Sample records for corneal blindness working

  1. Turning the tide of corneal blindness

    Directory of Open Access Journals (Sweden)

    Matthew S Oliva


    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.

  2. Corneal blindness and current major treatment concern-graft scarcity

    Directory of Open Access Journals (Sweden)

    Kah Hie Wong


    Full Text Available According to World Health Organization, the global prevalence of blindness in 2010 was 39 million people, among which 4% were due to corneal opacities. Often, the sole resort for visual restoration of patients with damaged corneas is corneal transplantation. However, despite rapid developments of surgical techniques, instrumentations and immunosuppressive agents, corneal blindness remains a prevalent global health issue. This is largely due to the scarcity of good quality corneal grafts. In this review, the causes of corneal blindness, its major treatment options, and the major contributory factors of corneal graft scarcity with potential solutions are discussed.

  3. Prevalence and associated factors of corneal blindness in Ningxia in northwest China

    Directory of Open Access Journals (Sweden)

    Xun-Lun Sheng


    Full Text Available AIM:To describe the prevalence and demographic characteristics of corneal blindness in an urban and rural region of Ningxia, located in the northwest part of China.METHODS:A stratified, randomized sampling procedure was employed in the study, including urban and rural area of all age group. Visual acuity, anterior segment and ocular fundus were checked. Related factor of corneal disease, including age, gender, education status, ethnic group, location and occupation, were identified according to uniform customized protocol. An eye was defined to be corneal blindness if the visual acuity was <20/400 due to a corneal disease.RESULTS:Three thousand individuals (1290 from urban area and 1710 from rural area participated in the investigation, with a response rate of 80.380%. The prevalence of corneal blindness was 0.023% in both eyes and 0.733% in at least one eye. The blindness in at least one eye with varied causes was present in 106 participants (3.533% and in bilateral eyes in 34 participants (1.133%. The corneal diseases accounted for 20.754% of blindness in at least one eye and 20.588% of bilateral blindness. The prevalence of corneal disease was higher in older and Han ethnic group, especially those who occupied in agriculture and outdoor work. People with corneal blindness were more likely to be older and lower education. Rural population were more likely to suffer from bilateral corneal blindness than the urban population in ≥59-year group (χ2=6.716, P=0.019. Infectious, trauma and immune corneal disease were the three leading causes of corneal disease. Trauma corneal disease was more likely leading to blindness in one eye. However, infectious and immune corneal diseases make more contribution to the bilateral corneal blindness.CONCLUSION: Corneal blindness is a significant burden of in Ningxia population, encompassing a variety of corneal infections and trauma; the majority of those were avoidable. Health promotion strategies and good


    Directory of Open Access Journals (Sweden)

    E. Ramadevi


    Full Text Available BACKGROUND Corneal disease is responsible for less than 2% of blindness in children in industrialised countries. In poor countries of the world, corneal scarring occurs due to vitamin A deficiency, measles and ophthalmia neonatorum. Thus, corneal disease is an important cause of blindness among children living in developing nations, which already carry a major burden of blindness. The aim of the study is to study the1. Prevalence of corneal blindness in the paediatric age group. 2. Causes of corneal blindness in the paediatric age group. 3. Morbidity of corneal blindness in the paediatric age group. MATERIALS AND METHODS It was cross-sectional observational study. Study Period- December 2014 to August 2016. Study Done- Government General Hospital, Kakinada. Sample Size- 50 patients. Inclusion Criteria- Children of age group 6 to 12 years with corneal blindness who have attended the outpatient department during the study period. Exclusion Criteria- Children with childhood blindness other than corneal pathology. Study Tools- Predesigned, semi-structured questionnaire regarding age, sex and age of onset of visual loss, laterality, history of ocular injury, vitamin A immunisation, family history of consanguinity and place of residence and socioeconomic status was taken. Visual acuity was measured using an E optotype and Landolt broken C chart with best corrected vision. Visual loss was classified according to the WHO categories of visual impairment. Ophthalmic examination was done by slit lamp and B scan. RESULTS Ocular trauma and corneal ulcers are most common cause of corneal blindness. 84% of corneal blindness cases were preventable and curable. CONCLUSION Trauma was the commonest cause of corneal blindness followed by infectious keratitis. 84% of corneal blindness was preventable and curable. Most causes of corneal blindness were avoidable.

  5. Corneal optics after reading, microscopy and computer work. (United States)

    Collins, Michael J; Buehren, Tobias; Bece, Andrej; Voetz, Stephanie C


    To compare lid-induced changes in corneal optics following reading, microscopy and computer work. Nine subjects with normal ocular health were recruited for the study. Five subjects were myopic, two were emmetropic, one was astigmatic and one was hyperopic. Corneal topography was measured before and after 60 mins of reading a novel, performing a blood cell counting task on a microscope and Internet searching. Corneal topography data were used to derive the corneal wavefront Zernike coefficients up to the fourth order. A meridian analysis of instantaneous corneal power along the upper 90-degree semi-meridian was performed to examine local changes caused by eyelid pressure. Digital photography was used to capture body posture and eyelid position during the tasks. Each of the three tasks showed systematically different effects on both the characteristics and location of corneal topography changes. Reading and microscopy generally exhibited larger and more centrally located changes compared with the computer task. Differences in wavefront aberration characteristics between the three tasks were apparent in both lower and higher order aberrations. The location of corneal distortions differed significantly between microscopy and computer work, with microscopy causing distortions to occur closer to the videokeratoscope measurement axis compared with computer work (p = 0.015). Reading, microscopy and computer work have different effects on corneal aberrations. The results are in agreement with the hypothesis that lid-induced corneal aberrations may play a role in myopia development.

  6. Prevalence and Determinants of Corneal Blindness in a Semi-Urban ...

    African Journals Online (AJOL)


    Jul 26, 2017 ... Purpose: To determine the prevalence and determinants of corneal blindness in a semi-urban population of Southwest Nigeria. Materials and Methods: This population-based, cross-sectional study was conducted over a period of two months from 3rd March to. 30th April 2014. A multi-stage sampling ...

  7. factors influencing corneal blindness in children in a rural communi

    African Journals Online (AJOL)


    Clinical Lecturer, MSc Course Director for Community Eye Health, International Centre for Eye Health, London School of. 2. Hygiene and ..... A-rich foods. Box 4. Measles and Blindness ...our women are conscious of the fact that measles affects the eyes. That is why they use uli (local indigo dye) to paint the eyes in a bid.

  8. Our experience with Solcoseryl Eye-Gel in the treatment of corneal lesions. A randomised double-blind study (with 1 color plate). (United States)

    Erbe, W; Herrmann, R; Körner, W F; Rohde-Germann, H; Straub, W


    A comparative study of Solcoseryl Eye-Gel versus a 2.4% cysteine eye-gel was carried out under controlled conditions (randomised and double-blind) on a total of 61 patients with corneal lesions (52 foreign body injuries, 9 corneal erosions). The results showed a marked superiority of Solcoseryl Eye-Gel with respect to more rapid healing and also with respect to the possible subsequent development of a corneal macula.

  9. Corneal dystrophies

    Directory of Open Access Journals (Sweden)

    Klintworth Gordon K


    diseases (mucopolysaccharidoses, lipidoses, mucolipidoses, and several skin diseases (X-linked ichthyosis, keratosis follicularis spinolosa decalvans. The management of the corneal dystrophies varies with the specific disease. Some are treated medically or with methods that excise or ablate the abnormal corneal tissue, such as deep lamellar endothelial keratoplasty (DLEK and phototherapeutic keratectomy (PTK. Other less debilitating or asymptomatic dystrophies do not warrant treatment. The prognosis varies from minimal effect on the vision to corneal blindness, with marked phenotypic variability.

  10. Corneal Laceration

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    Full Text Available ... What Is Corneal Laceration? Corneal Laceration Symptoms What Causes Corneal Laceration? Corneal Laceration Diagnosis Corneal Laceration Treatment ... the corneal laceration is deep enough it can cause a full thickness laceration. This is when the ...

  11. 20 CFR 404.1584 - Evaluation of work activity of blind people. (United States)


    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Evaluation of work activity of blind people... Evaluation of work activity of blind people. (a) General. If you are blind (as explained in § 404.1581), we... gainful activity are the same for blind people as for others. See § 404.1574(b)(2) for the earnings...

  12. Corneal Ulcer (United States)

    ... Stories Español Eye Health / Eye Health A-Z Corneal Ulcer Sections What Is a Corneal Ulcer? Corneal Ulcer ... Ulcer Diagnosis Corneal Ulcer Treatment What Is a Corneal Ulcer? Leer en Español: ¿Qué es una úlcera de ...

  13. Blindness (United States)

    ... Specific Prevalence Rates for Blindness by Age and Race/Ethnicity Table for 2010 U.S. Age-Specific Prevalence ... Race/Ethnicity 2010 Prevalence Rates of Blindness by Race Table for 2010 Prevalence Rates of Blindness by ...

  14. Contact Lens Related Corneal Ulcer


    Loh, KY; Agarwal, P


    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...



    Padmaja; Nageswara Rao


    Corneal ulcers are the common cause of corneal blindness. Of the corneal ulcers, majority of the cases are because of the fungal etiology. The present study is aimed to identify the pathogenic organisms responsible for corneal infections. Majority of the cases are secondary to trauma. Of the fungal cases, Aspergillus is found to be the predominant fungus affecting corneal ulcers, followed by bacteria affecting the corneal ulcers.

  16. Common genetic variants near the Brittle Cornea Syndrome locus ZNF469 influence the blinding disease risk factor central corneal thickness.

    Directory of Open Access Journals (Sweden)

    Yi Lu


    Full Text Available Central corneal thickness (CCT, one of the most highly heritable human traits (h(2 typically>0.9, is important for the diagnosis of glaucoma and a potential risk factor for glaucoma susceptibility. We conducted genome-wide association studies in five cohorts from Australia and the United Kingdom (total N = 5058. Three cohorts were based on individually genotyped twin collections, with the remaining two cohorts genotyped on pooled samples from singletons with extreme trait values. The pooled sample findings were validated by individual genotyping the pooled samples together with additional samples also within extreme quantiles. We describe methods for efficient combined analysis of the results from these different study designs. We have identified and replicated quantitative trait loci on chromosomes 13 and 16 for association with CCT. The locus on chromosome 13 (nearest gene FOXO1 had an overall meta-analysis p-value for all the individually genotyped samples of 4.6x10(-10. The locus on chromosome 16 was associated with CCT with p = 8.95x10(-11. The nearest gene to the associated chromosome 16 SNPs was ZNF469, a locus recently implicated in Brittle Cornea Syndrome (BCS, a very rare disorder characterized by abnormal thin corneas. Our findings suggest that in addition to rare variants in ZNF469 underlying CCT variation in BCS patients, more common variants near this gene may contribute to CCT variation in the general population.

  17. Evaluation of the attentional capacities and working memory of early and late blind persons. (United States)

    Pigeon, Caroline; Marin-Lamellet, Claude


    Although attentional processes and working memory seem to be significantly involved in the daily activities (particularly during navigating) of persons who are blind and who use these abilities to compensate for their lack of vision, few studies have investigated these mechanisms in this population. The aim of this study is to evaluate the selective, sustained and divided attention, attentional inhibition and switching and working memory of blind persons. Early blind, late blind and sighted participants completed neuropsychological tests that were designed or adapted to be achievable in the absence of vision. The results revealed that the early blind participants outperformed the sighted ones in selective, sustained and divided attention and working memory tests, and the late blind participants outperformed the sighted participants in selective, sustained and divided attention. However, no differences were found between the blind groups and the sighted group in the attentional inhibition and switching tests. Furthermore, no differences were found between the early and late blind participants in this set of tests. These results suggest that early and late blind persons can compensate for the lack of vision by an enhancement of the attentional and working memory capacities. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Blindness (United States)

    ... doctors may do surgery to remove it. Is Learning Different? A baby who is blind can still ... do amazing things in many different fields, including music, the arts, and even sports. Serious vision problems ...

  19. Mobility of persons who are blind: How the attentional processes and working memory are involved?


    PIGEON, Caroline; MARIN-LAMELLET, Claude


    Although navigation without vision seems to strongly mobilize the attentional processes and the working memory, few studies seem to be conducted about the link between these processes and the mobility of people who are blind. The main aim of this PhD work is to consider the attentional and working memory capacities of people who are blind and investigate the attentional processes involved during the navigation activity. In the first part of this PhD work, blind participants (early and late) p...

  20. Infliximab eye drops treatment in corneal neovascularization. (United States)

    Voiculescu, O B; Voinea, L M


    Corneal neovascularization is a serious condition that may arise secondary to chemical burns, ischemia, infection, trauma, and inflammation and represents a major cause of blindness. This study investigated the efficacy of topical application of infliximab [tumor necrosis factor-a (TNF-a) monoclonal antibody] in the treatment of corneal neovascularization in the rabbit model.

  1. Complications from Infective Corneal Conditions Treated by ...

    African Journals Online (AJOL)

    Background: Complications from infective corneal conditions are an important cause of blindness in adults and children. The eyelids play a major role in the pathogenesis of staphyloma and the perforation of descemetoceles. Tarsorrhaphy could, therefore, be beneficial in treating serious complications from infective corneal ...

  2. Pattern of corneal opacity in Ibadan, Nigeria | Ashaye | Annals of ...

    African Journals Online (AJOL)

    Background: The prevalence and causes of corneal blindness vary from one region of the world to another. There is even variation within the developing countries of Africa. Method: A retrospective review of 675 patients with corneal scarring out of the 3,753 new patients corneal scarring in patients attending the eye clinic of ...

  3. Corneal Laceration

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    Full Text Available ... Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Corneal Laceration ... Laceration Treatment What Is Corneal Laceration? Leer en Español: ¿Qué Es una Laceración de la Córnea? Written ...

  4. Corneal Laceration

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    Full Text Available ... Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Corneal Laceration ... Laceration Treatment What Is Corneal Laceration? Leer en Español: ¿Qué es una laceración de la córnea? Written ...

