroimmunology and Neurovirology Redefine Central Nervous System "Immune Privilege".

    Science.gov (United States)

    Solomos, Andreas C; Rall, Glenn F

    2016-04-20

    The central nervous system (CNS) coordinates all aspects of life, autonomic and sentient, though how it has evolved to contend with pathogenic infections remains, to a great degree, a mystery. The skull and cerebrospinal fluid (CSF) provide protection from blunt force contacts, and it was once thought that the blood-brain barrier (BBB) was a fortress that restricted pathogen entry and limited inflammation. Recent studies, however, have caused a revision of this viewpoint: the CNS is monitored by blood-borne lymphocytes, but can use alternative strategies to prevent or resolve many pathogenic challenges. In this Review, we discuss emerging principles that indicate how the CNS is immunologically unique from peripheral tissues. We focus on developments that include glymphatics, recently characterized brain lymphatic vessels, distinctions in innate and adaptive immune strategies, novel points of entry for neurotropic viruses, and, finally, how the periphery can influence CNS homeostasis and immune responses within the brain. Collectively, these attributes demand a re-evaluation of immunity in the brain: not privileged, but distinct. PMID:26854733

  15. Role of Human Corneal Stroma-Derived Mesenchymal-Like Stem Cells in Corneal Immunity and Wound Healing.

    Science.gov (United States)

    Veréb, Zoltán; Póliska, Szilárd; Albert, Réka; Olstad, Ole Kristoffer; Boratkó, Anita; Csortos, Csilla; Moe, Morten C; Facskó, Andrea; Petrovski, Goran

    2016-01-01

    Corneal tissue regeneration is of crucial importance for maintaining normal vision. We aimed to isolate and cultivate human corneal stroma-derived mesenchymal stem-like cells (CSMSCs) from the central part of cadaver corneas and study their phenotype, multipotency, role in immunity and wound healing. The isolated cells grew as monolayers in vitro, expressed mesenchymal- and stemness-related surface markers (CD73, CD90, CD105, CD140b), and were negative for hematopoietic markers as determined by flow cytometry. CSMSCs were able to differentiate in vitro into fat, bone and cartilage. Their gene expression profile was closer to bone marrow-derived MSCs (BMMSCs) than to limbal epithelial stem cells (LESC) as determined by high-throughput screening. The immunosuppressive properties of CSMSCs were confirmed by a mixed lymphocyte reaction (MLR), while they could inhibit proliferation of activated immune cells. Treatment of CSMSCs by pro-inflammatory cytokines and toll-like receptor ligands significantly increased the secreted interleukin-6 (IL-6), interleukin-8 (IL-8) and C-X-C motif chemokine 10 (CXCL-10) levels, as well as the cell surface adhesion molecules. CSMSCs were capable of closing a wound in vitro under different stimuli. These cells thus contribute to corneal tissue homeostasis and play an immunomodulatory and regenerative role with possible implications in future cell therapies for treating sight-threatening corneal diseases. PMID:27195722

  16. Corneal topographic changes after 20-gauge pars plana vitrectomy associated with scleral buckling for the treatment of rhegmatogenous retinal detachment

    Directory of Open Access Journals (Sweden)

    Alexandre Achille Grandinetti

    2013-04-01

    Full Text Available PURPOSE: To evaluate the changes in corneal topography after 20-gauge pars plana vitrectomy associated with scleral buckling for the repair of rhegmatogenous retinal detachment. METHODS: Twenty-five eyes of 25 patients with rhegmatogenous retinal detachment were included in this study. 20-gauge pars plana vitrectomy associated with scleral buckling was performed in all patients. The corneal topography of each was measured before surgery and one week, one month, and three months after surgery by computer-assisted videokeratoscopy. RESULTS: A statistically significant central corneal steepening (average, 0,9 D , p<0,001 was noted one week after surgery. The total corneal astigmatism had a significant increase in the first postoperative month (p=0,007. All these topographic changes persisted for the first month but returned to preoperative values three months after the surgery. CONCLUSION: Pars plana vitrectomy with scleral buckling was found to induce transient changes in corneal topography.

  17. Fate Mapping Mammalian Corneal Epithelia.

    Science.gov (United States)

    Richardson, Alexander; Wakefield, Denis; Di Girolamo, Nick

    2016-04-01

    The anterior aspect of the cornea consists of a stratified squamous epithelium, thought to be maintained by a rare population of stem cells (SCs) that reside in the limbal transition zone. Although migration of cells that replenish the corneal epithelium has been studied for over a century, the process is still poorly understood and not well characterized. Numerous techniques have been employed to examine corneal epithelial dynamics, including visualization by light microscopy, the incorporation of vital dyes and DNA labels, and transplantation of genetically marked cells that have acted as cell and lineage beacons. Modern-day lineage tracing utilizes molecular methods to determine the fate of a specific cell and its progeny over time. Classically employed in developmental biology, lineage tracing has been used more recently to track the progeny of adult SCs in a number of organs to pin-point their location and understand their movement and influence on tissue regeneration. This review highlights key discoveries that have led researchers to develop cutting-edge genetic tools to effectively and more accurately monitor turnover and displacement of cells within the mammalian corneal epithelium. Collating information on the basic biology of SCs will have clinical ramifications in furthering our knowledge of the processes that govern their role in homeostasis, wound-healing, transplantation, and how we can improve current unsatisfactory SC-based therapies for patients suffering blinding corneal disease. PMID:26774909

  18. Systemic cyclosporine and corneal transplantation.

    Science.gov (United States)

    Ziaei, Mohammed; Ziaei, Fatemeh; Manzouri, Bita

    2016-02-01

    Corneal transplantation is the most commonly performed tissue transplant boasting over a century of history, science, and tradition. While favorable outcomes have been reported after penetrating keratoplasty, rejection remains a major cause of graft failure. The long-term survival rates of this relatively immunologically privileged tissue are only just comparable to those of vascularized organs. While corticosteroids treatment remains the gold standard for postoperative immunomodulation, other agents have been utilized in an ongoing effort to improve graft survival and patient outcomes. One of the most promising immunomodulatory substances whose immunosuppressive effect has revolutionized solid organ transplantation is cyclosporine (CsA). A calcineurin inhibitor, cyclosporine has been used as an immunosuppressive agent in corneal transplantation since the 1980's. Although some studies have shown beneficial effects of cyclosporine in both low- and high-risk corneal transplant patients the use of cyclosporine in rejection prophylaxis and treatment remain controversial and disputable. We herein present a literature review on the role of systemic cyclosporine in corneal transplantation.

  19. Systemic cyclosporine and corneal transplantation.

    Science.gov (United States)

    Ziaei, Mohammed; Ziaei, Fatemeh; Manzouri, Bita

    2016-02-01

    Corneal transplantation is the most commonly performed tissue transplant boasting over a century of history, science, and tradition. While favorable outcomes have been reported after penetrating keratoplasty, rejection remains a major cause of graft failure. The long-term survival rates of this relatively immunologically privileged tissue are only just comparable to those of vascularized organs. While corticosteroids treatment remains the gold standard for postoperative immunomodulation, other agents have been utilized in an ongoing effort to improve graft survival and patient outcomes. One of the most promising immunomodulatory substances whose immunosuppressive effect has revolutionized solid organ transplantation is cyclosporine (CsA). A calcineurin inhibitor, cyclosporine has been used as an immunosuppressive agent in corneal transplantation since the 1980's. Although some studies have shown beneficial effects of cyclosporine in both low- and high-risk corneal transplant patients the use of cyclosporine in rejection prophylaxis and treatment remain controversial and disputable. We herein present a literature review on the role of systemic cyclosporine in corneal transplantation. PMID:26463642

  20. Development and Beam-Shape Analysis of an Integrated Fiber-Optic Confocal Probe for High-Precision Central Thickness Measurement of Small-Radius Lenses

    Directory of Open Access Journals (Sweden)

    Boonsong Sutapun

    2015-04-01

    Full Text Available This work describes a new design of a fiber-optic confocal probe suitable for measuring the central thicknesses of small-radius optical lenses or similar objects. The proposed confocal probe utilizes an integrated camera that functions as a shape-encoded position-sensing device. The confocal signal for thickness measurement and beam-shape data for off-axis measurement can be simultaneously acquired using the proposed probe. Placing the probe’s focal point off-center relative to a sample’s vertex produces a non-circular image at the camera’s image plane that closely resembles an ellipse for small displacements. We were able to precisely position the confocal probe’s focal point relative to the vertex point of a ball lens with a radius of 2.5 mm, with a lateral resolution of 1.2 µm. The reflected beam shape based on partial blocking by an aperture was analyzed and verified experimentally. The proposed confocal probe offers a low-cost, high-precision technique, an alternative to a high-cost three-dimensional surface profiler, for tight quality control of small optical lenses during the manufacturing process.

  1. The effect of 193 nm excimer laser radiation on the human corneal endothelial cell density

    Energy Technology Data Exchange (ETDEWEB)

    Isager, P.; Hjortdal, J.Oe.; Ehlers, N. [Aarhus Univ. Hospital, Dept. of Ophthalmology, Aarhus (Denmark)

    1996-06-01

    The effect of 193 nm excimer laser radiation on human corneal endothelial cell density was examined. Fifty-five eyes from 35 patients underwent photorefractive keratectomy for myopia. Photomicrographs of the endothelium were taken a short time before the operation and on an average of 7 months postoperatively with a specular microscope. The average endothelial cell densities were preoperatively 3375 {+-} 266 cells/mm{sup 2} (means {+-} SD) and postoperatively 3348 {+-} 287 cells/mm{sup 2}, corresponding to a fall of 27 cells/mm{sup 2} (N = 55). This fall in endothelial cell density was not statistically significant. A significant correlation between the change in cell density and age of the patient was found, with older patients losing more cells (N = 35, 2p < 0.05). The magnification of the specular microscope was found to change with corneal thickness. The importance of correcting the endothelial cell densities for corneal thickness is discussed. (au) 14 refs.

  2. Corneal stroma microfibrils

    KAUST Repository

    Hanlon, Samuel D.

    2015-03-01

    Elastic tissue was first described well over a hundred years ago and has since been identified in nearly every part of the body. In this review, we examine elastic tissue in the corneal stroma with some mention of other ocular structures which have been more thoroughly described in the past. True elastic fibers consist of an elastin core surrounded by fibrillin microfibrils. However, the presence of elastin fibers is not a requirement and some elastic tissue is comprised of non-elastin-containing bundles of microfibrils. Fibers containing a higher relative amount of elastin are associated with greater elasticity and those without elastin, with structural support. Recently it has been shown that the microfibrils, not only serve mechanical roles, but are also involved in cell signaling through force transduction and the release of TGF-β. A well characterized example of elastin-free microfibril bundles (EFMBs) is found in the ciliary zonules which suspend the crystalline lens in the eye. Through contraction of the ciliary muscle they exert enough force to reshape the lens and thereby change its focal point. It is believed that the molecules comprising these fibers do not turn-over and yet retain their tensile strength for the life of the animal. The mechanical properties of the cornea (strength, elasticity, resiliency) would suggest that EFMBs are present there as well. However, many authors have reported that, although present during embryonic and early postnatal development, EFMBs are generally not present in adults. Serial-block-face imaging with a scanning electron microscope enabled 3D reconstruction of elements in murine corneas. Among these elements were found fibers that formed an extensive network throughout the cornea. In single sections these fibers appeared as electron dense patches. Transmission electron microscopy provided additional detail of these patches and showed them to be composed of fibrils (~10nm diameter). Immunogold evidence clearly

  3. Intraocular lens power calculations using a Scheimpflug camera to measure corneal power.

    Science.gov (United States)

    Xu, K; Hao, Y; Qi, H

    2014-07-01

    We measured corneal power using an Oculus Pentacam(®) to assess its accuracy for calculating intraocular lens (IOL) power after myopic refractive surgery. A series of corneal power measurements were performed on 22 patients (43 eyes) who had undergone myopic refractive surgery. In 37 of the 43 eyes, phacoemulsification and IOL implantation subsequently were performed. Conventional keratometry and three corneal measurements (mean true net power, central true net power, and 4.5 mm equivalent K reading) obtained using a Pentacam were analyzed and compared to values derived from the clinical history method. Prediction errors of three Pentacam corneal power measurements inserted in third generation IOL formulas also were compared. Analysis of the variance showed that only two Pentacam corneal measurements, mean true net power and central true net power, were not significantly different from those of the clinical history method. Mean true net power was correlated more closely with the clinical history method corneal power than other corneal power values. The one-sample t-test showed that of three Pentacam corneal measurements combined with third-generation formulas, only the mean true net power inserted in the SRK/T implant power calculation formula was not significantly different from zero. The percentages of eyes within ± 0.50 D and ± 1.00 D of the refractive prediction error of this method were 67.6% and 86.5%, respectively. Mean true net power inserted in the SRK/T formula can be used to calculate directly IOL power after myopic refractive surgery.

  4. Measuring Corneal Haze by Using Scheimpflug Photography and Confocal Microscopy

    Science.gov (United States)

    McLaren, Jay W.; Wacker, Katrin; Kane, Katrina M.; Patel, Sanjay V.

    2016-01-01

    Purpose We compared corneal backscatter estimated from a Scheimpflug camera with backscatter estimated from a clinical confocal microscope across a wide range of corneal haze. Methods A total of 59 corneas from 35 patients with a range of severity of Fuchs' endothelial corneal dystrophy and 15 corneas from 9 normal participants were examined using a Scheimpflug camera (Pentacam) and a confocal microscope (ConfoScan 4). The mean image brightness from the anterior 120 μm, midcornea, and posterior 60 μm of the cornea across the central 2 mm recorded by the Scheimpflug camera and analogous regions from the confocal microscope were measured and standardized. Differences between instruments and correlations between backscatter and disease severity were determined by using generalized estimating equation models. Results Backscatter measured by the two instruments in the anterior and midcornea were correlated (r = 0.67 and 0.43, respectively, P < 0.001), although in the posterior cornea they were not correlated (r = 0.13, P = 0.66). Measured with the Scheimpflug camera, mean backscatter from the anterior and midcornea were greater, whereas backscatter from the posterior cornea was lower (P < 0.001) than that measured by the confocal microscope. Backscatter from the anterior cornea was correlated with disease severity for both instruments (Scheimpflug, r = 0.55, P < 0.001; confocal, r = 0.49, P = 0.003). Conclusions The Scheimpflug camera and confocal microscope should not be used interchangeably to measure corneal haze. The ability to detect changes in backscatter with disease severity is superior with the Scheimpflug camera. However, the confocal microscope provides higher resolution of corneal structure. PMID:26803798

  5. In vivo Confocal Microscopy Report after Lasik with Sequential Accelerated Corneal Collagen Cross-Linking Treatment

    Directory of Open Access Journals (Sweden)

    Cosimo Mazzotta

    2014-04-01

    Full Text Available We report the first pilot qualitative confocal microscopic analysis of a laser in situ keratomileusis (Lasik treatment combined with sequential high-fluence accelerated corneal collagen cross-linking, denominated Lasik XTra, by means of HRT II laser scanning in vivo confocal microscopy after a 6-month follow-up. After obtaining approval from the Siena University Hospital Institutional Review Board, a 33-year-old female patient underwent a Lasik XTra procedure in her left eye. Confocal analysis demonstrated induced slight corneal microstructural changes by the interaction between UV-A, riboflavin and corneal stromal collagen, beyond the interface to a depth of 160 µm, without adverse events at the interface and endothelial levels. This application may be considered a prophylactic biomechanical treatment, stiffening the intermediate corneal stroma to prevent corneal ectasia and stabilizing the clinical results of refractive surgery. According to our preliminary experiences, this combined approach may be useful in higher-risk Lasik patients for hyperopic treatments, high myopia and lower corneal thicknesses.

  6. Management of corneal bee sting

    Directory of Open Access Journals (Sweden)

    Razmjoo H

    2011-12-01

    Full Text Available Hassan Razmjoo1,2, Mohammad-Ali Abtahi1,2,4, Peyman Roomizadeh1,3, Zahra Mohammadi1,2, Seyed-Hossein Abtahi1,3,41Medical School, Isfahan University of Medical Sciences (IUMS; 2Ophthalmology Ward, Feiz Hospital, IUMS; 3Isfahan Medical Students Research Center (IMSRC, IUMS; 4Isfahan Ophthalmology Research Center (IORC, Feiz Hospital, IUMS, Isfahan, IranAbstract: Corneal bee sting is an uncommon environmental eye injury that can result in various ocular complications with an etiology of penetrating, immunologic, and toxic effects of the stinger and its injected venom. In this study we present our experience in the management of a middle-aged male with a right-sided deep corneal bee sting. On arrival, the patient was complaining of severe pain, blurry vision with acuity of 160/200, and tearing, which he had experienced soon after the injury. Firstly, we administered conventional drugs for eye injuries, including topical antibiotic, corticosteroid, and cycloplegic agents. After 2 days, corneal stromal infiltration and edema developed around the site of the sting, and visual acuity decreased to 100/200. These conditions led us to remove the stinger surgically. Within 25 days of follow-up, the corneal infiltration decreased gradually, and visual acuity improved to 180/200. We suggest a two-stage management approach for cases of corneal sting. For the first stage, if the stinger is readily accessible or primary dramatic reactions, including infiltration, especially on the visual axis, exist, manual or surgical removal would be indicated. Otherwise, we recommend conventional treatments for eye injuries. Given this situation, patients should be closely monitored for detection of any worsening. If the condition does not resolve or even deteriorates, for the second stage, surgical removal of the stinger under local or generalized anesthesia is indicated.Keywords: bee sting, stinger, cornea, removal, management, surgery

  7. Turning the tide of corneal blindness

    Directory of Open Access Journals (Sweden)

    Matthew S Oliva

    2012-01-01

    Full Text Available Corneal diseases represent the second leading cause of blindness in most developing world countries. Worldwide, major investments in public health infrastructure and primary eye care services have built a strong foundation for preventing future corneal blindness. However, there are an estimated 4.9 million bilaterally corneal blind persons worldwide who could potentially have their sight restored through corneal transplantation. Traditionally, barriers to increased corneal transplantation have been daunting, with limited tissue availability and lack of trained corneal surgeons making widespread keratoplasty services cost prohibitive and logistically unfeasible. The ascendancy of cataract surgical rates and more robust eye care infrastructure of several Asian and African countries now provide a solid base from which to dramatically expand corneal transplantation rates. India emerges as a clear global priority as it has the world′s largest corneal blind population and strong infrastructural readiness to rapidly scale its keratoplasty numbers. Technological modernization of the eye bank infrastructure must follow suit. Two key factors are the development of professional eye bank managers and the establishment of Hospital Cornea Recovery Programs. Recent adaptation of these modern eye banking models in India have led to corresponding high growth rates in the procurement of transplantable tissues, improved utilization rates, operating efficiency realization, and increased financial sustainability. The widespread adaptation of lamellar keratoplasty techniques also holds promise to improve corneal transplant success rates. The global ophthalmic community is now poised to scale up widespread access to corneal transplantation to meet the needs of the millions who are currently blind.

  8. Turning the tide of corneal blindness.

    Science.gov (United States)

    Oliva, Matthew S; Schottman, Tim; Gulati, Manoj

    2012-01-01

    Corneal diseases represent the second leading cause of blindness in most developing world countries. Worldwide, major investments in public health infrastructure and primary eye care services have built a strong foundation for preventing future corneal blindness. However, there are an estimated 4.9 million bilaterally corneal blind persons worldwide who could potentially have their sight restored through corneal transplantation. Traditionally, barriers to increased corneal transplantation have been daunting, with limited tissue availability and lack of trained corneal surgeons making widespread keratoplasty services cost prohibitive and logistically unfeasible. The ascendancy of cataract surgical rates and more robust eye care infrastructure of several Asian and African countries now provide a solid base from which to dramatically expand corneal transplantation rates. India emerges as a clear global priority as it has the world's largest corneal blind population and strong infrastructural readiness to rapidly scale its keratoplasty numbers. Technological modernization of the eye bank infrastructure must follow suit. Two key factors are the development of professional eye bank managers and the establishment of Hospital Cornea Recovery Programs. Recent adaptation of these modern eye banking models in India have led to corresponding high growth rates in the procurement of transplantable tissues, improved utilization rates, operating efficiency realization, and increased financial sustainability. The widespread adaptation of lamellar keratoplasty techniques also holds promise to improve corneal transplant success rates. The global ophthalmic community is now poised to scale up widespread access to corneal transplantation to meet the needs of the millions who are currently blind.

  9. Clinical applications of corneal confocal microscopy

    Directory of Open Access Journals (Sweden)

    Mitra Tavakoli

    2008-06-01

    Full Text Available Mitra Tavakoli1, Parwez Hossain2, Rayaz A Malik11Division of Cardiovascular Medicine, University of Manchester and Manchester Royal Infirmary, Manchester, UK; 2University of Southampton, Southampton Eye Unit, Southampton General Hospital, Southampton, UKAbstract: Corneal confocal microscopy is a novel clinical technique for the study of corneal cellular structure. It provides images which are comparable to in-vitro histochemical techniques delineating corneal epithelium, Bowman’s layer, stroma, Descemet’s membrane and the corneal endothelium. Because, corneal confocal microscopy is a non invasive technique for in vivo imaging of the living cornea it has huge clinical potential to investigate numerous corneal diseases. Thus far it has been used in the detection and management of pathologic and infectious conditions, corneal dystrophies and ecstasies, monitoring contact lens induced corneal changes and for pre and post surgical evaluation (PRK, LASIK and LASEK, flap evaluations and Radial Keratotomy, and penetrating keratoplasty. Most recently it has been used as a surrogate for peripheral nerve damage in a variety of peripheral neuropathies and may have potential in acting as a surrogate marker for endothelial abnormalities.Keywords: corneal confocal microscopy, cornea, infective keratitis, corneal dystrophy, neuropathy

  10. Chronic exposure to the ultraviolet radiation levels from arc welding does not result in obvious damage to the human corneal endothelium.

    Science.gov (United States)

    Oblak, Emil; Doughty, Michael J

    2002-11-01

    Occupational exposure of the cornea to ultraviolet radiation (UVR, e.g. in welding) is a well-known cause of 'arc eye' (photo-keratoconjunctivitis), but has also been considered to be a risk for the development of alterations in the size (polymegethism) and shape (pleomorphism) of the deeper-lying human corneal endothelial cells. Human data are however limited and so a further study was undertaken, with a control group. Non-contact specular micrographs of the central region of the corneal endothelium were obtained from 40 white males aged between 32 and 63 years; 20 were arc welders with an average of 25 +/- 7 years job experience, while the others were office workers (n = 20). All the welders reported occupational exposure to UVR (i.e. welders 'flashes') and up to 3 times per year. None of the subjects had a history of contact lens wear, major eye disease or surgery. The endothelial image was scanned, projected onto an overlay and cell border marking carried out in a masked fashion. The overlay was independently analysed, by a customised semi-automated method, providing cell-border-adjusted data on cell areas and cell shape (sides) on 124 to 260 cells per image. The endothelial cell density (ECD) values were also calculated from individual cell area values. All corneas appeared to be healthy, and showed no fluorescein staining indicating damage to the surface epithelium. Central corneal thickness values were normal at 0.531 +/- 0.031 (mean +/- SD) and 0.527 +/- 0.036 mm in the welders and non-welders respectively. All endothelia appeared healthy, with no evidence of cell oedema. The group-mean endothelial cell area was 393 +/- 35 and 392 +/- 21 microm2, ECD values were 2855 +/- 224 cells mm(-2) and 2852 +/- 210 cells mm(-2), while the percentages of 6-sided cells were 60 +/- 5.2 and 59 +/- 4.1% respectively. Cell area distributions were statistically identical (p > or = 0.8), and cell area-side relationships were marginally, but not statistically different. This

  11. Visual outcome after corneal transplantation for corneal perforation and iris prolapse in 37 horses

    DEFF Research Database (Denmark)

    Henriksen, Michala de Linde; Plummer, C. E.; Mangan, B.;

    2012-01-01

    We wanted to investigate the visual outcome of horses presented with iris prolapse and treated with corneal transplantation.......We wanted to investigate the visual outcome of horses presented with iris prolapse and treated with corneal transplantation....

  12. [Regeneration and fibrosis of corneal tissues].

    Science.gov (United States)

    Simirskiĭ, V N

    2014-01-01

    In this review, the features of the regeneration of corneal tissue and its disorders leading to the development of fibrosis are considered. The data on the presence of stem (clonogenic) cell pool in the corneal tissues (epithelium, endothelium, stroma) are given; these cells can serve as a source for regeneration of the tissues at injury or various diseases. The main steps of regeneration of corneal tissues and their disorders that lead to outstripping proliferation of myofibroblasts and secretion of extracellular matrix in the wound area and eventually cause the formation of connective tissue scar and corneal opacity are considered. Particular attention is given to the successes of translational medicine in the treatment of corneal tissue fibrosis. The methods of cell therapy aimed at the restoration of stem cell pool of corneal tissues are the most promising. Gene therapy provides more opportunities; one of its main objectives is the suppression of the myofibroblast proliferation responsible for the development of fibrosis.

  13. [Keratoconus, the most common corneal dystrophy. Can keratoplasty be avoided?].

    Science.gov (United States)

    Arne, Jean Louis; Fournié, Pierre

    2011-01-01

    Keratoconus is the most common form of corneal dystrophy. It consists of a non inflammatory progressive thinning process that leads to conical ectasia of the cornea, causing high myopia and astigmatism. In more advanced cases, opacities can be seen at the apex of the cone. Traditional conservative management of keratoconus begins with spectacle correction and contact lenses. Surgery is recommended when a stable contact lens fit fails to provide adequate vision. Keratoplasty was long the only surgical treatment, but recent years have seen the introduction of new surgical options:--Collagen cross-linking stiffens the cornea and can halt disease progression;--Intrastromal corneal rings can reduce astigmatism and improve visual acuity;--Intraocular lenses are valuable additional options for the correction of refractive errors. Currently, keratoplasty is mainly restricted to patients with opacities of the central cornea. PMID:22039707

  14. Glaucoma and Corneal Transplant Procedures

    Directory of Open Access Journals (Sweden)

    Ammar M. Al-Mahmood

    2012-01-01

    Full Text Available Glaucoma after corneal transplantation is a leading cause of ocular morbidity after penetrating keratoplasty. The incidence reported is highly variable and a number of etiologic factors have been identified. A number of treatment options are available; surgical intervention for IOP control is associated with a high incidence of graft failure. IOP elevation is less frequently seen following deep anterior lamellar keratoplasty. Descemet's striping-automated endothelial keratoplasty is also associated with postprocedure intraocular pressure elevation and secondary glaucoma and presents unique surgical challenges in patients with preexisting glaucoma surgeries. Glaucoma exists in up to three-quarters of patients who undergo keratoprosthesis surgery and the management if often challenging. The aim of this paper is to highlight the incidence, etiology, and management of glaucoma following different corneal transplant procedures. It also focuses on the challenges in the diagnosis of glaucoma and intraocular pressure monitoring in this group of patients.

  15. Optimization model for UV-Riboflavin corneal cross-linking

    Science.gov (United States)

    Schumacher, S.; Wernli, J.; Scherrer, S.; Bueehler, M.; Seiler, T.; Mrochen, M.

    2011-03-01

    Nowadays UV-cross-linking is an established method for the treatment of keraectasia. Currently a standardized protocol is used for the cross-linking treatment. We will now present a theoretical model which predicts the number of induced crosslinks in the corneal tissue, in dependence of the Riboflavin concentration, the radiation intensity, the pre-treatment time and the treatment time. The model is developed by merging the difussion equation, the equation for the light distribution in dependence on the absorbers in the tissue and a rate equation for the polymerization process. A higher concentration of Riboflavin solution as well as a higher irradiation intensity will increase the number of induced crosslinks. However, performed stress-strain experiments which support the model showed that higher Riboflavin concentrations (> 0.125%) do not result in a further increase in stability of the corneal tissue. This is caused by the inhomogeneous distribution of induced crosslinks throughout the cornea due to the uneven absorption of the UV-light. The new model offers the possibility to optimize the treatment individually for every patient depending on their corneal thickness in terms of efficiency, saftey and treatment time.

  16. Transparent, resilient human amniotic membrane laminates for corneal transplantation.

    Science.gov (United States)

    Hariya, Takehiro; Tanaka, Yuji; Yokokura, Shunji; Nakazawa, Toru

    2016-09-01

    This study evaluated a new technique to toughen and optically clarify human amniotic membrane (AM) tissue, which is naturally thin and clouded, and determined the suitability of the altered tissue for corneal transplantation. The technique created a tissue laminate by repeatedly depositing wet layers of AM and dehydrating them, followed by chemical cross-linking to tighten integration at the layer interfaces and within the layers, thereby improving the physical properties of the laminates by increasing light transmittance and mechanical strength. Interestingly, this improvement only occurred in laminates with at least 4 layers. Cross-linking also improved the resistance of the laminates to collagenase degradation, such as occurs in corneal melting. This study also confirmed that the AM tissue was biocompatible by inserting AM monolayers into the corneal stroma of rabbits, and by performing lamellar keratoplasty in rabbits with cross-linked AM laminates. The laminates were sufficiently thick and resilient to need only one set of sutures, whereas in previously described multi-layer AM transplantation technique, each layer required separate sutures. The current findings are a promising advance in the engineering of novel biomaterials and the alteration of existing tissues for medical use. PMID:27267629

  17. Corneal alterations induced by topical application of commercial latanoprost, travoprost and bimatoprost in rabbit.

    Directory of Open Access Journals (Sweden)

    Wensheng Chen

    Full Text Available Prostaglandin (PG analogs, including latanoprost, travoprost, and bimatoprost, are currently the most commonly used topical ocular hypotensive medications. The purpose of this study was to investigate the corneal alterations in rabbits following exposure to commercial solution of latanoprost, travoprost and bimatoprost. A total of 64 New Zealand albino rabbits were used and four groups of treatments were constituted. Commercial latanoprost, travoprost, bimatoprost or 0.02% benzalkonium chloride (BAK was applied once daily to one eye each of rabbits for 30 days. The contralateral untreated eyes used as controls. Schirmer test, tear break-up time (BUT, rose Bengal and fluorescein staining were performed on days 5, 10, 20, and 30. Central corneal changes were analyzed by in vivo confocal microscopy, and the corneal barrier function was evaluated by measurement of corneal transepithelial electrical resistance on day 5. Whole mount corneas were analyzed by using fluorescence confocal microscopy for the presence of tight-junction (ZO-1, occludin and adherens-junction (E-cadherin, β-catenin proteins, actin cytoskeleton, proliferative marker Ki67 and cell apoptosis in the epithelium. Topical application of commercial PG analogs resulted in significant corneal epithelial and stromal defects while no significant changes in aqueous tear production, BUT, rose bengal and fluorescein staining scores on day 5. Commercial PG analogs induced dislocation of ZO-1 and occludin from their normal locus, disorganization of cortical actin cytoskeleton at the superficial layer, and disruption of epithelial barrier function. The eyes treated with 0.02% BAK and latanoprost exhibited significantly reduced Schirmer scores, BUT, and increased fluorescein staining scores on days 10 and 30, respectively. Topical application of commercial PG analogs can quickly impair the corneal epithelium and stroma without tear deficiency. Commercial PG analogs break down the barrier

  18. Corneal alterations induced by topical application of commercial latanoprost, travoprost and bimatoprost in rabbit.

    Science.gov (United States)

    Chen, Wensheng; Dong, Nuo; Huang, Caihong; Zhang, Zhenhao; Hu, Jiaoyue; Xie, Hui; Pan, Juxin; Liu, Zuguo

    2014-01-01

    Prostaglandin (PG) analogs, including latanoprost, travoprost, and bimatoprost, are currently the most commonly used topical ocular hypotensive medications. The purpose of this study was to investigate the corneal alterations in rabbits following exposure to commercial solution of latanoprost, travoprost and bimatoprost. A total of 64 New Zealand albino rabbits were used and four groups of treatments were constituted. Commercial latanoprost, travoprost, bimatoprost or 0.02% benzalkonium chloride (BAK) was applied once daily to one eye each of rabbits for 30 days. The contralateral untreated eyes used as controls. Schirmer test, tear break-up time (BUT), rose Bengal and fluorescein staining were performed on days 5, 10, 20, and 30. Central corneal changes were analyzed by in vivo confocal microscopy, and the corneal barrier function was evaluated by measurement of corneal transepithelial electrical resistance on day 5. Whole mount corneas were analyzed by using fluorescence confocal microscopy for the presence of tight-junction (ZO-1, occludin) and adherens-junction (E-cadherin, β-catenin) proteins, actin cytoskeleton, proliferative marker Ki67 and cell apoptosis in the epithelium. Topical application of commercial PG analogs resulted in significant corneal epithelial and stromal defects while no significant changes in aqueous tear production, BUT, rose bengal and fluorescein staining scores on day 5. Commercial PG analogs induced dislocation of ZO-1 and occludin from their normal locus, disorganization of cortical actin cytoskeleton at the superficial layer, and disruption of epithelial barrier function. The eyes treated with 0.02% BAK and latanoprost exhibited significantly reduced Schirmer scores, BUT, and increased fluorescein staining scores on days 10 and 30, respectively. Topical application of commercial PG analogs can quickly impair the corneal epithelium and stroma without tear deficiency. Commercial PG analogs break down the barrier integrity of corneal

  19. A novel closed cell culture device for fabrication of corneal epithelial cell sheets.

    Science.gov (United States)

    Nakajima, Ryota; Kobayashi, Toyoshige; Moriya, Noboru; Mizutani, Manabu; Kan, Kazutoshi; Nozaki, Takayuki; Saitoh, Kazuo; Yamato, Masayuki; Okano, Teruo; Takeda, Shizu

    2015-11-01

    Automation technology for cell sheet-based tissue engineering would need to optimize the cell sheet fabrication process, stabilize cell sheet quality and reduce biological contamination risks. Biological contamination must be avoided in clinical settings. A closed culture system provides a solution for this. In the present study, we developed a closed culture device called a cell cartridge, to be used in a closed cell culture system for fabricating corneal epithelial cell sheets. Rabbit limbal epithelial cells were cultured on the surface of a porous membrane with 3T3 feeder cells, which are separate from the epithelial cells in the cell cartridges and in the cell-culture inserts as a control. To fabricate the stratified cell sheets, five different thicknesses of the membranes which were welded to the cell cartridge, were examined. Multilayered corneal epithelial cell sheets were fabricated in cell cartridges that were welded to a 25 µm-thick gas-permeable membrane, which was similar to the results with the cell-culture inserts. However, stratification of corneal epithelial cell sheets did not occur with cell cartridges that were welded to 100-300 µm-thick gas-permeable membranes. The fabricated cell sheets were evaluated by histological analyses to examine the expression of corneal epithelial-specific markers. Immunohistochemical analyses showed that a putative stem cell marker, p63, a corneal epithelial differentiation maker, CK3, and a barrier function marker, Claudin-1, were expressed in the appropriate position in the cell sheets. These results suggest that the cell cartridge is effective for fabricating corneal epithelial cell sheets.

  20. Efecto de la sedación con dexmedetomidina sobre la presión intraocular y el espesor central de la córnea en perros (Effects of the dexmedetomidine sedation on intraocular pressure and on the central cornea thickness in the dog

    Directory of Open Access Journals (Sweden)

    Cristóbal-Gómez, L.

    2009-05-01

    Full Text Available ResumenDeterminar el efecto de la sedación con dexmedetomidinasobre la presión intraocular (PIO y el espesor central de la córnea (ECC en perros Material y métodos: Estudio realizado en 10 perros a los que se midió la PIO y ECC basales y tras administración tópica de tropicamida 1%. Seguidamente sedamos con dexmedetomidina 5µg/kg IV y valoramos PIO y ECC a los 5,10, 15 y 20 minutos post-sedación. Los valores medios se compararon mediante la prueba t de Student para muestras pareadas. Resultados: Los valores medios basales de PIO fueron media ± D.E. 10,95 ± 1,70 mmHg; y 571 ± 21,42 µm para el ECC. No existe asociación significativa entre PIO y ECC (r= -0,2399. La midriasis no varió significativamente los valores de PIO (P= 0,3665 pero sí el ECC (P=5,6109x10-6. La sedación con dexmedetomidina no varía significativamente los valores de PIO ni ECC (P>0,05. Conclusiones midriasis provocada por tropicamida 1% disminuyesignificativamente el ECC pero no la PIO. La sedación condexmedetomidina 5 mg/kg IV no varía significativamente los valores basales de PIO ni del ECC.SummaryObjective: to determine the effects of the dexmedetomidine sedation onintraocular pressure (IOP and on the central corneal thickness (CCT.Material and methods: this study has been performed over 10 dogstreated in the Veterinary Clinical Hospital of Córdoba University. The IOP and the CCT were measured before and after administration of one drop of 1% tropicamide. Thereafter, they were sedated with dexmedetomidine 5 µg/kg IV, and IOP and CCT were evaluated at 5, 10, 15 and 20 minutes after sedation. A t-Student test was performed with paired samples of mean values in order to compare both groups.Results: Basal values of IOP were 10.95 ± 1.70 mmHg, whereas CCTmean values were 571 ± 21.42µm. There were no statistically significant association between IOP and CCT (Pearson correlation r= -0.2399.Mydriasis did not significantly change the values of IOP (P= 0

  1. Feline corneal sequestration Seqüestração corneana dos felinos

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    Arianne Pontes Oriá

    2001-06-01

    Full Text Available Corneal sequestration is a disease unique to domestic cats, clinically characterized by chronicity; signs of ocular pain with the development of a dark brown to black, opaque, oval, paracentral or central corneal plaque. The purpose of this review article was to approach and discuss about the etiology, clinical manifestations, diagnosis, and treatment of the corneal sequestrum.Seqüestro corneano é uma doença única dos gatos domésticos. Caracterizada clinicamente pela crônicidade, sinais de dor ocular, com desenvolvimento de placa marrom a enegrecida, opaca, de localização central ou paracentral. O propósito deste artigo de revisão é abordar e discutir questões sobre a etiologia, manifestações clínicas, diagnóstico e tratamento da enfermidade.