  5. Corneal Laceration

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


    Directory of Open Access Journals (Sweden)



    Full Text Available 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. The presenting symptoms of contact lens related corneal ulcers include eye discomfort, foreign body sensation and lacrimation. More serious symptoms are redness (especially circum-corneal injection, severe pain, photophobia, eye discharge and blurring of vision. The diagnosis is established by a thorough slit lamp microscopic examination with fluorescein staining and corneal scraping for Gram stain and culture of the infective organism. Delay in diagnosing and treatment can cause permanent blindness, therefore an early referral to ophthalmologist and commencing of antimicrobial therapy can prevent visual loss.

  7. Minimising Corneal Scarring from the use of Harmful Traditional Eye ...

    African Journals Online (AJOL)

    Corneal scarring is the fourth largest cause of blindness globally, and a much more prominent factor in developing countries. Blindness from corneal scarring is largely a preventable phenomenon, and is capable of causing significant morbidity that can last for a lifetime. A significant proportion of these cases are caused by ...

  8. Corneal injury (United States)

    ... page: // Corneal injury To use the sharing features on this page, ... Hockberger RS, Walls RM, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ed. Philadelphia, PA: Elsevier ...

  9. Corneal Laceration

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    Full Text Available ... Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Eye ... What Is Corneal Laceration? Leer en Español: ¿Qué ...

  10. Corneal Laceration

    Medline Plus

    Full Text Available ... itself. A corneal laceration is a very serious injury and requires immediate medical attention to avoid severe ... Ask an Ophthalmologist Answers Did my traumatic brain injury cause early cataracts? Jan 21, 2018 Did I ...

  11. Corneal Laceration

    Medline Plus

    Full Text Available ... and causes a ruptured globe, a tear into the eyeball itself. A corneal laceration is a very serious injury and requires immediate medical attention to avoid severe vision loss. If your eye ...

  12. Corneal Laceration

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    Full Text Available ... may increase bleeding after you have finished protecting the eye, see a physician immediately Next Corneal Laceration Symptoms Related Ask an Ophthalmologist Answers Did my traumatic brain injury cause early cataracts? Jan 21, 2018 Did ...

  13. Corneal Laceration

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    Full Text Available ... inflammatory drugs. These drugs thin the blood and may increase bleeding after you have finished protecting the ... Rise Jun 30, 2017 People with Advanced Keratoconus May Have A Future Alternative to Full Corneal Transplantation ...

  14. Corneal Laceration

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    Full Text Available ... part of a paper cup and tape this piece to the area around the eye. Wear this ... it possible that wearing two contact lenses in one eye could have caused a corneal ulcer? Jun ...

  15. Corneal Laceration

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    Full Text Available ... increase bleeding after you have finished protecting the eye, see a physician immediately Next Corneal Laceration Symptoms Related Ask an Ophthalmologist Answers Did my traumatic brain injury cause early cataracts? Jan 21, 2018 Did ...

  16. Corneal Laceration

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    Full Text Available ... the blood and may increase bleeding after you have finished protecting the eye, see a physician immediately ... Jun 30, 2017 People with Advanced Keratoconus May Have A Future Alternative to Full Corneal Transplantation Nov ...

  17. Pharmacological treatment for infectious corneal ulcers. (United States)

    Miller, Darlene


    Cornea ulceration and infectious keratitis are leading causes of corneal morbidity and blindness. Infectious causes are among the most frequent and most severe. Management strategies for bacterial corneal ulcers have changed significantly over the last decades, however with a more limited progress in the treatment and management of nonbacterial, infectious ulcers. This paper provides an overview of the current principles, strategies and treatment choices for infectious corneal ulcers in adults. Topical application with a broad-spectrum antimicrobial remains the preferred method for the pharmacological management of infectious corneal ulcers. Increasing reports of clinical failures and in vitro resistance to antibiotics to treat the most common infectious (bacterial) corneal ulcers are increasing concerns. New approaches for improvement in the pharmacological management of corneal ulcers should focus on strategies for a more rational and evidence-based use of current antimicrobials and development of products to modulate the host immune response and to neutralize microbial toxins and other immune modulators.

  18. 20 CFR 404.1585 - Trial work period for persons age 55 or older who are blind. (United States)


    ... who are blind. 404.1585 Section 404.1585 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL... § 404.1585 Trial work period for persons age 55 or older who are blind. If you become eligible for disability benefits even though you were doing substantial gainful activity because you are blind and age 55...

  19. Working memory for vibrotactile frequencies: comparison of cortical activity in blind and sighted individuals. (United States)

    Burton, Harold; Sinclair, Robert J; Dixit, Sachin


    In blind, occipital cortex showed robust activation to nonvisual stimuli in many prior functional neuroimaging studies. The cognitive processes represented by these activations are not fully determined, although a verbal recognition memory role has been demonstrated. In congenitally blind and sighted (10 per group), we contrasted responses to a vibrotactile one-back frequency retention task with 5-s delays and a vibrotactile amplitude-change task; both tasks involved the same vibration parameters. The one-back paradigm required continuous updating for working memory (WM). Findings in both groups confirmed roles in WM for right hemisphere dorsolateral prefrontal (DLPFC) and dorsal/ventral attention components of posterior parietal cortex. Negative findings in bilateral ventrolateral prefrontal cortex suggested task performance without subvocalization. In bilateral occipital cortex, blind showed comparable positive responses to both tasks, whereas WM evoked large negative responses in sighted. Greater utilization of attention resources in blind were suggested as causing larger responses in dorsal and ventral attention systems, right DLPFC, and persistent responses across delays between trials in somatosensory and premotor cortex. In sighted, responses in somatosensory and premotor areas showed iterated peaks matched to stimulation trial intervals. The findings in occipital cortex of blind suggest that tactile activations do not represent cognitive operations for nonverbal WM task. However, these data suggest a role in sensory processing for tactile information in blind that parallels a similar contribution for visual stimuli in occipital cortex of sighted. © 2010 Wiley-Liss, Inc.

  20. A native-like corneal construct using donor corneal stroma for tissue engineering.

    Directory of Open Access Journals (Sweden)

    Jing Lin

    Full Text Available Tissue engineering holds great promise for corneal transplantation to treat blinding diseases. This study was to explore the use of natural corneal stroma as an optimal substrate to construct a native like corneal equivalent. Human corneal epithelium was cultivated from donor limbal explants on corneal stromal discs prepared by FDA approved Horizon Epikeratome system. The morphology, phenotype, regenerative capacity and transplantation potential were evaluated by hematoxylin eosin and immunofluorescent staining, a wound healing model, and the xeno-transplantation of the corneal constructs to nude mice. An optically transparent and stratified epithelium was rapidly generated on donor corneal stromal substrate and displayed native-like morphology and structure. The cells were polygonal in the basal layer and became flattened in superficial layers. The epithelium displayed a phenotype similar to human corneal epithelium in vivo. The differentiation markers, keratin 3, involucrin and connexin 43, were expressed in full or superficial layers. Interestingly, certain basal cells were immunopositive to antibodies against limbal stem/progenitor cell markers ABCG2 and p63, which are usually negative in corneal epithelium in vivo. It suggests that this bioengineered corneal epithelium shared some characteristics of human limbal epithelium in vivo. This engineered epithelium was able to regenerate in 4 days following from a 4mm-diameter wound created by a filter paper soaked with 1 N NaOH. This corneal construct survived well after xeno-transplantation to the back of a nude mouse. The transplanted epithelium remained multilayer and became thicker with a phenotype similar to human corneal epithelium. Our findings demonstrate that natural corneal stroma is an optimal substrate for tissue bioengineering, and a native-like corneal construct has been created with epithelium containing limbal stem cells. This construct may have great potential for clinical use in

  1. Short term memory and working memory in blind versus sighted children

    NARCIS (Netherlands)

    Withagen, A.; Kappers, A.M.L.; Vervloed, M.P.J.; Knoors, H.; Verhoeven, L.


    There is evidence that blind people may strengthen their memory skills to compensate for absence of vision. However, which aspects of memory are involved is open to debate and a developmental perspective is generally lacking. In the present study, we compared the short term memory (STM) and working

  2. Short term memory and working memory in blind versus sighted children. (United States)

    Withagen, Ans; Kappers, Astrid M L; Vervloed, Mathijs P J; Knoors, Harry; Verhoeven, Ludo


    There is evidence that blind people may strengthen their memory skills to compensate for absence of vision. However, which aspects of memory are involved is open to debate and a developmental perspective is generally lacking. In the present study, we compared the short term memory (STM) and working memory (WM) of 10-year-old blind children and sighted children. STM was measured using digit span forward, name learning, and word span tasks; WM was measured using listening span and digit span backward tasks. The blind children outperformed their sighted peers on both STM and WM tasks. The enhanced capacity of the blind children on digit span and other STM tasks confirms the results of earlier research; the significantly better performance of the blind children relative to their sighted peers on verbal WM tasks is a new interesting finding. Task characteristics, including the verbal nature of the WM tasks and strategies used to perform these tasks, are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Corneal Transplantation

    DEFF Research Database (Denmark)

    Hjortdal, Jesper Østergaard

    Corneal transplantation has been performed for more than 100 years. Until 15 years ago the state-of-the art type of transplantation was penetrating keratoplasty, but since the start of this millennium, newly designed surgical techniques have developed considerably. Today, the vast majority of ker...

  4. Corneal Laceration

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    Full Text Available ... Contacts Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Corneal ... vision. Privacy Policy Related Top 5 Eye Health Stories of 2017 Dec 21, 2017 Solar Eclipse Inflicts ...

  5. Corneal topography

    DEFF Research Database (Denmark)

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


    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 the ...

  6. Corneal Laceration

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    Full Text Available ... Laundry Packets On the Rise Jun 30, 2017 People with Advanced Keratoconus May Have A Future Alternative to Full Corneal Transplantation Nov 29, ... Contact Us About the Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of ...

  7. Corneal Intelligence

    African Journals Online (AJOL)


    Corneal Intelligence. Ian Murdoch. Institute of Ophthalmology, Bath Street, London. In 2002, the ocular hypertension treatment study (OHTS) published their results. This study had taken 1636 ocular hypertensives. 1, 2. (IOP 24-32mmHg) and randomized them to receive therapy or no therapy. The primary outcome of the ...

  8. Corneal Laceration

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    Full Text Available ... lenses in one eye could have caused a corneal ulcer? Jun 05, 2015 Find an Ophthalmologist Advanced Search Ask an Ophthalmologist Browse Answers Free Newsletter Get ophthalmologist-reviewed tips and information about eye health and ... The Academy Professionals: ...

  9. Corneal neovascularization and biological therapy. (United States)

    Voiculescu, O B; Voinea, L M; Alexandrescu, C


    Corneal avascularity is necessary for the preservation of optimal vision. The cornea maintains a dynamic balance between pro- and antiangiogenic factors that allows it to remain avascular under normal homeostatic conditions. Corneal neovascularization (NV) is a condition that can develop in response to inflammation, hypoxia, trauma, or limbal stem cell deficiency and it is a significant cause of blindness. New therapeutic options for diseases of the cornea and ocular surface are now being explored in experimental animals and clinical trials. Antibody based biologics are being tested for their ability to reduce blood and lymphatic vessel ingrowth into the cornea, and to reduce inflammation. Numerous studies have shown that biologics with specificity for VEGF A such as bevacizumab and ranibizumab (a recombinant antibody and an antibody fragment, respectively) or anti-tumor necrosis factor-α microantibody, are effective in the treatment of corneal neovascularization.

  10. The management of cornea blindness from severe corneal scarring, with the Athens Protocol (transepithelial topography-guided PRK therapeutic remodeling, combined with same-day, collagen cross-linking

    Directory of Open Access Journals (Sweden)

    Kanellopoulos AJ


    Full Text Available Anastasios John Institute, Athens, Greece; Manhattan Eye, Ear and Throat Hospital, New York, NY, USA; New York University Medical School, New York, NY, USAPurpose: To evaluate the safety and efficacy of combined transepithelial topography-guided photorefractive keratectomy (PRK therapeutic remodeling, combined with same-day, collagen cross-linking (CXL. This protocol was used for the management of cornea blindness due to severe corneal scarring.Methods: A 57-year-old man had severe corneal blindness in both eyes. Both corneas had significant central scars attributed to a firework explosion 45 years ago, when the patient was 12 years old. Corrected distance visual acuity (CDVA was 20/100 both eyes (OU with refraction: +4.00, –4.50 at 135° in the right eye and +3.50, –1.00 at 55° in the left. Respective keratometries were: 42.3, 60.4 at 17° and 35.8, 39.1 at 151.3°. Cornea transplantation was the recommendation by multiple cornea specialists as the treatment of choice. We decided prior to considering a transplant to employ the Athens Protocol (combined topography-guided partial PRK and CXL in the right eye in February 2010 and in the left eye in September 2010. The treatment plan for both eyes was designed on the topography-guided wavelight excimer laser platform.Results: Fifteen months after the right eye treatment, the right cornea had improved translucency and was topographically stable with uncorrected distance visual acuity (UDVA 20/50 and CDVA 20/40 with refraction +0.50, –2.00 at 5°. We noted a similar outcome after similar treatment applied in the left eye with UDVA 20/50 and CDVA 20/40 with –0.50, –2.00 at 170° at the 8-month follow-up.Conclusion: In this case, the introduction of successful management of severe cornea abnormalities and scarring with the Athens Protocol may provide an effective alternative to other existing surgical or medical options.Keywords: Athens Protocol, collagen cross

  11. Corneal donations in South Africa: A 15-year review | York | South ...

    African Journals Online (AJOL)

    Background. Corneal pathology is one of the leading causes of preventable blindness in South Africa (SA). A corneal transplant can restore or significantly improve vision in most cases. However, in SA there is a gross shortage of corneal tissue available to ophthalmologists. Little has been published describing the ...

  12. The experiences of teachers of mathematics in classroom work with blind people

    Directory of Open Access Journals (Sweden)

    Helen Bolaños-González


    Full Text Available This article aims to present the point of view of professors of mathematics about the comprehensive care for the blind or low-vision population. It is important to collect the experiences that Mathematics teachers of the National University of Costa Rica have had with students with visual disabilities, and thus to have a history of what has been done, and the results obtained when applying some methodological strategies. This paper seeks to represent the teachers’ opinion on the challenges they must face to carry out the methodological approach and the evaluation process of teaching Mathematics. The development of the research was based on a case study of a blind student who repeatedly failed the course of Differential and Integral Calculus, and therefore interviewing the staff responsible for giving him attention during the second semester 2014 was considered. Based on the above, the information provided by the teachers and the staff responsible for providing supervision and support to students with visual disabilities was analyzed. Such information represents the experiences of students in courses of Mathematics and the main characteristics of their learning. Among the most important results of this work are the features of the methodology and the process of evaluation used in a Mathematics class for blind students, as well as the major needs visually-impaired students have in this discipline, in order to improve the favorable conditions that the School of Mathematics of the National University of Costa Rica has been creating in relation with inclusive education

  13. [The status quo and expectation of corneal research in China]. (United States)

    Shi, Weiyun; Xie, Lixin


    In China, corneal disease is currently the second leading cause of blindness. Severe donor shortage, insufficient technique supports and promotion, and the lack of corneal disease specialists due to poor systematic training are all urgent problems to be resolved. The last 5 years have witnessed a considerable progress in basic and clinical researches of corneal disease. Investigations on the pathogenesis and treatment of fungal keratitis have won an international reputation. Results from the study of corneal reconstruction with tissue-engineered and acellular matrix corneas have been tested in clinical trials with good preliminary performance. Moreover, the clinical researches of corneal refractive surgery have kept pace with the latest international progresses. However, Descemet's membrane endothelial keratoplasty needs further promotion, and the development and application of keratoprosthesis remains a blank. Although keratoprosthesis and corneal collagen cross-linking have been widely applied in Europe with satisfactory clinical efficacy, they are still under assessment by China Food and Drug Administration for approval of use.

  14. Corneal reconstruction by stem cells and bioengineering

    Directory of Open Access Journals (Sweden)

    Arjamaa O


    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

  15. Blind Astronomers (United States)

    Hockey, Thomas A.


    The phrase "blind astronomer” is used as an allegorical oxymoron. However, there were and are blind astronomers. What of famous blind astronomers? First, it must be stated that these astronomers were not martyrs to their craft. It is a myth that astronomers blind themselves by observing the Sun. As early as France's William of Saint-Cloud (circa 1290) astronomers knew that staring at the Sun was ill-advised and avoided it. Galileo Galilei did not invent the astronomical telescope and then proceed to blind himself with one. Galileo observed the Sun near sunrise and sunset or through projection. More than two decades later he became blind, as many septuagenarians do, unrelated to their profession. Even Isaac Newton temporarily blinded himself, staring at the reflection of the Sun when he was a twentysomething. But permanent Sun-induced blindness? No, it did not happen. For instance, it was a stroke that left Scotland's James Gregory (1638-1675) blind. (You will remember the Gregorian telescope.) However, he died days later. Thus, blindness little interfered with his occupation. English Abbot Richard of Wallingford (circa 1291 - circa 1335) wrote astronomical works and designed astronomical instruments. He was also blind in one eye. Yet as he further suffered from leprosy, his blindness seems the lesser of Richard's maladies. Perhaps the most famous professionally active, blind astronomer (or almost blind astronomer) is Dominique-Francois Arago (1786-1853), director until his death of the powerful nineteenth-century Paris Observatory. I will share other _ some poignant _ examples such as: William Campbell, whose blindness drove him to suicide; Leonhard Euler, astronomy's Beethoven, who did nearly half of his life's work while almost totally blind; and Edwin Frost, who "observed” a total solar eclipse while completely sightless.

  16. Equine corneal stromal abscesses

    DEFF Research Database (Denmark)

    Henriksen, M. D. L.; Andersen, P. H.; Plummer, C. E.


    The last 30 years have seen many changes in the understanding of the pathogenesis and treatment of equine corneal stromal abscesses (SAs). Stromal abscesses were previously considered an eye problem related to corneal bacterial infection, equine recurrent uveitis, corneal microtrauma and corneal...... foreign bodies in horses. They were more commonly diagnosed in horses living in subtropical climatic areas of the world. Therapeutic recommendations to treat equine SAs were historically nearly always a medical approach directed at bacteria and the often associated severe iridocyclitis. Today...... the pathogenesis of most equine SAs appears to be more often related to fungal inoculation of the anterior corneal stroma followed by posterior migration of the fungi deeper into the corneal stroma. There is also now an increased incidence of diagnosis of corneal SAs in horses living in more temperate climates...

  17. Applications of biomaterials in corneal wound healing

    Directory of Open Access Journals (Sweden)

    I-Lun Tsai


    Full Text Available Disease affecting the cornea is a common cause of blindness worldwide. To date, the amniotic membrane (AM is the most widely used clinical method for cornea regeneration. However, donor-dependent differences in the AM may result in variable clinical outcomes. To overcome this issue, biomaterials are currently under investigation for corneal regeneration in vitro and in vivo. In this article, we highlight the recent advances in hydrogels, bioengineered prosthetic devices, contact lenses, and drug delivery systems for corneal regeneration. In clinical studies, the therapeutic effects of biomaterials, including fibrin and collagen-based hydrogels and silicone contact lenses, have been demonstrated in damaged cornea. The combination of cells and biomaterials may provide potential treatment in corneal wound healing in the future.

  18. Community Based Training--Non-Traditional Curriculum Options for Work and Independent Living Training of Secondary Deaf-Blind Adolescents. (United States)

    Dildy, Dennis

    Age appropriate training programs in natural environments for deaf-blind adolescents help to develop functional skills, with the ultimate goal of independent living and work placement. Other approaches to the education of handicapped children entail activity for the sake of activity, or babysitting and fun activities. The actual training of a…

  19. Corneal cross-linking in the treatment of corneal ulcers. (United States)

    Price, Marianne O; Price, Francis W


    New treatments for corneal ulcers are needed to address challenges with antibiotic resistance, cost, and specificity requiring timely pathogen identification. This review assesses the evidence regarding safety and efficacy of corneal cross-linking (CXL) as an adjunct or stand-alone treatment. To date approximately 200 clinical cases of CXL used with various types of infectious keratitis have been reported in about 30 publications. Most employed the CXL protocol developed for keratoconus as an adjunct to antibiotics for resistant ulcers, and a number of cases resolved after this intervention. However, a few studies raised concerns about resurgence and perforation when CXL was utilized with deep fungal infections. The infiltrate depth is an important consideration, because the standard CXL treatment is cytotoxic (to keratocytes) to a depth of approximately 200-300 μm and 50% of the energy is absorbed within the first 100 μm. CXL was used successfully as a monotherapy in approximately 16 eyes with early bacterial or shallow fungal infections. Further work is needed to develop optimized CXL protocols for treatment of corneal ulcers, define the appropriate conditions for use, and determine the safety and efficacy relative to standard antibiotic treatments.

  20. Restoration of Corneal Transparency by Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Sharad K. Mittal


    Full Text Available Transparency of the cornea is indispensable for optimal vision. Ocular trauma is a leading cause of corneal opacity, leading to 25 million cases of blindness annually. Recently, mesenchymal stem cells (MSCs have gained prominence due to their inflammation-suppressing and tissue repair functions. Here, we investigate the potential of MSCs to restore corneal transparency following ocular injury. Using an in vivo mouse model of ocular injury, we report that MSCs have the capacity to restore corneal transparency by secreting high levels of hepatocyte growth factor (HGF. Interestingly, our data also show that HGF alone can restore corneal transparency, an observation that has translational implications for the development of HGF-based therapy.

  1. Intrastromal corneal ring implants for corneal thinning disorders: an evidence-based analysis. (United States)


    progressively thins causing a cone-like bulge or forward protrusion in response to the normal pressure of the eye. Thinning occurs primarily in the stoma layers and is believed to be a breakdown in the collagen network. This bulging can lead to an irregular shape or astigmatism of the cornea and, because the anterior part of the cornea is largely responsible for the focusing of light on the retina, results in loss of visual acuity. This can make even simple daily tasks, such as driving, watching television or reading, difficult to perform. Keratoconus (KC) is the most common form of corneal thinning disorder and is a noninflammatory chronic disease process. Although the specific causes of the biomechanical alterations that occur in KC are unknown, there is a growing body of evidence to suggest that genetic factors may play an important role. KC is a rare condition (management for this condition follows a step-wise approach depending on disease severity. Contact lenses are the primary treatment of choice when there is irregular astigmatism associated with the disease. When patients can no longer tolerate contact lenses or when lenses no longer provide adequate vision, patients are referred for corneal transplant. Keratoconus is one of the leading indications for corneal transplants and has been so for the last three decades. Yet, despite high graft survival rates of up to 20 years, there are reasons to defer receiving transplants for as long as possible. Patients with keratoconus are generally young and life-long term graft survival would be an important consideration. The surgery itself involves lengthy time off work and there are potential complications from long term steroid use following surgery, as well as the risk of developing secondary cataracts, glaucoma etc. After transplant, recurrent KC is possible with need for subsequent intervention. Residual refractive errors and astigmatism can remain challenging after transplantation and high refractive surgery rates and re

  2. Corneal endothelium of the Magellanic penguin (Spheniscus magellanicus) by scanning electron microscopy. (United States)

    Pigatto, João A T; Laus, José L; Santos, Jaime M; Cerva, Cristine; Cunha, Luciana S; Ruoppolo, Valéria; Barros, Paulo S M


    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.

  3. Corneal regeneration by induced human buccal mucosa cultivated on an amniotic membrane following alkaline injury. (United States)

    Man, Rohaina Che; Yong, Then Kong; Hwei, Ng Min; Halim, Wan Haslina Wan Abdul; Zahidin, Aida Zairani Mohd; Ramli, Roszalina; Saim, Aminuddin Bin; Idrus, Ruszymah Binti Hj


    Various clinical disorders and injuries, such as chemical, thermal, or mechanical injuries, may lead to corneal loss that results in blindness. PURPOSE : The aims of this study were to differentiate human buccal mucosa (BMuc) into corneal epithelial-like cells, to fabricate engineered corneal tissue using buccal mucosal epithelial cells, and to reconstruct a damaged corneal epithelium in a nude rat model. BMuc were subjected to 10 d of induction factors to investigate the potential of cells to differentiate into corneal lineages. Corneal stem cell markers β1-integrin, C/EBPδ, ABCG2, p63, and CK3 were upregulated in the gene expression analysis in induced BMuc, whereas CK3 and p63 showed significant protein expression in induced BMuc compared to the uninduced cells. BMuc were then left to reach 80% confluency after differential trypsinization. The cells were harvested and cultivated on a commercially available untreated air-dried amniotic membrane (AM) in a Transwell system in induction medium. The corneal constructs were fabricated and then implanted into damaged rat corneas for up to 8 weeks. A significant improvement was detected in the treatment group at 8 weeks post-implantation, as revealed by slit lamp biomicroscopy analysis. The structure and thickness of the corneal layer were also analyzed using histological staining and time-domain optical coherence tomography scans and were found to resemble a native corneal layer. The protein expression for CK3 and p63 were continuously detected throughout the corneal epithelial layer in the corneal construct. In conclusion, human BMuc can be induced to express a corneal epithelial-like phenotype. The addition of BMuc improves corneal clarity, prevents vascularization, increases corneal thickness and stromal alignment, and appears to have no adverse effect on the host after implantation.

  4. Working memory training for adult hearing aid users: study protocol for a double-blind randomized active controlled trial. (United States)

    Henshaw, Helen; Ferguson, Melanie A


    One in ten people aged between 55 to 74 years have a significant hearing impairment in their better hearing ear (as defined by audiometric hearing thresholds). However, it is becoming increasingly clear that the challenges faced by older listeners cannot be explained by the audiogram alone. The ability for people with hearing loss to use cognition to support speech perception allows for compensation of the degraded auditory input. This in turn offers promise for new cognitive-based rehabilitative interventions. Working memory is known to be highly associated with language comprehension and recent evidence has shown significant generalization of learning from trained working memory tasks to improvements in sentence-repetition skills of children with severe to profound hearing loss. This evidence offers support for further investigation into the potential benefits of working memory training to improve speech perception abilities in other hearing impaired populations. This is a double-blind randomized active controlled trial aiming to assess whether a program of working memory training results in improvements in untrained measures of cognition, speech perception and self-reported hearing abilities in adult hearing aid users aged (50 to 74 years) with mild-to-moderate hearing loss hearing aid users, compared with an active control group who receive a placebo version of the working memory training program. The present study aims to generate high-quality preliminary evidence for the efficacy of working memory training for adult hearing aid users with mild-to-moderate sensorineural hearing loss who are existing hearing aid users. This trial addresses a number of gaps in the published literature assessing training interventions for people with hearing loss, and in the general literature surrounding working memory training, such as the inclusion of an active control group, participant and tester blinding, and increased transparency in reporting. Clinical

  5. Impact of facial conformation on canine health: corneal ulceration. (United States)

    Packer, Rowena M A; Hendricks, Anke; Burn, Charlotte C


    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 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.