  2. Evaluation of corneal changes after myopic LASIK using the Pentacam®

    Directory of Open Access Journals (Sweden)

    Khairat YM

    2013-09-01

    Full Text Available Yehia M Khairat, Yasser H Mohamed, Ismail ANO Moftah, Narden N Fouad Department of Ophthalmology, Faculty of Medicine, El-Minya University, Egypt Background: In this study, we used a Pentacam® device to evaluate the corneal changes that occur after laser-assisted in situ keratomileusis (LASIK. Methods: Our study included 60 eyes of 32 patients. All patients were treated for myopia and myopic astigmatism using LASIK. The eyes were examined preoperatively and 3 months postoperatively using a Pentacam to assess corneal changes with regard to curvature, elevation, and asphericity of the cornea. Results: A statistically significant decrease in mean keratometric power of the anterior corneal surface (P = 0.001 compared with its pre-LASIK value was detected after 3 months, but there was no significant change in keratometric power of the posterior surface (P = 0.836. Asphericity (Q-value of the anterior and posterior surfaces increased significantly after LASIK (P = 0.001. A significant forward bulge of the anterior corneal surface 4 mm and 7 mm from the central zone was detected 3 months post-LASIK (P = 0.001 for both, but there was no significant increase in posterior elevation at 4 mm and 7 mm from the center (P = 0.637 and P = 0.26, respectively. No cases of post-LASIK ectasia were detected. Correlation between different parameters of the corneal surface revealed an indirect relation between changes in pachymetry and anterior corneal elevation at 4 mm and 7 mm from the central zone (r = −0.27, P = 0.13, and r = −0.37, P = 0.04, respectively, and a direct proportion between changes in pachymetry and mean keratometric power of the anterior and posterior corneal surfaces (r = 0.7, P = 0.001 and r = 0.4, P = 0.028, respectively. Conclusion: LASIK causes significant changes at the anterior corneal surface but the effect is subtle and insignificant at the posterior surface. Keywords: LASIK, laser-assisted in situ keratomileusis, Pentacam®, corneal

  3. Corneal staining after treatment with topical tetracycline

    NARCIS (Netherlands)

    R. Lapid-Gortzak; C.P. Nieuwendaal; A.R. Slomovic; L. Spanjaard

    2006-01-01

    Purpose: The purpose of this paper is to report a case of corneal staining after treatment with topical tetracycline. Methods: A patient with crystalline keratopathy caused by Streptococcus viridans after corneal transplantation was treated topically with tetracycline eye drops, based on results of

  4. Corynebacterium macginleyi isolated from a corneal ulcer

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    Kathryn Ruoff

    2010-02-01

    Full Text Available We report the isolation of Corynebacterium macginleyi from the corneal ulcer culture of a patient, later enrolled in the Steroids for Corneal Ulcer Trial (SCUT. To our knowledge this is the first published report from North America of the recovery of C. macginleyi from a serious ocular infection.

  5. Clinical Significance of Central Corneal Thickness in the Management of Glaucoma%角膜中央厚度在青光眼处理中的临床意义

    Institute of Scientific and Technical Information of China (English)

    Carolyn Y.Shih,MD; Joshua S.Graff Zivin,PhD; Stephen L.Trokel,MD; James C.Tsai,MD; 李晓宇

    2005-01-01

    目的:评价角膜中央厚度测定在青光眼及可疑青光眼患者临床处理中的作用.方法:对188例连续患者进行横断面的、回顾性研究.用超声角膜测厚法测量角膜中央厚度,用Gold-mann压平眼压计测量相应的眼压.运用线性及数学(Orssengo-Pye)算法对眼压进行校正.定义校正前后眼压变化值≥1.5mm H-g(1kPa=7.5mm Hg)为测量显著性改变,校正前后眼压变化值≥3.0mm Hg为结果显著性改变.同时统计了有测量显著性或结果显著性改变的患者的治疗方案变化,如局部抗青光眼用药的变化及增加或取消抗青光眼激光及手术的变化.结果:运用线性校正模型,188例患者中105例(55.9%)至少有测量显著性眼压改变,67例(35.6%)眼压改变介于1.5~3.0mm Hg,38例(20.2%)有结果显著性眼压改变(≥3.0mm Hg).188例患者中16例(8.5%)有局部用药的变化,4例(2.1%)有激光治疗的改变,6例(3.2%)有抗青光眼手术治疗的改变.同时运用指数校正模型(OrssengoPre)得出相似的结果.结论:运用超声测量法进行的角膜中央厚度测定在青光眼及可疑青光眼患者的临床处理中具显著意义.

  6. Comparison of central corneal thickness measurement with Pentacam, Sirius and an ultrasonic pachymeter%Pentacam和Sirius地形图系统与超声测厚仪角膜厚度的对比研究

    Institute of Scientific and Technical Information of China (English)

    郭慧; 顾宝文; 杨旭; 张醇; 肖海华

    2012-01-01

    目的:探讨Sirius与Pentacam及超声测厚仪测量中央角膜厚度的一致性.方法:对51例102眼正常人采用Pentacam和Sirius及超声角膜测厚仪三种仪器测量角膜厚度,记录并比较三种方法测量所得中央角膜厚度结果,同时运用Bland-Altman法绘制图表分析两两间一致性.结果:A超中央角膜厚度平均值低于 Pentacam的平均值,Sirius中央角膜厚度的平均值最接近A超平均值.Sirius与Pentacam一致性的比较:其Bland-Altman图中3.92%的点在95%一致性界限以外.在一致性界限以内,Sirius与Pentacam中央角膜厚度差值的绝对值最大为19.5μm.Sirius与A超一致性的比较:其Bland-Altman图中2.94%的点在95%一致性界限以外.在一致性界限以内,Sirius与A超中央角膜厚度差值的绝对值最大为18.667μm.Pentacam与A超一致性的比较:其Bland-Altman图中5 82%点在95%一致性界限以外.在一致性界限以内,Pentacam与A超中央角膜厚度差值的绝对值最大为25 33μm.结论:Sirius系统与Pentacam系统具有良好的一致性,且Sirius系统比Pentacam系统更接近A超角膜测厚的结果.

  7. Corneal abrasions associated with pepper spray exposure.

    Science.gov (United States)

    Brown, L; Takeuchi, D; Challoner, K

    2000-05-01

    Pepper spray containing oleoresin capsicum is used by law enforcement and the public as a form of nonlethal deterrent. Stimulated by the identification of a case of a corneal abrasion associated with pepper spray exposure, a descriptive retrospective review of a physician-maintained log of patients presenting to a jail ward emergency area over a 3-year period was performed. The objective was to give some quantification to the frequency with which an emergency physician could expect to see corneal abrasions associated with pepper spray exposure. Of 100 cases of pepper spray exposure identified, seven patients had sustained corneal abrasions. We conclude that corneal abrasions are not rare events when patients are exposed to pepper spray and that fluorescein staining and slit lamp or Wood's lamp examination should be performed on all exposed patients in whom corneal abrasions cannot be excluded on clinical grounds. PMID:10830682

  8. Corneal Topographical Changes Flollowing Strabismus Surgery

    Institute of Scientific and Technical Information of China (English)

    MaiGH; WangZ

    1999-01-01

    Purpose:To study corneal topographical changes after strabismus surgery.Methods:Computer-aided corneal topography was used in 43 strabismus patients(45 eyes)one or two days prior to and six or seven ays after strabismus surgery.The spherical and cylindrical equivalents were calculated based on the simulated keratometry.Results:After the surgery,only the changes at 3mm in the inferior quadrant were statistically significant.The changes at 3mm in the rest quadrants and the changes at 7mm were no significant.Significant changes in spherical equivalent were found post-operatively.neither the horizontal nor the verical meridional equivalent showed significant changes after surgery.Conclusions:The results of corneal topographical changes following strabismus surgery in our preliminary study indicated the little effect of strabismus surgery on corneal curvature and corneal astigmatism.

  9. Corneal neovascularization and contemporary antiangiogenic therapeutics.

    Science.gov (United States)

    Hsu, Chih-Chien; Chang, Hua-Ming; Lin, Tai-Chi; Hung, Kuo-Hsuan; Chien, Ke-Hung; Chen, Szu-Yu; Chen, San-Ni; Chen, Yan-Ting

    2015-06-01

    Corneal neovascularization (NV), the excessive ingrowth of blood vessels from conjunctiva into the cornea, is a common sequela of disease insult that can lead to visual impairment. Clinically, topical steroid, argon laser photocoagulation, and subconjunctival injection of bevacizumab have been used to treat corneal NV. Sometimes, the therapies are ineffective, especially when the vessels are large. Large vessels are difficult to occlude and easily recanalized. Scientists and physicians are now dedicated to overcoming this problem. In this article, we briefly introduce the pathogenesis of corneal NV, and then highlight the existing animal models used in corneal NV research-the alkali-induced model and the suture-induced model. Most of all, we review the potential therapeutic targets (i.e., vascular endothelial growth factor and platelet-derived growth factor) and their corresponding inhibitors, as well as the immunosuppressants that have been discovered in recent years by corneal NV studies.

  10. Management of pediatric corneal limbal dermoids

    Directory of Open Access Journals (Sweden)

    Pirouzian A

    2013-03-01

    Full Text Available Amir Pirouzian1,21Tayani Institute, Division of Ophthalmology and Cornea, Mission Viejo in affiliation with Children’s Hospital of Orange County at Mission Hospital, CA, USA; 2Rady’s Children’s Hospital of San Diego, San Diego, CA, USAAbstract: This paper reviews the data in the published literature (PubMed from 1937 to 2011 concerning the medical and surgical management of pediatric limbal dermoids. Current standard medical treatment for grade I pediatric limbal dermoids (ie, with superficial corneal involvment is initially conservative. In stages II (ie, affecting the full thickness of the cornea with/without endothelial involvement and III (ie, involvement of entire cornea and anterior chamber, a combination of excision, lamellar keratoplasty, and amniotic membrane and limbal stem cell tranplantation are advocated. Combinations of these approaches seem to yield better and more stable long-term ocular surface cosmesis and fewer complications in comparison with traditional methods of excision and lamellar keratoplasty. Management of amblyopia (i.e. occlusion treatment, chemical penalization with/without spectacle wear, etc must continue after surgical excision to yield optimal results when or if the surgery is done at a younger age.Keywords: limbal dermoid, amniotic membrane, surgical management, tissue adhesive

  11. NK cells modulate the inflammatory response to corneal epithelial abrasion and thereby support wound healing

    Science.gov (United States)

    Natural killer cells are lymphocytes of the innate immune system that have crucial cytotoxic and regulatory roles in adaptive immunity and inflammation. Herein, we consider a role for these cells in corneal wound healing. After a 2-mm central epithelial abrasion of the mouse cornea, a subset of clas...

  12. Corneal Sensitivity and Dry Eye Symptoms in Patients with Keratoconus

    Science.gov (United States)

    Dienes, Lóránt; Kiss, Huba J.; Perényi, Kristóf; Nagy, Zoltán Z.; Acosta, M. Carmen; Gallar, Juana; Kovács, Illés

    2015-01-01

    Purpose To investigate corneal sensitivity to selective mechanical, chemical, and thermal stimulation and to evaluate their relation to dry eye symptoms in patients with keratoconus. Methods Corneal sensitivity to mechanical, chemical, and thermal thresholds were determined using a gas esthesiometer in 19 patients with keratoconus (KC group) and in 20 age-matched healthy subjects (control group). Tear film dynamics was assessed by Schirmer I test and by the non-invasive tear film breakup time (NI-BUT). All eyes were examined with a rotating Scheimpflug camera to assess keratoconus severity. Results KC patients had significatly decreased tear secretion and significantly higher ocular surface disease index (OSDI) scores compared to controls (5.3±2.2 vs. 13.2±2.0 mm and 26.8±15.8 vs. 8.1±2.3; p0.05). The mean threshold for selective mechanical (KC: 139.2±25.8 vs. control: 109.1±24.0 ml/min), chemical (KC: 39.4±3.9 vs. control: 35.2±1.9%CO2), heat (KC: 0.91±0.32 vs. control: 0.54±0.26 Δ°C) and cold (KC: 1.28±0.27 vs. control: 0.98±0.25 Δ°C) stimulation in the KC patients were significantly higher than in the control subjects (p0.05), whereas in the control subjects both mechanical (r = 0.52, p = 0.02), chemical (r = 0.47, p = 0.04), heat (r = 0.26, p = 0.04) and cold threshold (r = 0.40, p = 0.03) increased with age. In the KC group, neither corneal thickness nor tear flow, NI-BUT or OSDI correlated significantly with mechanical, chemical, heat or cold thresholds (p>0.05 for all variables). Conclusions Corneal sensitivity to different types of stimuli is decreased in patients with keratoconus independently of age and disease severity. The reduction of the sensory input from corneal nerves may contribute to the onset of unpleasant sensations in these patients and might lead to the impaired tear film dynamics. PMID:26495846

  13. The construction of sutureless cataract incision and the management of corneal astigmatism.

    Science.gov (United States)

    Hall, G W; Krischer, C; Mobasher, B; Rajan, S D

    1993-02-01

    Extrapolating information from equations that govern fluid flow, a theoretical formula is developed for a sutureless cataract incision. This theoretical formula defines the resistance of aqueous outflow as a function of three variables: length of cataract incision, the length of the scleral tunnel, the tortuosity of the outflow channel, and one constant friction factor. The nonlinear relationship of corneal incisions to length, depth, and distance from the visual axis is also examined with respect to their effect on central corneal curvature and control of astigmatism. Finite element analysis of differential equations is discussed as the most plausible technique for predicting these incisional effects.

  14. Terahertz sensing in corneal tissues

    Science.gov (United States)

    Bennett, David B.; Taylor, Zachary D.; Tewari, Pria; Singh, Rahul S.; Culjat, Martin O.; Grundfest, Warren S.; Sassoon, Daniel J.; Johnson, R. Duncan; Hubschman, Jean-Pierre; Brown, Elliott R.

    2011-05-01

    This work introduces the potential application of terahertz (THz) sensing to the field of ophthalmology, where it is uniquely suited due to its nonionizing photon energy and high sensitivity to water content. Reflective THz imaging and spectrometry data are reported on ex-vivo porcine corneas prepared with uniform water concentrations using polyethylene glycol (PEG) solutions. At 79% water concentration by mass, the measured reflectivity of the cornea was 20.4%, 14.7%, 11.7%, 9.6%, and 7.4% at 0.2, 0.4, 0.6, 0.8, and 1 THz, respectively. Comparison of nine corneas hydrated from 79.1% to 91.5% concentration by mass demonstrated an approximately linear relationship between THz reflectivity and water concentration, with a monotonically decreasing slope as the frequency increases. The THz-corneal tissue interaction is simulated with a Bruggeman model with excellent agreement. THz applications to corneal dystrophy, graft rejection, and refractive surgery are examined from the context of these measurements.

  15. EDC/NHS cross-linked collagen foams as scaffolds for artificial corneal stroma.

    Science.gov (United States)

    Vrana, N E; Builles, N; Kocak, H; Gulay, P; Justin, V; Malbouyres, M; Ruggiero, F; Damour, O; Hasirci, V

    2007-01-01

    In this study, a highly porous collagen-based biodegradable scaffold was developed as an alternative to synthetic, non-degradable corneal implants. The developed method involved lyophilization and subsequent stabilization through N-ethyl-N'-[3-dimethylaminopropyl] carbodiimide/N-hydroxy succinimide (EDC/NHS) cross-linking to yield longer lasting, porous scaffolds with a thickness similar to that of native cornea (500 microm). For collagen-based scaffolds, cross-linking is essential; however, it has direct effects on physical characteristics crucial for optimum cell behavior. Hence, the effect of cross-linking was studied by examining the influence of cross-linking on pore size distribution, bulk porosity and average pore size. After seeding the foam with human corneal keratocytes, cell proliferation, cell penetration into the scaffold and ECM production within the scaffold were studied. After a month of culture microscopical and immunohistochemical examinations showed that the foam structure did not undergo any significant loss of integrity, and the human corneal keratocytes populated the scaffold with cells migrating both longitudinally and laterally, and secreted some of the main constituents of the corneal ECM, namely collagen types I, V and VI. The foams had a layer of lower porosity (skin layer) both at the top and the bottom. Foams had an optimal porosity (93.6%), average pore size (67.7 microm), and chemistry for cell attachment and proliferation. They also had a sufficiently rapid degradation rate (73.6+/-1.1% in 4 weeks) and could be produced at a thickness close to that of the natural corneal stroma. Cells were seeded at the top surface of the foams and their numbers there was higher than the rest, basically due to the presence of the skin layer. This is considered to be an advantage when epithelial cells need to be seeded for the construction of hemi or full thickness cornea. PMID:17988518

  16. Self-organized centripetal movement of corneal epithelium in the absence of external cues

    Science.gov (United States)

    Lobo, Erwin P.; Delic, Naomi C.; Richardson, Alex; Raviraj, Vanisri; Halliday, Gary M.; di Girolamo, Nick; Myerscough, Mary R.; Lyons, J. Guy

    2016-08-01

    Maintaining the structure of the cornea is essential for high-quality vision. In adult mammals, corneal epithelial cells emanate from stem cells in the limbus, driven by an unknown mechanism towards the centre of the cornea as cohesive clonal groups. Here we use complementary mathematical and biological models to show that corneal epithelial cells can self-organize into a cohesive, centripetal growth pattern in the absence of external physiological cues. Three conditions are required: a circumferential location of stem cells, a limited number of cell divisions and mobility in response to population pressure. We have used these complementary models to provide explanations for the increased rate of centripetal migration caused by wounding and the potential for stem cell leakage to account for stable transplants derived from central corneal tissue, despite the predominantly limbal location of stem cells.

  17. Self-organized centripetal movement of corneal epithelium in the absence of external cues

    Science.gov (United States)

    Lobo, Erwin P.; Delic, Naomi C.; Richardson, Alex; Raviraj, Vanisri; Halliday, Gary M.; Di Girolamo, Nick; Myerscough, Mary R.; Lyons, J. Guy

    2016-01-01

    Maintaining the structure of the cornea is essential for high-quality vision. In adult mammals, corneal epithelial cells emanate from stem cells in the limbus, driven by an unknown mechanism towards the centre of the cornea as cohesive clonal groups. Here we use complementary mathematical and biological models to show that corneal epithelial cells can self-organize into a cohesive, centripetal growth pattern in the absence of external physiological cues. Three conditions are required: a circumferential location of stem cells, a limited number of cell divisions and mobility in response to population pressure. We have used these complementary models to provide explanations for the increased rate of centripetal migration caused by wounding and the potential for stem cell leakage to account for stable transplants derived from central corneal tissue, despite the predominantly limbal location of stem cells. PMID:27499113

  18. A Case of Medication-Resistant Acanthamoeba Keratitis Treated by Corneal Crosslinking in Turkey

    Directory of Open Access Journals (Sweden)

    Goktug Demirci

    2013-01-01

    Full Text Available Purpose. To report a case of medication-resistant acanthamoeba keratitis (AK treated successfully by corneal crosslinking (CXL. Methods. A 26-year-old male with medication-resistant AK underwent a standard CXL procedure with local anesthesia, followed by central corneal epithelial debridement, application of riboflavin 0.1%, and UV-A irradiation. Results. The patient experienced a dramatic symptomatic improvement within 24 hours. At two months, keratitis was healed with a semitransparent paracentral scar that did not affect visual acuity. Conclusions. Our experience, considered in the context of recent studies, suggests that CXL may be an option for selected patients with medication-resistant AK and corneal melting. CXL allows patients to avoid emergency keratoplasty and experience rapid symptomatic relief.

  19. Distribution of posterior corneal astigmatism according to axis orientation of anterior corneal astigmatism.

    Directory of Open Access Journals (Sweden)

    Toshiyuki Miyake

    Full Text Available To investigate the distribution of posterior corneal astigmatism in eyes with with-the-rule (WTR and against-the-rule (ATR anterior corneal astigmatism.We retrospectively examined six hundred eight eyes of 608 healthy subjects (275 men and 333 women; mean age ± standard deviation, 55.3 ± 20.2 years. The magnitude and axis orientation of anterior and posterior corneal astigmatism were determined with a rotating Scheimpflug system (Pentacam HR, Oculus when we divided the subjects into WTR and ATR anterior corneal astigmatism groups.The mean magnitudes of anterior and posterior corneal astigmatism were 1.14 ± 0.76 diopters (D, and 0.37 ± 0.19 D, respectively. We found a significant correlation between the magnitudes of anterior and posterior corneal astigmatism (Pearson correlation coefficient r = 0.4739, P<0.001. In the WTR anterior astigmatism group, we found ATR astigmatism of the posterior corneal surface in 402 eyes (96.6%. In the ATR anterior astigmatism group, we found ATR posterior corneal astigmatism in 82 eyes (73.9%. Especially in eyes with ATR anterior corneal astigmatism of 1 D or more and 1.5 D or more, ATR posterior corneal astigmatism was found in 28 eyes (59.6% and 9 eyes (42.9%, respectively.WTR anterior astigmatism and ATR posterior astigmatism were found in approximately 68% and 91% of eyes, respectively. The magnitude and the axis orientation of posterior corneal astigmatism were not constant, especially in eyes having high ATR anterior corneal astigmatism, as is often the case in patients who have undergone toric IOL implantation.

  20. Confocal comparison of corneal reinnervation after small incision lenticule extraction (SMILE and femtosecond laser in situ keratomileusis (FS-LASIK.

    Directory of Open Access Journals (Sweden)

    Meiyan Li

    Full Text Available PURPOSE: To evaluate corneal reinnervation, and the corresponding corneal sensitivity and keratocyte density after small incision lenticule extraction (SMILE and femtosecond laser in situ keratomileusis (FS-LASIK. METHODS: In this prospective, non-randomized observational study, 18 patients (32 eyes received SMILE surgery, and 22 patients (42 eyes received FS-LASIK surgery to correct myopia. The corneal subbasal nerve density and microscopic morphological changes in corneal architecture were evaluated by confocal microscopy prior to surgery and at 1 week, 1 month, 3 months, and 6 months after surgery. A correlation analysis was performed between subbasal corneal nerve density and the corresponding keratocyte density and corneal sensitivity. RESULTS: The decrease in subbasal nerve density was less severe in SMILE-treated eyes than in FS-LASIK-treated eyes at 1 week (P = 0.0147, 1 month (P = 0.0243, and 3 months (P = 0.0498, but no difference was detected at the 6-month visit (P = 0.5277. The subbasal nerve density correlated positively with central corneal sensitivity in both groups (r = 0.416, P<0.0001, and r = 0.2567, P = 0.0038 for SMILE group and FS-LASIK group, respectively. The SMILE-treated eyes have a lower risk of developing peripheral empty space with epithelial cells filling in (P = 0.0005. CONCLUSIONS: The decrease in subbasal nerve fiber density was less severe in the SMILE group than the FS-LASIK group in the first 3 months following the surgeries. The subbasal nerve density was correlated with central corneal sensitivity.

  1. Technology needs for corneal transplant surgery

    Science.gov (United States)

    Vaddavalli, Pravin K.; Yoo, Sonia H.

    2011-03-01

    Corneal transplant surgery has undergone numerous modifications over the years with improvements in technique, instrumentation and eye banking. The main goals of corneal transplantation are achieving excellent optical clarity with long-term graft survival. Penetrating, anterior and posterior lamellar surgery along with femtosecond laser technology have partially met these goals, but outcomes are often unpredictable and surgeon dependent. Technology to predictably separate stroma from Descemet's membrane, techniques to minimize endothelial cell loss, improvements in imaging technology and emerging techniques like laser welding that might replace suturing, eventually making corneal transplantation a refractively predictable procedure are on the wish list of the cornea surgeon.

  2. In vivo confocal microscopy of the cornea: New developments in image acquisition, reconstruction and analysis using the HRT-Rostock Corneal Module

    OpenAIRE

    Petroll, W. Matthew; Robertson, Danielle M.

    2015-01-01

    The optical sectioning ability of confocal microscopy allows high magnification images to be obtained from different depths within a thick tissue specimen, and is thus ideally suited to the study of intact tissue in living subjects. In vivo confocal microscopy has been used in a variety of corneal research and clinical applications since its development over 25 years ago. In this article we review the latest developments in quantitative corneal imaging with the Heidelberg Retinal Tomograph wi...

  3. Keratocytes are induced to produce collagen type II: A new strategy for in vivo corneal matrix regeneration.

    Science.gov (United States)

    Greene, Carol Ann; Green, Colin R; Dickinson, Michelle E; Johnson, Virginia; Sherwin, Trevor

    2016-09-10

    The stroma, the middle layer of the cornea, is a connective tissue making up most of the corneal thickness. The stromal extracellular matrix (ECM) consists of highly organised lamellae which are made up of tightly packed fibrils primarily composed of collagens type I and V. This layer is interspersed with keratocytes, mesenchymal cells of neural crest origin. We have previously shown that adult corneal keratocytes exhibit phenotypic plasticity and can be induced into a neuronal phenotype. In the current study we evaluated the potential of keratocytes to produce collagen type II via phenotypic reprogramming with exogenous chondrogenic factors. The cornea presents a challenge to tissue engineers owing to its high level of organisation and the phenotypic instability of keratocytes. Traditional approaches based on a scar model do not support the engineering of functional stromal tissue. Type II collagen is not found in the adult cornea but is reported to be expressed during corneal development, raising the possibility of using such an approach to regenerate the corneal ECM. Keratocytes in culture and within intact normal and diseased tissue were induced to produce collagen type II upon treatment with transforming growth factor Beta3 (TGFβ3) and dexamethasone. In vivo treatment of rat corneas also resulted in collagen type II deposition and a threefold increase in corneal hardness and elasticity. Furthermore, the treatment of corneas and subsequent deposition of collagen type II did not cause opacity, fibrosis or scarring. The induction of keratocytes with specific exogenous factors and resulting deposition of type II collagen in the stroma can potentially be controlled by withdrawal of the factors. This might be a promising new approach for in vivo corneal regeneration strategies aimed at increasing corneal integrity in diseases associated with weakened ectatic corneal tissue such as keratoconus. PMID:27539660

  4. A study on the effect of the corneal biomechanical properties undergoing overnight orthokeratology%角膜塑形术治疗近视眼安全性的探讨

    Institute of Scientific and Technical Information of China (English)

    毛欣杰; 黄橙赤; 陈琳; 吕帆

    2010-01-01

    Objective To evaluate the changes of corneal biomechanical properties and corneal topography undergoing overnight orthokeratology treatment. Methods Thirty teenagers with low andmoderate myopia with age of 11.67±1.63,myopia(-2.56±0.86)D,were included and were fitted with Ortho-K CL. The corneal biomechanical properties,including corneal hysteresis (CH),corneal resistance factor(CRF),goldmann-correlated lOP(IOPg) and corneal-compensated intraocular pressure(IOPcc) were measured with ocular response analyzer(ORA).Corneal topography,central corneal thickness(CCT) and corneal endothelium density were measured with computerized corneal topography,optical coherence tomography(OCT) and non contact specular microscope respectively.The measurements were taken at pre-wear,1 day and 7,30,90,180 days after orthokeratology.Only data from the right eyes were analysed.Results All subjects were significantly reduced the myopia amount after 1 day of lens Wear.The corneal curvature flattening(F=38.837,P<0.01)became slightly down to stable after the first week.There were significant decrease in CH and CRF after the orthokeratology treatment within the first week,and CH and CRF reversed and thereafeter into the original level at 3-month and 6-month follow up.IOPg and IOPcc decreased and reached the lowwest level at 1-week visit and after then became down to stable.There were significant reduction in CCT after 1 week(F=4.739,P<0.05).There were no significant changes in corneal endothelium density during orthokeratology treatment for 6 months.Conclusions The amount of myopia reduction with orthokeratology occurred mostly within 1 week while the corneal biomechanical properties such as CH and CRF were decreased. However the corneal biomechanical properties are reversal to the original level thereafter and remain unchanged within the 6 months follow up visits.It proves that orthokeratology does not demage corneal microsturcture.The early sign of reduction may due to the temporal

  5. Photodynamic therapy with verteporfin for corneal neovascularization

    Directory of Open Access Journals (Sweden)

    Abdullah A Al-Torbak

    2012-01-01

    Results: At the last follow-up visit, 22 (66.7% eyes showed a decrease in corneal neovascularization and evidence of vascular thrombosis. Complete vascular occlusion was achieved in 14 (42.4% eyes, partial occlusion was achieved in 8 (24.2% eyes, and the vessels were patent in 11 (33.3% eyes. The corneal neovascularization score and depth of the vessels were found to be significant risk factors for failure (P = 0.0001 and 0.046, respectively. However, the diagnoses or causes of corneal neovascularisation were not statistically significant. No significant systemic or ocular complications associated with photodynamic therapy were observed. Conclusion: Photodynamic therapy with verteporfin was effective for the treatment of corneal neovascularization in the majority of the cases in this study.

  6. Critical head, thickness of fine-grained deposit, and skeletal elastic storage arrays of the SUB package of the Central Valley Hydrologic Model

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the SUB package arrays for the model grid, critical head, thickness of fine-grained deposits, and skeletal-elastic-storage used in the...

  7. Detecting thermal phase transitions in corneal stroma by fluorescence micro-imaging analysis

    Science.gov (United States)

    Matteini, P.; Rossi, F.; Ratto, F.; Bruno, I.; Nesi, P.; Pini, R.

    2008-02-01

    Thermal modifications induced in corneal stroma were investigated by the use of fluorescence microscopy. Freshly extracted porcine corneas were immersed for 5 minutes in a water bath at temperatures in the 35-90°C range and stored in formalin. The samples were then sliced in 200-μm-thick transversal sections and analyzed under a stereomicroscope to assess corneal shrinkage. Fluorescence images of the thermally treated corneal samples were acquired using a slow-scan cooled CCD camera, after staining the slices with Indocyanine Green (ICG) fluorescent dye which allowed to detect fluorescence signal from the whole tissue. All measurements were performed using an inverted epifluorescence microscope equipped with a mercury lamp. The thermally-induced modifications to the corneal specimens were evaluated by studying the grey level distribution in the fluorescence images. For each acquired image, Discrete Fourier Transform (DFT) and entropy analyses were performed. The spatial distribution of DFT absolute value indicated the spatial orientation of the lamellar planes, while entropy was used to study the image texture, correlated to the stromal structural transitions. As a result, it was possible to indicate a temperature threshold value (62°C) for high thermal damage, resulting in a disorganization of the lamellar planes and in full agreement with the measured temperature for corneal shrinkage onset. Analysis of the image entropy evidenced five strong modifications in stromal architecture at temperatures of ~45°C, 53°C, 57°C, 66°C, 75°C. The proposed procedure proved to be an effective micro-imaging method capable of detecting subtle changes in corneal tissue subjected to thermal treatment.

  8. Chlorpromazine-induced corneal endothelial phototoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Hull, D.S.; Csukas, S.; Green, K.

    1982-04-01

    Chlorpromazine, which has been used extensively for the treatment of psychiatric disorders, is known to accumulate in the posterior corneal stroma, lens, and uveal tract. Because it is a phototoxic compound, the potential exists for it to cause cellular damage after light exposure. Specular microscopic perfusion of corneal endothelial cells in darkness with 0.5 mM chlorpromazine HCl resulted in a swelling rate of 18 +/- 2 micrometer/hr, whereas corneas exposed to long-wavelength ultraviolet light for 3 min in the presence of 0.5 mM chlorpromazine swelled at 37 +/- 9 micrometer/hr (p less than 0.01). Preirradiation of 0.5 mM chlorpromazine solution with ultraviolet light for 30 min and subsequent corneal perfusion with the solution resulted in a corneal swelling rate of 45 +/- 19 micrometer/hr. Cornea endothelial cells perfused with 0.5 mM chlorpromazine that was preirradiated with ultraviolet light showed marked swelling on scanning electron microscopic examination, whereas those perfused with nonirradiated chlorpromazine were flat and showed a normal mosaic pattern. Combining either 500 U/ml catalase or 290 U/ml superoxide dismutase with chlorpromazine did not alter photoinduction of corneal swelling. The data suggest that corneal endothelial chlorpromazine phototoxicity is secondary to cytotoxic products resulting from the photodynamically induced decomposition of chlorpromazine and is not caused by hydrogen peroxide or superoxide anion generated during the phototoxic reaction.

  9. Phenotypic Spectrum of Granular Corneal Dystrophy Type II in Two Italian Families Presenting an Unusual Granular Corneal Dystrophy Type I Clinical Appearance

    Directory of Open Access Journals (Sweden)

    Cosimo Mazzotta

    2015-01-01

    Full Text Available Clinical, instrumental, and genetic findings are reported in Italian families with Type II Granular Corneal Dystrophies (GCD2 presenting an initial unusual presentation of a Granular Corneal Dystrophy Type I (GCD1 phenotypic spectrum in female descendants. Slit-lamp examinations showed the typical phenotypic features of GCD2 in both mothers and a phenotypic appearance of GCD1 in both daughters. Despite the different phenotypic onset, the genetic diagnostic testing revealed the presence of a mutation in the TGFB-I gene, typical of GCD2 in both cases, excluding GCD1. Patients who were clinically suspected of corneal dystrophy need a genetic confirmatory testing for certain diagnosis. Genetic test may help to find the specific mutation distinguishing between different phenotypic spectra with relative diagnostic and prognostic implications. The study demonstrates that the phenotypic spectrum of genetically confirmed granular corneal dystrophies in patients may change over time. Since the R124H mutation has also been described in clinically asymptomatic individuals prior to LASIK, who then develop dramatic deposition, suggesting that this particular mutation and phenotype may be sensitive to, precipitated, or modified by central cornea trauma, a careful familial anamnesis excluding cornel dystrophies and specific preoperative genetic test are recommended prior to LASIK.

  10. "All-laser" endothelial corneal transplant in human patients

    Science.gov (United States)

    Rossi, Francesca; Menabuoni, Luca; Malandrini, Alex; Canovetti, Annalisa; Lenzetti, Ivo; Pini, Roberto

    2012-03-01

    Femtosecond laser sculpturing of corneal tissue is commonly used for the preparation of endothelial flaps. Diode laser welding of ocular tissues is a procedure that enables minimally invasive suturing of tissues. The combination of these laser based techniques results in a new approach to minimally invasive ophthalmic surgery, such as in endothelial corneal transplant (or endothelial keratoplasty - EK). In this work we present the "all laser" EK performed in human subjects. 24 pseudophakic patients with bullous keratopathy underwent EK: the femtosecond laser was used to prepare the 100 ìm thick and 8.5 mm diameter donor Descemet endothelial flap. After staining the stromal layer of the donor flap with a liquid ICG solution, the donor flap was inserted in the recipient eye by the use of the Busin injector. Then, the endothelial layer was laser-welded to the recipient eye (10 laser spots around the periphery of the flap), in order to reduce the risk of postoperative dislocation of the transplanted flap. A transplanted flap engraftment was observed in all the treated eyes. The staining procedure used to perform laser welding also enabled to evidence the stromal side of the donor flap, so as the flap was always placed in the right side position. The endothelial cells counts in both the laserwelded flaps and in a control group were in good agreement. The proposed technique is easy to perform and enables the reduction of postoperative endothelial flap dislocations.

  11. Effect of topical administration of tramadol on corneal wound healing in rats.

    Science.gov (United States)

    Cuvas Apan, Ozgun; Ozer, Murat Atabey; Takir, Selcuk; Apan, Alparslan; Sengul, Demet

    2016-10-01

    In this study, we aimed to investigate the effects of topical tramadol administration on corneal wound healing, and examine ophthalmic structures and intraocular pressure 7 days after tramadol administration. The experiments were conducted on eight male Wistar rats (250-300 g). After ophthalmic examination, epithelial cell layers in the central cornea were wounded. Rats received 30 μL of tramadol hydrochloride in one eye (Group Tramadol) and the same volume of vehicle in the other (Group Control) every 12 h for 7 days. Both eyes were stained with fluorescein dye, photographed, and wound area was calculated every 8 h until complete healing was observed. Eye blink frequency and corneal reflex tests were measured before and after drug administrations. After 7 days, slit lamp biomicroscopy, fundoscopy, Goldmann applanation tonometry, and histological evaluation were performed. There was no difference in the corneal wound healing rates between the tramadol and control groups. Reduction in wound area over time was also similar; group-time interaction was insignificant (F = 738.911; p = 0.225). Tramadol application resulted in blinking and blepharospasm for 30 s, but vehicle did not. Corneal reflex was intact and eye blink frequency test results were similar in all measurement times in both groups. Slit lamp biomicroscopy, fundoscopy, and intraocular pressures were within normal range. Corneal cells appeared unaffected by the repeated doses of tramadol for 7 days. Topical tramadol application on the cornea did not cause any side effect, except for initial temporary blinking and blepharospasm. Corneal wound healing was not affected, either.

  12. Human tears reveal insights into corneal neovascularization.

    Directory of Open Access Journals (Sweden)

    Nadia Zakaria

    Full Text Available Corneal neovascularization results from the encroachment of blood vessels from the surrounding conjunctiva onto the normally avascular cornea. The aim of this study is to identify factors in human tears that are involved in development and/or maintenance of corneal neovascularization in humans. This could allow development of diagnostic tools for monitoring corneal neovascularization and combination monoclonal antibody therapies for its treatment. In an observational case-control study we enrolled a total of 12 patients with corneal neovascularization and 10 healthy volunteers. Basal tears along with reflex tears from the inferior fornix, superior fornix and using a corneal bath were collected along with blood serum samples. From all patients, ocular surface photographs were taken. Concentrations of the pro-angiogenic cytokines interleukin (IL-6, IL-8, Vascular Endothelial Growth Factor (VEGF, Monocyte Chemoattractant Protein 1 (MCP-1 and Fas Ligand (FasL were determined in blood and tear samples using a flow cytometric multiplex assay. Our results show that the concentration of pro-angiogenic cytokines in human tears are significantly higher compared to their concentrations in serum, with highest levels found in basal tears. Interestingly, we could detect a significantly higher concentration of IL- 6, IL-8 and VEGF in localized corneal tears of patients with neovascularized corneas when compared to the control group. This is the first study of its kind demonstrating a significant difference of defined factors in tears from patients with neovascularized corneas as compared to healthy controls. These results provide the basis for future research using animal models to further substantiate the role of these cytokines in the establishment and maintenance of corneal neovascularization.

  13. 角膜塑形术后角膜生物力学属性研究%The short-term influence of orthokeratology on corneal biomechanical properties

    Institute of Scientific and Technical Information of China (English)

    毛欣杰; 周杭帅; 刘然; 吴从霞

    2012-01-01

    Outcome Measures Mean spherical equivalent(SE), keratometric curvature, central corneal thickness (CCT), CH, CRF. Results Mean SE decreased from -3.72±1.82 D (baseline) to -2.12±1.93 D (immediately after one night wearing) and recovered to —2.59±1.98D (4 hours after removed). Keratometric curvature were significantly reduced from 41.95±1.12 D (baseline) to 41.22±1.34 D (immediately after one night wearing) and recovered to 41.44±40.10 D (4 hours after removed). One night post-wearing, the mean CCT of all subjects were significantly increased from 535.9±34.5 μm to 553.3±36.6 μm (P=0.000)and recovered to 535.0+ 40.3 μm 4 hours after lens removal. CRF increased from 10.0±1.4 mm Hg to 10.7±1.5 mm Hg in the effect phase (P=0.037)and decreased to 9.6+1.2 mm Hg in 4 hours after lens removal. There was no difference of CRF between pre-wearing and 4 hours after lens removal (P=0.148). There was no significant change in CH throughout the study (P=0.163). Conclusion Corneal biomechanics changed with corneal shape after short-term orthokeratology. The corneal biomechanical measurements can be used as a method observing corneal micro-structural changes after orthokeratology.

  14. The outer vactank, an object of 7.6m diameter and 13m length is built up of three cylindrical parts. The central part that is integral part of the central barrel and the the extension on either side each one 4.5m long. These extensions house the shoulders that will support and prestress the CMS Coil. To weld the extensions onto the central part a full penetration weld of 24m length and 45 mm thickness has to be done by hand from inside and outside the vacuum tank and its deformation is controled permanently.

    CERN Multimedia

    Hubert Gerwig

    2001-01-01

    The outer vacuum tank will hold the coil suspension system and transmits the weight of the inner detectors to the central barrel. Its thickness is staggered. In the central part its thickness is 60 mm and then goes down to 30 mm at the extremity.

  15. Role of Decorin Core Protein in Collagen Organisation in Congenital Stromal Corneal Dystrophy (CSCD.

    Directory of Open Access Journals (Sweden)

    Christina S Kamma-Lorger

    Full Text Available The role of Decorin in organising the extracellular matrix was examined in normal human corneas and in corneas from patients with Congenital Stromal Corneal Dystrophy (CSCD. In CSCD, corneal clouding occurs due to a truncating mutation (c.967delT in the decorin (DCN gene. Normal human Decorin protein and the truncated one were reconstructed in silico using homology modelling techniques to explore structural changes in the diseased protein. Corneal CSCD specimens were also examined using 3-D electron tomography and Small Angle X-ray diffraction (SAXS, to image the collagen-proteoglycan arrangement and to quantify fibrillar diameters, respectively. Homology modelling showed that truncated Decorin had a different spatial geometry to the normal one, with the truncation removing a major part of the site that interacts with collagen, compromising its ability to bind effectively. Electron tomography showed regions of abnormal stroma, where collagen fibrils came together to form thicker fibrillar structures, showing that Decorin plays a key role in the maintenance of the order in the normal corneal extracellular matrix. Average diameter of individual fibrils throughout the thickness of the cornea however remained normal.

  16. Role of Decorin Core Protein in Collagen Organisation in Congenital Stromal Corneal Dystrophy (CSCD).

    Science.gov (United States)

    Kamma-Lorger, Christina S; Pinali, Christian; Martínez, Juan Carlos; Harris, Jon; Young, Robert D; Bredrup, Cecilie; Crosas, Eva; Malfois, Marc; Rødahl, Eyvind; Meek, Keith M; Knupp, Carlo

    2016-01-01

    The role of Decorin in organising the extracellular matrix was examined in normal human corneas and in corneas from patients with Congenital Stromal Corneal Dystrophy (CSCD). In CSCD, corneal clouding occurs due to a truncating mutation (c.967delT) in the decorin (DCN) gene. Normal human Decorin protein and the truncated one were reconstructed in silico using homology modelling techniques to explore structural changes in the diseased protein. Corneal CSCD specimens were also examined using 3-D electron tomography and Small Angle X-ray diffraction (SAXS), to image the collagen-proteoglycan arrangement and to quantify fibrillar diameters, respectively. Homology modelling showed that truncated Decorin had a different spatial geometry to the normal one, with the truncation removing a major part of the site that interacts with collagen, compromising its ability to bind effectively. Electron tomography showed regions of abnormal stroma, where collagen fibrils came together to form thicker fibrillar structures, showing that Decorin plays a key role in the maintenance of the order in the normal corneal extracellular matrix. Average diameter of individual fibrils throughout the thickness of the cornea however remained normal. PMID:26828927

  17. Genetics Home Reference: lattice corneal dystrophy type I

    Science.gov (United States)

    ... Diagnosis & Management These resources address the diagnosis or management of lattice corneal dystrophy type I: American Foundation for the Blind: Living with Vision Loss Genetic Testing Registry: Lattice corneal dystrophy Type ...

  18. Corneal Stromal Bioequivalents Secreted on Patterned Silk Substrates

    OpenAIRE

    Wu, Jian; Rnjak-Kovacina, Jelena; Du, Yiqin; Funderburgh, Martha L.; Kaplan, David L.; Funderburgh, James L.

    2014-01-01

    Emulating corneal stromal tissue is believed to be the most challenging step in bioengineering an artificial human cornea because of the difficulty in reproducing its highly ordered microstructure, the key to the robust biomechanical properties and optical transparency of this tissue. We conducted a comparative study to assess the feasibility of human corneal stromal stem cells (hCSSCs) and human corneal fibroblasts (hCFs) in the generation of human corneal stromal tissue on groove-patterned ...

  19. [Representation and mathematical analysis of human corneal surface].

    Science.gov (United States)

    Tălu, Stefan; Tălu, Mihai; Giovanzana, Stefano

    2011-01-01

    In the description and analysis of human corneal surface are used various mathematical models based on parametric representations, used in biomechanical studies and 3D solid modeling of the cornea. Mathematical models are important into the biomechanics of the cornea to model the corneal behavior. Corneal biomechanics also has the potential to improve outcomes in refractive surgery. The objective of this paper is to present the most representative mathematical models currently used for modeling of human corneal in optics and biomechanics fields.

  20. Evaluation of corneal higher order aberrations in normal topographic patterns

    OpenAIRE

    Mirzajani, Ali; Aghataheri, Sattar; Ghoreishi, Mohammad; Jafarzadepour, Ebrahim; Mohammadinia, Mohadese

    2016-01-01

    Purpose This study reports the characteristics of corneal higher order aberrations (HOAs) in eyes with normal topographic pattern using the Pentacam scheimpflug system. Methods In this prospective, observational, comparative study, 165 eyes of 97 patients separated into five groups based on corneal topographic patterns were enrolled. All eyes received a comprehensive ophthalmologic examination including corneal tomographic analysis with the Pentacam system. Keratometry, corneal cylinder, and ...

  1. Bilateral coexistence of keratoconus and macular corneal dystrophy

    Directory of Open Access Journals (Sweden)

    Ghazi Al-Hamdan

    2009-01-01

    The authors hereby report a 21-year-old female who presented with the typical signs and topographic evidence of keratoconus in association with macular corneal dystrophy. Histopathologic evaluation from the excised corneal button after corneal transplant confirmed the diagnosis. To our knowledge, there is only one previous report in the literature linking the association of keratoconus and macular corneal dystrophy in the same eye bilaterally.

  2. Acute Corneal Hydrops 3 Years after Intra-corneal Ring Segments and Corneal Collagen Cross-linking

    Science.gov (United States)

    Antonios, Rafic; Dirani, Ali; Fadlallah, Ali; Chelala, Elias; Hamadeh, Adib; Jarade, Elias

    2016-01-01

    This case report describes a 15-year-old male with allergic conjunctivitis and keratoconus, who underwent uneventful intra-corneal ring segment (ICRS) implantation and corneal collagen cross-linking (CXL) in the right eye. During the follow-up periods, the patient was noted to have several episodes of allergic conjunctivitis that were treated accordingly. At the 2 years postoperatively, he presented with another episode of allergic conjunctivitis and progression of keratoconus was suspected on topography. However, the patient was lost to follow-up, until he presented with acute hydrops at 3 years postoperatively. There are no reported cases of acute corneal hydrops in cross-linked corneas. We suspect the young age, allergic conjunctivitis and eye rubbing may be a risk factors associated with possible progression of keratoconus after CXL. Prolonged follow-up and aggressive control of the allergy might be necessary in similar cases. PMID:26957859

  3. Corneal Phaeohyphomycosis Caused by Bipolaris hawaiiensis

    Directory of Open Access Journals (Sweden)

    Winai Chaidaroon

    2016-07-01

    Full Text Available Purpose: To report a rare case of keratitis infected by Bipolaris hawaiiensis. Methods: A patient who was diagnosed as fungal keratitis caused by B. hawaiiensis was retrospectively reviewed for history, clinical characteristics, risk factors, laboratory findings, treatments, and outcomes. Results: A 63-year-old man with a history of trauma and saw dust in the left eye presented with a corneal ulcer. Eye examination revealed whitish infiltration with a feathery edge and small brownish deposits in the anterior stroma of the left cornea. Numerous septate hyphal fragments were detected in a corneal specimen, and nucleotide sequence analysis identified B. hawaiiensis. Treatment was started with 5% natamycin eyedrops and oral itraconazole. Subsequently, a corneal plaque developed which did not respond to medication and debridement. The patient underwent therapeutic penetrating keratoplasty. Conclusions: B. hawaiiensis is a rare cause of corneal phaeohyphomycosis. A brownish pigmented infiltration is an important diagnostic clue, however microbiologic studies are required to obtain a definite diagnosis. Although antifungal medication and debridement are the mainstay of most corneal fungal infection, therapeutic penetrating keratoplasty can prevent morbidity related to this fungal infection.

  4. Astigmatism in relation to length and site of corneal lacerations

    Directory of Open Access Journals (Sweden)

    Srihari Atti

    2016-01-01

    Conclusions: The corneal astigmatism depends upon the length and site of corneal laceration. Severity of astigmatism was directly proportion to the length of corneal laceration. The wound was nearer to the centre of the cornea, the greater was the astigmatism. [Int J Res Med Sci 2016; 4(1.000: 165-168

  5. Efficacy of Tectonic Corneal Patch Graft for Progressive Peripheral Corneal Thinning

    Directory of Open Access Journals (Sweden)

    Cafer Tanrıverdio

    2014-12-01

    Full Text Available Objectives: To report the results of tectonic corneal patch graft (TCPG in patients with progressive peripheral corneal thinning (PCT. Materials and Methods: In this study, we included 8 patients who underwent TCPG for PCT or perforated corneal ulceration at Ankara Training and Research Hospital. Results: We performed TCPG in 7 patients for PCT and in 1 patient for perforated corneal ulceration. Mean age was 57.2±16.7 (38- 82 years. Postoperative follow-up time ranged from 6 to 24 months (mean 13.9±6.7. Possible etiologies leading to progressive PCT were trachoma, infectious corneal ulcer, and rheumatoid arthritis-severe dry eye in 2 patients each. Other 2 patients had a progressive PCT following ocular surgery. One of the patients with infectious corneal ulcer also had a trauma caused by a scissor. Amnion membrane transplantation was performed in 3 patients prior to TCPG. While the anatomic success was achieved in all 8 patients, best-corrected visual acuity (BCVA was 0.1 or better in 4 patients (50%. Postoperative BCVA was better than preoperative BCVA in 6 patients (75%. Local peripheral anterior synechiae developed in two eyes. Conclusion: TCPG is a useful therapeutic option in selected cases of corneal thinning and perforations because it effectively restores the integrity of the globe and allows acceptable visual results. (Turk J Ophthalmol 2014; 44: 440-4

  6. The effect of Gonioscopy on keratometry and corneal surface topography

    Directory of Open Access Journals (Sweden)

    DeBroff Brian M

    2006-06-01

    . Conclusion Reversible steepening of the central corneal surface is produced by the act of gonioscopy as measured by Sim K, whereas no significant differences were present with Auto-K measurements. The type of Gonioscope used does not appear to influence these results. If topographically derived Sim K is used to calculate the power of the intraocular lens implant, we recommend waiting a minimum of 20 minutes before measuring the corneal curvature after gonioscopy with either Goldmann or Sussman contact lenses.

  7. Limit of blank and limit of detection of Plasmodium falciparum thick blood smear microscopy in a routine setting in Central Africa

    OpenAIRE

    Joanny, Fanny; Löhr, Sascha JZ; Engleitner, Thomas; Lell, Bertrand; Mordmüller, Benjamin

    2014-01-01

    Background Proper malaria diagnosis depends on the detection of asexual forms of Plasmodium spp. in the blood. Thick blood smear microscopy is the accepted gold standard of malaria diagnosis and is widely implemented. Surprisingly, diagnostic performance of this method is not well investigated and many clinicians in African routine settings base treatment decisions independent of microscopy results. This leads to overtreatment and poor management of other febrile diseases. Implementation of q...

  8. Using H/V Spectral Ratio Analysis to Map Sediment Thickness and to Explain Macroseismic Intensity Variation of a Low-Magnitude Seismic Swarm in Central Belgium

    Science.gov (United States)

    Van Noten, K.; Lecocq, T.; Camelbeeck, T.

    2013-12-01

    Between 2008 and 2010, the Royal Observatory of Belgium received numerous ';Did You Feel It'-reports related to a 2-year lasting earthquake swarm at Court-Saint-Etienne, a small town in a hilly area 20 km SE of Brussels, Belgium. These small-magnitude events (-0.7 ≤ ML ≤ 3.2, n = c. 300 events) were recorded both by the permanent seismometer network in Belgium and by a locally installed temporary seismic network deployed in the epicentral area. Relocation of the hypocenters revealed that the seismic swarm can be related to the reactivation of a NW-SE strike-slip fault at 3 to 6 km depth in the basement rocks of the Lower Palaeozoic London-Brabant Massif. This sequence caused a lot of emotion in the region because more than 60 events were felt by the local population. Given the small magnitudes of the seismic swarm, most events were more often heard than felt by the respondents, which is indicative of a local high-frequency earthquake source. At places where the bedrock is at the surface or where it is covered by thin alluvial sediments ( 30 m). In those river valleys that have a considerable alluvial sedimentary cover, macroseismic intensities are again lower. To explain this variation in macroseismic intensity we present a macroseismic analysis of all DYFI-reports related to the 2008-2010 seismic swarm and a pervasive H/V spectral ratio (HVSR) analysis of ambient noise measurements to model the thickness of sediments covering the London-Brabant Massif. The HVSR method is a very powerful tool to map the basement morphology, particularly in regions of unknown subsurface structure. By calculating the soil's fundamental frequency above boreholes, we calibrated the power-law relationship between the fundamental frequency, shear wave velocity and the thickness of sediments. This relationship is useful for places where the sediment thickness is unknown and where the fundamental frequency can be calculated by H/V spectral ratio analysis of ambient noise. In a

  9. Corneal endothelial changes in superficial epithelial keratopathy.

    Science.gov (United States)

    Brooks, A M; Grant, G; Gillies, W E

    1986-05-01

    A series of five cases is described in which superficial punctate keratopathy was associated with endothelial cell changes. The most striking change was the presence of dark areas or blebs, usually two to four cell diameters in extent. There was also distortion and crumpling of the corneal endothelium, mild pleomorphism and polymegathism of the endothelial cells, with a reduced cell count in some cases. These blebs have previously been reported in hard and soft contact lens wearers and are due to intercellular oedema with separation of endothelial cells from Descemet's membrane. Anoxia and interference with osmosis have been proposed as possible mechanisms for the production of these blebs, but our cases demonstrate that fine disruption of the corneal epithelium can affect the integrity of the corneal endothelium and may lead to significant damage over a long period of time. PMID:3801208

  10. Evaluation of Fungal Keratitis using a Newly Developed Computer Program, Optscore, for Grading Digital Corneal Photographs

    Science.gov (United States)

    Toutain-Kidd, Christine M.; Porco, Travis C.; Kidd, Eric M.; Srinivasan, M; Prajna, Namperumalsamy V.; Acharya, Nisha; Lietman, Thomas; Zegans, Michael E.

    2016-01-01

    Purpose To validate computer software developed to assess digital corneal photographs of fungal keratitis in clinical research. Methods A cornea specialist and five medical students (after training) graded on two occasions 100 corneal photographs of patients with fungal keratitis using Optscore software. Variables assessed were lesion area, location, degree of opacity, percentage of the ulcer lying within a central 4mm circle of the cornea. Intraclass correlation coefficients (ICCs) were used to assess intragrader reliability, agreement of the students with the corneal specialist, and the reliability of the group mean of the student raters. The area determined using Optscore was compared to the area estimated from slit lamp and to visual acuity. Results As a group, medical students achieved an ICC greater than 0.9 for five out of the seven assessed variables. Similar levels of consistency were found after analyzing the graders’ individual results compared to the specialist. The area estimated using slit lamp examination was highly correlated with the mean area determined by Optscore, as was the logarithm of the minimum angle of resolution visual acuity at enrollment. Conclusions Non-expert graders using Optscore to assess digital photographs of fungal keratitis are self-consistent, agree with an expert grader both as a group and individually, and measurements of ulcer area obtained from Optscore are highly correlated with measurements of the same patients obtained on clinical examination. These observations support the validity of Optscore for assessing corneal pathology associated with fungal keratitis and make it a promising clinical research tool. PMID:24467559

  11. Evaluation of Epithelial Integrity with Various Transepithelial Corneal Cross-Linking Protocols for Treatment of Keratoconus

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    Suphi Taneri

    2014-01-01

    Full Text Available Purpose. Corneal collagen cross-linking (CXL has been demonstrated to stiffen cornea and halt progression of ectasia. The original protocol requires debridement of central corneal epithelium to facilitate diffusion of a riboflavin solution to stroma. Recently, transepithelial CXL has been proposed to reduce risk of complications associated with epithelial removal. Aim of the study is to evaluate the impact of various transepithelial riboflavin delivery protocols on corneal epithelium in regard to pain and epithelial integrity in the early postoperative period. Methods. One hundred and sixty six eyes of 104 subjects affected by progressive keratoconus underwent transepithelial CXL using 6 different riboflavin application protocols. Postoperatively, epithelial integrity was evaluated at slit lamp and patients were queried regarding their ocular pain level. Results. One eye had a corneal infection associated with an epithelial defect. No other adverse event including endothelial decompensation or endothelial damage was observed, except for epithelial damages. Incidence of epithelial defects varied from 0 to 63%. Incidence of reported pain varied from 0 to 83%. Conclusion. Different transepithelial cross-linking protocols have varying impacts on epithelial integrity. At present, it seems impossible to have sufficient riboflavin penetration without any epithelial disruption. A compromise between efficacy and epithelial integrity has to be found.

  12. Corneal collagen crosslinking for keratoconus. A review

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    M. M. Bikbov

    2014-10-01

    Full Text Available Photochemical crosslinking is widely applied in ophthalmology. Its biochemical effect is due to the release of singlet oxygen that promotes anaerobic photochemical reaction. Keratoconus is one of the most common corneal ectasia affecting 1 in 250 to 250 000 persons. Currently, the rate of iatrogenic ectasia following eximer laser refractive surgery increases due to biomechanical weakening of the cornea. Morphologically and biochemically, ectasia is characterized by corneal layers thinning, contact between the stroma and epithelium resulting from Bowman’s membrane rupture, chromatin fragmentation in keratocyte nuclei, phagocytosis, abnormal staining and arrangement of collagen fibers, enzyme system disorders, and keratocyte apoptosis. In corneal ectasia, altered enzymatic processes result in the synthesis of abnormal collagen. Collagen packing is determined by the activity of various extracellular matrix enzymes which bind amines and aldehydes of collagen fiber amino acids. In the late stage, morphological changes of Descemet’s membrane (i.e., rupture and detachment develop. Abnormal hexagonal-shaped keratocytes and their apoptosis are the signs of endothelial dystrophy. The lack of analogs in domestic ophthalmology encouraged the scientists of Ufa Eye Research Institute to develop a device for corneal collagen crosslinking. The parameters of ultraviolet (i.e., wavelength, exposure time, power to achieve the desired effect were identified. The specifics of some photosensitizers in the course of the procedure were studied. UFalink, a device for UV irradiation of cornea, and photosensitizer Dextralink were developed and adopted. Due to the high risk of endothelial damage, this treatment is contraindicated in severe keratoconus (CCT less than 400 microns. Major effects of corneal collagen crosslinking are the following: Young’s modulus (modulus of elasticity increase by 328.9 % (on average, temperature tolerance increase by 5

  13. Current status of accelerated corneal cross-linking

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    Michael Mrochen

    2013-01-01

    Full Text Available Corneal cross-linking with riboflavin is a technique to stabilize or reduce corneal ectasia, in diseases such as keratoconus and post-laser-assisted in situ keratomileusis (LASIK ectasia. There is an interest by patient as well as clinicians to reduce the overall treatment time. Especially, the introduction of corneal cross-linking in combination with corneal laser surgery demands a shorter treatment time to assure a sufficient patient flow. The principles and techniques of accelerated corneal cross-linking is discussed.

  14. Intrastromal injection of bevacizumab in patients with corneal neovascularization

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    Ana Carolina Cabreira Vieira

    2012-08-01

    Full Text Available Corneal neovascularization (NV not only reduces visual acuity, but it also causes loss of the cornea's immune privilege, strongly contributing to a worse prognosis in penetrating keratoplasty. Several mediators participate in corneal angiogenesis, and the role of vascular endothelial growth factor (VEGF has been extensively proven. Anti-VEGF agents have been shown to be effective in slowing the growth of corneal neovessels. Bevacizumab, an anti-VEGF agent, has been successfully used in the treatment of corneal neovascularization. In this paper, we report a series of patients who underwent intracorneal bevacizumab injections to treat corneal vascularization.

  15. Research progress of cultivation and identification of human corneal endothelial cell in vitro%人角膜内皮细胞的体外培养及其鉴定的研究进展

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    贺美宁; 刘二华; 谭钢

    2014-01-01

    Corneal transparence and thickness mostly depend on corneal endothelial cells. The shortage of transplant -grade donor corneal tissues and limited in vitro expansion of human corneal endothelial cells prompted further impetus for the development of tissue-engineered human corneal endothelium reconstructed in vitro. The culture method of human corneal endothelial cell has been widely used. The standard used to evaluate and identify the human corneal endothelial cells cultivated in vitro has not been established. The objective of this article is to summarize the further study on identification and cultivation of human corneal endothelial cell in vitro.%角膜内皮细胞对维持角膜的透明性和厚度起着关键性的作用。人体内角膜内皮细胞有限的增殖能力及角膜供体的短缺,使组织工程人角膜内皮的体外重建受到了关注。目前,人角膜内皮细胞的培养方法已基本成熟。但是体外培养的人角膜内皮细胞的功能评价及鉴定标准却尚未建立。本文就人角膜内皮细胞的体外培养及其鉴定的研究进展进行综述。

  16. [Cross-linking and intrastromal corneal ring segment].

    Science.gov (United States)

    Renesto, Adimara da Candelaria; Sartori, Marta; Campos, Mauro

    2011-01-01

    Corneal cross-linking is a procedure used for stabilizing the cornea in patients with progressive keratoconus by increasing corneal rigidity, and it is also used in corneal inflammatory melting process. The intrastromal corneal ring segments act by flattening the center of the cornea. Originally designed for the correction of mild myopia, the segments are now being used for reduction of keratoconus in order to improve the uncorrected visual acuity, the best spectacle corrected visual acuity, to allow good tolerance to the use of contact lenses and delay the need for corneal grafting procedures. The present text presents a review of corneal cross-linking and insertion of intrastromal corneal ring segments, emphasizing their indications, results and complications related until now. PMID:21670914

  17. Corneal Higher Order Aberrations in Granular, Lattice and Macular Corneal Dystrophies

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    Yagi-Yaguchi, Yukari; Yamaguchi, Takefumi; Okuyama, Yumi; Satake, Yoshiyuki; Tsubota, Kazuo; Shimazaki, Jun

    2016-01-01

    Purpose To evaluate the corneal higher-order aberrations (HOAs) in granular, lattice and macular corneal dystrophies. Methods This retrospective study includes consecutive patients who were diagnosed as granular corneal dystrophy type2 (GCD2; 121 eyes), lattice corneal dystrophies type 1, type 3A (LCDI; 20 eyes, LCDIIIA; 32 eyes) and macular corneal dystrophies (MCD; 13 eyes), and 18 healthy control eyes. Corneal HOAs were calculated using anterior segment optical coherence tomography, and the correlations between HOAs and visual acuity were analyzed. Results HOAs of the total cornea within 4 mm diameter were significantly larger in GCD2 (0.17 ± 0.35 μm), in LCDI (0.33 ± 0.27), LCDIIIA (0.61 ± 1.56) and in MCD (0.23 ± 0.18), compared with healthy controls (0.09 ± 0.02μm, all P GCD2 (0.32 ± 0.48), in LCDI (0.60 ± 0.46), LCDIIIA (0.83 ± 2.29) and in MCD (0.44 ± 0.24), compared with healthy controls (0.19 ± 0.06, all P GCD2, there was no significant correlation between logMAR and HOAs (r = 0.113, P = 0.227). In MCD, LCDI and LCDIIIA, logMAR was positively significantly correlated with HOAs (r = 0.620 and P = 0.028, r = 0.587 and P = 0.007, r = 0.614 and P < 0.001, respectively). Conclusions Increased HOAs occur in eyes with corneal dystrophies, especially in eye with LCD and MCD. Larger amount corneal HOAs are associated with poorer visual acuity in patients with LCD and MCD. PMID:27536778

  18. CORNEAL STROMAL THINNING: A RARE CORNEAL COMPLICATION AFTER BARE SCL ERA PTERYG I UM EXCISION TECHNIQUE

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    Sulaiman Abdul

    2015-06-01

    Full Text Available INTRODUCTION : Bare sclera technique without using any anti - mitotic drugs are commonly employed in rural population. Corneal dellen formation and recurrence of pterygium are more common in these cases. But the corneal complication like stromal thinning, necrosis of corne a and sclera are not common. The corneal epithelium is a highly differentiated cell type that is self - renewing. Also corneal epithelium is important for the stromal replacement in the situations like chemical, thermal burns, ocular surgery like pterygium s urgery. Interference with status of stem cell replacement and as a consequent to it, stromal thinning is occurring in the pterygium surgery. P atient 1: A 68 yr s. old male patient underwent pterygium surgery ( B aresclera excision technique. After 30 days he developed corneal thinning with the punched out partial stromal loss without perforation or descmetocele or scleral thinning. Patient 2: A 60yr s. old male patient underwent pterygium surgery 2months back, he developed same type of corneal thinning. Both P atients were treated with tear drops and improved. CONCLUSION : The stromal thinning in these two cases is may be due to chemical factors like collagenase which might have been released from the traumatised conjunctival epithelial cells causing thinning wit hout replacement of stroma by limbal stem cells.

  19. Atypical Herpes simplex keratitis (HSK presenting as a perforated corneal ulcer with a large infiltrate in a contact lens wearer: multinucleated giant cells in the Giemsa smear offered a clue to the diagnosis

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    Vemuganti Geeta K

    2001-04-01

    Full Text Available Abstract Purpose To report a case of atypical herpes simplex keratitis initially diagnosed as bacterial keratitis, in a contact lens wearer. Results Case report of an 18-year-old woman using contact lenses who presented with pain, redness and gradual decrease in vision in the right eye. Examination revealed a paracentral large stromal infiltrate with a central 2-mm perforation. Corneal and conjunctival scrapings were collected for microbiological investigations. Corneal tissue was obtained following penetrating keratoplasty. Corneal scraping revealed no microorganisms. Giemsa stained smear showed multinucleated giant cells. Conjunctival, corneal scrapings and tissue were positive for herpes simplex virus - 1 (HSV antigen. Corneal tissue was positive for HSV DNA by PCR. Conclusions Atypical HSV keratitis can occur in contact lens wearers. A simple investigation like Giemsa stain may offer a clue to the diagnosis.

  20. Autophagy in granular corneal dystrophy type 2.

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    Choi, Seung-Il; Kim, Eung Kweon

    2016-03-01

    Autophagy is a lysosomal degradative process that is essential for cellular homeostasis and metabolic stress adaptation. Defective autophagy is involved in the pathogenesis of many diseases including granular corneal dystrophy type 2 (GCD2). GCD2 is an autosomal dominant disorder caused by substitution of histidine for arginine at codon 124 (R124H) in the transforming growth factor β-induced gene (TGFBI) on chromosome 5q31. Transforming growth factor β-induced protein (TGFBIp) is degraded by autophagy, but mutant-TGFBIp accumulates in autophagosomes and/or lysosomes, despite significant activation of basal autophagy, in GCD2 corneal fibroblasts. Furthermore, inhibition of autophagy induces cell death of GCD2 corneal fibroblasts through active caspase-3. As there is currently no pharmacological treatment for GCD2, development of novel therapies is required. A potential strategy for preventing cytoplasmic accumulation of mutant-TGFBIp in GCD2 corneal fibroblasts is to enhance mutant-TGFBIp degradation. This could be achieved by activation of the autophagic pathway. Here, we will consider the role and the potential therapeutic benefits of autophagy in GCD2, with focus on TGFBIp degradation, in light of the recently established role of autophagy in protein degradation.

  1. Serological profile of candidates for corneal donation

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    Adroaldo Lunardelli

    2014-10-01

    Full Text Available Objetive: The purpose of this study is to map the serological profile of candidates to corneal donation at Irmandade Santa Casa de Misericórdia de Porto Alegre, identifying the percentage of disposal by serology and the marker involved. Methods: There have been analised – retrospectively – the results of serology of all corneal donors, made between the period of 1st january 2006 and 31st december 2012. Data analised were related to age, gender and the results of serology pertinent to viral markers (HBsAg, anti-HBc, anti-HCV and anti-HIV, these, determined by immunosorbent tests (ELISA. Results: In the period of the study, there were 2476 corneal donors at the institution, with a major incidence on the male gender, on an average of 58.7 years old. 23% of retention because of serological unfitness was also identified, that is, 570 samples were non-negative to any of the used tests. The marker anti- HBc was the most prevalent on the studied population, followed by the Hepatitis C virus (HCV and by the Human Immunodeficiency Virus (HIV. Conclusion: From the data found through this study, it is essential to have the participation of an efficient service on the serological evaluation of the candidates to corneal donation, once the security of the receptor must be taken into consideration in a population of donors with 23% of unfitness prevalence, in which the most prevalent marker is the one of Hepatits B.

  2. Corneal injuries from liquid detergent pods.

    Science.gov (United States)

    Gray, Michael E; West, Constance E

    2014-10-01

    Laundry and dishwasher detergent "pods" were introduced to the United States market in 2010 and are sold by several manufacturers. They represent a high percentage of household cleaning product exposure in the United Kingdom. We present a consecutive case series of 10 children seen in a 9-month period with corneal injuries from exposure to liquid detergent pods.

  3. Peptide Amphiphiles in Corneal Tissue Engineering

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    Martina Miotto

    2015-08-01

    Full Text Available The increasing interest in effort towards creating alternative therapies have led to exciting breakthroughs in the attempt to bio-fabricate and engineer live tissues. This has been particularly evident in the development of new approaches applied to reconstruct corneal tissue. The need for tissue-engineered corneas is largely a response to the shortage of donor tissue and the lack of suitable alternative biological scaffolds preventing the treatment of millions of blind people worldwide. This review is focused on recent developments in corneal tissue engineering, specifically on the use of self-assembling peptide amphiphiles for this purpose. Recently, peptide amphiphiles have generated great interest as therapeutic molecules, both in vitro and in vivo. Here we introduce this rapidly developing field, and examine innovative applications of peptide amphiphiles to create natural bio-prosthetic corneal tissue in vitro. The advantages of peptide amphiphiles over other biomaterials, namely their wide range of functions and applications, versatility, and transferability are also discussed to better understand how these fascinating molecules can help solve current challenges in corneal regeneration.

  4. Change in corneal curvature induced by surgery

    NARCIS (Netherlands)

    G. van Rij (Gabriel)

    1987-01-01

    textabstractThe first section deals with the mechanisms by which sutures, incisions and intracorneal contact lenses produce a change in corneal curvature. To clarify the mechanisms by which incisions and sutures produce astigmatism, we made incisions and placed sutures in the corneoscleral limbus of

  5. [Future Innovative Medicine for Corneal Diseases].

    Science.gov (United States)

    Nishida, Kohji

    2016-03-01

    Japan faces an aging population and a declining birth rate, so medical professionals and the public are seeking next-generation ophthalmological treatments to preserve and restore visual function. Two fields lie at the heart of this future concept of ophthalmological treatments. The first is predictive medicine and early intervention and treatment. This field is based on precision medicine to treat chronic conditions such as keratoconus, glaucoma, and macular degeneration while the condition is latent or soon after it has developed. The second field is regenerative therapy. This field includes cell therapy, regenerative medicine, artificial corneas and retinal implants. Precision medicine is the concept of examining the effects of genomic information and environmental factors on the onset or progression of a condition. Precision medicine involves dividing patients with a given condition into subgroups and then developing an appropriate method of preventing or treating that condition for each group. This may prove useful in treating corneal conditions such as keratoconus and dry eye. To accomplish that goal, however, overarching genomic, imaging, and biomarker studies must be conducted. Markers related to the onset or progression of a condition must also be identified. This paper describes results of preliminary study of 2 types of markers: biomarkers, and genetic markers. These markers have been used in efforts to predict the onset or progression of keratoconus. The development of regenerative medicine requires basic studies of stem cells and microenvironments (niches) in which to sustain those cells. N-cadherin is a cell adhesion molecule, and the current authors are the first to contend that this molecule plays an important role in the corneal epithelial stem cell niche. In addition, the current authors are the first to report that corneal endothelial cells expressing p75 may potentially be corneal endothelial precursor cells. Capitalizing on the results of that

  6. [Future Innovative Medicine for Corneal Diseases].