  6. Normative values for corneal nerve morphology assessed using corneal confocal microscopy: a multinational normative data set. (United States)

    Tavakoli, Mitra; Ferdousi, Maryam; Petropoulos, Ioannis N; Morris, Julie; Pritchard, Nicola; Zhivov, Andrey; Ziegler, Dan; Pacaud, Danièle; Romanchuk, Kenneth; Perkins, Bruce A; Lovblom, Leif E; Bril, Vera; Singleton, J Robinson; Smith, Gordon; Boulton, Andrew J M; Efron, Nathan; Malik, Rayaz A


    Corneal confocal microscopy is a novel diagnostic technique for the detection of nerve damage and repair in a range of peripheral neuropathies, in particular diabetic neuropathy. Normative reference values are required to enable clinical translation and wider use of this technique. We have therefore undertaken a multicenter collaboration to provide worldwide age-adjusted normative values of corneal nerve fiber parameters. A total of 1,965 corneal nerve images from 343 healthy volunteers were pooled from six clinical academic centers. All subjects underwent examination with the Heidelberg Retina Tomograph corneal confocal microscope. Images of the central corneal subbasal nerve plexus were acquired by each center using a standard protocol and analyzed by three trained examiners using manual tracing and semiautomated software (CCMetrics). Age trends were established using simple linear regression, and normative corneal nerve fiber density (CNFD), corneal nerve fiber branch density (CNBD), corneal nerve fiber length (CNFL), and corneal nerve fiber tortuosity (CNFT) reference values were calculated using quantile regression analysis. There was a significant linear age-dependent decrease in CNFD (-0.164 no./mm(2) per year for men, P < 0.01, and -0.161 no./mm(2) per year for women, P < 0.01). There was no change with age in CNBD (0.192 no./mm(2) per year for men, P = 0.26, and -0.050 no./mm(2) per year for women, P = 0.78). CNFL decreased in men (-0.045 mm/mm(2) per year, P = 0.07) and women (-0.060 mm/mm(2) per year, P = 0.02). CNFT increased with age in men (0.044 per year, P < 0.01) and women (0.046 per year, P < 0.01). Height, weight, and BMI did not influence the 5th percentile normative values for any corneal nerve parameter. This study provides robust worldwide normative reference values for corneal nerve parameters to be used in research and clinical practice in the study of diabetic and other peripheral neuropathies. © 2015 by the American Diabetes Association

  7. Causes of blindness and career choice among pupils in a blind ...

    African Journals Online (AJOL)

    0.3 million in Africa, 0.1 million in Latin America and 0.1 million in the rest of the World.[3,4]. Studies from blind school in some parts of Nigeria[5-7] shows that most of theblindness are from avoidable causes like cataract, glaucoma, corneal infection and measles. This study sets to identify the causes of blindness.

  8. Corneal Protection for Burn Patients (United States)


    Create ectropion by blepharoplasty in New Zealand white rabbits. Assess epithelial defects and corneal ulcers . Measure inflammatory cytokines and...7, with corneal ulceration developing in the most severe cases by week 3. Histopathological results revealed epithelium infiltrated by heterophilic...excellent surgical model of evaporative dry eye. Damage to the cornea and conjunctiva manifesting as punctate epithelial erosions and corneal ulceration is

  9. A comparison of the causes of blindness certifications in England and Wales in working age adults (16-64 years), 1999-2000 with 2009-2010. (United States)

    Liew, Gerald; Michaelides, Michel; Bunce, Catey


    To report on the causes of blindness certifications in England and Wales in working age adults (16-64 years) in 2009-2010; and to compare these with figures from 1999 to 2000. Analysis of the national database of blindness certificates of vision impairment (CVIs) received by the Certifications Office. Working age (16-64 years) population of England and Wales. Number and cause of blindness certifications. The Certifications Office received 1756 CVIs for blindness from persons aged between 16 and 64 inclusive between 1 April 2009 and 31 March 2010. The main causes of blindness certifications were hereditary retinal disorders (354 certifications comprising 20.2% of the total), diabetic retinopathy/maculopathy (253 persons, 14.4%) and optic atrophy (248 persons, 14.1%). Together, these three leading causes accounted for almost 50% of all blindness certifications. Between 1 April 1999 and 31 March 2000, the leading causes of blindness certification were diabetic retinopathy/maculopathy (17.7%), hereditary retinal disorders (15.8%) and optic atrophy (10.1%). For the first time in at least five decades, diabetic retinopathy/maculopathy is no longer the leading cause of certifiable blindness among working age adults in England and Wales, having been overtaken by inherited retinal disorders. This change may be related to factors including the introduction of nationwide diabetic retinopathy screening programmes in England and Wales and improved glycaemic control. Inherited retinal disease, now representing the commonest cause of certification in the working age population, has clinical and research implications, including with respect to the provision of care/resources in the NHS and the allocation of research funding.

  10. Causes of childhood blindness in a developing country and an underdeveloped country. (United States)

    Santos-Bueso, E; Dorronzoro-Ramírez, E; Gegúndez-Fernández, J A; Vinuesa-Silva, J M; Vinuesa-Silva, I; García-Sánchez, J


    The causes of childhood blindness depend on factors such as geographic location or the human development index of the populations under study. The main causes in developed countries are genetic and hereditary diseases, while infectious and contagious diseases, together with nutritional and vitamin deficiencies, are the main causes in underdeveloped countries (UDCs). Study of the causes of blindness among children admitted to a regional centre in Nador, Morocco, and among children in Mekele, Ethiopia. The study was carried out in collaboration with two non-governmental organizations based in Madrid, Spain. First, we worked with Fudación Adelias in June 2010, and with Proyecto Visión in October 2012. The study comprised a total of 27 children in Morocco and 85 in Ethiopia. The average age of the children was 10.92 and 6.94 years, respectively. The main causes of blindness in Morocco were hereditary pathologies (25.92%) and refractive errors (14.82%), although trauma (7.40%) and corneal disease (7.40%) are relevant. Among the children from Ethiopia, corneal disease (27.05%) and trauma (20%) were the main causes of blindness, while congenital and hereditary diseases had a lower prevalence (4.70%). The causes of blindness depend on the human development index of the populations under study. While corneal disease and trauma are the main causes observed in UDCs like Ethiopia, hereditary pathologies and refractive errors are the main causes within the Moroccan population studied. A mixed form can be observed in this country, as the cause of blindness found in developed countries, such as congenital and hereditary pathologies which are present alongside the causes normally found in LDCs. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  11. Confident failures: Lapses of working memory reveal a metacognitive blind spot. (United States)

    Adam, Kirsten C S; Vogel, Edward K


    Working memory performance fluctuates dramatically from trial to trial. On many trials, performance is no better than chance. Here, we assessed participants' awareness of working memory failures. We used a whole-report visual working memory task to quantify both trial-by-trial performance and trial-by-trial subjective ratings of inattention to the task. In Experiment 1 (N = 41), participants were probed for task-unrelated thoughts immediately following 20% of trials. In Experiment 2 (N = 30), participants gave a rating of their attentional state following 25% of trials. Finally, in Experiments 3a (N = 44) and 3b (N = 34), participants reported confidence of every response using a simple mouse-click judgment. Attention-state ratings and off-task thoughts predicted the number of items correctly identified on each trial, replicating previous findings that subjective measures of attention state predict working memory performance. However, participants correctly identified failures on only around 28% of failure trials. Across experiments, participants' metacognitive judgments reliably predicted variation in working memory performance but consistently and severely underestimated the extent of failures. Further, individual differences in metacognitive accuracy correlated with overall working memory performance, suggesting that metacognitive monitoring may be key to working memory success.

  12. Medicated ocular bandages and corneal health: potential excipients and active pharmaceutical ingredients. (United States)

    Zidan, Ghada; Rupenthal, Ilva D; Greene, Carol; Seyfoddin, Ali


    Corneal blindness can occur due to improper healing of the corneal tissues after induced injury or abrasion which can be accidental, pathogenic, or after corneal surgery. Abnormal regulation of the healing mechanisms can lead to corneal opacity. Reducing inflammation and promoting epithelial wound healing are crucial for scar-free corneal recovery without eyesight complications. Current approaches for corneal wound healing involve amniotic membrane (AM) bandages, bandage contact lenses (BCL), and collagen shields in conjunction with frequent administration of therapeutic eye drops. The problem with eye drops is poor bioavailability and patient incompliance that might lead to corneal wound healing complications and poor clinical outcomes. Various methods have been proposed for loading drugs into medicated bandage lenses. There are advantages and limitations associated with each technique regarding the ease of manufacture, drug loading, release kinetics, and suitability with various therapeutics and hydrogel types. There is still, however, no drug-eluting corneal bandage on the market despite the need for such a convenient and cost-efficient strategy for corneal wound healing. This review will highlight materials and therapeutics that can be used in medicated ocular bandages and various ways of incorporating drugs, while discussing the limitations and challenges associated with bringing medicated ocular bandages in the market.

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

    Directory of Open Access Journals (Sweden)

    E. Yu. Markova


    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.

  14. Terahertz sensing in corneal tissues (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.


    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. PMID:21639581

  15. Modeling Corneal Oxygen with Scleral Gas Permeable Lens Wear. (United States)

    Compañ, Vicente; Aguilella-Arzo, Marcel; Edrington, Timothy B; Weissman, Barry A


    The main goal of this current work is to use an updated calculation paradigm, and updated boundary conditions, to provide theoretical guidelines to assist the clinician whose goal is to improve his or her scleral gas permeable (GP) contact lens wearing patients' anterior corneal oxygen supply. Our model uses a variable value of corneal oxygen consumption developed through Monod equations that disallows negative oxygen tensions within the stroma to predict oxygen tension at the anterior corneal surface of scleral GP contact lens wearing eyes, and to describe oxygen tension and flux profiles, for various boundary conditions, through the lens, tears, and cornea. We use several updated tissue and boundary parameters in our model. Tear exchange with GP scleral lenses is considered nonexistent in this model. The majority of current scleral GP contact lenses should produce some levels of corneal hypoxia under open eye conditions. Only lenses producing the thinnest of tear vaults should result in anterior corneal surface oxygen tensions greater than a presumed critical oxygen tension of 100 mmHg. We also find that corneal oxygen tension and flux are each more sensitive to modification in tear vault than to changes in lens oxygen permeability, within the ranges of current clinical manipulation. Our study suggests that clinicians would be prudent to prescribe scleral GP lenses manufactured from higher oxygen permeability materials and especially to fit without excessive corneal clearance.

  16. A randomized triple blind trial to assess the effect of an anthelmintic programme for working equids in Morocco

    Directory of Open Access Journals (Sweden)

    Christley Robert M


    Full Text Available Abstract Background Gastro-intestinal parasitism has been identified as a significant cause of disease in working equids in many countries. This randomized triple-blind trial was designed to assess the impact of an anthelmintic treatment programme (using oral ivermectin and fenbendazole comparing treated and placebo control populations of working donkeys, mules and horses in field conditions in Morocco. In particular, we assessed animal body weight and condition score, together with a questionnaire-based owner evaluation of number of subjective animal health parameters. Faecal worm egg count was also measured. Results 239 animals completed the full study, 130 in the treatment group and 109 in the control group. Although the average animal weight increased during the study, this change was not significantly different between the two groups. Animals in the treatment group had a significantly lower strongyle worm egg count and increased in body condition score compared to animals in the control group at each examination during the study period. Owners of animals in the treatment group reported improvement in health and work ability and a beneficial effect on pruritus during the early period of the study. These differences in owner perception between treatment groups had disappeared in the latter stages of the study. Conclusion This study demonstrated that a routine anthelmintic treatment programme of three treatments annually can have a significant effect on faecal worm egg count. There may be beneficial consequences for the animal health and productivity. Further research on other populations of working equids in different environments would facilitate the objective planning of effective parasite control strategies for specific situations and provide better understanding of the likely clinical benefits of such programmes.

  17. Expansion and cryopreservation of porcine and human corneal endothelial cells. (United States)

    Marquez-Curtis, Leah A; McGann, Locksley E; Elliott, Janet A W


    Impairment of the corneal endothelium causes blindness that afflicts millions worldwide and constitutes the most often cited indication for corneal transplants. The scarcity of donor corneas has prompted the alternative use of tissue-engineered grafts which requires the ex vivo expansion and cryopreservation of corneal endothelial cells. The aims of this study are to culture and identify the conditions that will yield viable and functional corneal endothelial cells after cryopreservation. Previously, using human umbilical vein endothelial cells (HUVECs), we employed a systematic approach to optimize the post-thaw recovery of cells with high membrane integrity and functionality. Here, we investigated whether improved protocols for HUVECs translate to the cryopreservation of corneal endothelial cells, despite the differences in function and embryonic origin of these cell types. First, we isolated endothelial cells from pig corneas and then applied an interrupted slow cooling protocol in the presence of dimethyl sulfoxide (Me 2 SO), with or without hydroxyethyl starch (HES). Next, we isolated and expanded endothelial cells from human corneas and applied the best protocol verified using porcine cells. We found that slow cooling at 1 °C/min in the presence of 5% Me 2 SO and 6% HES, followed by rapid thawing after liquid nitrogen storage, yields membrane-intact cells that could form monolayers expressing the tight junction marker ZO-1 and cytoskeleton F-actin, and could form tubes in reconstituted basement membrane matrix. Thus, we show that a cryopreservation protocol optimized for HUVECs can be applied successfully to corneal endothelial cells, and this could provide a means to address the need for off-the-shelf cryopreserved cells for corneal tissue engineering and regenerative medicine. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Chronic pesticide exposure and consequential keratectasia & corneal neovascularisation. (United States)

    Sanyal, Shalini; Law, Atrayo; Law, Sujata


    Ocular toxicity as a consequence of chronic pesticide exposure is one of the health hazards caused due to extended exposure to pesticides. The cornea, due to its position as the outer ocular layer and its role in protecting the internal layers of the eye; is gravely affected by this xenobiotic insult to the eye, leading to ocular irritation and damage to normal vision. The deleterious effects of chronic pesticide exposure on the various corneal layers and the ocular risks involved therein, were explored by mimicking the on-field scenario. Cytological, histological and flowcytometric parameters were taken into consideration to determine the enhanced risk of corneal neovascularisation and keratectasia, specifically, keratoconus. Chronic exposure to pesticides leads to heightened ocular morbidity wherein there were visible pathophysiological changes to the ocular surface. The cornea was found to be adversely affected with visible protuberance in a cone-like shape, characteristic of keratoconus in a majority of the experimental animals. Further analyses revealed a detrimental impact on all the corneal layers and an amplified expression of inflammation markers such as TNF-α, VCAM-1 and ICAM-1. Additionally, it was found that post pesticide exposure, the corneal surface developed hypoxia, leading to a significant increase of angiogenesis promoting factors and consequential neovascularisation. Apart from ocular toxicity, chronic exposure to pesticides significantly increases the risks of keratectasia and corneal neovascularisation; disorders which lead to diminished vision and if untreated, blindness. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Human corneal epithelial subpopulations

    DEFF Research Database (Denmark)

    Søndergaard, Chris Bath


    subpopulations in human corneal epithelium using a combination of laser capture microdissection and RNA sequencing for global transcriptomic profiling. We compared dissociation cultures, using either expansion on γ-irradiated NIH/3T3 feeder cells in serum-rich medium or expansion directly on plastic in serum......-free EpiLife medium, using a range of physiologically relevant oxygen concentrations (2%, 5%, 10%, 15% and 20%). Using immunocytochemistry and advanced fluorescence microscopy, cells were characterized regarding growth, cell cycle distribution, colony-forming efficiency (CFE), phenotypes...... 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...