    Science.gov (United States)

    Nishida, Kohji

    2016-03-01

    Japan faces an aging population and a declining birth rate, so medical professionals and the public are seeking next-generation ophthalmological treatments to preserve and restore visual function. Two fields lie at the heart of this future concept of ophthalmological treatments. The first is predictive medicine and early intervention and treatment. This field is based on precision medicine to treat chronic conditions such as keratoconus, glaucoma, and macular degeneration while the condition is latent or soon after it has developed. The second field is regenerative therapy. This field includes cell therapy, regenerative medicine, artificial corneas and retinal implants. Precision medicine is the concept of examining the effects of genomic information and environmental factors on the onset or progression of a condition. Precision medicine involves dividing patients with a given condition into subgroups and then developing an appropriate method of preventing or treating that condition for each group. This may prove useful in treating corneal conditions such as keratoconus and dry eye. To accomplish that goal, however, overarching genomic, imaging, and biomarker studies must be conducted. Markers related to the onset or progression of a condition must also be identified. This paper describes results of preliminary study of 2 types of markers: biomarkers, and genetic markers. These markers have been used in efforts to predict the onset or progression of keratoconus. The development of regenerative medicine requires basic studies of stem cells and microenvironments (niches) in which to sustain those cells. N-cadherin is a cell adhesion molecule, and the current authors are the first to contend that this molecule plays an important role in the corneal epithelial stem cell niche. In addition, the current authors are the first to report that corneal endothelial cells expressing p75 may potentially be corneal endothelial precursor cells. Capitalizing on the results of that

  7. Effect of chemical composition on corneal tissue response to photopolymerized materials comprising 2-hydroxyethyl methacrylate and acrylic acid

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    Lai, Jui-Yang, E-mail: jylai@mail.cgu.edu.tw

    2014-01-01

    The purpose of this work was to investigate the relationship between the feed composition of 2-hydroxyethyl methacrylate (HEMA)/acrylic acid (AAc) and hydrogel material compatibility towards ocular anterior segment tissues, particularly the corneal endothelium. The monomer solutions of HEMA and AAc were mixed at varying volume ratios of 92:0, 87:5, 82:10, 77:15, and 72:20, and were subjected to UV irradiation. Then, the 7-mm-diameter membrane implants made from photopolymerized materials were placed into the ocular anterior chamber for 4 days and assessed by biomicroscopic examinations, corneal thickness measurements, and quantitative real-time reverse transcription polymerase chain reaction analyses. The poly(HEMA-co-AAc) implants prepared from the solution mixture containing 0–10 vol.% AAc displayed good biocompatibility. However, with increasing volume ratio of AAc and HEMA from 15:77 to 20:72, the enhanced inflammatory response, decreased endothelial cell density, and increased ocular score and corneal thickness were observed, probably due to the influence of surface charge of copolymer membranes. On the other hand, the ionic pump function of corneal endothelium exposed to photopolymerized membranes was examined by analyzing the Na{sup +},K{sup +}-ATPase alpha 1 subunit (ATP1A1) expression level. The presence of the implants having higher amount of AAc incorporated in the copolymers (i.e., 15.1 to 24.7 μmol) and zeta potential (i.e., -38.6 to − 56.5 mV) may lead to abnormal transmembrane transport. It is concluded that the chemical composition of HEMA/AAc has an important influence on the corneal tissue responses to polymeric biomaterials. - Highlights: • We examine the corneal tissue responses to photopolymerized biomaterials. • Carboxyl groups in copolymers increased with increasing volume ratio of AAc/HEMA. • 15–20 vol.% AAc raised ocular score and caused corneal endothelial loss and edema. • High anionic charge density stimulated inflammation

  8. Comparative results of corneal curvature measurements with three different keratometers after radial keratotomy

    Institute of Scientific and Technical Information of China (English)

    ZHAO Lu; ZHANG Li; WANG Yan-ling; WANG Wei; YAN Yan

    2011-01-01

    Background Corneal curvatures measured by conventional instruments after refractive surgeries were greater than the real values.This study on the instruments and methods for measuring corneal curvature was carried out with the aim of determining an accurate,simple and effective method to evaluate corneal refractive power after radial keratotomy (RK).Methods A retrospective study was carried out on 52 eyes of 42 patients with a history of RK.The postoperative measurements after RK were performed with a manual keratometer (Rodenstock,Munchen-Hamburg,Germany),a corneal topographer (Tomey TMS-1) and an automated IOLMaster keratometer (Carl Zeiss GmbH,USA).The results obtained from analyzing clinical histories (clinical history method,CHM) were compared to the postoperative measurements with a two-way analysis of variance.Adjusted keratometry was used to correct the corneal central refractive power (K) values of the three keratometers.The CHM results were also compared to the corrected K values obtained with the three keratometers using the same statistical method.Results The smallest mean value was found for the CHM ((36.61±9.23) diopters).The K values obtained with the CHM were very different from the results obtained with the three different instruments.The corrected K values obtained with the IOLMaster were the closest to the K values from the CHM.Conclusions It was shown that K values from measurements with the three instruments were higher.When the power of the intraocular lens of the patients after RK was calculated,the errors of the K values measured with the instruments should be taken into consideration.

  9. Oxygen-deficient metabolism and corneal edema.

    Science.gov (United States)

    Leung, B K; Bonanno, J A; Radke, C J

    2011-11-01

    Wear of low-oxygen-transmissible soft contact lenses swells the cornea significantly, even during open eye. Although oxygen-deficient corneal edema is well-documented, a self-consistent quantitative prediction based on the underlying metabolic reactions is not available. We present a biochemical description of the human cornea that quantifies hypoxic swelling through the coupled transport of water, salt, and respiratory metabolites. Aerobic and anaerobic consumption of glucose, as well as acidosis and pH buffering, are incorporated in a seven-layer corneal model (anterior chamber, endothelium, stroma, epithelium, postlens tear film, contact lens, and prelens tear film). Corneal swelling is predicted from coupled transport of water, dissolved salts, and especially metabolites, along with membrane-transport resistances at the endothelium and epithelium. At the endothelium, the Na+/K+ - ATPase electrogenic channel actively transports bicarbonate ion from the stroma into the anterior chamber. As captured by the Kedem-Katchalsky membrane-transport formalism, the active bicarbonate-ion flux provides the driving force for corneal fluid pump-out needed to match the leak-in tendency of the stroma. Increased lactate-ion production during hypoxia osmotically lowers the pump-out rate requiring the stroma to swell to higher water content. Concentration profiles are predicted for glucose, water, oxygen, carbon dioxide, and hydronium, lactate, bicarbonate, sodium, and chloride ions, along with electrostatic potential and pressure profiles. Although the active bicarbonate-ion pump at the endothelium drives bicarbonate into the aqueous humor, we find a net flux of bicarbonate ion into the cornea that safeguards against acidosis. For the first time, we predict corneal swelling upon soft-contact-lens wear from fundamental biophysico-chemical principles. We also successfully predict that hypertonic tear alleviates contact-lens-induced edema. PMID:21820076

  10. Electrospun Scaffolds for Corneal Tissue Engineering: A Review

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    Bin Kong

    2016-07-01

    Full Text Available Corneal diseases constitute the second leading cause of vision loss and affect more than 10 million people globally. As there is a severe shortage of fresh donated corneas and an unknown risk of immune rejection with traditional heterografts, it is very important and urgent to construct a corneal equivalent to replace pathologic corneal tissue. Corneal tissue engineering has emerged as a practical strategy to develop corneal tissue substitutes, and the design of a scaffold with mechanical properties and transparency similar to that of natural cornea is paramount for the regeneration of corneal tissues. Nanofibrous scaffolds produced by electrospinning have high surface area–to-volume ratios and porosity that simulate the structure of protein fibers in native extra cellular matrix (ECM. The versatilities of electrospinning of polymer components, fiber structures, and functionalization have made the fabrication of nanofibrous scaffolds with suitable mechanical strength, transparency and biological properties for corneal tissue engineering feasible. In this paper, we review the recent developments of electrospun scaffolds for engineering corneal tissues, mainly including electrospun materials (single and blended polymers, fiber structures (isotropic or anisotropic, functionalization (improved mechanical properties and transparency, applications (corneal cell survival, maintenance of phenotype and formation of corneal tissue and future development perspectives.

  11. Emodin ameliorates lipopolysaccharides-induced corneal inflammation in rats

    Institute of Scientific and Technical Information of China (English)

    Guo-Ling; Chen; Jing-Jing; Zhang; Xin; Kao; Lu-Wan; Wei; Zhi-Yu; Liu

    2015-01-01

    · AIM: To investigate the effect of emodin on pseudomonas aeruginosa lipopolysaccharides(LPS)-induced corneal inflammation in rats.· METHODS: Corneal infection was induced by pseudomonas aeruginosa LPS in Wistar rats. The inflammation induced by LPS were examined by slit lamp microscope and cytological checkup of aqueous humor.Corneal tissue structure was observed by hematoxylin and eosin(HE) staining. The activation of nuclear factor kappa B(NF-κB) was determined by Western blot.Messenger ribonucleic acid(m RNA) of tumor necrosis factor-α(TNF-α) and intercellular adhesion molecule-1(ICAM-1) in LPS-challenged rat corneas were measured with reverse transcription-polymerase chain reaction(RT-PCR).· RESULTS: Typical manifestations of acute corneal inflammation were observed in LPS-induce rat model,and the corneal inflammatory response and structure were improved in rats pretreated with emodin. Treatment with emodin could improve corneal structure, reduce corneal injure by reducing corneal inflammatory response. Emodin could inhibit the decreasing lever of inhibitor of kappa B alpha(IкBα) express, and the m RNA expression of TNF-α and ICAM-1 in corneal tissues was also inhibited by emodin. The differences were statistically significant between groups treated with emodin and those without treatment(P <0.01).·CONCLUSION: Emodin could ameliorate LPS-induced corneal inflammation, which might via inhibiting the activation of NF-κB.

  12. Manifestaciones corneales en las enfermedades sistémicas Corneal manifestations in systemic diseases

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    J. Zarranz-Ventura

    2008-01-01

    Full Text Available Un gran número de enfermedades sistémicas presentan manifestaciones corneales dentro de su espectro de enfermedad. El estudio detallado de todos los cuadros que asocian patología corneal resulta inabarcable, por ello se presentan las enfermedades más prevalentes o características. Este estudio contempla las enfermedades pulmonares y conectivopatías (colagenosis, enfermedades reumatológicas y enfermedades inflamatorias idiopáticas, las enfermedades dermatológicas, cardiovasculares, hematológicas y la patología digestiva y hepatopancreática. Se contemplan también, por ocasionar alteraciones corneales, las enfermedades endocrinas y metabólicas con algunas situaciones de malnutrición y estados carenciales, las infecciones sistémicas y las enfermedades renales. Otro área que produce afectación corneal es la patología otorrinolaringológica y las enfermedades genéticas. Se repasa brevemente la toxicidad y las alteraciones corneales provocadas por fármacos.Systemic diseases affecting the cornea have a wide range of manifestations. The detailed study of all pathologies that cause corneal alteration is unapproachable, so we have centered our interest in the most prevalent or characteristic of them. In this paper we have divided these pathologies in sections to facilitate their study. Pulmonar and conective tissue (like colagen, rheumatologic and idiopathic inflamatory diseases, dermatologic, cardiovascular, hematologic, digestive and hepatopancreatic diseases with corneal alteration are described. Endocrine and metabolic diseases, malnutrition and carential states are also studied, as well as some otorhinolaryngologic and genetic diseases that affect the cornea. Finally, a brief report of ocular toxicity induced by drugs is referred.

  13. Corneal Graft Rejection: Incidence and Risk Factors

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    Alireza Baradaran-Rafii

    2008-12-01

    Full Text Available

    PURPOSE: To determine the incidence and risk factors of late corneal graft rejection after penetrating keratoplasty (PKP. METHODS: Records of all patients who had undergone PKP from 2002 to 2004 without immunosuppressive therapy other than systemic steroids and with at least one year of follow up were reviewed. The role of possible risk factors such as demographic factors, other host factors, donor factors, indications for PKP as well as type of rejection were evaluated. RESULTS: During the study period, 295 PKPs were performed on 286 patients (176 male, 110 female. Mean age at the time of keratoplasty was 38±20 (range, 40 days to 90 years and mean follow up period was 20±10 (range 12-43 months. Graft rejection occurred in 94 eyes (31.8% at an average of 7.3±6 months (range, 20 days to 39 months after PKP. The most common type of rejection was endothelial (20.7%. Corneal vascularization, regrafting, anterior synechiae, irritating sutures, active inflammation, additional anterior segment procedures, history of trauma, uncontrolled glaucoma, prior graft rejection, recurrence of herpetic infection and eccentric grafting increased the rate of rejection. Patient age, donor size and bilateral transplantation had no significant influence on graft rejection. CONCLUSION: Significant risk factors for corneal graft rejection include

  14. Avaliação da qualidade de corte do microceratótomo Masyk® na confecção de lamela corneana pediculada em olhos porcinos Evaluation of the cut quality of the Masyk® microkeratome in obtaining corneal flap from porcine eyes

    Directory of Open Access Journals (Sweden)

    Gustavo Victor

    2006-02-01

    Full Text Available OBJETIVO: Avaliar a qualidade de corte do microceratótomo Masyk® na confecção de lamela corneana pediculada em olhos porcinos. MÉTODOS: Realizou-se estudo prospectivo na Eye Clinic Day Hospital (São Paulo, Brasil em 31 olhos porcinos divididos em 2 grupos: 15 olhos nos quais se utilizou a plataforma de 160 µm e anel de sucção de 9,5 mm de diâmetro (Grupo 1 e 16 olhos, submetidos à plataforma de 140 µm e anel de sucção de 8,5 mm de diâmetro (Grupo 2. As espessuras efetivas das lamelas foram aferidas pelo paquímetro P55 (Paradigm, EUA e os diâmetros verticais do leito estromal com compasso cirúrgico. RESULTADOS: Não ocorreram complicações durante a utilização do microceratótomo e não foram identificadas lamelas livres, perfuradas ou incompletas. No grupo 1, a média das espessuras efetiva foi de 146,33 ± 15,43 µm, com variação entre 127 e 186 µm. A média das medidas do diâmetro vertical do leito residual foi de 9,39 ± 0,26 mm, com variação entre 8,90 e 9,85 mm. No grupo 2, a média das espessuras efetiva foi de 128,75 ± 18,83 µm, com variação entre 71 e 178 µm. A média das medidas do diâmetro do leito residual foi de 8,27 ± 0,20 mm, com variação entre 7,95 e 8,65 mm. CONCLUSÃO: O microceratótomo Masyk® mostrou-se eficaz e seguro em confeccionar lamelas corneanas pediculadas de espessura e diâmetros adequados em olhos porcinos.PURPOSE: Evaluation of the cut quality of the Masyk® microkeratome in obtaining corneal flap from porcine eyes. METHODS: Prospective study with 31 porcine eyes divided into two groups: 15 eyes with programmed flap thickness of 160 µm and 9.5 mm diameter (Group 1, and 16 eyes with programmed flap thickness of 140 µm and 8.5 mm diameter (Group 2. Corneal thickness was calculated with a P55 pachymeter (Paradigm, USA and the diameter with compass. RESULTS: No complications were observed during the use of the microkeratome. In group 1, the central corneal thickness mean was 146

  15. Effects of aberrant Pax6 gene dosage on mouse corneal pathophysiology and corneal epithelial homeostasis.

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    Richard L Mort

    Full Text Available Altered dosage of the transcription factor PAX6 causes multiple human eye pathophysiologies. PAX6⁺/⁻ heterozygotes suffer from aniridia and aniridia-related keratopathy (ARK, a corneal deterioration that probably involves a limbal epithelial stem cell (LESC deficiency. Heterozygous Pax6(+/Sey-Neu (Pax6⁺/⁻ mice recapitulate the human disease and are a good model of ARK. Corneal pathologies also occur in other mouse Pax6 mutants and in PAX77(Tg/- transgenics, which over-express Pax6 and model human PAX6 duplication.We used electron microscopy to investigate ocular defects in Pax6⁺/⁻ heterozygotes (low Pax6 levels and PAX77(Tg/- transgenics (high Pax6 levels. As well as the well-documented epithelial defects, aberrant Pax6 dosage had profound effects on the corneal stroma and endothelium in both genotypes, including cellular vacuolation, similar to that reported for human macular corneal dystrophy. We used mosaic expression of an X-linked LacZ transgene in X-inactivation mosaic female (XLacZ(Tg/- mice to investigate corneal epithelial maintenance by LESC clones in Pax6⁺/⁻ and PAX77(Tg/- mosaic mice. PAX77(Tg/- mosaics, over-expressing Pax6, produced normal corneal epithelial radial striped patterns (despite other corneal defects, suggesting that centripetal cell movement was unaffected. Moderately disrupted patterns in Pax6⁺/⁻ mosaics were corrected by introducing the PAX77 transgene (in Pax6⁺/⁻, PAX77(Tg/- mosaics. Pax6(Leca4/+, XLacZ(Tg/- mosaic mice (heterozygous for the Pax6(Leca4 missense mutation showed more severely disrupted mosaic patterns. Corrected corneal epithelial stripe numbers (an indirect estimate of active LESC clone numbers declined with age (between 15 and 30 weeks in wild-type XLacZ(Tg/- mosaics. In contrast, corrected stripe numbers were already low at 15 weeks in Pax6⁺/⁻ and PAX77(Tg/- mosaic corneas, suggesting Pax6 under- and over-expression both affect LESC clones.Pax6⁺/⁻ and PAX77(Tg

  16. Changes in thickness of each layer of developing chicken cornea after administration of caffeine.

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    Hieronim Bartel

    2010-08-01

    Full Text Available The aim of the study was the presentation of changes in thickness of each layer of a developing cornea, that came into being under an influence of caffeine which was administered to chicken embryos. Research materials were 26 chicken embryos from breeding eggs that had been incubated. Breeding eggs were divided into two groups: control (n=30 in which Ringer liquid was given, and experimental (n=30 in which teratogenic dose of caffeine was administrated - 3.5 mg/egg. In 36th hour of incubation solutions were given with cannula through a hole in an egg shell directly onto amniotic membrane. After closing the hole with paraffin, eggs were put back into incubator. On 10th and 19th day of incubation corneas were taken for morphometric and morphological analysis. In experimental groups reduction of corneal thickness, thickening of corneal epithelium and corneal endothelium as well as Bowman's and Descemet's membranes, decrease of thickness of corneal stroma in comparison with the control group have been observed. Caffeine causes thickness changes of all layers and decreases the total thickness of a developing cornea.

  17. Induction of corneal collagen cross-linking in experimental corneal alkali burns in rabbits

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    Marcello Colombo-Barboza

    2014-10-01

    Full Text Available Objective: To evaluate the effect of riboflavin-ultraviolet-A-induced cross-linking (CXL following corneal alkali burns in rabbits. Methods: The right corneas and limbi of ten rabbits were burned using a 1N solution of NaOH and the animals were then divided into two groups: a control group submitted to clinical treatment alone and an experimental group that was treated 1 h after injury with CXL, followed by the same clinical treatment as administered to the controls. Clinical parameters were evaluated post-injury at 1, 7, 15, and 30 days by two independent observers. Following this evaluation, the corneas were excised and examined histologically. Results: There were no statistically significant differences in clinical parameters, such as hyperemia, corneal edema, ciliary injection, limbal ischemia, secretion, corneal neovascularization, symblepharon, or blepharospasm, at any of the time-points evaluated. However, the size of the epithelial defect was significantly smaller in the CXL group (p<0.05 (day 15: p=0.008 and day 30: p=0.008 and the extent of the corneal injury (opacity lesion was also smaller (day 30: p=0.021. Histopathology showed the presence of collagen bridges linking the collagen fibers in only the CXL group. Conclusions: These results suggest that the use of CXL may improve the prognosis of acute corneal alkali burns.

  18. EXPERIMENTAL STUDY ON THE CORNEAL ENDOTHELIUM OF TRAUMATIC CATARACT

    Institute of Scientific and Technical Information of China (English)

    1991-01-01

    The cell morphology of corneal endothelium in 84 mice with experimental traumatic cataract was investigated with stained corneal buttons. In the experimental group, the boundaries between adjacent corneal endothelial cells were significantly distorted, some cell boundaries manifested degenerative changes that led to coalescence of the cells. The mean density and mean area of endothelial cells of the controls showed significant difference from those of the experimental group during the 12 weeks of observ...

  19. Corneal Tissue Engineering: Recent Advances and Future Perspectives

    OpenAIRE

    Ghezzi, Chiara E.; Rnjak-Kovacina, Jelena; Kaplan, David L

    2015-01-01

    To address the growing need for corneal transplants two main approaches are being pursued: allogenic and synthetic materials. Allogenic tissue from human donors is currently the preferred choice; however, there is a worldwide shortage in donated corneal tissue. In addition, tissue rejection often limits the long-term success of this approach. Alternatively, synthetic homologs to donor corneal grafts are primarily considered temporary replacements until suitable donor tissue becomes available,...

  20. Experimental study on cryotherapy for fungal corneal ulcer

    OpenAIRE

    Chen, Yingxin; Yang, Weijia; Gao, Minghong; Belin, Michael Wellington; Yu, Hai; Yu, Jing

    2015-01-01

    Background Fungal corneal ulcer is one of the major causes of visual impairment worldwide. Treatment of fungal corneal ulcer mainly depends on anti-fungal agents. In the current study, we developed an integrated combination therapy of cryotherapy and anti-fungal agents to facilitate effective treatment of fungal corneal ulcer. Methods Rabbit models of cornea infection were established using a combined method of intrastromal injection and keratoplasty. After treatment with cryotherapy and anti...

  1. Spontaneous corneal perforation in ocular rosacea

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    Al Arfaj Khalid

    2010-01-01

    Full Text Available Rosacea is a dermatologic condition that affects the midfacial region. Ocular rosacea is most frequently diagnosed when cutaneous signs and symptoms are also present. Ocular manifestations are essentially confined to the eyelids and ocular surface. Ocular involvement ranges from minor irritation, dryness, and blurry vision to potentially severe ocular surface disruption including corneal ulcers, vascularization and rarely perforation. We present a 49-year-old Saudi Arabian female with the diagnosis of rosacea who presented with a peripheral corneal performation. The perforation was successfully managed by surgical repair, oral doxycycline and topical steroid. The final best corrected visual acuity was 20/30 after treatment. Early referral to an ophthalmologist and careful long-term follow-up are recommended.

  2. Corneal hymenoptera stings: A new therapeutic approach

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    Mauricio Vélez

    2012-12-01

    Full Text Available Purpose: We describe five cases, (4 children, with ocular sequelae from honeybee or wasp sting injuries to the eye treated with anterior chamber irrigation to reduce the venom concentration and subsequent complications. All patients were treated on the Ophthalmology Service of Hospital Universitario San Vicente de Paul, Medellín, Colombia. Methods: Small case series. Patients with hymenoptera corneal sting injuries were treated in the operating room by performing an anterior chamber washout with balanced saline solution and triamcinolone in an effort to minimize the tissue damage induced by bee venom. Results: Early clearing of inflammation and more rapid recovery of baseline acuity was associated with early surgical intervention. Late complications included corneal decompensation, iris heterochromia, paralytic mydriasis, glaucoma and cataract; these complications are irreversible and sight threatening. Conclusion: Performing an early anterior chamber washout is a treatment option for this type of trauma, since it results in faster resolution and fewer late complications. 

  3. Clinical correlates of common corneal neovascular diseases: a literature review

    Institute of Scientific and Technical Information of China (English)

    Nizar; Saleh; Abdelfattah; Mohamed; Amgad; Amira; A; Zayed; Hamdy; Salem; Ahmed; E; Elkhanany; Heba; Hussein; Nawal; Abd; El-Baky

    2015-01-01

    A large subset of corneal pathologies involves the formation of new vessels(neovascularization), leading to compromised visual acuity. This article aims to review the clinical causes and presentations of corneal neovascularization(CNV) by examining the mechanisms behind common CNV-related corneal pathologies, with a particular focus on herpes simplex stromal keratitis,contact lenses-induced keratitis and CNV secondary to keratoplasty. Moreover, we reviewed CNV in the context of different types of corneal transplantation and keratoprosthesis, and summarized the most relevant treatment available so far.

  4. RECURRENT CORNEAL EROSION SYNDROME (a review

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    S. V. Trufanov

    2015-01-01

    Full Text Available Recurrent corneal erosion (RCE syndrome is characterized by episodes of recurrent spontaneous epithelial defects. Main clinical symptoms (pain, redness, photophobia, lacrimation occurred at night. Corneal lesions revealed by slit lamp exam vary depending on the presence of corneal epithelium raise, epithelial microcysts or epithelial erosions, stromal infiltrates and opacities. Microtraumas, anterior corneal dystrophies, and herpesvirus give rise to RCE. Other causes or factors which increase the risk of RCE syndrome include meibomian gland dysfunction, keratoconjunctivitis sicca, diabetes, and post-LASIK conditions. Basal membrane abnormalities and instability of epithelial adhesion to stroma play a key role in RCE pathogenesis. Ultrastructural changes in RCE include abnormalities of basal epithelial cells and epithelial basal membrane, absence or deficiency of semi-desmosomes, loss of anchor fibrils. Increase in matrix metalloproteinases and collagenases which contribute to basal membrane destruction results in recurrent erosions and further development of abnormal basal membrane. The goals of RCE therapy are to reduce pain (in acute stage, to stimulate re-epithelization, and to restore «adhesion complex» of basal membrane. In most cases, RCE responds to simple conservative treatment that includes lubricants, healing agents, and eye patches. RCEs that are resistant to simple treatment, require complex approach. Non-invasive methods include long-term contact lens use, instillations of autologous serum (eye drops, injections of botulinum toxin (induces ptosis, antiviral agent use or oral intake of metalloproteinase inhibitors. Cell membrane stabilizers, i.e., antioxidants, should be included into treatment approaches as well. Antioxidant effect of Emoxipine promotes tissue reparation due to the prevention of cell membrane lipid peroxidation as well as due to its anti-hypoxic, angioprotective, and antiplatelet effects. If conservative therapy

  5. Correlation between Corneal Endothelial Cell Loss and Location of Phacoemulsification Incision

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    Hamid Gharaee

    2011-01-01

    Full Text Available Purpose: To assess the relationship between corneal endothelial cell loss after phacoemulsification and the location of the clear corneal incision. Methods: A total of 92 patients (92 eyes with senile cataracts who met the study criteria were included in this cross sectional study and underwent phacoemulsification. The incision site was determined based on the steep corneal meridian according to preoperative keratometry. Endothelial cell density was measured using specular microscopy in the center and 3 mm from the center of the cornea in the meridian of the incisions (temporal, superior, and superotemporal. Phacoemulsification was performed by a single surgeon using the phaco chop technique through a 3.2 mm clear cornea incision. Endothelial cell loss (ECL was evaluated 1 week, and 1 and 3 months postoperatively. Results: At all time points during follow-up, ECL was comparable among the 3 incision sites, both in the central cornea and in the meridian of the incision (P > 0.05 for all comparisons. However, 3 months postoperatively, mean central ECL with superior incisions and mean sectoral ECL with temporal incisions were slightly higher. Superotemporal incisions entailed slightly less ECL than the other 2 groups. Overall, one month after surgery, mean central ECL was 10.8% and mean ECL in the sector of the incisions was 14.0%. Axial length and effective phaco time (EFT were independent predictors of postoperative central ECL (P values 0.005 and < 0.0001, respectively. Conclusion: A superotemporal phacoemulsification incision may entail less ECL as compared to other incisions (although not significantly different. The amount of central ECL may be less marked in patients with longer axial lengths and with procedures utilizing less EFT.

  6. Corneal Collagen Cross-Linking with Hypoosmolar Riboflavin Solution in Keratoconic Corneas

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    Shaofeng Gu

    2014-01-01

    Full Text Available Purpose. To report the 12-month outcomes of corneal collagen cross-linking (CXL with a hypoosmolar riboflavin and ultraviolet-A (UVA irradiation in thin corneas. Methods. Eight eyes underwent CXL using a hypoosmolar riboflavin solution after epithelial removal. The corrected distance visual acuity (CDVA, manifest refraction, the mean thinnest corneal thickness (MTCT, and the endothelial cell density (ECD were evaluated before and 6 and 12 months after CXL. Results. The MTCT was 413.9 ± 12.4 μm before treatment and reduced to 381.1 ± 7.3 μm after the removal of the epithelium. After CXL, the thickness decreased to 410.3 ± 14.5 μm at the last follow-up. Before treatment, the mean K-value of the apex of the keratoconus corneas was 58.7 ± 3.5 diopters and slightly decreased (57.7 ± 4.9 diopters at 12 months. The mean CDVA was 0.54 ± 0.23 logarithm of the minimal angle of resolution before treatment and increased to 0.51 ± 0.21 logarithm at the last follow-up. The ECD was 2731.4 ± 191.8 cells/mm2 before treatment and was 2733.4 ± 222.6 cells/mm2 at 12 months after treatment. Conclusions. CXL with a hypoosmolar riboflavin in thin corneas seems to be a promising method for keratoconic eyes with the mean thinnest corneal thickness less than 400 μm without epithelium.

  7. 角膜塑形镜对青少年近视患者视力及角膜形态变化的影响%Effect of orthokeratology on visual acuity and corneal shape change in myopic adolescents

    Institute of Scientific and Technical Information of China (English)

    张博; 唐伟; 周文艳; 单多; 刘平; 胡琦

    2016-01-01

    AlM:To investigate the effect of orthokeratology on vision and corneal shape change in myopic adolescents. METHODS:Ninety-seven young patients ( 176 eyes ) with myopia wearing orthokeratology were randomly selected. Spherical equivalent ( SE ) , uncorrected visual acuity ( UCVA ) , best corrected visual acuity ( BCVA ) , corneal curvature and central corneal thickness were examined before, after wearing at 1d, 1wk, 1, 3 and 6mo. The results were compared and analyzed. RESULTS:SE decreased and UCVA increased at 1d, 1wk, 1, 3 and 6mo after wearing orthokeratology, the difference was statistically significant ( P 0. 05 ). The difference of corneal curvature after wearing orthokeratology for 1d, 1wk, 1, 3 and 6mo compared with before was statistically significant ( P CONCLUSlON:Orthokeratology can effectively reduce the degree of myopia, and significantly improve the uncorrected visual acuity.%目的:探讨角膜塑形镜对青少年近视患者视力及角膜形态变化的影响。  方法:随机选取97例176眼配戴角膜塑形镜的青少年近视患者,在戴镜前、戴镜后1d,1wk,1、3、6lo检查平均等效球镜度(spherical equivalent,SE)、裸眼视力(uncorrected visual acuity, UCVA )、矫正视力( best corrected visual acuity,BCVA)、角膜曲率及角膜中央厚度,对比分析检查结果。  结果:配戴角膜塑形镜后1d,1wk,1、3、6lo 的 SE 下降, UCVA明显改善,与戴镜前比较差异具有统计学意义( P0.05);配戴角膜塑形镜后1d,1wk,1、3、6lo的角膜曲率与戴镜前比较差异具有统计学意义(P  结论:角膜塑形镜能有效降低近视度,显著提高裸眼视力。

  8. Study of Topical Human Umbilical Cord Blood Serum in the Treatment of Alkaline Corneal Epithelial Wounds in Rabbit Model

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    B Sharifi

    2011-04-01

    Full Text Available Introduction & Objective: One of the important functions of the cornea is to maintain normal vision by refracting light onto the lens and retina. This property is dependent in part on the ability of the corneal epithelium to undergo continuous renewal. Ocular surface failure which follows a variety of endogenous and exogenous precipitating factors, the most common being: chemical trauma, infection, alkaline burn, inflammation and hereditary conditions, lid or lash abnormalities, tear deficiency or reduced sensation. The core principal underpinning management strategy for ocular surface failure is establishing or promoting new growth of healthy conjunctiva and corneal epithelium. This process is mediated by many proteins that are inducers of corneal cell migration, proliferation, and differentiation. The current study was performed to investigate the efficacy of umbilical cord serum on alkaline corneal epithelial wound healing in the rabbit model. Materials & Methods: In this study conducted at Yasuj University of Medical Sciences in 2010, thirty two rabbits were randomly assigned into two equal groups. Central corneal alkali wound was formed in one eye of the rabbits by applying a 6-mm round filter paper, soaked in 1 N NaOH, for 60 seconds. Group one of animals received umbilical cord blood serum and group two received Sno*Tear in the eyes. The treatment was dosed 4 times a day with the eye drops, and epithelial wound closure was recorded using slit lamp. The data were analyzed to determine the rate of wound closure. Results: The mean wound radius closure rate was 0.77 mm/day (SD=0.013 for umbilical cord blood serum-treated eyes, 0.73 mm/day (SD=0.018 for artificial tear-treated eyes. Conclusion: This study shows that alkali-injured corneal epithelial wound heal faster when treated with umbilical cord blood serum than with artificial tear in rabbit model.

  9. Putative epidermal stem cell convert into corneal epithelium-like cell under corneal tissue in vitro

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Rhesus putative epidermal stem cells are being investigated for their potential use in regenerative corneal epithelium-like cells, which may provide a practical source of autologous seed cells for the construction of bioengineered corneas. The goal of this study was to investigate the potential of epi-dermal stem cells for trans-differentiation into corneal epithelium-like cells. Rhesus putative epidermal stem cells were isolated by type IV collagen attachment method. Flow cytometry analysis, immuno-histology and RT-PCR were conducted to identify the expression of specific markers (β1, α6 integrin, K15, K1/K10, K3/K12 and CD71) on the isolated rapid attaching cells. The isolated cells were cocultured with human corneal limbal stroma and corneal epithelial cells. After coculture, the expression of the same specific markers was evaluated in order to identify expression difference caused by the coculture conditions. K3/K12 expression was analyzed in coculture cells on day 2, 4, 6, 8 and 10. Putative epi-dermal stem cells in conditioned culture media were used as control. Putative epidermal stem cells were predominant in rapid attaching cells by type IV collagen attachment isolation. Before being co-cultured, the rhesus putative epidermal stem cells expressed K15, α6 and β1 integrin, but no CD71, K1/K10 and K3/K12. After coculture, these cells expressed K3/K12 (a marker of corneal epithelial cells), K15 and β 1 integrin, but no K1/K10. Cells being not coculture converted into terminally differentiated cells expressing K1/K10. These results indicate that rhesus putative epidermal stem cells can trans-differentiate into corneal epithelium-like cells and, therefore, may have potential therapeutic application as autologous seed cells for the construction of bioengineered corneas.

  10. Putative epidermal stem cell convert into corneal epithelium-like cell under corneal tissue in vitro

    Institute of Scientific and Technical Information of China (English)

    GAO Nan; CUI GuangHui; WANG ZhiChong; HUANG Bing; GE Jian; LU Rong; ZHANG KeFei; FAN ZhiGang; LU Li; PENG Zhan

    2007-01-01

    Rhesus putative epidermal stem cells are being investigated for their potential use in regenerative corneal epithelium-like cells, which may provide a practical source of autologous seed cells for the construction of bioengineered corneas. The goal of this study was to investigate the potential of epidermal stem cells for trans-differentiation into corneal epithelium-like cells. Rhesus putative epidermal stem cells were isolated by type IV collagen attachment method. Flow cytometry analysis, immunohistology and RT-PCR were conducted to identify the expression of specific markers (β1, α6 integrin, K15, K1/K10, K3/K12 and CD71) on the isolated rapid attaching cells. The isolated cells were cocultured with human corneal limbal stroma and corneal epithelial cells. After coculture, the expression of the same specific markers was evaluated in order to identify expression difference caused by the coculture conditions. K3/K12 expression was analyzed in coculture cells on day 2, 4, 6, 8 and 10. Putative epidermal stem cells in conditioned culture media were used as control. Putative epidermal stem cells were predominant in rapid attaching cells by type IV collagen attachment isolation. Before being cocultured, the rhesus putative epidermal stem cells expressed K15, α6 and β1 integrin, but no CD71, K1/K10 and K3/K12. After coculture, these cells expressed K3/K12 (a marker of corneal epithelial cells), K15 and β 1 integrin, but no K1/K10. Cells being not coculture converted into terminally differentiated cells expressing K1/K10. These results indicate that rhesus putative epidermal stem cells can trans-differentiate into corneal epithelium-like cells and, therefore, may have potential therapeutic application as autologous seed cells for the construction of bioengineered corneas.