  20. Increasing work-place healthiness with the probiotic Lactobacillus reuteri: A randomised, double-blind placebo-controlled study

    Directory of Open Access Journals (Sweden)

    Stan Vlaicu


    Full Text Available Abstract Background Short term illnesses, usually caused by respiratory or gastrointestinal diseases are disruptive to productivity and there is relatively little focus on preventative measures. This study examined the effect of the probiotic Lactobacillus reuteri protectis (ATCC55730 on its ability to improve work-place healthiness by reducing short term sick-leave caused by respiratory or gastrointestinal infections. Methods 262 employees at TetraPak in Sweden (day-workers and three-shift-workers that were healthy at study start were randomised in a double-blind fashion to receive either a daily dose of 108 Colony Forming Units of L. reuteri or placebo for 80 days. The study products were administered with a drinking straw. 181 subjects complied with the study protocol, 94 were randomised to receive L. reuteri and 87 received placebo. Results In the placebo group 26.4% reported sick-leave for the defined causes during the study as compared with 10.6% in the L. reuteri group (p L. reuteri group (p L. reuteri group(p

  1. Dynamic corneal deformation response and integrated corneal tomography

    Directory of Open Access Journals (Sweden)

    Marcella Q Salomão


    Full Text Available Measuring corneal biomechanical properties is still challenging. There are several clinical applications for biomechanical measurements, including the detection of mild or early forms of ectatic corneal diseases. This article reviews clinical applications for biomechanical measurements provided by the Corvis ST dynamic non contact tonometer

  2. Dynamic corneal deformation response and integrated corneal tomography (United States)

    Salomão, Marcella Q; Hofling-Lima, Ana Luisa; Faria-Correia, Fernando; Lopes, Bernardo Teixeira; Rodrigues-Barros, Sandra; Roberts, Cynthia J; Ambrósio, Renato


    Measuring corneal biomechanical properties is still challenging. There are several clinical applications for biomechanical measurements, including the detection of mild or early forms of ectatic corneal diseases. This article reviews clinical applications for biomechanical measurements provided by the Corvis ST dynamic non contact tonometer PMID:29480246

  3. Genetics of corneal endothelial dystrophies

    Indian Academy of Sciences (India)


    Dec 31, 2009 ... Kallam Anji Reddy Molecular Genetics Laboratory, Prof Brien Holden Eye Research Centre,. L. V. Prasad Eye Institute, ... Keywords. genetics; corneal dystrophy; corneal endothelium; gene mapping; mutations. Journal of Genetics .... PPCD and autosomal dominant keratoconus (including ker- atoconus in ...

  4. The Sokoto blind beggars: causes of blindness and barriers to rehabilitation services. (United States)

    Balarabe, Aliyu Hamza; Mahmoud, Abdulraheem O; Ayanniyi, Abdulkabir Ayansiji


    To determine the causes of blindness and the barriers to accessing rehabilitation services (RS) among blind street beggars (bsb) in Sokoto, Nigeria. A cross-sectional survey of 202 bsb (VA blindness were diagnosed by clinical ophthalmic examination. There were 107 (53%) males and 95 (47%) females with a mean age of 49 years (SD 12.2). Most bsb 191 (94.6%) had non-formal education. Of 190 (94.1%) irreversibly bsb, 180/190 (94.7%) had no light perception (NPL) bilaterally. The major causes of blindness were non-trachomatous corneal opacity (60.8%) and trachoma corneal opacity (12.8%). There were 166 (82%) blind from avoidable causes and 190 (94.1%) were irreversibly blind with 76.1% due to avoidable causes. The available sub-standard RS were educational, vocational and financial support. The barriers to RS in the past included non-availability 151 (87.8%), inability to afford 2 (1.2%), unfelt need 4 (2.3%), family refusal 1 (0.6), ignorance 6 (3.5%) and being not linked 8 (4.7%). The barriers to RS during the study period included inability of 72 subjects (35.6%) to access RS and 59 (81.9%) were due to lack of linkage to the existing services. Corneal opacification was the major cause of blindness among bsb. The main challenges to RS include the inadequate services available, societal and users factors. Renewed efforts are warranted toward the prevention of avoidable causes of blindness especially corneal opacities. The quality of life of the blind street beggar should be improved through available, accessible and affordable well-maintained and sustained rehabilitation services.

  5. Corneal Ectasia and Hydrops in Ocular Hypotony: The Corneal Crease. (United States)

    Farooq, Asim V; Soin, Ketki; Williamson, Samantha; Joslin, Charlotte E; Cortina, Maria S; Tu, Elmer Y


    To report the association of chronic ocular hypotony with the development of progressive corneal ectasia and hydrops. Retrospective case series. Three patients with ocular hypotony were referred for corneal evaluation and found to have ectasia and acute corneal hydrops in their hypotonous eye(s). Clinically, the globes were easily deformable with either external digital palpation and/or simple blinking. All 3 patients had a history of chronic iridocyclitis, including one with juvenile idiopathic arthritis. In each case, the area of thinning was narrow and arcuate in configuration, distinctive from other ectatic disorders. Also uncharacteristically, the acute hydrops resolved rapidly within 2 to 3 weeks without surgical intervention. In 1 case, severe thinning with perforation occurred requiring urgent penetrating keratoplasty. This case series demonstrates a unique clinical entity in which corneal ectasia and hydrops developed in the setting of ocular hypotony and easily deformable corneas, in a pattern unlike previously described forms of ectasia. Acute hydrops, even with associated corneal perforation, demonstrated a short and self-limited course. Corneal ectasia and irregular astigmatism should be suspected as a cause of unexplained visual loss in the ever-increasing number of patients with chronic, stable ocular hypotony. Further study is warranted to determine the pathophysiology of corneal ectasia in this setting, which may include mechanical and inflammatory factors.

  6. Keratoconus Detection Based on a New Corneal Volumetric Analysis. (United States)

    Cavas-Martínez, Francisco; Bataille, Laurent; Fernández-Pacheco, Daniel G; Cañavate, Francisco J F; Alio, Jorge L


    There are numerous tomographic indices for the detection of keratoconus risk. When the indexes based on corneal volume are analyzed, two problems are presented: on the one hand, they are not very sensitive to the detection of incipient cases of keratoconus because they are not locally defined in the primary developmental region of the structural abnormalities; and on the other hand, they do not register the geometric decompensation driven by the asymmetry present during the disease progression. This work performed a morphogeometric modeling of the cornea by the aid of CAD tools and using raw topographic data (Sirius system, CSO, Firenze). For this method, four singular points present on the corneal surfaces were located and the following parameters based on corneal volume were calculated: VOL mct , defined by the points of minimal thickness; VOL aap , defined by the anterior corneal apex, and VOL pap , defined by the posterior corneal apex. The results demonstrate that a further reduction of corneal volume in keratoconus happens and significantly progresses along the disease severity level. The combination of optical and volumetric data, that collect the sensitivity of the asymmetry generated by the disease, allows an accurate detection of incipient cases and follow up of the disease progression.

  7. A clinical microbiological study of corneal ulcer patients at western Gujarat, India. (United States)

    Somabhai Katara, Rajesh; Dhanjibhai Patel, Nilesh; Sinha, Mala


    Corneal ulcer is a major cause of blindness throughout the world. When the cornea is injured by foreign particles, there are chances of infection by the organism and development of ulcer. Bacterial infection in the cornea is invariably an alteration of the defense mechanism of the outer eye. It is essential to determine the local etiology within a given region when planning a corneal ulcer management strategy. Laboratory evaluation is necessary to establish the diagnosis and to guide the antibiotic therapy. One hundred corneal ulcer patients were studied by collecting their corneal scraping samples and processing at Clinical Microbiology department of Shree Meghaji Petharaj Shah Medical College, Jamnagar, Gujarat, India during a period of 17 months. All clinical microbiology laboratory procedures followed standard protocols described in the literature. 40 (40%) patients from the age group of 20-70 years had been confirmed as - any organism culture positive - within the corneal ulcer patient population. Fungi were isolated from 26 (26%) corneal ulcer patients. The bacterial etiology was confirmed in 14 (14%) corneal ulcer patients. The major risk factors for mycotic keratitis were vegetative injury (16, (62%)), followed by conjunctivitis (4, (15%)), and blunt trauma (3, (11%)). Pseudomonas aeruginosa was the most commonly isolated bacterium (6, (43%)), followed by Proteus spp. (4, (29%)). Corneal Infections due to bacteria and filamentous fungi are a frequent cause of corneal damage. Microbiological investigation is an essential tool in the diagnosis of these infections. The frequency of fungal keratitis has risen over the past 20 to 30 years. Prognosis of bacterial corneal infection has improved since the introduction of specific antibacterial therapy.

  8. Sclerocorneal graft and sequential removal of melted cornea after severe corneal burn with perforation. (United States)

    Viestenz, Anja; Seitz, Berthold; Struck, Hans-Gert; Viestenz, Arne


    Corneal burn grade IV usually leads to blindness. Several different surgical techniques remain challenging owing to the extensive tissue damage. Here, we introduce a novel technique with a 15 mm corneoscleral and limbal homologous graft combined with sequential autologous corneal removal ab interno, with a vitrectomy probe to save the anterior chamber angle. In vivo anatomy with optical coherence tomography is the surgical key. A large 15 mm sclerocorneal graft is sutured on top of the remainder of the destroyed cornea and sclera after removal of the epithelium and conjunctiva, with anterior synechiolysis if necessary, peripheral iridectomy and conjunctivoplasty. The recipient central corneal stroma is not removed, primarily to protect the anterior chamber angle. After three weeks, the collagenolytic central recipient corneal stroma can be removed with a small 23 g vitrectomy probe, respecting the lens and scleral spur. The corneoscleral graft remains clear under systemic and local immunosuppression. Intraocular pressure is well controlled because the anterior chamber angle is respected. Recurrent corneal erosions need close follow-up. Therapeutic soft contact lenses can support topical therapy. In cases of sclercorneal graft decompensation or rejection after 3-5 years, a new sclerocorneal graft (with limbal donation) seems to be superior to perforating keratoplasty without limbal stem cell transplantation. Repeated sclerocorneal grafts after severe corneal burn with limbal transplantation and maintenance of the complete anterior angle structure are a successful option for preventing blindness and achieving good visual acuity. Clin. Anat. 31:39-42, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. Inhibition of multiple pathogenic pathways by histone deacetylase inhibitor SAHA in a corneal alkali-burn injury model (United States)

    Li, Xinyu; Zhou, Qinbo; Hanus, Jakub; Anderson, Chastain; Zhang, Hongmei; Dellinger, Michael; Brekken, Rolf; Wang, Shusheng


    Neovascularization (NV) in the cornea is a major cause of vision impairment and corneal blindness. Hemangiogenesis and lymphangiogenesis induced by inflammation underlie the pathogenesis of corneal NV. The current mainstay treatment, corticosteroid, treats the inflammation associated with corneal NV, but is not satisfactory due to such side effects as cataract and the increase in intraocular pressure. It is imperative to develop a novel therapy that specifically targets the hemangiogenesis, lymphangiogenesis and inflammation pathways underlying corneal NV. Histone deacetylase inhibitors (HDACi) have been in clinical trials for cancer and other diseases. In particular, HDACi suberoylanilide hydroxamic acid (SAHA, vorinostat, Zolinza) has been approved by the FDA for the treatment of cutaneous T-cell lymphoma. The functional mechanism of SAHA in cancer and especially in corneal NV remains unclear. Here, we show that topical application of SAHA inhibits neovascularization in an alkali-burn corneal injury model. Mechanistically, SAHA inhibits corneal NV by repressing hemangiogenesis, inflammation pathways and previously overlooked lymphangiogenesis. Topical SAHA is well tolerated on the ocular surface. In addition, the potency of SAHA in corneal NV appears to be comparable to the current steroid therapy. SAHA may possess promising therapeutic potential in alkali-burn corneal injury and other inflammatory neovascularization disorders. PMID:23186311

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

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    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.

  11. The Impact of Type 1 Diabetes Mellitus on Corneal Epithelial Nerve Morphology and the Corneal Epithelium


    Cai, Daniel; Zhu, Meifang; Petroll, W. Matthew; Koppaka, Vindhya; Robertson, Danielle M.


    Diabetic corneal neuropathy can result in chronic, sight-threatening corneal pathology. Although the exact etiology is unknown, it is believed that a reduction in corneal sensitivity and loss of neurotrophic support contributes to corneal disease. Information regarding the relationship between nerve loss and effects on the corneal epithelium is limited. We investigated changes in the corneal epithelium and nerve morphology using three-dimensional imaging in vivo and in situ in a streptozotoci...

  12. [Methods for sealing of corneal perforations]. (United States)

    Samoilă, O; Totu, Lăcrămioara; Călugăru, M


    A variety of corneal pathology can lead to corneal ulcers and perforations. A deep corneal ulcer may need surgical treatment to allow good volume restoration and reepithelisation. Corneal perforation must be sealed and when the perforation is large, the task of repairing the defect can be underwhelming. The elegant solution is the corneal transplant, but this is not always readily available, especially in undeveloped countries. We present here two cases with different solutions to seal the perforated cornea: the first one has a large peripheral defect and it is successfully sealed with scleral patch and the second one is central with small perforation and is successfully sealed with multilayered amniotic membrane. Both cases are followed for over 12 months and demonstrate good corneal restoration (both on clinical examination and corneal topography). Sclera and amniotic membrane can be used to seal corneal defects when corneal transplant is not readily available.

  13. Corneal densitometry as an indicator of corneal health. (United States)

    Otri, Ahmad Muneer; Fares, Usama; Al-Aqaba, Mouhamed A; Dua, Harminder S


    To establish prospectively the normal values of corneal density of healthy subjects using the Pentacam Scheimpflug system (Oculus, Inc., Wetzlar, Germany) and to investigate alteration in corneal density during active and healed stages of bacterial keratitis. Prospective, comparative case series. Sixty-four eyes of 40 healthy controls and 36 eyes of 35 patients with bacterial keratitis were studied. This study was conducted at the Queen's Medical Centre, Nottingham, United Kingdom. A Pentacam system was used to study corneal density. Corneal densitometry readings in subjects with bacterial keratitis were recorded during the active stage and 4 to 6 weeks after complete healing. Densitometry was recorded at the site of infection and at a point in clear cornea furthest away from the infectious infiltrate. Corneal thickness also was measured. Densitometry values of normal cornea, at the site of corneal ulcer or abscess, and at a distant point of clear cornea during active and healed keratitis. The mean densitometry value of normal corneas was 12.3 ± 2.4. In infectious keratitis, the densitometry values were greatest at the site of the active infection and significantly more than in controls. The densitometry values at the points of clear cornea furthest away from the site of infection also were significantly higher than in controls during active disease, but failed to return to normal values, despite complete resolution of infection. The density of the infiltrates was much higher than that of residual scars after healing of ulcers. No correlation was found between the pachymetry and the densitometry values. Densitometry of active infectious corneal infiltrates is more than that resulting from the corneal scarring after healing. Persistent increase in density of clear cornea furthest away from the focus of corneal infection suggests that the host response extends beyond the immediate area of infection and indeed may occur through the entire cornea. These changes

  14. Corneal Confocal Microscopy Detects Corneal Nerve Damage in Patients Admitted With Acute Ischemic Stroke. (United States)

    Khan, Adnan; Akhtar, Naveed; Kamran, Saadat; Ponirakis, Georgios; Petropoulos, Ioannis N; Tunio, Nahel A; Dargham, Soha R; Imam, Yahia; Sartaj, Faheem; Parray, Aijaz; Bourke, Paula; Khan, Rabia; Santos, Mark; Joseph, Sujatha; Shuaib, Ashfaq; Malik, Rayaz A


    Corneal confocal microscopy can identify corneal nerve damage in patients with peripheral and central neurodegeneration. However, the use of corneal confocal microscopy in patients presenting with acute ischemic stroke is unknown. One hundred thirty patients (57 without diabetes mellitus [normal glucose tolerance], 32 with impaired glucose tolerance, and 41 with type 2 diabetes mellitus) admitted with acute ischemic stroke, and 28 age-matched healthy control participants underwent corneal confocal microscopy to quantify corneal nerve fiber density, corneal nerve branch density, and corneal nerve fiber length. There was a significant reduction in corneal nerve fiber density, corneal nerve branch density, and corneal nerve fiber length in stroke patients with normal glucose tolerance ( P diabetes mellitus ( P nerve fiber density ( r =-0.187, P =0.03; r =-0.229 P =0.01), corneal nerve fiber length ( r =-0.228, P =0.009; r =-0.285; P =0.001), and corneal nerve branch density ( r =-0.187, P =0.033; r =-0.229, P =0.01). Multiple linear regression showed no independent associations between corneal nerve fiber density, corneal nerve branch density, and corneal nerve fiber length and relevant risk factors for stroke. Corneal confocal microscopy is a rapid noninvasive ophthalmic imaging technique that identifies corneal nerve fiber loss in patients with acute ischemic stroke. © 2017 American Heart Association, Inc.

  15. Corneal topography indices after corneal collagen crosslinking for keratoconus and corneal ectasia: one-year results. (United States)

    Greenstein, Steven A; Fry, Kristen L; Hersh, Peter S


    To evaluate changes in corneal topography indices after corneal collagen crosslinking (CXL) in patients with keratoconus and corneal ectasia and analyze associations of these changes with visual acuity. Cornea and refractive surgery subspecialty practice. Prospective randomized controlled clinical trial. Corneal collagen crosslinking was performed in eyes with keratoconus or ectasia. Quantitative descriptors of corneal topography were measured with the Pentacam topographer and included 7 indices: index of surface variance, index of vertical asymmetry, keratoconus index, central keratoconus index, minimum radius of curvature, index of height asymmetry, and index of height decentration. Follow-up was 1 year. The study comprised 71 eyes, 49 with keratoconus and 22 with post-LASIK ectasia. In the entire patient cohort, there were significant improvements in the index of surface variance, index of vertical asymmetry, keratoconus index, and minimum radius of curvature at 1 year compared with baseline (all P ectasia subgroups. Improvements in postoperative indices were not correlated with changes in corrected or uncorrected distance visual acuity. There were improvements in 4 of 7 topography indices 1 year after CXL, suggesting an overall improvement in corneal shape. However, no significant correlation was found between the changes in individual topography indices and changes in visual acuity after CXL. Copyright © 2011. Published by Elsevier Inc.

  16. Corneal thickness changes after corneal collagen crosslinking for keratoconus and corneal ectasia: one-year results. (United States)

    Greenstein, Steven A; Shah, Vinnie P; Fry, Kristen L; Hersh, Peter S


    To determine the changes in corneal thickness over time after corneal collagen crosslinking (CXL) for keratoconus and corneal ectasia. Cornea and refractive surgery subspecialty practice. Prospective randomized controlled clinical trial. Corneal thickness at the apex, thinnest point, and pupil center were measured using Scheimpflug imaging (Pentacam) at baseline and 1, 3, 6, and 12 months after CXL. The treatment group was compared with both a sham-procedure control group and a fellow-eye control group. Associations with clinical outcomes (uncorrected and corrected distance visual acuities and maximum keratometry) were analyzed. The study comprised 82 eyes, 54 with keratoconus and 28 with ectasia after laser in situ keratomileusis. The mean preoperative thinnest pachymetry was 440.7 μm ± 52.9 (SD). After CXL, the cornea thinned at 1 month (mean change -23.8 ± 28.7 μm; Pcorneal thickness between 3 months and 6 months (mean +20.5 ± 20.4 μm; Pcorneal thickness was more rapid in ectasia than in keratoconus. There was no association between the degree of corneal thinning at 3 months and clinical outcomes after CXL. After CXL, the cornea thins and then recovers toward baseline thickness. The cause and implications of corneal thickness changes after CXL remain to be elucidated. No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  17. Corneal Sparing Conjunctival Abrasion

    Directory of Open Access Journals (Sweden)

    Hamid Ehsani-Nia


    Full Text Available History of present illness: A 15-year-old male was transported to the emergency department via ambulance as a trauma activation after being struck by an automobile while jogging. Patient was alert and oriented, with no focal neurological deficits and no loss of consciousness. The patient complained of right eye foreign body sensation. Significant findings: Physical exam was significant for multiple broken teeth, multiple minor abrasions on the face, and fine shards of shattered glass on his face and hair. His right eye had conjunctival injection, with no signs of subconjunctival hemorrhage or ocular penetration. Vision, extraocular movement, and pupillary exam were grossly intact. Fluorescein staining with slit lamp exam with cobalt blue filter examination of the right eye revealed superficial bulbar conjunctival uptake of fluorescein dye staining an area of the conjunctiva inferior to the limbus 5 mm vertical by 2 mm horizontal (estimation by photo provided. No foreign bodies were visualized in the inferior fornix. These findings were consistent with superficial conjunctival abrasion. The exam noted sparing of the corneal epithelium. Discussion: The conjunctiva is a thin, transparent membrane covering the ocular surface from the corneal limbus to the posterior eyelid margin.1 When damaged, the patient will classically have a “foreign body” sensation. It is important to identify the extent of the injury as not extending over the cornea, and also to search for lodged foreign bodies that damage the conjunctiva further with each blink. Classically retained foreign bodies will form a linear and vertical pattern of staining with fluorescein.2,3 Fluorescein stains expose basement membrane and fluoresces bright green under ultraviolet light, thus indicating areas of damage in contrast to its surrounding tissue.4,5 In the setting of acute trauma, urgent Ophthalmologic consultation is indicated if there is anterior chamber hemorrhage, a ruptured or

  18. Corneal stromal dystrophies: a clinical pathologic study

    Directory of Open Access Journals (Sweden)

    Elvira Barbosa Abreu


    Full Text Available INTRODUCTION: Corneal dystrophy is defined as bilateral and symmetric primary corneal disease, without previous associated ocular inflammation. Corneal dystrophies are classified according to the involved corneal layer in superficial, stromal, and posterior dystrophy. Incidence of each dystrophy varies according to the geographic region studied. PURPOSE: To evaluate the prevalence of stromal corneal dystrophies among corneal buttons specimens obtained by penetrating keratoplasty (PK in an ocular pathology laboratory and to correlate the diagnosis with patient age and gender. METHODS: Corneal button cases of penetrating keratoplasty from January-1996 to May-2009 were retrieved from the archives of The Henry C. Witelson Ophthalmic Pathology Laboratory and Registry, Montreal, Canada. The cases with histopathological diagnosis of stromal corneal dystrophies were stained with special stains (Peroxid acid Schiff, Masson trichrome, Congo red analyzed under polarized light, and alcian blue for classification and correlated with epidemiological information (age at time of PK and gender from patients' file. RESULTS: 1,300 corneal buttons cases with clinical diagnose of corneal dystrophy were retrieved. Stromal corneal dystrophy was found in 40 (3.1% cases. Lattice corneal dystrophy was the most prevalent with 26 cases (65%. Nineteen were female (73.07% and the PK was performed at average age of 59.3 years old. Combined corneal dystrophy was found in 8 (20% cases, 5 (62.5% of them were female and the average age of the penetrating keratoplasty was 54.8 years old. Granular corneal dystrophy was represented by 5 (12.5% cases, and 2 (40% of them were female. Penetrating keratoplasty was performed at average age of 39.5 years old in granular corneal dystrophy cases. Macular corneal dystrophy was present in only 1 (2.5% case, in a 36 years old female. CONCLUSION: Systematic histopathological approach and evaluation, including special stains in all stromal

  19. Corneal asphericity in eye bank eyes implanted with the intrastromal corneal ring. (United States)

    Burris, T E; Holmes-Higgin, D K; Silvestrini, T A; Scholl, J A; Proudfoot, R A; Baker, P C


    To evaluate the effects of the intrastromal corneal ring, a device developed to reduce myopia, on corneal asphericity in a large set of eye bank eyes. Forty-one deturgesced eye bank eyes were implanted with intrastromal corneal rings of five different thicknesses, ranging from 0.25 mm to 0.45 mm. Corneal asphericity, before and after implantation, was examined using two different metrologies. Corneal asphericity profiles were produced from dioptric power data collected from videokeratography. To statistically assess the corneal asphericity differences between exam times for each intrastromal corneal ring thickness, dependent sample confidence intervals (95%) were calculated for the mean differences between preoperative and postoperative measures for each topographic diameter zone. Laser holographic interferometry was used to inspect corneal asphericity in one eye bank eye case study for four intrastromal corneal ring sizes. Wave unit map and geometric zonal spot ray tracing analyses derived from laser holographic interferometry topography were surveyed. Videokeratographic analysis suggested that preoperative corneal shape was prolate, i.e., flattened from central to paracentral cornea. Corneal shape became more prolate with intrastromal corneal ring implantation for all intrastromal corneal ring thicknesses. Laser holographic interferometry demonstrated that prolate asphericity was preserved with the intrastromal corneal ring sizes tested and that optical collection efficiency of the cornea was not diminished. Using two different measurement techniques, this eye bank eye study demonstrated that intrastromal corneal rings maintain prolate corneal asphericity.

  20. Quiste dermoide corneal bilateral

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    Michel Guerra Almaguer

    Full Text Available El dermoide es un tipo de coristoma (tejido embrionario normal en una localización anormal que afecta con frecuencia la córnea. Aparece como una masa sólida, blanca, redonda y elevada. Suele localizarse en el limbo inferotemporal, aunque puede hacerlo en cualquier lugar del globo ocular o de la órbita. Se presenta un paciente masculino, de 8 años de edad, quien desde su nacimiento muestra una mancha blanca en ambos ojos, agudeza visual sin corrección de movimiento de mano a 33 centímetros en el ojo derecho y percepción luminosa en el ojo izquierdo. En la exploración oftalmológica de ambos ojos se apreciaron lesiones blanquecinas sobre la córnea. Se le realizó exéresis del quiste y queratoplastia lamelar de ambos ojos, con resultados visuales satisfactorios. Se concluye que el caso presenta un quiste dermoide corneal bilateral.