  11. Hipertensão ocular "mascarada" por edema de córnea após cirurgia da catarata Ocular hipertension confounded by corneal edema after cataract surgery

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    Bruno de Freitas Valbon

    2009-12-01

    intraocular pressure (IOP measurements in cases with thick and flatter corneas. This is thought to occur linearly based on mathematical and on experimental studies. However, such influence does exist, but this is more complex than the one anticipated by pachymetry and keratometry because it is related to corneal biomechanical properties. The ocular response analyzer (ORA Reichert provides the data related to the biomechanical properties of the cornea along with the IOP measurements that are calibrated for correlating to the Goldmann applanation and also compensated from corneal properties. Also corneal tomography with a pachymetric map evaluation characterizes the cornea beyond central thickness and anterior curvature. In this article, we report a case of a 77 years old female patient with low vision, photofobia and ocular pain 28 days after phacoemulsification and intraocular lens implant. In the first visit, GAT was 14mmHg, while IOPcc (ORA corneal compensated IOP was 25,6mmHg. Corneal hysteresis and resistance factor were low: 4,1 and 6,1mmHg respectively despite a central thickness of 601 micron. Corneal thickness spatial profile was attenuated with an edematous pattern that was also observed by the Scheimpflug images (Pentacam. Hypertensive uveitis was diagnosed and the patient was started on a fixed combination of timolol and brimonidine associate with prednisolone acetate. Three weeks after, the patient referred resolution of photofobia and marked improvement of vision. Clinically, edema was resolved as observed by corneal tomographyc and biomechanical findings.

  12. ROLE OF CORNEAL COLLAGEN CROSS LINKING IN KERATOCONUS

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    Atul

    2015-09-01

    Full Text Available To evaluate the outcome of collagen cross linkage using riboflavin 0.1% and ultraviolet A radiation of a wavelength 370nm . PURPOSE : To determine the effect of collagen cross linking for keratoconus on pachymetry , corneal topography, uncorrected visual acuity, specular count, IOP at 1, 3, 6 months . METHODS : The current study was designed as a prospective interventional trial of corneal collagen cross - linking in subjects with progressive keratoconus between a period of J anuary 2013 to J uly 2014 including 50 eyes of 30 patients. This study rece ived approval from Ethics committee. Informed written consent was obtained from all patients prior to treatment. RESULTS: Mean follow up period of 6 months. There was statistically significant decline in effective k readings from mean pre op (51.7D to pos t op value (49.65D . Pachymetry showed initial increase post operatively followed by reduction in corneal thickness in 3 month s follow up , followed by gradual increase in thickness over a period of 6 months though it was not equivalent to pre - operative values. paired t test p value was 0.00 1 in 1 n 3 month and 0. 043 in 6 month, concluding significant reduction in early post op period with im provement over time . Specular count reduced from pre - op (2673.80 levels to post - op (2654.60 levels ,the reduction in specular count was not statistically significant P value (0.014 The uncorrected visual acuity showed decrease in refractive error with in crease in visual acuity gradually over 6 months, log MAR scale visual acuity was used for statistical analysis with P value (0.001 which was statistically significant .visual acuity improved by 1.5 lines in snellens equivalence or from 0.5 to 0.4 in log MA R char y ± 20cells/mm 3 , P value(0. 001 . IOP statically show ed no significant change in pre - operative and post operatively , paired t test p value was 0. 44 showing it was not significant . CONCLUSIONS : 1. Visual acuity improved in

  13. Corneal stem cells and tissue engineering: Current advancesand future perspectives

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Major advances are currently being made in regenerativemedicine for cornea. Stem cell-based therapiesrepresent a novel strategy that may substituteconventional corneal transplantation, albeit there aremany challenges ahead given the singularities of eachcellular layer of the cornea. This review recapitulatesthe current data on corneal epithelial stem cells,corneal stromal stem cells and corneal endothelialcell progenitors. Corneal limbal autografts containingepithelial stem cells have been transplanted in humansfor more than 20 years with great successful rates,and researchers now focus on ex vivo cultures andother cell lineages to transplant to the ocular surface.A small population of cells in the corneal endotheliumwas recently reported to have self-renewal capacity,although they do not proliferate in vivo . Two mainobstacles have hindered endothelial cell transplantationto date culture protocols and cell delivery methods tothe posterior cornea in vivo . Human corneal stromalstem cells have been identified shortly after therecognition of precursors of endothelial cells. Stromalstem cells may have the potential to provide a directcell-based therapeutic approach when injected tocorneal scars. Furthermore, they exhibit the ability todeposit organized connective tissue in vitro and maybe useful in corneal stroma engineering in the future.Recent advances and future perspectives in the field arediscussed.

  14. Developmental Corneal Innervation: Interactions between Nerves and Specialized Apical Corneal Epithelial Cells

    OpenAIRE

    Kubilus, James K.; Linsenmayer, Thomas F.

    2010-01-01

    During developmental innervation of the chicken cornea, nerves interact with apical corneal epithelial cells to form synapse-like structures. In addition, these apical epithelial cells express class III β-tubulin, an isoform of β-tubulin generally thought to be neuron specific.

  15. Customized toric intraocular lens implantation for correction of extreme corneal astigmatism due to corneal scarring

    Directory of Open Access Journals (Sweden)

    R Bassily

    2010-03-01

    Full Text Available R Bassily, J LuckOphthalmology Department, Royal United Hospital, Combe Park, Bath, UKAbstract: A 76-year-old woman presented with decreased visual function due to cataract formation. Twenty-five years prior she developed right sided corneal ulceration that left her with 10.8 diopters (D of irregular astigmatism at 71.8° (steep axis. Her uncorrected visual acuity was 6/24 and could only ever wear a balanced lens due to the high cylindrical error. Cataract surgery was planned with a custom designed toric intraocular lens (IOL with +16.0 D sphere inserted via a wound at the steep axis of corneal astigmatism. Postoperative refraction was -0.75/+1.50 × 177° with a visual acuity of 6/9 that has remained unchanged at six-week follow-up with no IOL rotation. This case demonstrates the value of high power toric IOLs for the correction of pathological corneal astigmatism.Keywords: intraocular lens, corneal ulceration, visual acuity, scarring

  16. Paracentral Corneal Dellen:A Rare Sign of Graves Ophthalmopathy

    Institute of Scientific and Technical Information of China (English)

    Jianhua Yan; Zhongyao Wu

    2003-01-01

    Purpose: To report a rare sign, paracentral corneal dellen that developed in a middleaged female patient with Graves ophthalmopathy.Methods:A paracentral corneal dellen developed in the left eye in a 42-year-old woman who was diagnosed as Graves ophthalmopathy. The patient had remarkable upper eyelid retraction, upper eyelid lag and upward motility restriction. The Graves ophthalmopathy was classified as Grade V according to NOSPECS classification.Results:Local artificial tear film and 0.3% Tobramycin eye drops were administered to both eyes.Twenty-four hours later, the left corneal dellen disappeared.Conclusions:Graves ophthalmopathy can lead to paracentral corneal dellen because of severe upper eyelid retraction and upward motility restriction of the eye in spite of the lack of lagophthalmos. Artificial tear drop and antibiotic eye drop therapy helped even though the patient did not have corneal exposure.

  17. Contact Lens-Related Corneal Infections - United States, 2005-2015.

    Science.gov (United States)

    Cope, Jennifer R; Collier, Sarah A; Srinivasan, Krithika; Abliz, Erkinay; Myers, Ann; Millin, Courtney J; Miller, Andrew; Tarver, Michelle E

    2016-01-01

    Keratitis (inflammation of the cornea) can result from contact lens wear or other causes. Keratitis from all causes, including contact lens wear, results in approximately 1 million clinic and emergency department visits annually, with an estimated cost of $175 million in direct health care expenditures in 2010 (1). Approximately 41 million U.S. residents wear contact lenses, and in 2014, >99% of contact lens wearers surveyed reported at least one behavior that puts them at risk for a contact lens-related eye infection (2). The Center for Devices and Radiological Health at the Food and Drug Administration (FDA) regulates contact lenses as medical devices, and certain adverse events related to contact lenses are reported to FDA's Medical Device Report (MDR) database. To describe contact lens-related corneal infections reported to the FDA, 1,075 contact lens-related MDRs containing the terms "ulcer" or "keratitis" reported to FDA during 2005-2015 were analyzed. Among these 1,075 reports, 925 (86.0%) were reported by a contact lens manufacturer and 150 (14.0%) by an eye care provider or patient. Overall, 213 (19.8%) reports described a patient who had a central corneal scar, had a decrease in visual acuity, or required a corneal transplant following the event. Among the reports, 270 (25.1%) described modifiable factors known to be associated with an increased risk for contact lens-related corneal infections, including sleeping in contact lenses or poor contact lens hygiene; the remainder did not provide details that permitted determination of associated factors. Continued efforts to educate contact lens wearers about prevention of contact lens-related eye infections are needed. PMID:27538244

  18. Adjuvant corneal crosslinking to prevent hyperopic LASIK regression

    Directory of Open Access Journals (Sweden)

    Aslanides IM

    2013-03-01

    Full Text Available Ioannis M Aslanides, Achyut N MukherjeeEmmetropia Mediterranean Eye Clinic, Heraklion, Crete, GreecePurpose: To report the long term outcomes, safety, stability, and efficacy in a pilot series of simultaneous hyperopic laser assisted in situ keratomileusis (LASIK and corneal crosslinking (CXL.Method: A small cohort series of five eyes, with clinically suboptimal topography and/or thickness, underwent LASIK surgery with immediate riboflavin application under the flap, followed by UV light irradiation. Postoperative assessment was performed at 1, 3, 6, and 12 months, with late follow up at 4 years, and results were compared with a matched cohort that received LASIK only.Results: The average age of the LASIK-CXL group was 39 years (26–46, and the average spherical equivalent hyperopic refractive error was +3.45 diopters (standard deviation 0.76; range 2.5 to 4.5. All eyes maintained refractive stability over the 4 years. There were no complications related to CXL, and topographic and clinical outcomes were as expected for standard LASIK.Conclusion: This limited series suggests that simultaneous LASIK and CXL for hyperopia is safe. Outcomes of the small cohort suggest that this technique may be promising for ameliorating hyperopic regression, presumed to be biomechanical in origin, and may also address ectasia risk.Keyword: CXL

  19. Comparison of corneal histopathology changes between the rigid gas permeable contact lens wearers and the soft contact lens wearers%配戴RGPCL和SCL后角膜组织病理学变化的比较

    Institute of Scientific and Technical Information of China (English)

    韩治华; 胡楠

    2010-01-01

    in the SCL group than in the RGPCL group (F=4.262, P<0.05), and corneal vesicles and corneal gutata were occasionally observed. The density of the Langerhans cells both in the central and peripheral cornea was higher in the SCL group (F=5.362, P<0.05;F=-14.910, P<0.05), and the tortuosity of the nerve fibers increased significantly in the eyes of those wearing SCL compared with those wearing RGPCL. The density of the anterior stromal cells was lower (P<0.05) while the microdot densities in the stroma were higher in the SCL group than in the RGPCL group (P<0.05). The polymorphology of the corneal endothelial cells was more apparent in the SCL group, but the density of the endothelial cells was similar for the 2 groups. The thickness of the central corneal epithelium was thinner for SCL wearers compared to RGPCL wearers (F=-2.061, P<0.05). There were no differences for all of the indices within the same group at 3 months, 6 months and 12 months. Conclusion The corneal morphologic changes of RGPCL wearers are less severe than those of SCL wearers, suggesting that RGPCL wearing is a safe correction method.

  20. Intrastromal corneal ring segments delay corneal grafting in patients with keratoconus

    Directory of Open Access Journals (Sweden)

    Luiz Arthur F. Beniz

    2016-02-01

    Full Text Available ABSTRACT Purpose: To assess the impact of intrastromal corneal ring segments (ICRS as a surgical alternative to corneal grafting in patients with keratoconus who were scheduled for a corneal transplant. Methods: This single-surgeon, single-center, retrospective, observational case series study included 19 eyes of 18 patients (mean age, 23.36 ± 6.22 years with a confirmed diagnosis of keratoconus. These patients were enrolled from the State of Goiás, Brazil corneal graft waiting list. Following extensive pre-operative testing, including the measurement of best-corrected visual acuity (BCVA, applanation tonometry, biomicroscopy, funduscopy, pachymetry, and corneal topography, patients were implanted with Keraring® ICRS. Patients underwent clinical examination at postoperative days 1, 7, 30, 90, and 180 and were examined again 2 years following surgery. Results: At the 2-year cut-off following ICRS implantation (mean follow-up, 28.72 ± 4.71 months, there was a statistically significant improvement in BCVA (logMAR from 0.59 ± 0.35 preoperatively to 0.35 ± 0.45 postoperatively ( p <0.01. Three of 19 eyes (15.8% still required keratoplasty. In the remaining patients (84.2%, BCVA was managed with spectacles (52.6% or contact lenses (31.6%. One patient developed infectious keratitis, requiring removal of ICR at the first postoperative visit. Conclusion: ICRS implantation may be a surgical alternative to keratoplasty in patients with keratoconus. This procedure may delay or even eliminate the need for keratoplasty in such patients.

  1. Riboflavin concentration in corneal stroma after intracameral injection

    Institute of Scientific and Technical Information of China (English)

    Na; Li; Xiu-Jun; Peng; Zheng-Jun; Fan; Xu; Pang; Yu; Xia; Teng-Fei; Wu

    2015-01-01

    AIM: To evaluate the enrichment of riboflavin in the corneal stroma after intracameral injection to research the barrier ability of the corneal endothelium to riboflavin in vivo.METHODS: The right eyes of 30 New Zealand white rabbits were divided into three groups. Different concentrations riboflavin-balanced salt solutions(BSS)were injected into the anterior chamber(10 with 0.5%, 10 with 1%, and 10 with 2%). Eight corneal buttons of 8.5mm in diameter from each group were dissected at 30 min after injection and the riboflavin concentrations in the corneal stroma were determined using high-performance liquid chromatography(HPLC) after removing the epithelium and endothelium. The other two rabbits in every group were observed for 24 h and sacrificed. As a comparison, the riboflavin concentrations from 16 corneal stromal samples were determined using HPLC after instillation of 0.1% riboflavin-BSS solution for30 min on the corneal surface(8 without epithelium and 8with intact epithelium).RESULTS: The mean riboflavin concentrations were11.19, 18.97, 25.08, 20.18, and 1.13 μg/g for 0.5%, 1%, 2%,de-epithelialzed samples, and the transepithelial groups,respectively. The color change of the corneal stroma and the HPLC results showed that enrichment with riboflavin similar to classical de-epithelialized corneal collagen crosslinking(CXL) could be achieved by intracameral 1%riboflavin-BSS solution after 30min; the effect appeared to be continuous for at least 30 min.CONCLUSION: Riboflavin can effectively penetrate the corneal stroma through the endothelium after an intracameral injection in vivo, so it could be an enhancing method that could improve the corneal riboflavin concentration in transepithelial CXL.

  2. In Vivo Confocal Microscopic Observation of Lamellar Corneal Transplantation in the Rabbit Using Xenogenic Acellular Corneal Scaffolds as a Substitute

    Institute of Scientific and Technical Information of China (English)

    Yun Feng; Wei Wang

    2015-01-01

    Background:The limiting factor to corneal transplantation is the availability of donors.Research has suggested that xenogenic acellular corneal scaffolds (XACS) may be a possible alternative to transplantation.This study aimed to investigate the viability of performing lamellar corneal transplantation (LCT) in rabbits using canine XACS.Methods:Fresh dog corneas were decellularized by serial digestion,and LCT was performed on rabbit eyes using xenogeneic decellularized corneal matrix.Cellular and morphological changes were observed by slit-lamp,light,and scanning electron microscopy at 7,30 and 90 days postoperatively.Immunocytochemical staining for specific markers such as keratin 3,vimentin and MUC5AC,was used to identify cells in the graft.Results:Decellularized xenogenic corneal matrix remained transparent for about 1-month after LCT.The recipient cells were able to survive and proliferate into the grafts.Three months after transplantation,grafts had merged with host tissue,and graft epithelialization and vascularization had occurred.Corneal nerve fibers were able to grow into the graft in rabbits transplanted with XACS.Conclusions:Xenogenic acellular corneal scaffolds can maintain the transparency of corneal grafts about 1-month and permit growth of cells and nerve fibers,and is,therefore,a potential substitute or carrier for a replacement cornea.

  3. Fractal dimension based corneal fungal infection diagnosis

    Science.gov (United States)

    Balasubramanian, Madhusudhanan; Perkins, A. Louise; Beuerman, Roger W.; Iyengar, S. Sitharama

    2006-08-01

    We present a fractal measure based pattern classification algorithm for automatic feature extraction and identification of fungus associated with an infection of the cornea of the eye. A white-light confocal microscope image of suspected fungus exhibited locally linear and branching structures. The pixel intensity variation across the width of a fungal element was gaussian. Linear features were extracted using a set of 2D directional matched gaussian-filters. Portions of fungus profiles that were not in the same focal plane appeared relatively blurred. We use gaussian filters of standard deviation slightly larger than the width of a fungus to reduce discontinuities. Cell nuclei of cornea and nerves also exhibited locally linear structure. Cell nuclei were excluded by their relatively shorter lengths. Nerves in the cornea exhibited less branching compared with the fungus. Fractal dimensions of the locally linear features were computed using a box-counting method. A set of corneal images with fungal infection was used to generate class-conditional fractal measure distributions of fungus and nerves. The a priori class-conditional densities were built using an adaptive-mixtures method to reflect the true nature of the feature distributions and improve the classification accuracy. A maximum-likelihood classifier was used to classify the linear features extracted from test corneal images as 'normal' or 'with fungal infiltrates', using the a priori fractal measure distributions. We demonstrate the algorithm on the corneal images with culture-positive fungal infiltrates. The algorithm is fully automatic and will help diagnose fungal keratitis by generating a diagnostic mask of locations of the fungal infiltrates.

  4. Mycotic corneal ulcers in upper Assam

    Directory of Open Access Journals (Sweden)

    Reema Nath

    2011-01-01

    Full Text Available Purpose : To study the association of various risk factors and epidemiological variables of mycotic keratitis treated at a tertiary referral hospital of upper Assam. Materials and Methods: In this hospital-based prospective study a total of 310 consecutive corneal ulcer cases attending the ophthalmology outpatient department of Assam Medical College were enrolled between April 2007 and March 2009. After clinical and slit-lamp biomicroscopic examination in all suspected cases, smears and culture examination for fungus was done to establish the etiology. Demographic information and associated probable risk factors of individual cases were noted in a predesigned questionnaire. Results: In 188 (60.6% cases fungal etiology could be established. Out of them 67.6% were males. The most commonly affected age group was 41-50 years (25.5%. The maximum (23.4% cases were reported during the paddy harvesting season in Assam (January and February. Fungal element could be demonstrated in 65.2% cases in direct potassium hydroxide (KOH mount. The commonest predisposing factor was corneal injury (74.5%. While diabetes was a significant systemic predisposing factor in mixed bacterial and fungal infections in 11.1% cases, blocked naso-lacrimal duct was the local predisposing factor in 11.1% of cases. Fusarium solani (25% was the commonest isolate followed by Aspergillus species (19%, Curvularia species (18.5% and Penicillium species (15.2%. Yeasts were isolated in 2.7% (n=5 cases. Conclusions : Ocular trauma was the commonest cause of fungal corneal ulcer in Assam and Fusarium solani was the commonest species responsible for it. Most of the mycotic ulcer cases come from rural areas including the tea gardens.

  5. Clinical utility of the KAMRA corneal inlay.

    Science.gov (United States)

    Naroo, Shehzad Anjam; Bilkhu, Paramdeep Singh

    2016-01-01

    The treatment of presbyopia has been the focus of much scientific and clinical research over recent years, not least due to an increasingly aging population but also the desire for spectacle independence. Many lens and nonlens-based approaches have been investigated, and with advances in biomaterials and improved surgical methods, removable corneal inlays have been developed. One such development is the KAMRA™ inlay where a small entrance pupil is exploited to create a pinhole-type effect that increases the depth of focus and enables improvement in near visual acuity. Short- and long-term clinical studies have all reported significant improvement in near and intermediate vision compared to preoperative measures following monocular implantation (nondominant eye), with a large proportion of patients achieving Jaeger (J) 2 to J1 (~0.00 logMAR to ~0.10 logMAR) at the final follow-up. Although distance acuity is reduced slightly in the treated eye, binocular visual acuity and function remain very good (mean 0.10 logMAR or better). The safety of the inlay is well established and easily removable, and although some patients have developed corneal changes, these are clinically insignificant and the incidence appears to reduce markedly with advancements in KAMRA design, implantation technique, and femtosecond laser technology. This review aims to summarize the currently published peer-reviewed studies on the safety and efficacy of the KAMRA inlay and discusses the surgical and clinical outcomes with respect to the patient's visual function. PMID:27274194

  6. Clinical utility of the KAMRA corneal inlay

    Science.gov (United States)

    Naroo, Shehzad Anjam; Bilkhu, Paramdeep Singh

    2016-01-01

    The treatment of presbyopia has been the focus of much scientific and clinical research over recent years, not least due to an increasingly aging population but also the desire for spectacle independence. Many lens and nonlens-based approaches have been investigated, and with advances in biomaterials and improved surgical methods, removable corneal inlays have been developed. One such development is the KAMRA™ inlay where a small entrance pupil is exploited to create a pinhole-type effect that increases the depth of focus and enables improvement in near visual acuity. Short- and long-term clinical studies have all reported significant improvement in near and intermediate vision compared to preoperative measures following monocular implantation (nondominant eye), with a large proportion of patients achieving Jaeger (J) 2 to J1 (~0.00 logMAR to ~0.10 logMAR) at the final follow-up. Although distance acuity is reduced slightly in the treated eye, binocular visual acuity and function remain very good (mean 0.10 logMAR or better). The safety of the inlay is well established and easily removable, and although some patients have developed corneal changes, these are clinically insignificant and the incidence appears to reduce markedly with advancements in KAMRA design, implantation technique, and femtosecond laser technology. This review aims to summarize the currently published peer-reviewed studies on the safety and efficacy of the KAMRA inlay and discusses the surgical and clinical outcomes with respect to the patient’s visual function. PMID:27274194

  7. Clinical utility of the KAMRA corneal inlay.

    Science.gov (United States)

    Naroo, Shehzad Anjam; Bilkhu, Paramdeep Singh

    2016-01-01

    The treatment of presbyopia has been the focus of much scientific and clinical research over recent years, not least due to an increasingly aging population but also the desire for spectacle independence. Many lens and nonlens-based approaches have been investigated, and with advances in biomaterials and improved surgical methods, removable corneal inlays have been developed. One such development is the KAMRA™ inlay where a small entrance pupil is exploited to create a pinhole-type effect that increases the depth of focus and enables improvement in near visual acuity. Short- and long-term clinical studies have all reported significant improvement in near and intermediate vision compared to preoperative measures following monocular implantation (nondominant eye), with a large proportion of patients achieving Jaeger (J) 2 to J1 (~0.00 logMAR to ~0.10 logMAR) at the final follow-up. Although distance acuity is reduced slightly in the treated eye, binocular visual acuity and function remain very good (mean 0.10 logMAR or better). The safety of the inlay is well established and easily removable, and although some patients have developed corneal changes, these are clinically insignificant and the incidence appears to reduce markedly with advancements in KAMRA design, implantation technique, and femtosecond laser technology. This review aims to summarize the currently published peer-reviewed studies on the safety and efficacy of the KAMRA inlay and discusses the surgical and clinical outcomes with respect to the patient's visual function.

  8. IOL Power Calculation after Corneal Refractive Surgery

    Directory of Open Access Journals (Sweden)

    Maddalena De Bernardo

    2014-01-01

    Full Text Available Purpose. To describe the different formulas that try to overcome the problem of calculating the intraocular lens (IOL power in patients that underwent corneal refractive surgery (CRS. Methods. A Pubmed literature search review of all published articles, on keyword associated with IOL power calculation and corneal refractive surgery, as well as the reference lists of retrieved articles, was performed. Results. A total of 33 peer reviewed articles dealing with methods that try to overcome the problem of calculating the IOL power in patients that underwent CRS were found. According to the information needed to try to overcome this problem, the methods were divided in two main categories: 18 methods were based on the knowledge of the patient clinical history and 15 methods that do not require such knowledge. The first group was further divided into five subgroups based on the parameters needed to make such calculation. Conclusion. In the light of our findings, to avoid postoperative nasty surprises, we suggest using only those methods that have shown good results in a large number of patients, possibly by averaging the results obtained with these methods.

  9. Hypercalcemia Leads to Delayed Corneal Wound Healing in Ovariectomized Rats.

    Science.gov (United States)

    Nagai, Noriaki; Ogata, Fumihiko; Kawasaki, Naohito; Ito, Yoshimasa; Funakami, Yoshinori; Okamoto, Norio; Shimomura, Yoshikazu

    2015-01-01

    Hypercalcemia is often observed in postmenopausal women as well as in patients with primary hyperparathyroidism or malignant tumors. In this study, we investigated the relationship between calcium ion (Ca(2+)) levels in lacrimal fluid and the rate of corneal wound healing in hypercalcemia using ovariectomized (OVX) rat debrided corneal epithelium. We also determined the effects of Ca(2+) levels on cell adhesion, proliferation and viability in a human cornea epithelial cell line (HCE-T). The calcium content in bones of OVX rats decreased after ovariectomy. Moreover, the Ca(2+) content in the blood of OVX rats was increased 1 month after ovariectomy, and decreased. The Ca(2+) content in the lacrimal fluid of OVX rats was also increased after ovariectomy, and then decreased similarly as in blood. Corneal wound healing in OVX rats was delayed in comparison with Sham rats (control rats), and a close relationship was observed between the Ca(2+) levels in lacrimal fluid and the rate of corneal wound healing in Sham and OVX rats (y=-0.7863x+8.785, R=0.78, n=25). In addition, an enhancement in Ca(2+) levels caused a decrease in the viability in HCE-T cells. It is possible that enhanced Ca(2+) levels in lacrimal fluid may cause a decrease in the viability of corneal epithelial cells, resulting in a delay in corneal wound healing. These findings provide significant information that can be used to design further studies aimed at reducing corneal damage of patients with hypercalcemia.

  10. Cytocompatibility of Three Corneal Cell Types with Amniotic Membrane

    Institute of Scientific and Technical Information of China (English)

    CHENJian-su; CHENRui; XUJin-tang; DINGYong; ZHAOSong-bin; LISui-lian

    2004-01-01

    Rabbit limbal corneal epithelial cells, corneal endothelial cells and keratocytes were cultured on amniotic membrane. Phase contrast microscope examination was performed daily. Histological and scan electron microscopic examinations were carried out to observe the growth, arrangement and adhesion of cultivated cells. Results showed that three corneal cell types seeded on amniotic membrane grew well and had normal cell morphology. Cultured cells attached firmly on the surface of amniotic membrane. Corneal epithelial cells showed singular layer or stratification. Cell boundaries were formed and tightly opposed. Corneal endothelial cells showed cobblestone or polygonal morphologic characteristics that appeared uniform in size. The cellular arrangement was compact. Keratocytes elongated and showed triangle or dendritic morphology with many intercellular joints which could form networks. In conclusion, amniotic membrane has good scaffold property, diffusion effect and compatibility with corneal cells. The basement membrane side of amniotic membrane facilitated the growth of corneal epithelial cells and endothelial cells and cell junctions were tightly developed. The spongy layer of amniotic membrane facilitated the growth of keratocytes and intercellular joints were rich. Amniotic membrane is an ideal biomaterial for layering tissue engineered cornea.

  11. Corneal surface reconstruction - a short review

    Directory of Open Access Journals (Sweden)

    Madhavan H N

    2009-01-01

    Full Text Available Cornea is the clear, dome-shaped surface that covers the front of the eye and when damage due to burns or injury and several other diseases, stem cells residing in its rim called "limbus" are stimulated to multiply to support growth of new epithelial cells over its surface. If this ready source of stem cells is damaged or destroyed the natural repair is not possible and such a condition is known as corneal limbal stem cell deficiency (CLSCD disease. Stem cell transplant helps such persons to regenerate the corneal surface. Human corneal limbal stem cell transplantation is at present an established procedure with reasonable good clinical outcome particularly when autologous limbal epithelial tissue from a fellow unaffected eye is used. 1, 2 A major concern related to the autograft is the possibility of CLSCD at the donor site, 3 techniques that allowed the expansion of a small limbal biopsy in the laboratory using cell cultures that could be then transplanted to the affected eye have been developed ,4, 5 Human amniotic membrane (HAM is used as a scaffold for both culturing the human limbal epithelial cells and for ocular surface reconstruction with the cultured limbal epithelial cells. 4-7 However, researchers have used alternative scaffolds like collagen 8, fibrin gel 9 and cross-linked gel of fibronectin and fibrin. 10 All these are biological materials and also need for animal 3T3 feeder layer for stem cell cultures. The properties of HAM are unique including antiadhesive effects, bacteriostatic effects, wound protection, pain reduction, and improvement of epithelialization and characteristically lacking imunogenicity. The use of amniotic membrane transplantation (AMT to treat ocular surface abnormalities was first reported by Graziella Pellegrini, chief of stem cell laboratory at Giovanni Paolo Hospital in Venice, Italy, who was the first to demonstrate the limbal stem cell transplant in 1997. Amniotic membrane has been successfully used in

  12. Impact of facial conformation on canine health: corneal ulceration.

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    Rowena M A Packer

    Full Text Available Concern has arisen in recent years that selection for extreme facial morphology in the domestic dog may be leading to an increased frequency of eye disorders. Corneal ulcers are a common and painful eye problem in domestic dogs that can lead to scarring and/or perforation of the cornea, potentially causing blindness. Exaggerated juvenile-like craniofacial conformations and wide eyes have been suspected as risk factors for corneal ulceration. This study aimed to quantify the relationship between corneal ulceration risk and conformational factors including relative eyelid aperture width, brachycephalic (short-muzzled skull shape, the presence of a nasal fold (wrinkle, and exposed eye-white. A 14 month cross-sectional study of dogs entering a large UK based small animal referral hospital for both corneal ulcers and unrelated disorders was carried out. Dogs were classed as affected if they were diagnosed with a corneal ulcer using fluorescein dye while at the hospital (whether referred for this disorder or not, or if a previous diagnosis of corneal ulcer(s was documented in the dogs' histories. Of 700 dogs recruited, measured and clinically examined, 31 were affected by corneal ulcers. Most cases were male (71%, small breed dogs (mean± SE weight: 11.4±1.1 kg, with the most commonly diagnosed breed being the Pug. Dogs with nasal folds were nearly five times more likely to be affected by corneal ulcers than those without, and brachycephalic dogs (craniofacial ratio <0.5 were twenty times more likely to be affected than non-brachycephalic dogs. A 10% increase in relative eyelid aperture width more than tripled the ulcer risk. Exposed eye-white was associated with a nearly three times increased risk. The results demonstrate that artificially selecting for these facial characteristics greatly heightens the risk of corneal ulcers, and such selection should thus be discouraged to improve canine welfare.

  13. Estimation of Postmortem Interval by Detecting Thickness of Cornea Using Ultrasonic Method%超声法测量角膜厚度推断死亡时间

    Institute of Scientific and Technical Information of China (English)

    吕国丽; 姜富学; 许心舒; 蒋拥军; 李志刚; 王欣; 石河; 余礼聪; 许传超

    2012-01-01

    目的 用超声法测量角膜厚度,探索其死后变化规律.方法 11只家兔随机分为两组,分别为角膜上皮完整组及去角膜上皮组.后者采用机械刮除法去除角膜上皮.利用超声测厚仪连续监测两组动物的死后多个时间点的角膜厚度,并对角膜厚度变化与死亡时间进行相关回归分析.结果 超声法测量角膜上皮完整组死后兔角膜厚度的变化值与死亡时间呈非线性相关,且具有较强的相关性,相关系数为0.922,而去角膜上皮组的相关系数为0.822.结论 超声法测量角膜厚度对推断早期死亡时间具有较可靠的应用前景.完整的角膜上皮对于超声测量角膜厚度具有关键作用.%Objective To explore the postmortem changes of cornea thickness measured by ultrasonic pachymetry. Methods Eleven rabbits were randomly divided into two groups: one group with intact corneal epithelium and another group without intact corneal epithelium. In the later group, the corneal epithelium of the rabbit was scraped using mechanical elimination method. The corneal thickness was monitored continuously by ultrasonic pachymetry at several postmortem interval points in rabbits of the two groups. The changes of corneal thickness and postmortem interval were explored by relative regression analysis. Results The thickness of the cornea showed a strong non-linear correlation with the postmortem interval in the group with intact corneal epithelium. The group with intact corneal epithelium showed the correlation coefficient 0.922 and the group without intact corneal epithelium showed the correlation coefficient 0.822, respectively. Conclusion The corneal thickness measured by ultrasonic pachymetry shows a potential value for estimating early postmortem interval. The intact corneal epithelium is a crucial factor for the measurement of cornea thickness by ultrasonic pachymetry.

  14. Evaluation of retinal nerve fiber layer thickness measurement following laser in situ keratomileusis using scanning laser polarimetry

    Directory of Open Access Journals (Sweden)

    Dada Tanuj

    2007-01-01

    Full Text Available Aim: To evaluate the effect of laser-assisted in situ keratomileusis (LASIK on the measurement of retinal nerve fiber layer thickness by scanning laser polarimetry using customized corneal compensation in myopes. Materials and Methods: Scanning laser polarimetry was performed on 54 eyes of 54 healthy patients with myopia using the glaucoma diagnostics variable corneal compensation (GDx VCC instrument (Laser Diagnostic Technologies, San Diego, California before and a week after LASIK. The various parameters were compared using the Student′s t test. Results: No statistically significant change was observed in any of the retinal nerve fiber layer parameters before and after LASIK. Conclusions: While the measurement of retinal nerve fiber layer thickness by scanning laser polarimetry is affected by anterior segment birefringent properties and LASIK would be expected to produce changes in the same, customized corneal compensation using the GDx VCC seems to adequately compensate for these changes.

  15. Comparison of comeal thickness measurements using pentacam, orbscan Ⅱ, and A-ultrasonic pachymetry in myopia%Pentacam、Orbscan Ⅱ和A超测量中央角膜厚度的分析

    Institute of Scientific and Technical Information of China (English)

    雷玉琳; 郑秀云; 党光福; 刘素美

    2011-01-01

    日的比较Pentacam、Orbscan Ⅱ和A超三种角膜测犀仪检测近视眼中央角膜厚度的差异.方法 分别用Pcntacam眼前节分析仪、Orbscan Ⅱ角膜地形图仪及A超对角膜厚度进行检测,并将测量值进行统计学分析.结果 Pentacam测得角膜厚度为(536.01±32.33)μm,Orbscan Ⅱ测得近视眼角膜厚度为(539.21±37.45)μm,A超测得角膜厚度为(535.39±31.46)μm.Orbscan Ⅱ测量值与Pentacam和A超测量值差异均有统计学意义(P<0.001),Pentacam与A超测量值间的比较差异无统计学意义(P=0.095).三种测厚结果 显示高度正相关,Orb-scan-Pentacam、Orbscan-A超、Pcntacam-A超的相关系数r分别为0.917、0.906、0.965,回归方程如下:Orbscan(μm)=-30.699+[1.0622×Pentacam(μm)],Orbscan(μm)=-38.599+[1.0792×A超(μm)],Pen-tacam(μm)=5.424+[0.9919×A超(μm)].结论 在检测中央角膜厚度方面,Orbscan Ⅱ与Pcntacam及A超不可替代使用,Pentacam与A超可相互替代使用.%Objective To compare the central corneal thickness measurements using pentacam, orbscan Ⅱ and A-ultrasonic pachymeter in myopic eyes. Methods Central comeal thickness was measured and analyzed with pentacam, orbscan Ⅱ, and A-ultrasonics. Results The mean central corneal thickness measured by pentacam,orbscan Ⅱ ,and A-ultrasonics were (536.01 ±32.33) μm, (539.21 ±37.45)μm,and(535.39 ±31.46)μm,respectively. Significant difference was found between orbscan Ⅱ and pentacam or A-ultrasonic ( P < 0. 001 ). No significant difference was found between pentacam and A-ultrasonic(P =0.095 ). Positive relationships were found in the results of corneal thickness among the 3 methods. The correlation coefficient r of (orbscan-pentacam), (orbscan-A-ultrasonic), (pentacam-A-ultrasonic) were correpondinging 0. 917,0. 906, and 0. 965. The regression equations were "orbscan (μm) = - 30.699 + [ 1.062 2 × pentacam(μm)]", "orbscan(μm) =-38.599 + [1.0792 × A-ultrasonic (μm)]", and "pentacam(μm) = 5.424 + [ 0

  16. Genetics Home Reference: lattice corneal dystrophy type II

    Science.gov (United States)

    ... Diagnosis & Management These resources address the diagnosis or management of lattice corneal dystrophy type II: American Foundation for the Blind: Living with Vision Loss Genetic Testing Registry: Meretoja syndrome Merck Manual ...

  17. Corneal depositions in tyrosinaemia type I during treatment with Nitisinone.

    Science.gov (United States)

    Wisse, Robert P L; Wittebol-Post, Dienke; Visser, Gepke; van der Lelij, Allegonda

    2012-01-01

    We present a 17-year-old boy, diagnosed with tyrosinaemia type I at an age of 7 months, with new complaints of severe intermittent photophobia and burning eyes. His tyrosinaemia type I is treated with nitisinone and a protein-restricted diet. Dietary compliance is low since he entered puberty. His ocular complaints are attributable to subepithelial corneal deposits, resembling the common corneal phenotype of tyrosinaemia type II. Serum tyrosine levels were markedly elevated. Tyrosinaemia is a metabolic disease of tyrosine metabolism, subdivided into two types. Corneal deposits and photophobia are cardinal features of untreated tyrosinaemia type II, but not of type I. Novel treatment strategies (with nitisinone) for type I tyrosinaemia lead to a phenotype comparable with type II, including these corneal deposits. At follow-up visits his ocular complaints unfortunately remained unchanged, though he states his dietary compliance improved through the years. PMID:23203167

  18. Review of photokeratitis: Corneal response to ultraviolet radiation (UVR exposure*

    Directory of Open Access Journals (Sweden)

    L A. Moore

    2010-12-01

    Full Text Available The development of photokeratitis in response to natural solar ultraviolet radiation (UVR is prevalent in individuals participating in outdoor recreational activities in environments with high reflective surfaces, such as beach activities, water sports and snow skiing. Eye care practitioners (ECPs are frequently encouraged by manufacturers and researchers to recommend UVR-blocking eyewear in the form of sunglasses and contact lenses. However, little is known about the precise nature of the corneal tissue response in the development of photokeratitis. This paper reviews the mechanisms responsible for the development of photokeratitis. Clinical signs and symptoms of photokeratitis, UVR corneal threshold and action spectra, corneal cellular changes and ocular protection from corneal UVR exposure are discussed. The content of this article will be useful to ECPs in making appropriate recommendations when prescribing UVR-protec-tive eyewear. (S Afr Optom 2010 69(3 123-131

  19. Putative Corneal Neuralgia Responding to Vitamin D Supplementation

    Directory of Open Access Journals (Sweden)

    Eric L. Singman

    2013-09-01

    Full Text Available A patient with putative corneal neuralgia was incidentally discovered to have hypovitaminosis D. Supplementation of vitamin D appears to have led to a resolution of the patient's pain, whereas other efforts to treat the patient were unsuccessful.

  20. Choroidal thickness and central serous chorioretinopathy:a case-control study and Meta-analysis%脉络膜厚度与CSCR的病例对照研究与Meta分析

    Institute of Scientific and Technical Information of China (English)

    叶汉元; 杨安怀

    2015-01-01

    目的:定量分析中心性浆液性脉络膜视网膜病变( central serous chorioretinopathy,CSCR)患者黄斑中心凹下脉络膜厚度( subfoveal choroidal thickness,SFCT)改变。  方法:采用病例对照研究及Meta分析。连续的CSCR患者46例纳入研究,CSCR患者散瞳后前置镜眼底检查,荧光素眼底血管造影和吲哚菁绿血管造影检查确诊。选择同期年龄、性别、屈光度及眼轴匹配的正常人62例62眼作为正常对照组。用加强成像深度扫描OCT检测并比较CSCR组及对照组SFCT。单因素和多因素分析 SFCT 与各临床资料之间的关系。 Meta分析用Stata软件计算两组之间的加权均数差。  结果:CSCR患者的平均SFCT为397.34±83.91μm,正常对照组为274.48±62.57μm。 CSCR组SFCT较对照组明显增厚,差异有统计学意义(P  结论:CSCR患者黄斑中央凹下脉络膜较正常眼厚,增厚的SFCT与CSCR诊断存在相关性。%AIM:To investigate the changes of subfoveal choroidal thickness ( SFCT ) in central serous chorioretinopathy ( CSCR) eyes and to compare them with normal control eyes. METHODS: This was a case-control study and a Meta-analysis. Forty - six CSCR patients diagnosed by the fundus pre - set lens, fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were enrolled in this study. Sixty two age-, sex-, diopter- and axial length-matched 62 normal subjects ( 62 eyes ) were enrolled in this study as the control group. Using enhanced depth imaging optical coherence tomography ( EDI-OCT) , SFCT of CSCR eyes and normal control eyes were measured and compared. Univariate and multivariate linear regression analysis were performed to assess the association between SFCT and clinical factors. The Meta - analysis were conducted using the Stata software package to calculate the summary weighted mean differences ( WMDs) . RESULTS:The mean SFCT of the CSCR group and the normal control group was 397. 34±83. 91μm and

  1. Another Risk From Cigarette Smoking: Corneal Burn

    Directory of Open Access Journals (Sweden)

    Volkan Hürmeriç

    2012-12-01

    Full Text Available A 21-year-old male presented with corneal injury in his left eye after one of his friends had moved his arm backwards and accidentally hit his eye with the lit end of a cigarette. Slit lamp examination revealed epithelial defect and significant stromal edema at the superior temporal quadrant of the cornea. Cigarette ashes were noted in his lashes and inferior conjunctival fornix at the initial examination in the emergency service. 6 weeks after the injury, slit lamp examination revealed stromal thinning and haze in the temporal part of the cornea. His best spectacle-corrected distance visual acuity was 20/25 with a refractive error of -6.75x135 diopters in the left eye. Our case demonstrates that ocular thermal injury due to cigarette smoking can cause serious damage to the ocular tissues. (Turk J Oph thal mol 2012; 42: 484-5

  2. Evaluation of the PAR corneal topography system

    Science.gov (United States)

    Jindal, Prateek; Cheung, Susan; Pirouzian, Amir; Keates, Richard H.; Ren, Qiushi

    1995-05-01

    The purpose of this study was to evaluate the raster photogrammetry based Corneal Topography System by determining: inter-operator variability, reproducibility of images, effects of defocused and decentered images, and the precision of data at different optical zones. 4 human cadaver eyes were used to study the inter-operator variability. To study the reproducibility of images, 3 human cadaver eyes and a test surface doped with flourescine (provided by PAR Vision Systems Corporation) were focused and their images taken four successive times. Defocused and decentered images were taken of 4 human cadaver eyes and four times of the test surface mentioned above. The precision of defocused/decentered cadaver eyes was evaluated at the following optical zones: 3 mm, 4 mm, 5 mm, and 6 mm. All human cadaver eyes used in the above experiments had their epithelial layer removed before imaging. Average inter-operator variability was 0.06 D. In reproducibility attempts, there was an average deviation of 0.28 D for the human cadaver eyes and 0.04 D for the test surface. The defocused and decentered test surface gave an average deviation of 0.09 D. Defocused and decentered cadaver eyes resulted in an average deviation of 0.52 D, 0.37 D, 0.24 D, and 0.22 D at optical zones of 3 mm, 4 mm, 5 mm, and 6 mm, respectively. The imaging method employed by PAR Vision Systems Corporation virtually eliminates inter-operator variability. The PAR Corneal Topography System's clinical usefulness, however, could be improved by improving the reproducibility of images, decreasing the sensitivity to spatial alignment, and increasing accuracy over smaller optical zones.

  3. Clinical utility of the KAMRA corneal inlay

    Directory of Open Access Journals (Sweden)

    Naroo SA

    2016-05-01

    Full Text Available Shehzad Anjam Naroo, Paramdeep Singh Bilkhu Ophthalmic Research Group, School of Life & Health Sciences, Aston University, Birmingham, UK Abstract: The treatment of presbyopia has been the focus of much scientific and clinical research over recent years, not least due to an increasingly aging population but also the desire for spectacle independence. Many lens and nonlens-based approaches have been investigated, and with advances in biomaterials and improved surgical methods, removable corneal inlays have been developed. One such development is the KAMRA™ inlay where a small entrance pupil is exploited to create a pinhole-type effect that increases the depth of focus and enables improvement in near visual acuity. Short- and long-term clinical studies have all reported significant improvement in near and intermediate vision compared to preoperative measures following monocular implantation (nondominant eye, with a large proportion of patients achieving Jaeger (J 2 to J1 (~0.00 logMAR to ~0.10 logMAR at the final follow-up. Although distance acuity is reduced slightly in the treated eye, binocular visual acuity and function remain very good (mean 0.10 logMAR or better. The safety of the inlay is well established and easily removable, and although some patients have developed corneal changes, these are clinically insignificant and the incidence appears to reduce markedly with advancements in KAMRA design, implantation technique, and femtosecond laser technology. This review aims to summarize the currently published peer-reviewed studies on the safety and efficacy of the KAMRA inlay and discusses the surgical and clinical outcomes with respect to the patient’s visual function. Keywords: presbyopia, refractive surgery, implants, cornea

  4. [The use of iontophoresis in corneal crosslinking technique].

    Science.gov (United States)

    Stanca, Horia T; Tabacaru, Bogdana

    2013-01-01

    Iontophoresis is a method of facilitating the penetration of a drug through an intact tissue in the presence of an low intensity electrical current. In corneal crosslinking technique, iontophoresis is used for transepitelial impregnation of cornea with riboflavin. Compared to passive technique of corneal impregnation, iontophoresis shortens the time needed for impregnation, the time of exposure to UVA radiation and does not require de-epithelialisation.

  5. Delayed-onset endophthalmitis associated with corneal suture infections

    OpenAIRE

    Henry, Christopher R.; Flynn Jr., Harry W.; Miller, Darlene; Schefler, Amy C; Forster, Richard K.; Alfonso, Eduardo C.

    2013-01-01

    Background The purpose of the current study was to report the microbiology, risk factors, and treatment outcomes in patients with delayed-onset endophthalmitis associated with corneal suture infections. For this retrospective consecutive case series, a search of the ocular microbiology department database was performed to identify all patients with positive corneal and intraocular cultures (anterior chamber and/or vitreous) between 01 January 1995 and 01 January 2010. A subset of patients wit...

  6. Corneal depositions in tyrosinaemia type I during treatment with Nitisinone

    OpenAIRE

    Wisse, Robert P L; Wittebol-Post, Dienke; Visser, Gepke; Lelij, Allegonda

    2012-01-01

    We present a 17-year-old boy, diagnosed with tyrosinaemia type I at an age of 7 months, with new complaints of severe intermittent photophobia and burning eyes. His tyrosinaemia type I is treated with nitisinone and a protein-restricted diet. Dietary compliance is low since he entered puberty. His ocular complaints are attributable to subepithelial corneal deposits, resembling the common corneal phenotype of tyrosinaemia type II. Serum tyrosine levels were markedly elevated. Tyrosinaemia is a...

  7. On fractional Bessel equation and the description of corneal topography

    CERN Document Server

    Okrasiński, Wojciech

    2012-01-01

    In this note we apply a modified fractional Bessel differential equation to the problem of describing corneal topography. We find the solution in terms of the power series. This solution has an interesting behavior at infinity which is a generalization of the classical results for modified Bessel function of order 0. Our model fits the real corneal geometry data with an error of order of a few per cent.

  8. Dynamic Corneal Surface Mapping with Electronic Speckle Pattern Interferometry

    Science.gov (United States)

    Iqbal, S.; Gualini, M. M. S.

    2013-06-01

    In view of the fast advancement in ophthalmic technology and corneal surgery, there is a strong need for the comprehensive mapping and characterization techniques for corneal surface. Optical methods with precision non-contact approaches have been found to be very useful for such bio measurements. Along with the normal mapping approaches, elasticity of corneal surface has an important role in its characterization and needs to be appropriately measured or estimated for broader diagnostics and better prospective surgical results, as it has important role in the post-op corneal surface reconstruction process. Use of normal corneal topographic devices is insufficient for any intricate analysis since these devices operate at relatively moderate resolution. In the given experiment, Pulsed Electronic Speckle Pattern Interferometry has been utilized along with an excitation mechanism to measure the dynamic response of the sample cornea. A Pulsed ESPI device has been chosen for the study because of its micron-level resolution and other advantages in real-time deformation analysis. A bovine cornea has been used as a sample in the subject experiment. The dynamic response has been taken on a chart recorder and it is observed that it does show a marked deformation at a specific excitation frequency, which may be taken as a characteristic elasticity parameter for the surface of that corneal sample. It was seen that outside resonance conditions the bovine cornea was not that much deformed. Through this study, the resonance frequency and the corresponding corneal deformations are mapped and plotted in real time. In these experiments, data was acquired and processed by FRAMES plus computer analysis system. With some analysis of the results, this technique can help us to refine a more detailed corneal surface mathematical model and some preliminary work was done on this. Such modelling enhancements may be useful for finer ablative surgery planning. After further experimentation

  9. The Active Metabolite of Leflunomide A771726 Inhibits Corneal Neovascularization

    Institute of Scientific and Technical Information of China (English)

    Mingchang ZHANG; Nian HAO; Fang BIAN

    2008-01-01

    The effects of A771726, the active metabolite of leflunomide, on experimental rat corneal neovascularization (NV) in vivo and on cultured human umbilical vein endothelial cells in vitro were studied. The corneal NV was induced by alkali burn in 40 SD rats. The rats were randomly divided into 4 groups with 10 rats in each group. Group A was treated with 0.9% sodium chloride (control group), and group B, group C and group D were given different concentrations of A771726 eye drops (0.5%,l.0%,2.0% respectively) 4 times daily during days 0-28. The occurrence and development of corneal NV were observed at 4,7,14,21 and 28 day after alkali burn by a slit lamp microscope. The cultured human umbilical vein endothelial cells (ECV-304) were incubated with A771726 solution at different concentrations (20,40,80,160,320μmol/L) for 36h. The proliferation of cells was assessed by methyl thiazolyl tetrazolium (MTT), and the expression of proliferating cell nuclear antigen (PCNA) in cells was detected by using immunofluorescence under the laser confocal microscope. The rat model showed that the onset of corneal NV was delayed and progression of corneal NV was inhibited in the groups C and D. The corneal NV areas in groups C and D were significantly smaller than in groups A and B (P0.05). A771726 solution (≥40μmol/L) could inhibit proliferation of human umbilical vein endothelial cells and decrease the expression of PCNA in cells significantly. A771726, as the active metabolite of leflunomide, strongly prevented corneal NV induced by alkali burn in the in vivo model, and inhibited proliferation of human umbilical vein endothelial cells in the in vitro model. Therefore, A771726 may serve as an angiogenic inhibitor in the treatment of corneal NV.

  10. Inhibition of corneal inflammation following keratoplasty by birch leaf extract.

    Science.gov (United States)

    Wacker, Katrin; Gründemann, Carsten; Kern, Yvonne; Bredow, Laura; Huber, Roman; Reinhard, Thomas; Schwartzkopff, Johannes

    2012-04-01

    The objective of this study was to determine the effect of birch leaf (Betula pendula) extract (BPE) on corneal inflammation following keratoplasty in the rat model. T cells were stimulated in vitro in the presence of BPE. Proliferation, activation phenotype and the number of apoptotic/necrotic cells in cell culture were analyzed by flow cytometry. Corneal transplantation was performed between Fisher and Lewis rats. Recipient rats were either treated with cyclosporine A at a low dosage (Low-dose CsA=LDCsA) or received LDCsA in combination with BPE (2×1ml/day). Clinical signs for corneal inflammation and rejection time points were determined. Infiltrating leukocytes were analyzed histologically. BPE specifically inhibited T cell proliferation in vitro by inducing apoptosis. The phenotype was not affected. In vivo, BPE significantly delayed the onset of corneal opacification (p<0.05). The amount of infiltrating CD45(+) leukocytes and CD4(+) T cells (p<0.001) was significantly reduced by BPE, whereas infiltration of CD163(+) macrophages was not significantly different between the two groups. BPE selectively induces apoptosis of activated T cells. Accordingly, BPE treatment significantly reduces infiltrating T cells and subsequent corneal opacification following keratoplasty. Our findings suggest BPE as a promising anti-inflammatory drug to treat corneal inflammation.

  11. Inhibition of Corneal Neovascularization by Topical and Subconjunctival Tigecycline

    Directory of Open Access Journals (Sweden)

    Sertan Goktas

    2014-01-01

    Full Text Available Objective. To investigate the effects of topical and subconjunctival tigecycline on the prevention of corneal neovascularization. Materials and Methods. Following chemical burn, thirty-two rats were treated daily with topical instillation of 1 mg/mL tigecycline (group 1 or subconjunctival instillation of 1 mg/mL tigecycline (group 3 for 7 days. Control rats received topical (group 2 or subconjunctival (group 4 0.9% saline. Digital photographs of the cornea were taken on the eighth day after treatment and analyzed to determine the percentage area of the cornea covered by neovascularization. Corneal sections were analyzed histopathologically. Results. The median percentages of corneal neovascularization in groups 1 and 3 were 48% (95% confidence interval (CI, 44.2–55.8% and 33.5% (95% CI, 26.6–39.2%, respectively. The median percentages of corneal neovascularization of groups 1 and 3 were significantly lower than that of the control group (P=0.03 and P<0.001, resp.. Histologic examination of samples from groups 1 and 3 showed lower vascularity than that of control groups. Conclusion. Topical and subconjunctival administration of tigecycline seems to be showing promising therapeutic effects on the prevention of corneal neovascularization. Furthermore, subconjunctival administration of tigecycline is more potent than topical administration in the inhibition of corneal neovascularization.

  12. Corneal haze in course of Fuchs' endothelial dystrophy.

    Science.gov (United States)

    Pescosolido, N; Komaiha, C; Dapoto, L; Lenarduzzi, F; Nebbioso, M

    2012-07-01

    This article describes the observations obtained with confocal microscopy (CM) on the corneal structure in course of corneal edema in a patient with Fuchs endothelial corneal dystrophy (FD). The patient was a 40 year old male, suffering from second stage FD, in course of corneal edema and bullous keratopathy. The tissue structure was analyzed with CM confoscan CS4 (Nidek Technologies(®), Birmingham, UK) using the 40x mode. The CM has shown the presence of gaps due to corneal edema and a diffuse stromal hyper reflectivity related to the alteration of the extracellular matrix. It has also showed the presence of binucleate cells, assimilable to keratocytes, in cytokinesis which presented a typical fusiform aspect with two highly reflective nuclei awaiting cell division. The total number of cells was much lower than that of healthy control subjects of similar age, sex and race. The CM in this case suggests a significantly lower number of cells, presumably keratocytes, compared to normal range, but mostly it shows the presence of cells undergoing cytokinesis, which witnesses the active processes of collagenogenesis and possible vasculogenesis that represent early stages of loss of the normal corneal transparency. PMID:23007820

  13. Azithromycin (AZM) treatment increases survival of high risk corneal allotransplants

    Science.gov (United States)

    Medina, Carlos A.; Rowe, Alexander M.; Yun, Hongmin; Knickelbein, Jared E.; Lathrop, Kira L.; Hendricks, Robert L.

    2012-01-01

    Purpose To test the therapeutic efficacy of AZM, a macrolide antibiotic for prolonging murine “high risk” corneal allograft survival. Methods Fully MHC mismatched corneas were transplanted from C57BL/6 donors to BALB/c recipients with suture-induced vascularized “high risk” corneal beds. Recipient mice were either not treated or treated with topical AZM, oral AZM, or both. Evaluation of graft vascularization and clarity was performed in masked fashion. Lymph nodes were excised and analyzed for CD4, FoxP3, and CD44 by flow cytometry; and for T cell priming by proliferation and cytokine production in mixed lymphocyte cultures. Corneal whole mounts were evaluated by confocal microscopy. Results The incidence of graft rejection in the control group (81.8%) was significantly reduced by AZM treatment (18.2% topical, 21.7% oral, 33.3% topical + oral), although corneal vascularization was not affected by treatment. The frequency of corneas that retained complete clarity following transplantation was higher in the AZM treated groups. Reduced graft rejection in the AZM treated groups was not associated with a reduced allospecific T cell response or increased frequency of T regulatory cells. Conclusions AZM is effective in prolonging survival of “high risk” corneal allografts by an as yet undefined mechanism that does not appear to involve modulation of corneal neovascularization or allo-specific T cell priming. PMID:23407315

  14. Corneal organ cultures in tyrosinemia release chemotactic factors.

    Science.gov (United States)

    Lohr, K M; Hyndiuk, R A; Hatchell, D L; Kurth, C E

    1985-05-01

    Corneal inflammation with subsequent scarring and blindness occurs in the inherited human metabolic disease tyrosinemia type II, yet putative inflammatory mediators in this disorder and in the avascular cornea in general are poorly defined. In a Tyr-fed rat model of tyrosinemia type II, intracellular crystals, presumably Tyr, are hypothesized to be responsible for the increased lysosomal activity observed in corneal epithelial lesions. Because polymorphonuclear leukocytes (PMNs) are seen only at the site of these lesions, we used this model to study humoral mediators released from Tyr-fed rat corneal organ cultures. Only Tyr-fed rats developed stromal edema and linear granular opacities in gray edematous corneal epithelium, compatible with a noninfectious keratitis. Electron micrographs confirmed epithelial edema and showed focal epithelial necrosis with PMN invasion of the stroma. Only Tyr-fed rat corneal culture supernatants contained chemotactic activity that was heat labile and moderately trypsin sensitive. Four peaks with varying amounts of chemotactic activity were found on Sephadex G-75 chromatography. Although the identity of these peaks of activity has not yet been established, we suggest that they may be responsible for the PMN infiltration observed in this model of corneal inflammation.

  15. The Study of Corneal Topography in Myopic and Hyperopic Children

    Institute of Scientific and Technical Information of China (English)

    Lei Gao; Xuying Zhuo; Lusheng Ma; Ning Yu; Zhonghao Wang; Pengfei Jiang

    2005-01-01

    Purpose: To compare the differences of corneal topographies in myopic and hyperopic children and study the effect of Atropin on their changes.Methods: The refractive components of 136 eyes with different refractive conditions were measured with A-Scan and their corneal topographies with and without cycloplegia were obtained respectively.Results: The mean corneal power of zones 3mm (MD3, P=0.031 ) and minor keratometer K2 (P=0.003) of myopia are greater than those of hyperopia without cycloplegia. MD3 (P=0.009) and Keratometer K1 (P = 0.025) increased in hyperopic eyes, while MD3(P=0.033), K1 (P = 0.035) and K2 (P = 0.002) decreased in myopic eyes significantly after cycloplegia. Similarly, the mean corneal power of zones 5mm (MD5) and 7mm (MD7) in myopic eyes decreased dramatically (P ≤ 0.001 ).Conclusions: The corneal power was found to be greater in myopia than that in hyperopia. The effect of Atropin on corneal shape of myopia and hyperopia was in the opposite direction.

  16. Assessment of anterior and posterior corneal indices using two Scheimpflug analyzers

    Directory of Open Access Journals (Sweden)

    Daoud Charbel Fahd

    2014-01-01

    Full Text Available Purpose: To assess the agreement between the elevation and curvature measurements of the anterior and posterior corneal surfaces obtained using the Galilei Dual Scheimpflug Analyzer and those obtained using the Pentacam single Scheimpflug system. Methods: This prospective, noninterventional, diagnostic study was conducted at the Department of Ophthalmology at the American University of Beirut (Medical Center and included 60 eyes of 60 consecutive patients. Measurements were obtained using 2 different Scheimpflug analyzers (Galilei and Pentacam. The best-fit sphere was set at 8 mm in both machines. Pachymetry (CCT, anterior elevation (AE and posterior elevation (PE, and curvature were assessed. Pearson's correlation coefficients, comparison of means, and Bland-Altman plots were used to evaluate agreement between the 2 systems. Results: The average CCT (at the corneal apex was 533 ± 35 µm and 532 ± 37 µm (p=0.980, the average central AE was 1.25 ± 3.95 µm and 2.29 ± 5.28 µm (p=0.964, and the average central PE was 4.19 ± 8.18 µm and 5.42 ± 14.05 (p=0.956 µm with the Galilei and Pentacam, respectively. Conclusion: The Scheimpflug analyzers correlated well in the assessment of pachymetry, elevation, and curvature.

  17. Femtosecond laser assisted design of sutureless intrastromal graft as an alternative to partial thickness keratoplasty

    Science.gov (United States)

    Rossi, Francesca; Durkee, Heather; Pini, Roberto; Canovetti, Annalisa; Malandrini, Alex; Lenzetti, Ivo; Rubino, Pierangela; Leaci, Rosachiara; Neri, Alberto; Scaroni, Patrizia; Menabuoni, Luca; Macaluso, Claudio

    2014-02-01

    Minimally invasive laser assisted surgery in ophthalmology is continuously developing in order to find new surgical approaches, preserve patient tissue and improve surgical results in terms of cut precision, restoration of visual acuity, and invasiveness. In order to achieve these goals, the current approach in corneal transplant is lamellar keratoplasty, where only the anterior or posterior part of the patient's cornea is substituted depending on the lesion or pathology. In this work, we present a novel alternative approach: a case study of intrastromal sutureless transplant, where a portion of the anterior stroma of a donor cornea was inserted into the stroma of the recipient cornea, aiming to restore the correct thickness of the patient's cornea. The patient cornea was paracentrally thin, as the result of a trophic ulcer due to ocular pemphigoid. A discoid corneal graft from the anterior stroma of a donor eye was prepared: a femtosecond laser cut with a trapezoidal profile (thickness was 300 μm, minor and major basis were 3.00 and 3.50 mm, respectively). In the recipient eye, an intrastromal cut was also performed with the femtosecond laser using a specifically designed mask; the cut position was 275 μm in depth. The graft was loaded into an injector and inserted as an intrastromal presbyopic implant. The postoperative analysis evidenced a clear and stable graft that selectively restored corneal thickness in the thinned area. Intrastromal corneal transplant surgery is a minimally invasive alternative to anterior or posterior lamellar keratoplasty in select cases. We believe that Sutureless Intrastromal Laser Keratoplasty (SILK) could open up new avenues in the field of corneal transplantation by fully utilizing the potential and precision of existing lasers.

  18. 近视性高度屈光参差眼屈光参数和角膜生物学参数的研究%Research of refractive index and corneal biological parameter in high myopic anisometropia eyes

    Institute of Scientific and Technical Information of China (English)

    许爱琴; 方海珍

    2011-01-01

    Objective To investigate the differences of refractive index and corneal biological parameter in high myopic anisometropia.Methods Twenty three subjects who suffered anisometropia (spherical equivalent ≥6.00 D) were selected.For each subject,corneal hysteresis (CH) was measured by ORA (Ocular Response Analyzer),central corneal thickness (CCT) was measured by OCT,average keratometer value (mean K) and ocular axial length (AL) were measured by Zeiss IOL-Master,the results were tested by paired t-test and multiple linear regression.Result The differences of mean K,CCT for two eyes were not significant (P >0.05).Mean AL was (28.34± 1.10) mm (SD) in high myopic eyes compared with (24.53± 0.70) mm in the fellow eye,the difference was statistically significant (P <0.0001).The mean hysteresis in high myopic eyes and the fellow eyes was (10.00± 1.61)mmHg and (10.96± 1.38) mmHg,respectively; the difference was statistically significant (P <0.0001).The relationship between CH and AL and CCT was statistically significant (P <0.05).Conclusions Under the same gene and environment,the corneal hysteresis value is significantly lower in high myopia,which has no thinner cornea.It may be due to the change in cornea microstructure as a result of axial abnormal elongation.%目的 分析和研究近视性的高度屈光参差眼屈光参数及角膜生物学参数的差异性.方法 对23名近视性的高度屈光参差患者(双眼等效球镜SE差≥6.00D),用眼反应分析仪(Ocular Response Analyzer,ORA)测量角膜滞后性(Corneal Hyteresis,CH),用改进的光学相干断层扫描仪(OCT-3)测量中央角膜厚度(CCT),用IOL-Master测量角膜曲率(mean K)及眼轴长度(AL).统计处理采用配对t检验和多元线性回归分析.结果 近视程度高度眼平均AL(28.34±1.10)mm,低度眼平均AL( 24.53±0.70)mm,差异有统计学意义(P<0.01).双眼角膜平均曲率K差异无统计学意义(P>0.05).双眼CCT差异无统计学意义(P>0.05).

  19. New techniques to improve classical corneal collagen cross-linking treatment

    Institute of Scientific and Technical Information of China (English)

    Li Na; Peng Xiujun; Fan Zhengjun; Xia Yu; Wu Tengfei

    2014-01-01

    Objective The aim of this review is to comprehensively and unbiasedly summarize the improvements in the techniques for classical corneal collagen cross-linking (CXL) by covering the reasons for this improvement,measure,and effect to approach the future direction of the CXL.Data sources All articles used in this review were mainly retrieved from the PubMed database.Study selection Original articles and reviews were selected if they were related to the improvement in the technique of classical CXL.Data were mainly extracted from 94 articles,which are listed in the reference section of this review.Results This innovative research involves every step such as instrument preparation,epithelial management,riboflavin instillation,and UVA irradiation.These clinical and experimental results seem promising.Conclusions CXL treatment is the only recent promising method for preventing the progress of keratoconus.The limitations and potential complications that accompany classical CXL such as corneal thickness limitations,ultraviolet-A (UVA) light injury,and the impact of de-epithelialization encourage people to research new improvements in techniques.While this research needs to be further investigated,we hope our review can help related researchers and patients.

  20. Observation of posterior corneal vesicles with in vivo confocal microscopy and anterior segment OCT

    Directory of Open Access Journals (Sweden)

    Ryou Watanabe

    2010-10-01

    Full Text Available Ryou Watanabe, Toru Nakazawa, Nobuo FuseDepartment of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, JapanAbstract: The histopathology of posterior corneal vesicles (PCV has not yet been revealed. A 15-year-old girl, who was diagnosed by slit-lamp microscopy as PCV, was examined using specular microscopy, in vivo confocal microscopy, and anterior segment OCT (optical coherence tomography. Anterior segment OCT showed that the thickness of both corneas was within normal limits. At the same time, in vivo confocal microscopy revealed endothelial cells in the rounded dark areas, acellular hyporeflective layers on the Descemet’s membrane, and hyperreflective linear lesions. These findings were not reported previously by slit-lamp and specular microscopy. The abnormal findings only existed at the Descemet’s membrane and corneal endothelial layer. Previous reports dealing with posterior polymorphous dystrophy (PPMD examined using in vivo confocal microscopy reported almost the same findings, suggesting that PCV and PPMD may be the same at the microstructural level.Keywords: cornea, Descemet’s membrane, imaging

  1. Precision and agreement of corneal power measurements obtained using a new corneal topographer OphthaTOP.

    Directory of Open Access Journals (Sweden)

    Jinhai Huang

    Full Text Available To evaluate repeatability and reproducibility of anterior corneal power measurements obtained with a new corneal topographer OphthaTOP (Hummel AG, Germany and agreement with measurements by a rotating Scheimpflug camera (Pentacam HR, Oculus, Germany and an automated keratometer (IOLMaster, Carl Zeiss Meditec, Germany.The right eyes of 79 healthy subjects were prospectively measured three times with all three devices. Another examiner performed three additional scans with the OphthaTOP in the same session. Within one week, the first examiner repeated the measurements using the OphthaTOP. The flat simulated keratometry (Kf, steep K (Ks, mean K (Km, J0, and J45 were noted. Repeatability and reproducibility of measurements were assessed by within-subject standard deviation (Sw, repeatability (2.77 Sw, coefficient of variation (CoV, and intraclass correlation coefficient (ICC. Agreement between devices was assessed using 95% limits of agreement (LoA.Intraobserver repeatability and interobserver and intersession reproducibility of all measured parameters showed a 2.77 Sw of 0.29 diopter or less, a CoV of less than 0.24%, and an ICC of more than 0.906. Statistically significant differences (P<0.001 were found between the parameters analyzed by the three devices, except J0 and J45. The mean differences between OphthaTOP and the other two devices were small, and the 95% LoA was narrow for all results.The OphthaTOP showed excellent intraobserver repeatability and interobserver and intersession reproducibility of corneal power measurements. Good agreements with the other two devices in these parameters were found in healthy eyes.

  2. An experimental model of mycobacterial infection under corneal flaps

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    C.B.D. Adan

    2004-07-01

    Full Text Available In order to develop a new experimental animal model of infection with Mycobacterium chelonae in keratomileusis, we conducted a double-blind prospective study on 24 adult male New Zealand rabbits. One eye of each rabbit was submitted to automatic lamellar keratotomy with the automatic corneal shaper under general anesthesia. Eyes were immunosuppressed by a single local injection of methyl prednisolone. Twelve animals were inoculated into the keratomileusis interface with 1 µl of 10(6 heat-inactivated bacteria (heat-inactivated inoculum controls and 12 with 1 µl of 10(6 live bacteria. Trimethoprim drops (0.1%, w/v were used as prophylaxis for the surgical procedure every 4 h (50 µl, qid. Animals were examined by 2 observers under a slit lamp on the 1st, 3rd, 5th, 7th, 11th, 16th, and 23rd postoperative days. Slit lamp photographs were taken to document clinical signs. Animals were sacrificed when corneal disease was detected and corneal samples were taken for microbiological analysis. Eleven of 12 experimental rabbits developed corneal disease, and M. chelonae could be isolated from nine rabbits. Eleven of the 12 controls receiving a heat-inactivated inoculum did not develop corneal disease. M. chelonae was not isolated from any of the control rabbits receiving a heat-inactivated inoculum, or from the healthy cornea of control rabbits. Corneal infection by M. chelonae was successfully induced in rabbits submitted to keratomileusis. To our knowledge, this is the first animal model of M. chelonae infection following corneal flaps for refractive surgery to be described in the literature and can be used for the analysis of therapeutic responses.

  3. Phototherapeutic Keratectomy Combined with Photorefractive Keratectomy for Treatment of Myopia with Corneal Scars

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To evaluate the effect of phototherapeutic keratectomy combined with photorefractive keratectomy in the treatment of myopia with corneal scars, corneal epithelium was removed with laser plus scraping. Corneal scars were removed with PTK, followed by PRK for myopia. Healon was used to make corneal surface smoother during operation. 30 eyes of 24 cases of myopia with corneal scars were followed up for one year. Mean corrected vision was 0. 51 and myopic degree was -6.42D ?4.26D before operation. After operation, corneal scars of 21 eyes (70.0?) were removed in operative zone. The vision of 27 operated eyes (90. 0 %) was equal to or better than best corrected vision. Mean postoperative visual acuity was 0. 72. Corneal surface was smoother and astigmatism was reduced after the surgery. Our study showed that PTK combined with PRK is a safe and effective treatment for myopia with corneal scars.

  4. Corneal opacities--a diagnostic feature of the trisomy 8 mosaic syndrome.

    OpenAIRE

    Frangoulis, M; Taylor, D.

    1983-01-01

    An infant with trisomy 8 mosaicism had bilateral corneal opacities and multiple systemic anomalies. A review of the literature suggests that corneal opacities are a prominent feature of the syndrome and may have substantial clinical and diagnostic importance.

  5. Corneal endothelium of the Magellanic penguin (Spheniscus magellanicus) by scanning electron microscopy.

    Science.gov (United States)

    Pigatto, João A T; Laus, José L; Santos, Jaime M; Cerva, Cristine; Cunha, Luciana S; Ruoppolo, Valéria; Barros, Paulo S M

    2005-12-01

    The corneal endothelium is essential for the maintenance of the corneal transparency. The aim of this study was to examine the morphology of the endothelial surface and perform morphometric analysis of the normal corneal endothelial cells of the Magellanic penguin (Spheniscus magellanicus) using scanning electron microscopy. The present work demonstrates that the corneal endothelium of the Magellanic penguin is similar to those described in other vertebrates. PMID:17312730

  6. Influence of Interleukin-1α and Tumor Necrosis Factor-α Production on Corneal Graft Survival

    OpenAIRE

    Bosnar, Damir; Dekaris, Iva; Gabrić, Nikica; Markotić, Alemka; Lazić, Ratimir; Špoljarić, Ninoslav

    2006-01-01

    Aim: To determine pro-inflammatory cytokine secretion from human corneas with different pathology and to establish whether cytokine profile influences corneal graft outcome. Method: Secretion of both proinflammatory cytokine interleukin (IL)-1α and tumor necrosis factor (TNF)-α was measured after cultivation of 47 corneas collected from corneal graft recipients suffering from different corneal diseases. Non-inflammatory corneal diseases were keratoconus (n = 8), keratoglobus (n = 2), bullo...

  7. Bilateral Keratoconus and Corneal Hydrops Associated with Eye Rubbing in a 7-year-old Girl

    OpenAIRE

    Mahmoud-Reza Panahi-Bazaz; Farideh Sharifipour; Alireza Moghaddasi

    2014-01-01

    Purpose: To report a young child with bilateral keratoconus in the context of vernal keratoconjunctivitis (VKC) who developed bilateral corneal hydrops associated with eye rubbing, and to discuss the pathogenesis and review the pertinent literature. Case Report: A seven-year-old girl with VKC and asymmetric keratoconus developed corneal hydrops due to habitual eye rubbing. Corneal edema subsided within 16 weeks in her right eye and 9 weeks in the left eye with subsequent corneal scarring....