  1. Modafinil Improves Episodic Memory and Working Memory Cognition in Patients With Remitted Depression: A Double-Blind, Randomized, Placebo-Controlled Study. (United States)

    Kaser, Muzaffer; Deakin, Julia B; Michael, Albert; Zapata, Camilo; Bansal, Rachna; Ryan, Dragana; Cormack, Francesca; Rowe, James B; Sahakian, Barbara J


    Cognitive dysfunction is a core feature of depression and tends to persist even after mood symptoms recover, leading to detrimental effects on clinical and functional outcomes. However, most currently available treatments have not typically addressed cognition. Modafinil has been shown to have beneficial effects on cognitive function and therefore has the potential to improve cognition in depression. The objective of this double-blind, placebo-controlled study was to investigate the effects of modafinil on cognitive functions in patients with remitted depression. In total, 60 patients with remitted depression participated in the study. Cognitive functions were evaluated with tests of working memory, planning, attention, and episodic memory from the Cambridge Neuropsychological Test Automated Battery at the baseline session and after treatment. A double-blind, randomized, placebo-controlled, parallel groups design was used to assess the effects of single-dose (200 mg) modafinil ( n = 30) or placebo ( n = 30) on cognition and fatigue. The main outcome measures were neurocognitive test scores from the Cambridge Neuropsychological Test Automated Battery. Visual analogue scales for subjective feelings and fatigue were used as secondary measures. The modafinil group had significantly better performance on tests of episodic memory ( p = .01, η p 2 = .10) and working memory ( p = .04, η p 2 = .06). Modafinil did not improve planning or sustained attention. This study suggested that modafinil (200 mg) could improve episodic memory and working memory performance in patients with remitted depression. Modafinil may have potential as a therapeutic agent to help remitted depressed patients with persistent cognitive difficulties.

  2. Azithromycin and Doxycycline Attenuation of Acanthamoeba Virulence in a Human Corneal Tissue Model. (United States)

    Purssell, Andrew; Lau, Rachel; Boggild, Andrea K


    Amoebic keratitis is a potentially blinding eye infection caused by ubiquitous, free-living, environmental acanthamoebae, which are known to harbor bacterial endosymbionts. A Chlamydia-like endosymbiont has previously enhanced Acanthamoeba virulence in vitro. We investigated the potential effect of Acanthamoeba-endosymbiont coinfection in a human corneal tissue model representing clinical amoebic keratitis infection. Environmental and corneal Acanthamoeba isolates from the American Type Culture Collection were screened for endosymbionts by amplifying and sequencing bacterial 16S as well as Chlamydiales-specific DNA. Each Acanthamoeba isolate was used to infect EpiCorneal cells, a 3-dimensional human corneal tissue model. EpiCorneal cells were then treated with azithromycin, doxycycline, or control medium to determine whether antibiotics targeting common classes of bacterial endosymbionts attenuated Acanthamoeba virulence, as indicated by decreased observed cytopathic effect and inflammatory biomarker production. A novel endosymbiont closely related to Mycobacterium spp. was identified in Acanthamoeba polyphaga 50495. Infection of EpiCorneal cells with Acanthamoeba castellanii 50493 and A. polyphaga 50372 led to increased production of inflammatory cytokines and cytopathic effects visible under microscopy. These increases were attenuated by azithromycin and doxycycline. Our findings suggest that azithromycin and doxycycline may be effective adjuvants to standard antiacanthamoebal chemotherapy by potentially abrogating virulence-enhancing properties of bacterial endosymbionts. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail


    Directory of Open Access Journals (Sweden)

    Rekha Gyanchand


    Full Text Available BACKGROUND Requirement of donor cornea is essential to target the corneal blind. The best method to procure such corneas is from any major hospitals, which has a mortuary facility. The eye donation with hanging as the cause of death is very common in a mortuary setup. Some factors that are concerning regarding corneas procured from death due to hanging is the prolonged exposure of the cornea at the time of death, the exact time of death is not known, most of the cadavers are refrigerated for investigations as these arrive at the mortuary usually at night. Due to these reasons, the corneal surgeons are hesitant to use corneas procured from death due to hanging for corneal transplantation. Analysing these corneas would contribute to a great extent to the donor cornea pool in providing sight to the corneal blind, especially as majority are young individuals who commit suicide by hanging. In this study, the donor corneas were analysed with regards to corneal epithelial defect, endothelial cell morphology and utilisation of these corneas for transplantation. The aim of the HCRP study is to analyse the effect of death due to hanging on donor cornea. 1. Corneal epithelial status. 2. Corneal endothelial cell morphology. 3. Utilisation of corneas for transplantation. MATERIALS AND METHODS Donor corneas from 22 donors who died due to hanging were procured from hospital mortuary. All the 44 corneas were transplanted. Various parameters like demography, death to enucleation time, cadaver preservation in cold storage, endothelial cell density and utilisation of cornea for transplantation were noted. Design- Retrospective study. Statistical Analysis- Descriptive statistics, Pearson and Spearman correlation and Chi-square test were used to test the hypotheses. RESULTS Out of the 44 corneas analysed, 75% of the donors were refrigerated as a part of medicolegal investigations protocol. The average DTP time was 12 hours in refrigerated group and 5 hours in non

  4. Progress of research on corneal collagen cross-linking for corneal melting

    Directory of Open Access Journals (Sweden)

    Ke-Ren Xiao


    Full Text Available Corneal collagen cross-linking(CXLcould increase the mechanical strength, biological stability and halt ectasia progression due to covalent bond formed by photochemical reaction between ultraviolet-A and emulsion of riboflavin between collagen fibers in corneal stroma. Corneal melting is an autoimmune related noninfectious corneal ulcer. The mechanism of corneal melting, major treatment, the basic fundamental of ultraviolet-A riboflavin induced CXL and the clinical researches status and experiment in CXL were summarized in the study.

  5. Mitigating Scarring and Inflammation during Corneal Wound Healing using Nanofiber-Hydrogel Scaffolds (United States)

    Fu, Amy

    Due to the universal lack of donor tissue, there has been emerging interest in engineering materials to stimulate living cells to restore the features and functions of injured organs. We are particularly interested in developing materials for corneal use, where the necessity to maintain the tissue's transparency presents an additional challenge. Every year, there are 1.5 -- 2 million new cases of monocular blindness due to irregular healing of corneal injuries, dwarfing the approximately 150,000 corneal transplants performed. The large gap between the need and availability of cornea transplantation motivates us to develop a wound-healing scaffold that can prevent corneal blindness. To develop such a scaffold, it is necessary to regulate the cells responsible for repairing the damaged cornea, namely myofibroblasts, which are responsible for the disordered and non-refractive index matched scar that leads to corneal blindness. Using in vitro assays, we identified that protein nanofibers of certain orientation can promote cell migration and modulate the myofibroblast phenotype. The nanofibers are also transparent, easy to handle and non-cytotoxic. To adhere the nanofibers to a wound bed, we examined the use of two different in situ forming hydrogels: an artificial extracellular matrix protein (aECM)-based gel and a photo-crosslinkable heparin-based gel. Both hydrogels can be formed within minutes, are transparent upon gelation and are easily tunable. Using an in vivo mouse model for epithelial defects, we show that our corneal scaffolds (nanofibers together with hydrogel) are well-tolerated (no inflammatory response or turbidity) and support epithelium regrowth. We developed an ex vivo corneal tissue culture model where corneas that are wounded and treated with our scaffold can be cultured while retaining their ability to repair wounds for up to 21 days. Using this technique, we found that the aECM-based treatment induced a more favorable wound response than the

  6. Acute corneal hydrops in keratoconus

    Directory of Open Access Journals (Sweden)

    Prafulla K Maharana


    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.

  7. Ocular dimensions, corneal thickness, and corneal curvature in quarter horses with hereditary equine regional dermal asthenia. (United States)

    Badial, Peres R; Cisneros-Àlvarez, Luis Emiliano; Brandão, Cláudia Valéria S; Ranzani, José Joaquim T; Tomaz, Mayana A R V; Machado, Vania M; Borges, Alexandre S


    The aim of this study was to compare ocular dimensions, corneal curvature, and corneal thickness between horses affected with hereditary equine regional dermal asthenia (HERDA) and unaffected horses. Five HERDA-affected quarter horses and five healthy control quarter horses were used. Schirmer's tear test, tonometry, and corneal diameter measurements were performed in both eyes of all horses prior to ophthalmologic examinations. Ultrasonic pachymetry was performed to measure the central, temporal, nasal, dorsal, and ventral corneal thicknesses in all horses. B-mode ultrasound scanning was performed on both eyes of each horse to determine the dimensions of the ocular structures and to calculate the corneal curvature. Each corneal region examined in this study was thinner in the affected group compared with the healthy control group. However, significant differences in corneal thickness were only observed for the central and dorsal regions. HERDA-affected horses exhibited significant increases in corneal curvature and corneal diameter compared with unaffected animals. The ophthalmologic examinations revealed mild corneal opacity in one eye of one affected horse and in both eyes of three affected horses. No significant between-group differences were observed for Schirmer's tear test, intraocular pressure, or ocular dimensions. Hereditary equine regional dermal asthenia-affected horses exhibit decreased corneal thickness in several regions of the cornea, increased corneal curvature, increased corneal diameter, and mild corneal opacity. Additional research is required to determine whether the increased corneal curvature significantly impacts the visual accuracy of horses with HERDA. © 2014 American College of Veterinary Ophthalmologists.

  8. Corneal hysteresis: a useful tool in the diagnosis and management of primary open angle glaucoma. (United States)

    Molinari, Joseph F; Dance, Donnie D


    To describe a case of primary open angle glaucoma (POAG) and to illustrate a new principle in detecting and managing the disease using intraocular pressure (IOP) corneal hysteresis as a clinical guide. A case report is reviewed of a white 87-year-old male who was detected with ocular hypertension (OHTN) with bilateral asymmetrical corneal stiffness and POAG. A new indicator and alternative approach to determine and manage POAG is presented using evidence-based technology for clinical care and facilitating positive outcomes for one of the leading causes of blindness in the world.

  9. Progress in corneal wound healing (United States)

    Ljubimov, Alexander V.; Saghizadeh, Mehrnoosh


    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 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 epithelium, and

  10. [Results of corneal crosslinking for pellucid marginal corneal degeneration]. (United States)

    Bikbov, M M; Surkova, V K; Khalimov, A R; Usubov, E L

    to evaluate the clinical effectiveness of crosslinking in patients with progressive pellucid marginal corneal degeneration (PMCD). A total of 9 patients (16 eyes) with progressive PMCD were treated by standard crosslinking. The cornea was saturated with Dextralink solution and UV-A irradiated at 3 mW/cm2 for 30 minutes. The follow-up period was 12 months. One month after treatment, there was a slight decrease in uncorrected and best corrected visual acuity (UCVA and BCVA) - from 0.08±0.03 and 0.4±0.15 preoperatively down to 0.06±0.02 and 0.3±0.07, respectively, caused by pseudohaze of the cornea. Keratometric parameters (the average refractive power of the cornea, corneal astigmatism, and corneal thickness) did not change significantly. The demarcation line was identified in 56% of cases. By the 3-month follow-up, UCVA and BCVA improved up to 0.1±0.07 and 0.52±0.1, respectively. The refractive power of the cornea decreased by 2.0 diopters and corneal astigmatism - by 0.7 diopters reaching 46.8±2.7 and 5.1±1.3 diopters, respectively (p≤0.04). Central corneal thickness decreased by an average of 29 microns. The demarcation line remained visible in 25% of cases. At 6 months, BCVA averaged 0.58±0.13, at that, 56% of eyes gained 1 line and 31% - 2 lines. The refractive power of the cornea decreased down to 45.7±1.6 diopters, corneal astigmatism - down to 4.8±1.5 diopters. The demarcation line was not detected. At 1 year, there were no significant changes in the average values of optometric indices as compared to the 6-month period. Сonclusion. Pellucid marginal corneal degeneration should be regarded as a kind of primary ectasia, often bilateral and notable for its characteristic clinical picture and late onset. In progressive disease, photochemical crosslinking of the cornea contributes to the improvement of optometric parameters and stabilization of the process.

  11. Corneal stroma microfibrils

    KAUST Repository

    Hanlon, Samuel D.


    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


    African Journals Online (AJOL)


    Apr 10, 1971 ... At times one has had to improvise or temporize. cause the cornea to become taut, and in practice one ... In a donor eye the corneal surface flattens before the trephine and results in a trephine hole with sides ..... cornea that is clear and extends from just short of the central area to the limbus. In this way an ...

  13. PROSE treatment of corneal ectasia. (United States)

    Baran, Inna; Bradley, James A; Alipour, Fateme; Rosenthal, Perry; Le, Hong-Gam; Jacobs, Deborah S


    Prosthetic replacement of the ocular surface ecosystem (PROSE) uses custom designed and fabricated prosthetic devices in a treatment that restores vision, supports healing, reduces symptoms and improves quality of life in patients with complex corneal disease. We report the success rate for PROSE treatment of corneal ectasia. Records of 59 patients with corneal ectasia seen in consultation over 6 months were reviewed. Candidacy for treatment, topographic indices, change in visual acuity, achievement of satisfactory fit, device wear status and change in visual function at 6 months were recorded. Sixteen eyes were non-candidates because conventional correction was adequate. Trial devices were inserted but not dispensed for 13 eyes. No eyes were excluded for severity of ectasia. In the remaining 89 eyes, satisfactory fit was achieved and a device was dispensed. Twenty-one eyes (15 patients) had undergone penetrating keratoplasty. Device wear at 6 months was documented in 78/89 eyes (88%). NEI VFQ-25 score improved 27.6 points (pcorneal ectasia could be fitted with a PROSE device. PROSE treatment has a high success rate when measured by ability to achieve satisfactory fit, impact on visual acuity and 6 month data on both rate of continued wear and impact on visual function. PROSE treatment is an alternative to penetrating keratoplasty for patients with corneal ectasia who are contact lens intolerant. Copyright © 2012 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  14. Corneal ectasia after photorefractive keratectomy. (United States)

    Leccisotti, Antonio


    Corneal ectasia after photorefractive keratectomy (PRK) has only been occasionally reported, and its incidence has not been assessed. In a retrospective, non-comparative case series, incidence of corneal ectasia was evaluated in a personal consecutive 6453-case series of myopic PRK with a minimum follow-up of 18 months. Features and prognosis were evaluated in all patients with ectasia after PRK (in both personal and referred cases). Ectasia was detected in three eyes of two patients (patients 1 and 2) 3 years and 1 year after PRK performed elsewhere. In addition, in the personal PRK series, two eyes of two patients (patients 3 and 4) developed corneal ectasia 5 months after surgery (incidence: 0.03%). Pre-operatively, forme fruste keratoconus was present in patients 1, 3 and 4; keratoconus in the fellow eye in patient 2; pachymetry corneal ectasia in predisposed eyes, even after low myopic ablations. Forme fruste keratoconus and keratoconus in the fellow eye were the main pre-operative findings. Prognosis varies according to severity.