  8. Quantifying the effect of milli-molar glucose concentration on thickness of rabbit cornea with optical coherence tomography

    Science.gov (United States)

    Ghosn, Mohamad G.; Leba, Michael; Vijayananda, Astha; Ansari, Rafat R.; Larin, Kirill V.

    2009-02-01

    The cornea contributes about 65% of the eye's ability to refract light. Thus, any fluctuation in corneal thickness can cause noticeable changes in vision. The presence of glucose molecules induces a driving force for water to leave the collagen fibrils in the cornea due to the concentration gradient created, thus changing its thickness. In this study, the effect of various milli-molar glucose concentrations on corneal thickness was explored using Optical Coherence Tomography. Whole rabbit eyes were placed in a specially designed dish while immersed in saline to ensure proper hydration of the eye. The cornea was imaged for 10 minutes. In 30 minute increments, a higher concentration of glucose was added, bringing the overall glucose concentration to 10, 15, 20, 25, and 30 mM. The thickness of the cornea was measured every 2 minutes. Ultimately, an inverse relationship was observed, indicating that the increase in glucose concentration yielded a decrease in the corneal thickness. From three separate experiments, the cornea experienced 8 +/- 1, 27 +/- 1, 44 +/- 3, 58 +/- 3, and 64 +/- 3 μm decrease in thickness from its starting value while exposed to 10, 15, 20, 25, and 30 mM solutions of glucose, respectively. This relationship provides insight on the physiological changes of the cornea as a result of different glucose concentrations. This could potentially be useful in monitoring blood-glucose levels through the eye.

  9. Ipsilateral Lymphadenectomy to Inhibit Corneal Allograft Rejection in Rats

    Institute of Scientific and Technical Information of China (English)

    LING Shiqi; HU Yanhua

    2005-01-01

    In order to investigate the ipsilateral lymphadenectomy for inhibiting rejection in rat corneal transplantation, corneal allogenic transplantation models were established in rats. Eighteen female Wister rats were used as donors, and 36 Sprague Dawley rats as recipients. After penetrating corneal transplantation, recipients were randomly divided into 3 groups: group A (control group);group B, the ipsilateral lymphadenectomy group; group C, the bilateral lymphadenectomy group.Among 12 rats in each group, the corneas of 2 rats in each group were used for pathological study at day 14 after the transplantation, and the remaining 10 rats were used for studying corneal rejection by a slit lamp. The time points when allograft rejection occurred were recorded and mean survival time (MST) was compared. The results showed that MST in groups B and C was 46.30±9.464 days and 44.43 ± 7. 604 days, respectively, which was significantly prolonged as compared with that in group A (10.71±1. 567 days, P<0.01). There was no significant difference in MST between groups B and C (P>0.05). Itwas concluded that both bilateral and ipsilateral lymphadenectomy therapies could effectively inhibit the corneal allograft rejection. Ipsilateral lymphadenectomy is a less complex surgical procedure and is just as effective in preventing rejection.

  10. Trefoil peptides promote restitution of wounded corneal epithelial cells.

    Science.gov (United States)

    Göke, M N; Cook, J R; Kunert, K S; Fini, M E; Gipson, I K; Podolsky, D K

    2001-04-01

    The ocular surface shares many characteristics with mucosal surfaces. In both, healing is regulated by peptide growth factors, cytokines, and extracellular matrix proteins. However, these factors are not sufficient to ensure most rapid healing. Trefoil peptides are abundantly expressed epithelial cell products which exert protective effects and are key regulators of gastrointestinal epithelial restitution, the critical early phase of cell migration after mucosal injury. To assess the role of trefoil peptides in corneal epithelial wound healing, the effects of intestinal trefoil factor (ITF/TFF3) and spasmolytic polypeptide (SP/TFF2) on migration and proliferation of corneal epithelial cells were analyzed. Both ITF and SP enhanced restitution of primary rabbit corneal epithelial cells in vitro. While the restitution-enhancing effects of TGF-alpha and TGF-beta were both inhibited by neutralizing anti-TGF-beta-antibodies, trefoil peptide stimulation of restitution was not. Neither trefoil peptide significantly affected proliferation of primary corneal epithelial cells. ITF but not SP or pS2 mRNA was present in rabbit corneal and conjunctival tissues. In summary, the data indicate an unanticipated role of trefoil peptides in healing of ocular surface and demand rating their functional actions beyond the gastrointestinal tract.

  11. Discovery of molecular markers to discriminate corneal endothelial cells in the human body

    NARCIS (Netherlands)

    Yoshihara, Masahito; Ohmiya, Hiroko; Hara, Susumu; Kawasaki, Satoshi; Hayashizaki, Yoshihide; Itoh, Masayoshi; Kawaji, Hideya; Tsujikawa, Motokazu; Nishida, Kohji; Clevers, J.C.; van de Wetering, M.L.

    2015-01-01

    The corneal endothelium is a monolayer of hexagonal corneal endothelial cells (CECs) on the inner surface of the cornea. CECs are critical in maintaining corneal transparency through their barrier and pump functions. CECs in vivo have a limited capacity in proliferation, and loss of a significant nu

  12. Mechanism of initial attachment of corneal epithelial cells to polymeric surfaces.

    Science.gov (United States)

    Steele, J G; Johnson, G; Griesser, H J; Underwood, P A

    1997-12-01

    The initial attachment of cultured bovine corneal epithelial cells and stromal fibroblasts to two oxygen-containing synthetic polymers was studied. Cultured epithelial cells and stromal fibroblasts were seeded onto two oxygen-containing surfaces: 'tissue culture' polystyrene (TCPS) and a polymer film deposited by RF plasma deposition using a methylmethacrylate monomer (MMA/FEP). To establish the mechanism of cell attachment, the effect of the selective removal of the vitronectin and fibronectin from the serum used in the culture medium was tested. The attachment of cultured epithelial cells during the first 90 min of culture was reduced by 40% (TCPS)-80% (MMA/FEP) as a result of removing vitronectin from the medium. Attachment of these cells to TCPS was reduced by 85-95% when the serum was depleted of both fibronectin and vitronectin. However, depletion of fibronectin reduced cell attachment to TCPS by 20%, whilst on MMA/FEP cell attachment was equivalent, or higher, than that for intact serum. The attachment of cultured corneal stromal fibroblasts was similarly dependent on vitronectin but less dependent on fibronectin. Therefore, for the attachment of both cultured epithelial cells and fibroblasts to oxygen-containing surfaces in the presence of serum, there is a high requirement for serum vitronectin but a lesser requirement for fibronectin. The effects of the establishment of corneal epithelial cells in culture and the site of origin of the cells, were determined. Primary isolates of epithelial cells isolated from the limbal, central or peripheral regions of the cornea were less dependent on vitronectin for initial attachment to TCPS than were these cells after several passages in culture. Furthermore, the primary isolates were dramatically less responsive to vitronectin than the cultured cells. These results indicate that the mechanism of attachment of corneal epithelial cells to TCPS varies with the culture experience of the cells. Cells that are culture

  13. Measurement of epidermal thickness in a patient with psoriasis by computer-supported image analysis

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    Alper M.

    2004-01-01

    Full Text Available The aim of the present study was to measure full epidermal thickness, stratum corneum thickness, rete length, dermal papilla widening and suprapapillary epidermal thickness in psoriasis patients using a light microscope and computer-supported image analysis. The data obtained were analyzed in terms of patient age, type of psoriasis, total body surface area involvement, scalp and nail involvement, duration of psoriasis, and family history of the disease. The study was conducted on 64 patients and 57 controls whose skin biopsies were examined by light microscopy. The acquired microscopic images were transferred to a computer and measurements were made using image analysis. The skin biopsies, taken from different body areas, were examined for different parameters such as epidermal, corneal and suprapapillary epidermal thickness. The most prominent increase in thickness was detected in the palmar region. Corneal thickness was more pronounced in patients with scalp involvement than in patients without scalp involvement (t = -2.651, P = 0.008. The most prominent increase in rete length was observed in the knees (median: 491 µm, t = 10.117, P = 0.000. The difference in rete length between patients with a positive and a negative family history was significant (t = -3.334, P = 0.03, being 27% greater in psoriasis patients without a family history. The differences in dermal papilla distances among patients were very small. We conclude that microscope-supported thickness measurements provide objective results.

  14. Changes of thickness of retinal nerve fiber layer and central fovea of macula in children with ametropic amblyopia%屈光不正性弱视儿童视网膜神经纤维层和黄斑中心凹厚度的变化

    Institute of Scientific and Technical Information of China (English)

    金守梅; 冯运红; 谢静; 郑小媚; 陈兆升; 许锦芳

    2015-01-01

    Objective To compare the thickness of retinal nerve fiber layer (RNFL) and central fovea of macula in children with ametropic amblyopia. Methods A total of 25 children (50 eyes) with ametropic amblyopia and 24 normal children (48 eyes) were enrolled. Thickness of RNFL and central fovea of macula of all subjects were measured by the Optical Coherence Tomography and compared and analyzed. Results The average thickness of the RNFL of the ametropic amblyopia group 121.32±8.06μm was significantly higher than that of the normal group 104.63±6.24μm, 0.05. The average thicknesses of the retinal nerve fiber layer had a negative correlation with the axis in normal eyes,=-0.42, 0.05,而正常组患者的视网膜神经纤维层平均厚度与眼轴呈明显相关,r=-0.42,P<0.05。结论屈光不正性弱视可影响患者的视网膜神经纤维层厚度。

  15. Comparative study of visual acuity and aberrations after intralase femtosecond LASIK: small corneal flap versus big corneal flap

    Institute of Scientific and Technical Information of China (English)

    Ya-Li; Zhang; Lei; Liu; Chang-Xia; Cui; Ming; Hu; Zhao-Na; Li; Li-Jun; Cao; Xiu-Hua; Jing; Guo-Ying; Mu

    2014-01-01

    AIM:To study the effects of different flap sizes on visual acuity, refractive outcomes, and aberrations after femtosecond laser for laser keratomileusis (LASIK). ·METHODS: In each of the forty patients enrolled, 1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap, defined as the small flap, while the other eye was treated with a 8.6mm diameter corneal flap, defined as the big flap. Refractive errors, visual acuity, and higher -order aberrations were compared between the two groups at week 1, month 1 and 3 postoperatively. · RESULTS: The postoperative refractive errors and visual acuity all conformed to the intended goal. Postoperative higher -order aberrations were increased, especially in spherical aberration (Z12) and vertical coma (Z7). There were no statistically significant differences between the two groups in terms of postoperative refractive errors, visual acuity, root mean square of total HOAs (HO -RMS), trefoil 30° (Z6), vertical coma (Z7), horizontal coma (Z8), trefoil 0° (Z9), and spherical aberration (Z12) at any point during the postoperative follow-up. ·CONCLUSION: Both the small and big flaps are safe and effective procedures to correct myopia, provided the exposure stroma meets the excimer laser ablations. The personalized size corneal flap is feasible, as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error.

  16. [Cytological changes in patients with diabetes mellitus and corneal ulcer].

    Science.gov (United States)

    Raica, D; Turlea, M; Ciocmăreanu, M; Haidar, A; Demian, C; Jinga, F

    1999-01-01

    There were studied 11 diabetic patients, insulin dependents, from 4 were with juvenile diabetes mellitus. These were hospitalized in the Dept. Ophthalm. of the City Hospital of Arad, during 1996-1998, admitted with the diagnosis of corneal ulcer. There were made samples of the gathered secretion from the level of conjunctiva and of the grataj material, gathered at the level of the edges of the corneal ulcer. All samples were stained with the BPT-Drăgan method. There are described cytologic alterations, insisting on details that indicate the severity of the corneal disease. There are taken into consideration cytologic aspects in relationship with the clinical outcome of the disease, pointing out the cellular alterations which announce a nonfavourable prognosis. Cytologic results can improve the diagnosis and they are involved in therapeutic schedule. PMID:10641114

  17. Corneal wound healing is compromised by immunoproteasome deficiency.

    Directory of Open Access Journals (Sweden)

    Deborah A Ferrington

    Full Text Available Recent studies have revealed roles for immunoproteasome in regulating cell processes essential for maintaining homeostasis and in responding to stress and injury. The current study investigates how the absence of immunoproteasome affects the corneal epithelium under normal and stressed conditions by comparing corneas from wildtype (WT mice and those deficient in two immunoproteasome catalytic subunits (lmp7(-/-/mecl-1(-/-, L7M1. Immunoproteasome expression was confirmed in WT epithelial cells and in cells of the immune system that were present in the cornea. More apoptotic cells were found in both corneal explant cultures and uninjured corneas of L7M1 compared to WT mice. Following mechanical debridement, L7M1 corneas displayed delayed wound healing, including delayed re-epithelialization and re-establishment of the epithelial barrier, as well as altered inflammatory cytokine production compared to WT mice. These results suggest that immunoproteasome plays an important role in corneal homeostasis and wound healing.

  18. Cataract Surgery with a Refractive Corneal Inlay in Place

    Directory of Open Access Journals (Sweden)

    N. R. Stojanovic

    2015-01-01

    Full Text Available Purpose. To present a case of cataract surgery performed in a patient with a refractive corneal inlay in place. Methods. A 48-year-old female patient presented to our institute with bilateral cataract. The patient had undergone refractive corneal inlay implantation three years ago in her right, nondominant eye for presbyopia correction. Biometry and intraocular lens (IOL power calculation were performed without removing the inlay. Phacoemulsification and IOL insertion were carried out in both eyes in a usual manner. Results. On day one postoperatively, the patient achieved binocular uncorrected distance visual acuity 20/20 and uncorrected near visual acuity J1. The vision remained stable during the one-year follow-up period. Conclusion. Cataract surgery was performed in a standard manner in a patient with Presbia Microlens corneal inlay in place. Visual outcomes for both near and distance vision were satisfactory.

  19. Tectonic corneal graft for conjunctival rhinosporidiosis with scleral melt

    Directory of Open Access Journals (Sweden)

    Pushpa Jacob

    2011-01-01

    Full Text Available A 16 year old girl presented with irritation and watering of the right eye for 3 months. On examination, the superior perilimbal sclera was ectatic with incarcerated uveal tissue covered by conjunctiva. The conjunctiva showed discreet, yellow white mucoid spots. Excision biopsy of the conjunctiva showed subepithelial spherules of sporangia containing numerous endospores, suggestive of rhinosporidiosis. Diathermy was applied to flatten the staphyloma. The ectatic area was covered with a corneal patch graft. The patient was started on prednisolone acetate eye drops and oral dapsone for 6 months. Corneal graft was well incorporated and conjunctivalized by 3 months. Since the graft was not seen within the palpebral aperture, there was good cosmetic result. The corneal graft had the added advantage of transparency which allowed visualization of the underlying tissue to diagnose early recurrence. There was no recurrence at 6 months.

  20. Measurement of corneal tangent modulus using ultrasound indentation.

    Science.gov (United States)

    Wang, Li-Ke; Huang, Yan-Ping; Tian, Lei; Kee, Chea-Su; Zheng, Yong-Ping

    2016-09-01

    Biomechanical properties are potential information for the diagnosis of corneal pathologies. An ultrasound indentation probe consisting of a load cell and a miniature ultrasound transducer as indenter was developed to detect the force-indentation relationship of the cornea. The key idea was to utilize the ultrasound transducer to compress the cornea and to ultrasonically measure the corneal deformation with the eyeball overall displacement compensated. Twelve corneal silicone phantoms were fabricated with different stiffness for the validation of measurement with reference to an extension test. In addition, fifteen fresh porcine eyes were measured by the developed system in vitro. The tangent moduli of the corneal phantoms calculated using the ultrasound indentation data agreed well with the results from the tensile test of the corresponding phantom strips (R(2)=0.96). The mean tangent moduli of the porcine corneas measured by the proposed method were 0.089±0.026MPa at intraocular pressure (IOP) of 15mmHg and 0.220±0.053MPa at IOP of 30mmHg, respectively. The coefficient of variation (CV) and intraclass correlation coefficient (ICC) of tangent modulus were 14.4% and 0.765 at 15mmHg, and 8.6% and 0.870 at 30mmHg, respectively. The preliminary study showed that ultrasound indentation could be applied to the measurement of corneal tangent modulus with good repeatability and improved measurement accuracy compared to conventional surface displacement-based measurement method. The ultrasound indentation can be a potential tool for the corneal biomechanical properties measurement in vivo. PMID:27262352

  1. The theory and art of corneal cross-linking

    Directory of Open Access Journals (Sweden)

    Rebecca McQuaid

    2013-01-01

    Full Text Available Before the discovery of corneal cross-linking (CXL, patients with keratoconus would have had to undergo corneal transplantation, or wear rigid gas permeable lenses (RGPs that would temporarily flatten the cone, thereby improving the vision. The RGP contact lens (CL would not however alter the corneal stability and if the keratoconus was progressive, the continued steepening of the cone would occur under the RGP CL. To date, the Siena Eye has been the largest study to investigate long term effects of standard CXL. Three hundred and sixty-three eyes were treated and monitored over 4 years, producing reliable long-term results proving long-term stability of the cornea by halting the progression of keratoconus, and proving the safety of the procedure. Traditionally, CXL requires epithelial removal prior to corneal soakage of a dextran-based 0.1% riboflavin solution, followed by exposure of ultraviolet-A (UV-A light for 30 min with an intensity of 3 mW/cm2. A series of in vitro investigations on human and porcine corneas examined the best treatment parameters for standard CXL, such as riboflavin concentration, intensity, wavelength of UV-A light, and duration of treatment. Photochemically, CXL is achieved by the generation of chemical bonds within the corneal stroma through localized photopolymerization, strengthening the cornea whilst minimizing exposure to the surrounding structures of the eye. In vitro studies have shown that CXL has an effect on the biomechanical properties of the cornea, with an increased corneal rigidity of approximately 70%. This is a result of the creation of new chemical bonds within the stroma.

  2. The theory and art of corneal cross-linking.

    Science.gov (United States)

    McQuaid, Rebecca; Cummings, Arthur B; Mrochen, Michael

    2013-08-01

    Before the discovery of corneal cross-linking (CXL), patients with keratoconus would have had to undergo corneal transplantation, or wear rigid gas permeable lenses (RGPs) that would temporarily flatten the cone, thereby improving the vision. The RGP contact lens (CL) would not however alter the corneal stability and if the keratoconus was progressive, the continued steepening of the cone would occur under the RGP CL. To date, the Siena Eye has been the largest study to investigate long term effects of standard CXL. Three hundred and sixty-three eyes were treated and monitored over 4 years, producing reliable long-term results proving long-term stability of the cornea by halting the progression of keratoconus, and proving the safety of the procedure. Traditionally, CXL requires epithelial removal prior to corneal soakage of a dextran-based 0.1% riboflavin solution, followed by exposure of ultraviolet-A (UV-A) light for 30 min with an intensity of 3 mW/cm2. A series of in vitro investigations on human and porcine corneas examined the best treatment parameters for standard CXL, such as riboflavin concentration, intensity, wavelength of UV-A light, and duration of treatment. Photochemically, CXL is achieved by the generation of chemical bonds within the corneal stroma through localized photopolymerization, strengthening the cornea whilst minimizing exposure to the surrounding structures of the eye. In vitro studies have shown that CXL has an effect on the biomechanical properties of the cornea, with an increased corneal rigidity of approximately 70%. This is a result of the creation of new chemical bonds within the stroma. PMID:23925326

  3. Therapeutic effect and safety of accelarated transepithelial riboflavin-ultraviolet corneal collagen crosslinking for keratoconus%快速跨上皮核黄素-紫外光角膜胶原交联治疗圆锥角膜的临床疗效和安全性评价

    Institute of Scientific and Technical Information of China (English)

    张晶; 郑燕; 刘倩; 王玥; 李颖; 张秋露; 徐雯; 周跃华

    2016-01-01

    Background Researches showed that classic corneal collagen crosslinking (CXL) can effectively control the progression of keratoconus and corneal ectasia,but its adverse responses and complications are common due to the de-epithelial procedure.A transepithelial riboflavin-ultraviolet CXL surgery has applied in ophthalmology,but its effectiveness and safety evaluation is less.Objective This study was to evaluate the effectiveness and safety of rapid transepithelial riboflavin-ultraviolet CXL for keratoconus.Methods A prospective self-controlled study was designed.Forty-six eyes of 28 keratoconus patients scheduled to receive the rapid transepithelial riboflavin-ultraviolet CXL in Beijing Tongren Hospital from March to October in 2014 under the approval of this hospital and informed consent with a follow-up duration for one year.The spherical equivalent (SE) , astigmatic power, central corneal thickness (CCT), endothelial cell count, corneal topography parameters, the parameters from the anterior segment optical coherence tomography (AS-OCT) and corneal biomechanical parameters were examined before surgery and 1 week, 1 month,3 months,6 months and 12 months after surgery,and the results were compared among different time points to assess the effectiveness of transepithelial riboflavin-ultraviolet CXL for keratoconus.The postoperative irritation symptoms and adverse response were observed to evaluate the safety of surgery.Results No intraoperative complication and serious adverse postoperative infection were found in all the operated eyes.Slight irritation symptoms occurred in operated eyes 1 day after surgery and disappeared 3 days after surgery.A little reducing was seen in the spherical equivalent 1 month later, without significant difference among various time points (F =0.722, P =0.614).However, a significant reducing was found in astigmatic power in 12 months after surgery compared with before surgery (t =3.242,P =0.004).No considerably differences were seen in

  4. Bacterial corneal ulcer associated with common variable immune deficiency.

    Science.gov (United States)

    Tsui, Edmund; Deng, Jie; Siedlecki, Andrew N; Zegans, Michael E

    2016-12-01

    Common variable immune deficiency (CVID) is one of the most commonly diagnosed primary immunodeficiencies. Generally, patients have a history of recurrent sinopulmonary infections, hypogammaglobulinemia of two or more immunoglobulin isotypes, and impaired functional antibody responses. Reports of corneal involvement associated with CVID are limited. We describe a case of corneal ulceration associated with methicillin-resistant Staphylococcus aureus in a patient with CVID that developed while on monthly intravenous immunoglobulin infusions and in which there were no common risk factors for bacterial keratitis, such as prior history of ocular surface disease, trichiasis, trauma, or contact lens wear. PMID:27491761

  5. Minocycline Inhibits Alkali Burn-Induced Corneal Neovascularization in Mice

    OpenAIRE

    Ou Xiao; Zhao-lian Xie; Bin-wu Lin; Xiao-fang Yin; Rong-biao Pi; Shi-you Zhou

    2012-01-01

    The purpose of this study was to investigate the effects of minocycline on alkali burn-induced corneal neovascularization (CNV). A total of 105 mice treated with alkali burns were randomly divided into three groups to receive intraperitoneal injections of either phosphate buffered saline (PBS) or minocycline twice a day (60 mg/kg or 30 mg/kg) for 14 consecutive days. The area of CNV and corneal epithelial defects was measured on day 4, 7, 10, and14 after alkali burns. On day 14, a histopathol...

  6. Noninvasive spectroscopic diagnosis of superficial ocular lesions and corneal infections

    Energy Technology Data Exchange (ETDEWEB)

    Mourant, J.R.; Bigio, I.J.; Johnson, T.; Shimada, T. [Los Alamos National Lab., NM (United States); Gritz, D.C.; Storey-Held, K. [Texas Univ. Health Science Center, San Antonio, TX (United States). Dept. of Ophthalmology

    1994-02-01

    The potential of a rapid noninvasive diagnostic system to detect tissue abnormalities on the surface of the eye has been investigated. The optical scatter signal from lesions and normal areas on the conjunctival sclera of the human eye were measured in vivo. It is possible to distinguish nonpigmented pingueculas from other lesions. The ability of the system to detect malignancies could not be tested because none of the measured and biopsied lesions were malignant. Optical scatter and fluorescence spectra of bacterial and fungal suspensions, and corneal irritations were also collected. Both scattering and fluorescence show potential for diagnosing corneal infections.

  7. Multi-gene targeted antiangiogenic therapies for experimental corneal neovascularization

    OpenAIRE

    Chen, Peng; Yin, Hongmei; Wang, Yao; Mi, Jing; He, Wenxiao; Xie, Lixin; Wang, Yiqiang

    2010-01-01

    Purpose To determine the effectiveness of multigene-based anti-angiogenic gene therapies for experimental murine corneal neovascularization (corneal NV). Methods Recombinant retroviral vectors encoding murine endostatin (mEndo), murine-soluble vascular endothelial growth factor receptor-2 (msFlk-1), or murine-soluble Tie2 (msTie2) were constructed and packaged in PT67 cells. Viral titers were determined by infection of NIH3T3 cells. Expressions of mEndo, msFlk-1, and msTie2 were confirmed by ...

  8. Hypoxia preconditioning protects corneal stromal cells against induced apoptosis

    OpenAIRE

    Xing, Dongmei; Sun, Xingcai; Li, Jinhua; CUI, MIAO; Tan-Allen, Kah; Bonanno, Joseph A

    2005-01-01

    The purpose of this study, was to determine whether hypoxia preconditioning can protect corneal stromal cells from UV stress and cytokine mediated apoptosis. Two models were implemented. First, primary cultured bovine corneal fibroblasts were preconditioned with 0.5–1.5% O2 for 4 hr and stressed with UV-irradiation or stimulation of Fas receptor. Second, bovine eyes were preconditioned with 0.5% O2 for 4 hr and stressed by epithelial scraping to induce anterior keratocyte apoptosis. Cell fate...

  9. RTVue傅里叶光学相干断层扫描仪测量角膜参数的重复性和准确性评价%Repeatability and accuracy of corneal parameters measured by RTVue Fourier-domain optical coherence topography

    Institute of Scientific and Technical Information of China (English)

    华焱军; 黄锦海; 潘超; 王勤美

    2013-01-01

    膜地形图仪略大;RTVue FD-OCT获得的Rposterior/Ranterior比Gullstrand模型眼小,可能为建立更准确的标准化模型眼提供依据.%Background Corneal parameters (such as curvature,thickness,etc) are essential to the diagnosis of corneal related diseases,contact lenses fitting and corneal refractive surgery.Objective The aim of this study was to assess the repeatability and accuracy of corneal parameters obtained by RTVue Fourier-domain optical coherence topography (FD-OCT).Methods In this prospective study,77 eyes of 43 subjects with the refraction from-1.25 D to-10.00 D and astigmatism <2 D were enrolled in keratorefractive surgery center,Eye Hospital of Wenzhou Medical College.The anterior and posterior corneal curvature in 3 mm central zone (Ranterior and Rposterior),the ratio of posterior and anterior curvature (Rposterior/Ranterior),corneal central thickness (CCT),total corneal power(Knet),the simulated corneal power (Sim K),the anterior and posterior corneal power (Kanterior,Kposterior)were measured by FD-OCT.Corneal power (Km) was obtained by Topolyzer topography based on Placido ring.Three consecutive scans were acquired in every tested eye.Repeatability of FD-OCT measurement was assessed using the coefficient of variation CV),Cronbach Alpha and intra-class correlation coefficient (ICC).Repeated measure ANOVA was used to analyze the differences among SimK,Knet and Km.Pearson correlation analysis was used to analysis the correlation between SimK and K Knet and Km,SimK and Km.The agreement between Sim K and K Knet and Km,SimK and Km was assessed by Bland-Altman plots analysis.All the subjects understood the purpose of this investigation and written informed consent was obtained prior to the medical examination.Results The Ranterior,Rposterior,Rposterior/Ranterior,Kanterior,Kposterior,Sim K,Knet and CCT were (7.691 ±0.302) mm,(6.532±0.276) mm,0.849±0.014,(48.97±1.92)D,(-6.13±0.26)D,(43.95±1.72) D,(42.95±1.68) D and (545.20± 35.04) μm,respectively.The CV of all

  10. Effects of Silicone Hydrogel Contact Lens Application on Corneal High-order Aberration and Visual Guality in Patients with Corneal Opacities

    OpenAIRE

    Sevda Aydın Kurna; Sibel Aksoy; Tomris Şengör; Ayşe Sönmez

    2012-01-01

    Pur po se: Evaluation of the corneal high-order aberrations and visual quality changes after application of silicone hydrogel contact lenses in patients with corneal opacities due to various etiologies. Ma te ri al and Met hod: Fifteen eyes of 13 patients with corneal opacities were included in the study. During the ophthalmologic examination before and after contact lens application, visual acuity was measured with Snellen acuity chart and contrast sensitivity - with Bailey-Lowie Ch...

  11. Analysis of human transforming growth factor β-induced gene mutation in corneal dystrophy

    Institute of Scientific and Technical Information of China (English)

    李杨; 孙旭光; 任慧媛; 董冰; 王智群; 孙秀英

    2004-01-01

    Background Corneal dystrophy is a group of inherited blinding diseases of the cornea. This study was to identify the mutations of the keratoepithelin (KE) gene for proper diagnosis of corneal dystrophy. Methods Three families with corneal dystrophy were analysed. Thirteen individuals at risk for corneal dystrophy in family A, the proband and her son in family B, and the proband in family C were examined after their blood samples were obtained. Mutation screening of human transforming growth factor β-induced gene (BIGH3 gene) was performed. Results Five individuals in family A were found by clinical evaluation to be affected with granular corneal dystrophy and carried the BIGH3 mutation W555R. However, both probands in families B and C, also diagnosed with granular corneal dystrophy, harboured the BIGH3 mutation R124H. Conclusion Molecular genetic analysis can improve accurate diagnosis of corneal dystrophy.

  12. Corneal Biomechanical and Anterior Chamber Parameters Variations after 1-year of Transepithelial Corneal Collagen Cross-linking in Eyes of Children with Keratoconus

    Science.gov (United States)

    Salman, Abdelrahman Gaber

    2016-01-01

    Aim: To assess the changes in corneal hysteresis (CH) and corneal resistance factor (CRF) 1-year following transepithelial corneal collagen cross-linking (CXL) treatment in eyes of children with keratoconus. Methods: This case series was conducted in 22 eyes of 22 children. Children aged 0.05). Conclusion: Transepithelial CXL in keratoconus in pediatric age group seems to have good stability in corneal biomechanical parameters after 1-year. Further studies with a larger sample and better study design are recommended to confirm our findings. PMID:26957852

  13. Surgical induced astigmatism correlated with corneal pachymetry and intraocular pressure: transconjunctival sutureless 23-gauge versus 20-gauge sutured vitrectomy in diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    Yan; Shao; Li-Jie; Dong; Yan; Zhang; Hui; Liu; Bo-Jie; Hu; Ju-Ping; Liu; Xiao-Rong; Li

    2015-01-01

    AIM: To determine the difference of surgical induced astigmatism between conventional 20-gauge sutured vitrectomy and 23-gauge transconjunctival sutureless vitrectomy, and the influence of corneal pachymetry and intraocular pressure(IOP) on surgical induced astigmatism in diabetic patients.METHODS: This retrospective, consecutive case series consisted of 40 eyes of 38 diabetic subjects who underwent either 20-gauge or 23-gauge vitrectomy. The corneal curvature and thickness were measured with Scheimpflug imaging before surgery and 1wk; 1, 3mo after surgery. We compared the surgical induced astigmatism(SIA) on the true net power in 23-gauge group with that in 20-gauge group. We determined the correlation between corneal thickness change ratio, IOP and SIA measured by Pentacam. RESULTS: The mean SIAs were 1.082 ±0.085 D( mean ± SEM), 0.689 ±0.070 D and 0.459 ±0.063 D at postoperative 1wk; 1, 3mo respectively in diabetic subjects. The vitrectomy induced astigmatisms were declined significantly with time(F2,36=33.629, P =0.000)postoperatively. The 23-gauge surgery group induced significantly less astigmatism than 20-gauge surgery group(F1,37=11.046, P =0.020). Corneal thickness in diabetes elevated after surgery(F3,78=10.532, P =0.000).The linear regression analysis at postoperatively 1wk went as: SIA =-4.519 +4.931 change ratio(Port3) +0.026IOP(R2=0.46, P =0.000), whereas the rate of cornealthickness change and IOP showed no correlation with the change of astigmatism at postoperatively 1 and 3mo.CONCLUSION: There are significant serial changes in both 20-gauge and 23-gauge group in diabetic subjects.23-gauge induce less astigmatism than 20-gauge and become stable more rapidly than 20-gauge. The elevation of corneal thickness and IOP was associated with increased astigmatim at the early postoperative stage both in 23-gauge and 20-gauge surgery group.

  14. Advanced Corneal Cross-Linking System with Fluorescence Dosimetry

    Directory of Open Access Journals (Sweden)

    Marc D. Friedman

    2012-01-01

    Full Text Available Purpose. This paper describes an advanced system that combines corneal cross-linking with riboflavin with fluorescence dosimetry, the ability to measure riboflavin diffusion within the cornea both before and during UVA treatment. Methods and Results. A corneal cross-linking system utilizing a digital micromirror device (DMD was assembled and used to measure diffusion coefficients of 0.1% riboflavin in 20% dextran in porcine eyes. A value of (3.3±0.2×10−7 cm2/s was obtained for the stroma. Diffusion coefficients for the transepithelial formulation of 0.1% riboflavin in 0.44% saline and 0.02% BAK were also measured to be 4.7±0.3×10−8 cm2/s for epithelium only and (4.6±0.4×10−7 cm2/s for stroma only. Riboflavin consumption during a UVA treatment was also demonstrated. Conclusion. A new advanced corneal cross-linking system with fluorescence dosimetry of riboflavin has been demonstrated. It is hoped that this method may play a significant role in determining the underlying mechanisms of corneal cross-linking and assist with the development of additional riboflavin formulations. Moreover, dosimetry may prove valuable in providing a method to account for the biological differences between individuals, potentially informing cornea-specific UVA treatment doses in real time.

  15. A circum-corneal conjunctival nevus in a child

    DEFF Research Database (Denmark)

    Svahn, T.F.; Heegaard, Steffen; Prause, Jan Ulrik;

    2012-01-01

    An amelanotic, circum-corneal nevus in a 2-year-old child is described. The nevus presented at birth as a red spot in the nasal conjunctiva that subsequently enlarged to completely encircle the cornea. The tumour was partially removed three times, but at the age of 6 years, the nevus still covers...

  16. The response of healing corneal epithelium to grooved polymer surfaces.

    NARCIS (Netherlands)

    Evans, M.D.; McFarland, G.A.; Taylor, S.; Walboomers, X.F.

    2005-01-01

    Corneal epithelial wounds heal rapidly by the inwards growth of tissue with a contracting wound front. A synthetic polymer lens to correct refractive error (an implantable contact lens) could be incorporated into the cornea using this wound healing process. Topographical cues on the polymer surface

  17. Intrastromal corneal ring segments for management of keratoconus

    Directory of Open Access Journals (Sweden)

    Sri Ganesh

    2013-01-01

    Full Text Available Keratoconus is a progressive corneal ectasia, which can be managed both by conservative measures like glasses or contact lenses in non-progressive cases or surgical procedures like collagen crosslinking (CXL with or without adjuvant measures like intrastromal corneal rings segments (ICRS or topography guided ablation. Various kinds of ICRS are available to the surgeon, but it is most essential to be able to plan the implantation of the ring to optimize outcomes. Aims: The aim of this study is to evaluate the visual outcome and progression in patients of keratoconus implanted with ICRS. Materials and Methods: Two different types of ICRS-Intacs (Addition Technology and Kerarings (Mediphacos Inc. were implanted in 2 different cohorts of patients and were followed-up to evaluate the outcome of the procedure. All patients underwent a complete ocular examination including best spectacle corrected visual acuity, slit lamp examination fundus examination, corneal topography and pachymetry. The ICRS implantation is done with CXL to stop the progression of the disease. Improvement in uncorrected visual acuity (UCVA, best spectacle corrected visual acuity and topographic changes were analyzed. Results: A significant improvement in keratometry and vision was seen in both groups. Conclusion: ICRS have been found to reduce corneal irregularity and flatten keratometry with improvement in UCVA and best corrected visual acuity.

  18. Corneal biomechanical changes following toric soft contact lens wear

    Directory of Open Access Journals (Sweden)

    Somayeh Radaie-Moghadam

    2016-01-01

    Conclusion: CH and CRF decreased significantly one month after fitting toric soft contact lenses while CCT and K mean did not change significantly. Corneal biomechanical parameters may alter with toric soft contact lens use and such changes may have implications with long-term use such lenses.

  19. Corneal manifestations of selected systemic diseases: A review

    Directory of Open Access Journals (Sweden)

    Wayne D.H. Gillan

    2015-03-01

    Full Text Available The corneal manifestations of several selected systemic diseases are reviewed. Metabolic, immunologic and inflammatory and infectious diseases are included. A brief overview of each disease and how it manifests in the cornea is discussed. The importance of conducting a slit-lamp examination on every patient is emphasised.

  20. A comparison between keratoconus and normal population based corneal endothelium

    Directory of Open Access Journals (Sweden)

    Mohamad Aghazade Amiri

    2015-07-01

    Conclusion: Keratoconus does not have any considerable effect on cell density, polymegethism and pleomorphism, in mild and moderate stages and corneal opacity risk caused by intraocular surgeries (such as: Cataract or Glaucoma surgeries and some diseases (such as diabetes and uveitis is similar in keratoconic and normal eyes.

  1. Vignetting and Field of View with the KAMRA Corneal Inlay

    Directory of Open Access Journals (Sweden)

    Achim Langenbucher

    2013-01-01

    Full Text Available Purpose. To evaluate the effect of the KAMRA corneal inlay on the retinal image brightness in the peripheral visual field. Methods. A KAMRA inlay was “implanted” into a theoretical eye model in a corneal depth of 200 microns. Corneal radius was varied to a steep, normal, and flat (7.37, 7.77, and 8.17 mm version keeping the proportion of anterior to posterior radius constant. Pupil size was varied from 2.0 to 5.0 mm. Image brightness was determined for field angles from −70° to 70° with and without KAMRA and proportion of light attenuation was recorded. Results. In our parameter space, the attenuation in brightness ranges in between 0 and 60%. The attenuation in brightness is not affected by corneal shape. For large field angles where the incident ray bundle is passing through the peripheral cornea, brightness is not affected. For combinations of small pupil sizes (2.0 and 2.5 mm and field angles of 20–40°, up to 60% of light may be blocked with the KAMRA. Conclusion. For combinations of pupil sizes and field angles, the attenuation of image brightness reaches levels up to 60%. Our theoretical findings have to be clinically validated with detailed investigation of this vignetting effect.

  2. In Vivo Confocal Microscopy expanding horizons in corneal imaging

    NARCIS (Netherlands)

    T. Hillenaar (Toine)

    2012-01-01

    textabstractConfocal microscopy is an emerging optical technique that allows the living human cornea to be imaged on a cellular level. As such, confocal microscopy enables morphologic and quantitative analysis of corneal resident cells in health and disease and provides an exciting bridge between in

  3. 角膜生物力学分析仪与Goldmann眼压计眼压测量对比研究%Comparative study of corneal biomechanics analyzer and Goldmann applanadon tonometry in nonglaucomatous eyes

    Institute of Scientific and Technical Information of China (English)

    王家松; 张明昌; 张晓昭

    2013-01-01

    Objective To investigate the correlation of intraocular pressure (IOP) obtained by OCULUS Corvis ST comeal biomechanics analyzer (OCS) and Goldmann planation tonometry (GAT)in non-glaucomatous for central corneal thickness (CCT) and to evaluate the agreement and the interchangeablity of the IOP values obtained by the two instrument.Methods In a randomized order two or three consecutive IOP measurements were performed on 64 eyes of 32 non-glaucomatous subjects by one examiner using the two instruments.Furthermore,the CCT was obtained by OCULUS Corvis ST corneal analyzer.The matched t-test was determined to compare IOP readings between OCS and GAT.CCT and OCS/GAT IOP values.Bland-Altman analysis was applied to evaluate the agreement between the instruments.Results Mean IOP values obtained by both instruments were no significantly difference in different central corneal thickness (CCT<520m,n =12,t =-0.15,P >0.05; 520m<CCT<580m,n =44,t =0.12,P >0.05; CCT>580□m,n =8,t =0.59,P >0.05).Conclusions There are no significantly difference among the two instruments,and the correlation of them are high.They may replace each other in some kind of degree.%目的 探讨在不同的中央角膜厚度(CCT)下OCULUS Corvis ST角膜生物力学分析仪(OCS)与Goldmann压平眼压计(GAT)眼压(IOP)测量值的相关性,评价两者测量值的一致性及临床上两种眼压计测量值相互替换的可能性,为临床应用提供参考.方法 非青光眼病例32例(64只眼)分别用OCS和GAT进行眼压测量,两种仪器的测量顺序随机.同时用OCS测量CCT.OCS与GAT眼压测量值的相关性采用配对t检验,Bland-Altman分析法评价两种仪器IOP测量值的一致性.结果 在不同角膜厚度情况下,OCS与GAT的IOP测量值差异无统计学意义(CCT≤520.μm,n=12,t =-0.15,P>0.05;520 μm<CCT≤580 μm, n=44,t=0.12,P>0.05;CCT>580 μm,n=8,t =0.59,P>0.05).结论 两种方法测量的眼压值差异无统计学意义,且具有较好的

  4. Caveolin-1 associated adenovirus entry into human corneal cells.

    Directory of Open Access Journals (Sweden)

    Mohammad A Yousuf

    Full Text Available The cellular entry of viruses represents a critical area of study, not only for viral tropism, but also because viral entry dictates the nature of the immune response elicited upon infection. Epidemic keratoconjunctivitis (EKC, caused by viruses within human adenovirus species D (HAdV-D, is a severe, ocular surface infection associated with corneal inflammation. Clathrin-mediated endocytosis has previously been shown to play a critical role in entry of other HAdV species into many host cell types. However, HAdV-D endocytosis into corneal cells has not been extensively studied. Herein, we show an essential role for cholesterol rich, lipid raft microdomains and caveolin-1, in the entry of HAdV-D37 into primary human corneal fibroblasts. Cholesterol depletion using methyl-β-cyclodextrin (MβCD profoundly reduced viral infection. When replenished with soluble cholesterol, the effect of MβCD was reversed, allowing productive viral infection. HAdV-D37 DNA was identified in caveolin-1 rich endosomal fractions after infection. Src kinase activity was also increased in caveolin-1 rich endosomal fractions after infection, and Src phosphorylation and CXCL1 induction were both decreased in caveolin-1-/- mice corneas compared to wild type mice. siRNA knock down of caveolin-1 in corneal cells reduced chemokine induction upon viral infection, and caveolin-1-/- mouse corneas showed reduced cellular entry of HAdV-D37. As a control, HAdV-C2, a non-corneal pathogen, appeared to utilize the caveolar pathway for entry into A549 cells, but failed to infect corneal cells entirely, indicating virus and cell specific tropism. Immuno-electron microscopy confirmed the presence of caveolin-1 in HAdV-D37-containing vesicles during the earliest stages of viral entry. Collectively, these experiments indicate for the first time that HAdV-D37 uses a lipid raft mediated caveolin-1 associated pathway for entry into corneal cells, and connects the processes of viral entry with

  5. 单眼弱视儿童视网膜神经纤维层和黄斑中心凹厚度分析%Thickness of retinal nerve fiber layer and central fovea of macula in children with unilateral amblyopia

    Institute of Scientific and Technical Information of China (English)

    傅扬; 唐敏; 孙晓东; 许迅

    2012-01-01

    Objective To compare the thickness of peripapillary retinal nerve fiber layer ( RNFL) and central fovea of macula between amblyopic eyes and non-amblyopic eyes in children with unilateral amblyopia. Methods Twenty-three children with unilateral amblyopia were selected, the thickness of RNFL around optic disk ( superior, temporal, inferior and nasal quadrants) and mean thickness of RNFL were measured by optical coherence tomography ( OCT ) , the mean thickness of central fovea of 1 mm in diameter and the smallest thickness of cental fovea of macula were examined, and the differences between amblyopic eyes and non-amblyopic eyes were compared. Results The thickness of RNFL in the temporalquadrant in amblyopic eyes was smaller than that in non-amblyopic eyes (t = -4.671, P =0.000 1), while there was no significant difference in the thickness of RNFL in the superior, inferior or nasal quadrants and the mean thickness of RNFL between amblyopic eyes and non-amblyopic eyes (P >0.05) . There was no significant difference in the mean thickness of fovea of 1 mm in diameter between amblyopic eyes and non-amblyopic eyes (t = 0. 082 3, P = 0. 935 1) , while the smallest thickness in central fovea of macula in amblyopic eyes was smaller than that in non-amblyopic eyes (t = -2. 371 0, P = 0.026 9). Conclusion There exist differences in peripapillary RNFL and structure of macula between amblyopic eyes and non-amblyopic eyes in children with unilateral amblyopia.%目的 比较单眼弱视儿童弱视眼与非弱视眼的视盘周围神经纤维层(RNFL)和黄斑中心凹厚度的差异.方法 选取单眼弱视儿童23人,利用光学相干断层扫描(OCT)技术分别检测双眼视盘上方、颞侧、下方、鼻侧4个象限RNFL厚度及RNFL平均厚度,检测黄斑中心凹1 mm直径区域平均厚度和黄斑中心凹最小厚度,比较同一受检者弱视眼与非弱视眼的差异.结果 弱视眼视盘颞侧象限RNFL厚度小于非弱视眼(t=-4.671,P=0.000 1),而视盘

  6. Corneal collagen crosslinking in keratoconus and other eye disease

    Institute of Scientific and Technical Information of China (English)

    Adel; Alhayek; Pei-Rong; Lu

    2015-01-01

    Keratoconus is a condition characterized by biomechanical instability of the cornea, presenting in a progressive, asymmetric and bilateral way. Corneal collagen crosslinking(CXL) with riboflavin and Ultraviolet-A(UVA) is a new technique of corneal tissue strengthening that combines the use of riboflavin as a photo sensitizer and UVA irradiation. Studies showed that CXL was effective in halting the progression of keratoconus over a period of up to four years. The published studies also revealed a reduction of max K readings by more than 2 D, while the postoperative spherical equivalent(SEQ) was reduced by an average of more than 1 D and refractive cylinder decreased by about1 D. The major indication for the use of CXL is to inhibit the progression of corneal ecstasies, such as keratoconus and pellucid marginal degeneration. CXL may also be effective in the treatment and prophylaxis of iatrogenic keratectasia, resulting from excessively aggressive photo ablation. This treatment has been used to treat infectious corneal ulcers with apparent favorable results. Most recent studies demonstrate the beneficial impact of CXL for iatrogenic ecstasies, pellucid marginal degeneration, infectious keratitis, bullous keratopathy and ulcerative keratitis. Several long-term and short-term complications of CXL have been studied and documented. The possibility of a secondary infection after the procedure exists because the patient is subject to epithelial debridement and the application of a soft contact lens. Formation of temporary corneal haze,permanent scars, endothelial damage, treatment failure,sterile infiltrates, bullous keratopathy and herpes reactivation are the other reported complications of this procedure.

  7. Evaluation of intrastromal corneal ring segments for treatment of post-LASIK ectasia patients with a mechanical implantation technique

    Directory of Open Access Journals (Sweden)

    Zeki Tunc

    2011-01-01

    Full Text Available Aim: To evaluate the clinical outcomes of Keraring segment implantation in patients with post- laser-assisted in situ keratomileusis (LASIK ectasia, using a mechanical implantation technique. Materials and Methods: Twelve eyes of 10 patients with post-LASIK ectasia were enrolled. Intracorneal ring segments (ICRS were implanted after dissection of the tunnel using Tunc′s specially designed dissector under suction. A complete ophthalmic examination was performed, including uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, spherical equivalent, keratometric (K readings, inferosuperior asymmetry index (ISAI, and ultrasound pachymetry. All 3, 6, and 12-month follow-ups were completed, and statistical analysis was performed. Results: The mean preoperative UDVA for all eyes was 1.28 ± 0.59 logMAR. At 12 months, the mean UDVA was 0.36 ± 0.19 logarithm of the Minimum Angle of Resolution (logMAR (P=0.002, and the mean preoperative CDVA was 0.58 ± 0.3 logMAR, which improved to 0.15 ± 0.12 (P=0.002 at 1 year. There was a significant reduction in cylindrical refractive and spherical equivalent refractive error from -5.29 ± 2.47 diopters (D and -5.54 ± 5.04 D preoperatively to -1.47 ± 0.71 D and -0.74 ± 1.07 D (P=0.001, P=0.002, respectively, at 1 year. In the same period, the mean K- readings improved from 47.93 ± 4.84 D to 40.87 ± 2.36 D (P=0.002, and the mean ISAI improved from 5.34 ± 3.05 to 2.37 ± 1.68 (P=0.003. No significant changes in mean central corneal thickness were observed postoperatively. There were no major complications during or after surgery. Conclusion: ICRS implantation using a unique mechanical dissection technique is a safe and effective treatment for post-LASIK ectasia. All parameters showed improvement at 1-year follow-up.

  8. Accuracy of corneal trephination depth using the Moria single-use adjustable depth vacuum trephine system

    Directory of Open Access Journals (Sweden)

    Fenzl CR

    2014-11-01

    Full Text Available Carlton R Fenzl,1 Adam J Gess,2 Majid Moshirfar31John A Moran Eye Center, University of Utah, Salt Lake City, UT, 2Eye Doctors of Washington, Washington, DC, 3Cornea and Refractive Surgery Division, Department of Ophthalmology, Francis I Proctor Foundation, University of California San Francisco, San Francisco, CA, USABackground: The Moria single-use adjustable depth trephine is a device that allows a goal trephination depth to be set prior to the surgical procedure.Methods: Eleven fresh human cadaveric eyes were trephined using 8.0 mm Moria single-use adjustable vacuum trephines. Prior to trephination, the average corneal pachymetry in the peripheral 7–10 mm range was obtained using anterior segment optical coherence tomography. The trephination depth was set to 80% of that value. Light microscopy was used to image anteroposterior cross-sections of each corneal specimen. Digital protractor software was used to evaluate the trephination angle, depth, and length. All adequately processed specimens were included in the analysis. In addition, trephination angle data from a previous publication by Moshirfar et al were used as a comparison with those of this study.Results: Trephination analysis of depth compared with pachymetry revealed a mean of 83.7%±6.53% (95% confidence interval 79.8–87.6. Maximum and minimum trephined depths were 95.35% and 71.3%, respectively. Trephination depth compared with angular corneal thickness yielded a mean of 66.2%±4.79% (95% confidence interval 63.0–69.4. Maximum and minimum depths were 73.7% and 59.7%, respectively. Analysis of trephination angle yielded a mean of 130.2±3.57 degrees (95% confidence interval 127.8–132.61. Maximum and minimum angles were 135.5 degrees and 126 degrees, respectively. The standard deviation of the trephination angle of the Moria trephine was found to be significantly less than that of Hessburg-Barron and Hanna trephines calculated in the previous study.Conclusion: The Moria

  9. Thick film hydrogen sensor

    Science.gov (United States)

    Hoffheins, Barbara S.; Lauf, Robert J.

    1995-01-01

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors.

  10. Education and "Thick" Epistemology

    Science.gov (United States)

    Kotzee, Ben

    2011-01-01

    In this essay Ben Kotzee addresses the implications of Bernard Williams's distinction between "thick" and "thin" concepts in ethics for epistemology and for education. Kotzee holds that, as in the case of ethics, one may distinguish between "thick" and "thin" concepts of epistemology and, further, that this distinction points to the importance of…

  11. Review of developments in corneal transplantation in the regions of Brazil - Evaluation of corneal transplants in Brazil

    Science.gov (United States)

    Almeida, Hirlana Gomes; Hida, Richard Yudi; Kara-Junior, Newton

    2016-01-01

    The aim of this study was to identify inequalities in corneal donation and transplantation among the regions of Brazil. A transversal and retrospective study was specifically conducted using data from the Brazilian Transplant Registry collected by the Brazilian Association of Organ Transplantation between January 2002 and December 2014. The collected data were processed using descriptive statistical methods, and ptransplants, the annual rate of transplants per million people and the percentage of needed transplants performed in each of the five regions of Brazil. Family refusal and medical contraindication were the most frequent reasons for a lack of corneal donation. Although remarkable progress has been made in the last decade in each of the five Brazilian regions, health professionals’ lack of preparation to approach families with donation requests at the death of a family member appears to be the main obstacle to increasing the number of corneal donations. Thus, the present study suggests the implementation of public policies to make corneal transplants more effective, particularly given that there are considerable disparities in the effectiveness with which regional needs are met and in health professionals’ ability to perform transplants among the Brazilian regions, with higher rates in the South, Southeast and Midwest regions and lower rates in the North and Northeast regions. PMID:27652836

  12. Anterior Lamina Cribrosa Surface Depth in Open-Angle Glaucoma: Relationship with the Position of the Central Retinal Vessel Trunk

    Science.gov (United States)

    Oh, Baek-Lok; Kim, Hyunjoong; Girard, Michaël J. A.; Mari, Jean Martial; Kim, Tae-Woo

    2016-01-01

    Purpose To determine the factors influencing the anterior lamina cribrosa (LC) surface depth (LCD) in patients with open-angle glaucoma (OAG), focusing on the association between LCD and the position of the central retinal vessel trunk (CRVT) at the anterior LC surface. Methods Optic nerve heads of 205 OAG eyes were scanned using swept-source optical coherence tomography (SS-OCT). After processing the images using adaptive compensation, the LCD was determined from 11 horizontal B-scan images that divided the optic disc vertically into 12 equal parts. Eyes were divided into two groups (central or peripheral) according to where the CRVT exits from the anterior LC surface. The influence of CRVT position on LCD was evaluated, taking into account age, gender, untreated intraocular pressure (IOP), IOP at optic-disc scanning, retinal nerve fiber layer (RNFL) thickness, visual-field mean deviation, central corneal thickness, and axial length. Results Patients in the peripheral CRVT group were younger and more myopic, and had a larger mean LCD and thinner global RNFL than those in the central CRVT group (all P≤0.023). On multivariate analysis, the peripheral CRVT location was significantly associated with a larger LCD (P = 0.002), together with the significant association of younger age (P<0.001), higher untreated IOP (P = 0.010), and thinner RNFL (P = 0.003) on the larger LCD. Conclusion In OAG, CRVT location was an independent factor influencing the LCD, together with age, untreated IOP, and global RNFL thickness. The data indicate that the CRVT may contribute to the resistance of the LC against deformation. A longitudinal prospective observation is required to clarify this relationship. PMID:27355646

  13. Brm inhibits the proliferative response of keratinocytes and corneal epithelial cells to ultraviolet radiation-induced damage.

    Directory of Open Access Journals (Sweden)

    Nur Mohammad Monsur Hassan

    Full Text Available Ultraviolet radiation (UV from sunlight is the primary cause of skin and ocular neoplasia. Brahma (BRM is part of the SWI/SNF chromatin remodeling complex. It provides energy for rearrangement of chromatin structure. Previously we have found that human skin tumours have a hotspot mutation in BRM and that protein levels are substantially reduced. Brm-/- mice have enhanced susceptibility to photocarcinogenesis. In these experiments, Brm-/- mice, with both or a single Trp53 allele were exposed to UV for 2 or 25 weeks. In wild type mice the central cornea and stroma became atrophic with increasing time of exposure while the peripheral regions became hyperplastic, presumably as a reparative process. Brm-/-, Trp53+/-, and particularly the Brm-/- Trp53+/- mice had an exaggerated hyperplastic regeneration response in the corneal epithelium and stroma so that the central epithelial atrophy or stromal loss was reduced. UV induced hyperplasia of the epidermis and corneal epithelium, with an increase in the number of dividing cells as determined by Ki-67 expression. This response was considerably greater in both the Brm-/- Trp53+/+ and Brm-/- Trp53+/- mice indicating that Brm protects from UV-induced enhancement of cell division, even with loss of one Trp53 allele. Cell division was disorganized in Brm-/- mice. Rather than being restricted to the basement membrane region, dividing cells were also present in the suprabasal regions of both tissues. Brm appears to be a tumour suppressor gene that protects from skin and ocular photocarcinogenesis. These studies indicate that Brm protects from UV-induced hyperplastic growth in both cutaneous and corneal keratinocytes, which may contribute to the ability of Brm to protect from photocarcinogenesis.

  14. Influence of HLA-A, HLA-B, and HLA-DR matching on rejection of random corneal grafts using corneal tissue for retrospective DNA HLA typing

    NARCIS (Netherlands)

    M.C. Bartels (Marjolijn); H.G. Otten; B.E. van Gelderen; A. van der Lelij (Allegonda)

    2001-01-01

    textabstractAIM: To establish if coincidental HLA-A, HLA-B, and HLA-DR tissue matching is associated with a reduced likelihood of corneal graft rejection. METHODS: Organ culture preserved random donor corneas were used for penetrating keratoplasty (PKP). Corneal tissue from all gra

  15. 有中心集中荷载作用的任意变厚度的旋转扁薄壳的非线性弯曲%Nonlinear Bending of Revolving Shallow Shells with Arbitrarily Variable Thickness Under Central Loading

    Institute of Scientific and Technical Information of China (English)

    侯朝胜

    2011-01-01

    Heretofore few research on the axisymmetrical nonlinear bending of a circular plate or a revolving shallow shell with variable thickness under a central loading has been published. With cubic B-spline and logarithmic functions taken as trial functions,for the large deflection of a circular plate and nonlinear stability of a revolving shallow shell with arbitrarily variable thickness the solutions were computed by the method of point collocation. A circular plate was studied when subjected to action of a central loading or the compound load of it and reverse uniformly distributed loads, in which the central deflection of the circular plate was zero. Under a central loading,upper and lower critical loads of shells were calculated including conical shells, spherical shells and quartic polynomial shells with linearly or polynomial variable thickness. The results of the circular plate and spherical shell of an identical thickness were compared with those obtained by other methods. Results show higher precision and wider range of convergent loads can be reached by using the spline collocation method.%中心集中荷载作用的变厚度圆板或旋转扁壳的轴对称非线性弯曲,迄今鲜见研究成果.取三次B样条函数和对数函数为试函数,用配点法计算任意变厚度圆板的大挠度和旋转扁壳的非线性稳定.计算了中心集中荷载作用的圆板及它和反向均布荷载同时作用圆板且其中心挠度为零的特殊情形.给出了中心集中荷载作用下,线性或多项式型变厚度的圆锥壳、球壳或四次多项式型旋转壳的上、下临界荷载.等厚度圆板和球壳的计算结果同其他方法的结果做了比较.结果表明样条配点法有更高的精度和更大的荷载收敛范围.

  16. Minocycline inhibits alkali burn-induced corneal neovascularization in mice.

    Directory of Open Access Journals (Sweden)

    Ou Xiao

    Full Text Available The purpose of this study was to investigate the effects of minocycline on alkali burn-induced corneal neovascularization (CNV. A total of 105 mice treated with alkali burns were randomly divided into three groups to receive intraperitoneal injections of either phosphate buffered saline (PBS or minocycline twice a day (60 mg/kg or 30 mg/kg for 14 consecutive days. The area of CNV and corneal epithelial defects was measured on day 4, 7, 10, and14 after alkali burns. On day 14, a histopathological examination was performed to assess morphological change and the infiltration of polymorphonuclear neutrophils (PMNs. The mRNA expression levels of vascular endothelial growth factor (VEGF and its receptors (VEGFRs, basic fibroblast growth factor (bFGF, matrix metalloproteinases (MMPs, interleukin-1α, 1β, 6 (IL-1α, IL-1β, IL-6 were analyzed using real-time quantitative polymerase chain reaction. The expression of MMP-2 and MMP-9 proteins was determined by gelatin zymography. In addition, enzyme-linked immunosorbent assay was used to analyze the protein levels of VEGFR1, VEGFR2, IL-1β and IL-6. Minocycline at a dose of 60 mg/kg or 30 mg/kg significantly enhanced the recovery of the corneal epithelial defects more than PBS did. There were significant decreases of corneal neovascularization in the group of high-dosage minocycline compared with the control group at all checkpoints. On day 14, the infiltrated PMNs was reduced, and the mRNA expression of VEGFR1, VEGFR2, bFGF, IL-1β, IL-6, MMP-2, MMP-9, -13 as well as the protein expression of VEGFR2, MMP-2, -9, IL-1β, IL-6 in the corneas were down-regulated with the use of 60 mg/kg minocycline twice a day. Our results showed that the intraperitoneal injection of minocycline (60 mg/kg b.i.d. can significantly inhibit alkali burn-induced corneal neovascularization in mice, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors, inflammatory cytokines and MMPs.

  17. Hevin plays a pivotal role in corneal wound healing.

    Directory of Open Access Journals (Sweden)

    Shyam S Chaurasia

    Full Text Available BACKGROUND: Hevin is a matricellular protein involved in tissue repair and remodeling via interaction with the surrounding extracellular matrix (ECM proteins. In this study, we examined the functional role of hevin using a corneal stromal wound healing model achieved by an excimer laser-induced irregular phototherapeutic keratectomy (IrrPTK in hevin-null (hevin(-/- mice. We also investigated the effects of exogenous supplementation of recombinant human hevin (rhHevin to rescue the stromal cellular components damaged by the excimer laser. METHODOLOGY/PRINCIPAL FINDINGS: Wild type (WT and hevin (-/- mice were divided into three groups at 4 time points- 1, 2, 3 and 4 weeks. Group I served as naïve without any treatment. Group II received epithelial debridement and underwent IrrPTK using excimer laser. Group III received topical application of rhHevin after IrrPTK surgery for 3 days. Eyes were analyzed for corneal haze and matrix remodeling components using slit lamp biomicroscopy, in vivo confocal microscopy, light microscopy (LM, transmission electron microscopy (TEM, immunohistochemistry (IHC and western blotting (WB. IHC showed upregulation of hevin in IrrPTK-injured WT mice. Hevin (-/- mice developed corneal haze as early as 1-2 weeks post IrrPTK-treatment compared to the WT group, which peaked at 3-4 weeks. They also exhibited accumulation of inflammatory cells, fibrotic components of ECM proteins and vascularized corneas as seen by IHC and WB. LM and TEM showed activated keratocytes (myofibroblasts, inflammatory debris and vascular tissues in the stroma. Exogenous application of rhHevin for 3 days reinstated inflammatory index of the corneal stroma similar to WT mice. CONCLUSIONS/SIGNIFICANCE: Hevin is transiently expressed in the IrrPTK-injured corneas and loss of hevin predisposes them to aberrant wound healing. Hevin (-/- mice develop early corneal haze characterized by severe chronic inflammation and stromal fibrosis that can be rescued

  18. Ocean Sediment Thickness Contours

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean sediment thickness contours in 200 meter intervals for water depths ranging from 0 - 18,000 meters. These contours were derived from a global sediment...

  19. Deformidade corneana em usuário de lente de contato portador de ceratocone: relato de caso Corneal warpage in contact lens wearer with keratoconus: a case report

    Directory of Open Access Journals (Sweden)

    César Lipener

    1999-12-01

    Full Text Available Introdução: Alterações topográficas podem ocorrer secundariamente ao uso de uso de lentes de contato duras ou gelatinosas. O termo "corneal warpage" é utilizado para denominar as deformidades corneanas causadas pelas lentes. O quadro topográfico da fase inicial do ceratocone pode ser muito parecido com o de um paciente com este quadro. Objetivo: Mostrar um paciente portador de ceratocone, usuário de lentes de contato rígida gás-permeável (RGP que desenvolveu quadro de "corneal warpage", diagnosticado e acompanhado por topografias e exames clínicos seriados. Relato de caso: O paciente é um engenheiro de 40 anos com diagnóstico de ceratocone bilateral há 12 anos, usando lentes RGP desde então. No primeiro exame em 5/95, a refração de OD foi impossível de se determinar e a ceratometria era maior que 60,00 D. Foi feita topografia, que se mostrou compatível com ceratocone, tendo sido adaptada uma lente Soper, com visão de 20/70. Após um ano, uma topografia de controle mostrou aumento da curvatura central e aplanamento da periferia inferior. O uso da lente foi suspenso e após 6 meses houve regressão das mudanças, tendo sido adaptadas novas lentes com melhor padrão e visão de 20/40. Discussão: O caso apresentado evidencia a ocorrência de deformidade corneana em um portador de ceratocone usuário de lente RGP. O autor discute a fisiopatologia e o diagnóstico clínico e topográfico do "corneal warpage", lembrando que a exemplo de pacientes normais, os pacientes com ceratocone podem apresentar estas alterações, que devem ser diferenciadas da própria evolução da doença.Introduction: Topographical alterations may occur as a secondary result of the use of hard or soft contact lenses. The expression corneal warpage is used to describe the corneal deformities caused by the lenses. Topographical map of initial keratoconus can be very similar to that of a patient with corneal warpage. Purpose: To describe a contact lens

  20. Gelam honey potentiates ex vivo corneal keratocytes proliferation with desirable phenotype expression

    OpenAIRE

    Yusof, Alia Md; Abd Ghafar, Norzana; Kamarudin, Taty Anna; Hui, Chua Kien; Yusof, Yasmin Anum Mohd

    2016-01-01

    Background This study aimed to evaluate the effects of Gelam honey on corneal keratocytes proliferative capacity and phenotypic characterization via MTT assay, gene expression and immunocytochemistry. Methods Corneal keratocytes from New Zealand white rabbits were cultured in basal medium (BM) and serum enriched medium (BMS). Serial dilutions of Gelam honey (GH) were added to both media and cells were cultured until passage 1. MTT assay was performed on corneal keratocytes in both media to as...

  1. Human limbal biopsy–derived stromal stem cells prevent corneal scarring

    OpenAIRE

    Basu, Sayan; Hertsenberg, Andrew J.; Funderburgh, Martha L.; Burrow, Michael K.; Mann, Mary M.; Du, Yiqin; Lathrop, Kira L.; Syed-Picard, Fatima N.; Adams, Sheila M.; Birk, David E.; Funderburgh, James L.

    2014-01-01

    Conventional allograft therapy for corneal scarring is widespread and successful, but donor tissue is not universally available, and some grafts fail owing to rejection and complications such as endothelial failure. We investigated direct treatment of corneal scarring using autologous stem cells, a therapy that, if successful, could reduce the need for corneal grafts. Mesenchymal cells were expanded from small superficial, clinically replicable limbal biopsies of human cadaveric corneo-sclera...

  2. Risk Factors for Senile Corneal Arcus in Patients with Acute Myocardial Infarction

    OpenAIRE

    Moosavi, Mirnaghi; Sareshtedar, Ahmad; Zarei-Ghanavati, Siamak; Zarei-Ghanavati, Mehran; Ramezanfar, Nazanin

    2010-01-01

    Purpose To investigate the association between senile corneal arcus and atherosclerosis risk factors in patients with recent acute myocardial infarction. Methods In this cross sectional study, atherosclerosis risk factors including fasting blood sugar, total cholesterol and triglyceride levels were measured in 165 patients with recent (less than three months’ duration) acute myocardial infarction. Slitlamp examination was performed to detect corneal arcus. Associations between senile corneal ...

  3. Pirfenidone nanoparticles improve corneal wound healing and prevent scarring following alkali burn.

    Directory of Open Access Journals (Sweden)

    Sushovan Chowdhury

    Full Text Available PURPOSE: To evaluate the effects of pirfenidone nanoparticles on corneal re-epithelialization and scarring, major clinical challenges after alkali burn. METHODS: Effect of pirfenidone on collagen I and α-smooth muscle actin (α-SMA synthesis by TGFβ induced primary corneal fibroblast cells was evaluated by immunoblotting and immunocytochemistry. Pirfenidone loaded poly (lactide-co-glycolide (PLGA nanoparticles were prepared, characterized and their cellular entry was examined in primary corneal fibroblast cells by fluorescence microscopy. Alkali burn was induced in one eye of Sprague Dawley rats followed by daily topical treatment with free pirfenidone, pirfenidone nanoparticles or vehicle. Corneal re-epithelialization was assessed daily by flourescein dye test; absence of stained area indicated complete re-epithelialization and the time for complete re-epithelialization was determined. Corneal haze was assessed daily for 7 days under slit lamp microscope and graded using a standard method. After 7 days, collagen I deposition in the superficial layer of cornea was examined by immunohistochemistry. RESULTS: Pirfenidone prevented (P<0.05 increase in TGF β induced collagen I and α-SMA synthesis by corneal fibroblasts in a dose dependent manner. Pirfenidone could be loaded successfully within PLGA nanoparticles, which entered the corneal fibroblasts within 5 minutes. Pirfenidone nanoparticles but not free pirfenidone significantly (P<0.05 reduced collagen I level, corneal haze and the time for corneal re-epithelialization following alkali burn. CONCLUSION: Pirfenidone decreases collagen synthesis and prevents myofibroblast formation. Pirfenidone nanoparticles improve corneal wound healing and prevent fibrosis. Pirfenidone nanoparticles are of potential value in treating corneal chemical burns and other corneal fibrotic diseases.

  4. 人角膜内皮细胞增殖特性及能力的研究进展%Research progress on proliferative property and capacity of human corneal endothelium

    Institute of Scientific and Technical Information of China (English)

    潘飞; 姚玉峰

    2011-01-01

    Primary and secondary corneal endothelial decompensation leads to stromal edema,corneal opacity and loss of visual acuity. The pathogenesis of corneal endothelial decompensation is that adult corneal endothelium in vivo lacks of a robust proliferative response to injury, does not divide sufficiently to replace the lost cells. Previous studies indicate that cell-cell contact inhibition and transforming growth factor-beta2 (TGF-β2) in aqueous humor may be responsible for maintaining human endothelial cells in a non-replicative state in vivo. The results of the experimental investigation by using immunofluorescent staining of the cell cycle-associated proteins and cell proliferation marker Ki67 in corneal endothelium indicate that human corneal endothelial cells in vivo are arrested in the G1-phase and have not exited from the cell cycle. Successful outgrowth in culture of human corneal endothelial cells in vitro and the establishment of the immortalized human endothelial cell line, provide strong evidence that corneal endothelial cells retain proliferative capacity. Experiments with cell culture ex vivo demonstrate that corneal endothelial cells cultured from young donors grow more robustly than those from older donors, and cells cultured from peripheral area of corneas show greater cell density than central regions. Studies have demonstrated that in vitro human corneal endothelia undergo mitotic changes in response to stimulation of growth promoting agents,such as growth factors, EDTA and extracelluar matrix. Identification of corneal endothelial stem cells and isolation and culture of human endothelial precursor cells in vitro will be beneficial for further investigation regarding the mechanism of corneal endothelial regeneration as well as corneal endothelial cells in vitro culture.%原发性和继发性角膜内皮失代偿导致角膜基质水肿、角膜混浊和视力下降,其发生的病理生理基础在于成年人角膜内皮细胞失去增殖能力,损

  5. Topical antibiotics in the management of corneal ulcer

    Directory of Open Access Journals (Sweden)

    Reddy P

    1988-01-01

    Full Text Available A total of 82 patients suffering from corneal ulcer were treated with framycetin 0.5%, gentamicin 3 mg./ml, chloramphenicol 0.4% and a neomycin combination containing Polymixin B sulphate 5000 u, neomycin sulphate 1700 u and gramicidin 0.025 mg/mL in a Randomised comparative study. The commonest organism isolated was Staphylococcus followed by Pneumococcus, Streptococcus and Pseudomonas. The in vitro sensitivity of these isolates to framycetin was higher than that to others Framycetin produced both earlier and a greater degree of improvement in mean score of signs and symptoms than the other antibiotics. It can thus be concluded that framycetin has a better profile of antibacterial activity and clinical efficacy than some other commonly used topical antibiotics in the treatment of corneal ulcer.

  6. Transient Anisocoria after Corneal Collagen Cross-Linking

    Directory of Open Access Journals (Sweden)

    George D. Kymionis

    2014-01-01

    Full Text Available Purpose. To report a case with transient anisocoria after corneal collagen cross-linking (CXL. Methods. Case report. Results. A 24-year-old male underwent corneal collagen cross-linking (CXL in his right eye for keratoconus. At the end of the procedure, the pupil of the treated eye was irregular and dilated, while the pupil of the fellow eye was round, regular, and reactive (anisocoria. The following day, pupils were round, regular, and reactive in both eyes. Conclusion. Anisocoria may be a transient and innocuous complication after CXL. A possible cause for this complication might be the anesthetic drops used before and during the surgical procedure or/and the ultraviolet A irradiation during the treatment.

  7. Research Progress in Corneal Cross-linking Agents

    Institute of Scientific and Technical Information of China (English)

    Na Li; Xiujun Peng; Zhengjun Fan

    2014-01-01

    Corneal collagen cross-linking with UVA-riboflavin is cur-rently the only method for preventing the progression of kera-toconus from the pathological perspective. Topical application of a direct cross-linking agent is now attracting widespread at-tention in clinical settings..This article reviews the research progress in the application of indirect or direct cross-linking agents (e.g., riboflavin, glucose, ribose, glutaraldehyde, formaldehyde,.glyceraldehyde,.short chain aliphatic β-nitro alcohol, and genipin) in the treatment of corneal diseases and analyzes the cross-linking efficacy,.toxicity,.and merits and disadvantages of each cross-linking agent,.providing clinical information for further studies.

  8. Recurrent corneal ulceration in presence of synthetic microfibrils

    Directory of Open Access Journals (Sweden)

    Barsam A

    2011-06-01

    Full Text Available A Barsam1, N Patel1, H Laganowski2, HD Perry31Moorfields Eye Hospital, London, UK; 2Department of Ophthalmology, Queen Mary's Hospital, Sidcup, Kent, UK; 3Ophthalmic Consultants of Long Island, Nassau University, Long Island, NY, USAAbstract: Recurrence of microbial keratitis in the presence of protozoal infection is very rare and infrequently reported unless p