  15. Inhibition of TGF-β signaling enables human corneal endothelial cell expansion in vitro for use in regenerative medicine.

    Directory of Open Access Journals (Sweden)

    Naoki Okumura

    Full Text Available Corneal endothelial dysfunctions occurring in patients with Fuchs' endothelial corneal dystrophy, pseudoexfoliation syndrome, corneal endotheliitis, and surgically induced corneal endothelial damage cause blindness due to the loss of endothelial function that maintains corneal transparency. Transplantation of cultivated corneal endothelial cells (CECs has been researched to repair endothelial dysfunction in animal models, though the in vitro expansion of human CECs (HCECs is a pivotal practical issue. In this study we established an optimum condition for the cultivation of HCECs. When exposed to culture conditions, both primate and human CECs showed two distinct phenotypes: contact-inhibited polygonal monolayer and fibroblastic phenotypes. The use of SB431542, a selective inhibitor of the transforming growth factor-beta (TGF-β receptor, counteracted the fibroblastic phenotypes to the normal contact-inhibited monolayer, and these polygonal cells maintained endothelial physiological functions. Expression of ZO-1 and Na(+/K(+-ATPase maintained their subcellular localization at the plasma membrane. Furthermore, expression of type I collagen and fibronectin was greatly reduced. This present study may prove to be the substantial protocol to provide the efficient in vitro expansion of HCECs with an inhibitor to the TGF-β receptor, and may ultimately provide clinicians with a new therapeutic modality in regenerative medicine for the treatment of corneal endothelial dysfunctions.

  16. [Frequency of corneal ulcer: Retrospective study of 380 cases carried out in two centers in the DR Congo]. (United States)

    Ngoie Maloba, V; Ngayuna Nkiene, J; Tunku Kabamba, G; Chenge Borasisi, G


    To determine the frequency of corneal ulcer in our practice environment. This study was conducted at Saint-Joseph Hospital in Kinshasa and at the Lubumbashi University Clinics in the Democratic Republic of Congo from January 2011 to December 2014. We studied the frequency, demographic and clinical variables of corneal ulcer patients. A total of 380 cases of corneal ulcers were recorded out of 44,722 ophthalmologic consultations performed, with a frequency of 0.85% and a sex ratio ranging from 1.4 to 1.7 men to women. Corneal ulcer was diagnosed in patients of all ages; the mean age was 38.67±18.67 years. Patients with corneal ulcers presented for eye pain (80%), followed by tearing, photophobia, eye redness and blurred vision. The frequency of visual impairment was 10.30%; 2.1% of patients had vision reduced to light perception, and 1% of patients had no light perception. Corneal dystrophy was present in 41.6% of cases. Perforation of the globe and endophthalmitis were observed in 3.4% of cases each. Corneal ulceration is one of the leading causes of visual impairment and blindness in our practice environment. An early ophthalmologic consultation at the onset of symptoms and adequate management would improve the visual prognosis of patients. Copyright © 2017. Published by Elsevier Masson SAS.

  17. Management of corneal bee sting

    Directory of Open Access Journals (Sweden)

    Razmjoo H


    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

  18. Epidemiology of blinding eye diseases in Cross River State, Nigeria ...

    African Journals Online (AJOL)

    macular diseases and corneal diseases. The overall prevalence of these identified blinding eye diseases was 56.3%. Refractive error (62.8%)was the most prevalent followed by cataract (15.4%), glaucoma (11%), retinal/macular diseases (7%) ...

  19. [Cortical blindness]. (United States)

    Chokron, S


    Cortical blindness refers to a visual loss induced by a bilateral occipital lesion. The very strong cooperation between psychophysics, cognitive psychology, neurophysiology and neuropsychology these latter twenty years as well as recent progress in cerebral imagery have led to a better understanding of neurovisual deficits, such as cortical blindness. It thus becomes possible now to propose an earlier diagnosis of cortical blindness as well as new perspectives for rehabilitation in children as well as in adults. On the other hand, studying complex neurovisual deficits, such as cortical blindness is a way to infer normal functioning of the visual system. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  20. Morphology and neurochemistry of canine corneal innervation. (United States)

    Marfurt, C F; Murphy, C J; Florczak, J L


    To determine the architectural pattern and neuropeptide content of canine corneal innervation. Corneal nerve fibers in normal dog eyes were labeled immunohistochemically with antibodies against protein gene product (PGP)-9.5, calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal polypeptide (VIP), and tyrosine hydroxylase (TH). Relative innervation densities and distribution patterns for each fiber population were assessed qualitatively by serial line-drawing reconstructions and quantitatively by computer-assisted analyses. More than 99% of all corneal PGP-9.5-immunoreactive (IR) nerves contained both CGRP and SP, approximately 30% contained TH, and none contained VIP. Distribution patterns of corneal PGP-9.5-, CGRP-, SP-, and TH-IR nerves were indistinguishable, except that TH-IR fibers were absent from the corneal epithelium. Morphologically, canine corneal innervation consisted of a rich anterior stromal plexus, divided on the basis of morphologic criteria into anterior and posterior levels, and a rich epithelial innervation, characterized by large numbers of horizontally oriented, basal epithelial "leash" formations. Leash axons in all quadrants of the corneal epithelium oriented preferentially toward a common locus in the perilimbal cornea. The results of this study demonstrate for the first time the detailed architectural features, distinctive basal epithelial leash orientations, and peptidergic content of canine corneal innervation. The normal innervation pattern described in this study will provide other investigators with essential baseline data for assessing corneal nerve alterations in canine patients with spontaneous chronic corneal epithelial defects (SCCED) and other ocular diseases or injuries.

  1. Microbiological profile of corneal ulcer cases diagnosed in a tertiary care ophthalmological institute in Nepal. (United States)

    Suwal, Sharmila; Bhandari, Dinesh; Thapa, Pratigya; Shrestha, Mohan Krishna; Amatya, Jyoti


    Corneal ulcer, a major cause of monocular blindness in developing countries has consistently been listed as the major cause of blindness and visual disability in many of the developing nations in Asia, Africa and the Middle East, ranking second only to cataract. This study was carried out to determine the microbiological profile of corneal ulcer cases diagnosed among patients visiting Tilganga Institute of Ophthalmology (TIO), Nepal. A total of 101 corneal scrapping samples were tested for routine culture and antibiotic susceptibility at the pathology department of TIO Nepal from April to October 2014. Microorganisms were identified by using standard microbiological procedures following the manual of American Society for Microbiology (ASM) and their antibiotic susceptibility test, performed by Kirby-Bauer disc diffusion method in conformity with the CLSI guideline. Out of 101 samples analyzed, 44.6% (45/101) showed positive growth with bacterial isolates i.e., 56% (25/45), more prevalent than fungus i.e., 44% (20/45). Among bacteria Streptococcus pneumoniae (31.1%, N = 14) was isolated in highest number whereas Fusarium (13.4%, N = 6) was the most common fungus species. Pseudomonas aeruginosa was the only Gram negative bacteria isolated from corneal ulcer cases. All bacterial isolates were found to be susceptible to the quinolone group of antibiotics (moxifloxacin followed by ofloxacin and ciprofloxacin). These findings showcase the current trend in the microbiological etiology of corneal ulcer in Nepal, which have important public health implications for the treatment as well as prevention of corneal ulceration in the developing world.

  2. Working memory training in children with neuropsychiatric disorders and mild to borderline intellectual functioning, the role of coaching; a double-blind randomized controlled trial. (United States)

    Roording-Ragetlie, Sammy; Klip, Helen; Buitelaar, Jan; Slaats-Willemse, Dorine


    Working memory training (WMT) has been shown to offer therapeutic benefits to both patients with Attention-Deficit Hyperactivity Disorder (ADHD) and patients with mild to borderline Intellectual Disabilities (MBID; 60 effects and treatment benefits of WMT over placebo training are lacking. Owing to the nature of double-blind research designs in RCTs, children have received non-specific coaching not based on their actual training performance. Active coaching based on individual training results (such as in clinical practice) might enhance the efficacy of Cogmed WMT. Furthermore, clinical experience and the general treatment approach to these vulnerable children has shown that the intensity and duration of WMT is often too stressful. This study therefore investigated the efficacy of a less intensive, but more prolonged Cogmed WMT (including active personalized coaching and feedback) in reducing behavioral symptoms and improving neurocognitive functioning and academic achievements in children with MBID and neuropsychiatric disorders. A double-blind RCT with children (age 10.0-13.11) with neuropsychiatric disorders (ADHD and/or autism spectrum disorder (ASD)) and MBID (IQ: 60 working memory, executive functioning, academic achievements) before and after training and complete several questionnaires (behavioral problems, parenting style) with a 6 months follow-up. This study will add to the literature since the role of coaching in Cogmed WMT has not been studied before. It will also provide opportunities to investigate an alternative version of WMT in a large group of vulnerable children, for whom few evidence-based treatments are available. Ultimately, this will allow us to advise mental health care professionals and special education schools about the use of this type of intervention for children with MBID and neuropsychiatric disorders. Dutch Trial Register. NTR5223 . Registration date 06-09-2015.

  3. Evaluation of corneal symmetry after UV corneal crosslinking for keratoconus. (United States)

    Mofty, Hanan; Alzahrani, Khaled; Carley, Fiona; Harper, Sophie; Brahma, Arun; Au, Leon; Morley, Debbie; Hillarby, M Chantal


    The purpose of this study was to assess UV corneal crosslinking (CXL) treatment outcomes for keratoconus by evaluating the corneal regularity in patients through follow-up using the Oculus Pentacam. A total of 18 eyes from CXL patients with keratoconus were studied before and after CXL treatment, and six eyes from six patients who were not treated with CXL served as controls. Treated patients had Pentacam images taken before CXL treatment and regularly 3 months post treatment up to the 12th month. Controls were imaged during their first appointment and after 12 months. Symmetry and asphericity were evaluated and correlated with both best-corrected visual acuity (BCVA) and maximum K -readings. In the CXL-treated group, there was a significant improvement in the index of symmetrical variation (ISV) and keratoconus index (KI) at 3 months and in the index of height asymmetry (IHA) and minimum radius of curvature ( R min ) at 9 months post treatment. On the contrary, the untreated group's indices showed some significant worsening in ISV, KI, central keratoconus index (CKI), and R min . A novel finding in our study was a slight positive shift of anterior asphericity in the 6 mm, 7 mm, and 8 mm 3 months after treatment, which had a correlation with BCVA ( R 2 =0.390, p =0.053) and a strong correlation with maximum K -reading ( R 2 =0.690, p =0.005). However, the untreated group had no significant changes after 1 year. The corneal asymmetrical shape is associated with the spherical aberration alteration influenced by temporal evolution of surface ablation and increased corneal haze. However, insignificant changes in symmetry attest the stabilization effect on cornea postoperatively as compared with controls.

  4. Corneal Collagen Cross-linking for Treatment of Non-healing Corneal Ulcers. (United States)

    Zamani, Mitra; Panahi-Bazaz, Mahmoodreza; Assadi, Mona


    To evaluate the efficacy of corneal collagen cross-linking (CXL) for treatment of corneal ulcers not responding to antimicrobial therapy. Eight patients with corneal ulcers associated with corneal melting, not responding to conventional antibiotic therapy, were treated with CXL. The procedure was performed according to the standardized protocol for keratoconus. Preoperative medications were continued after CXL in all cases. Microbiological exams revealed Pseudomonas aeruginosa in 3 cases. Follow up continued from 1 to 10 months. In 6 of 8 eyes, progression of corneal melting was halted and complete epithelialization occurred. In one eye emergency keratoplasty was needed due to corneal perforation. A conjunctival flap was performed to treat severe localized corneal thinning in one of the patients a few days after CXL. Significant clinical improvement occurred in all cases of Pseudomonas aeruginosa keratitis. CXL can be considered as a promising new treatment in the management of refractory non-healing corneal ulcers, including Pseudomonas aeruginosa keratitis.

  5. Control of Scar Tissue Formation in the Cornea: Strategies in Clinical and Corneal Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Samantha L. Wilson


    Full Text Available Corneal structure is highly organized and unified in architecture with structural and functional integration which mediates transparency and vision. Disease and injury are the second most common cause of blindness affecting over 10 million people worldwide. Ninety percent of blindness is permanent due to scarring and vascularization. Scarring caused via fibrotic cellular responses, heals the tissue, but fails to restore transparency. Controlling keratocyte activation and differentiation are key for the inhibition and prevention of fibrosis. Ophthalmic surgery techniques are continually developing to preserve and restore vision but corneal regression and scarring are often detrimental side effects and long term continuous follow up studies are lacking or discouraging. Appropriate corneal models may lead to a reduced need for corneal transplantation as presently there are insufficient numbers or suitable tissue to meet demand. Synthetic optical materials are under development for keratoprothesis although clinical use is limited due to implantation complications and high rejection rates. Tissue engineered corneas offer an alternative which more closely mimic the morphological, physiological and biomechanical properties of native corneas. However, replication of the native collagen fiber organization and retaining the phenotype of stromal cells which prevent scar-like tissue formation remains a challenge. Careful manipulation of culture environments are under investigation to determine a suitable environment that simulates native ECM organization and stimulates keratocyte migration and generation.

  6. A thermoreversible hydrogel as a biosynthetic bandage for corneal wound repair. (United States)

    Pratoomsoot, Chayanin; Tanioka, Hidetoshi; Hori, Kuniko; Kawasaki, Satoshi; Kinoshita, Shigeru; Tighe, Patrick J; Dua, Harminder; Shakesheff, Kevin M; Rose, Felicity Rosamari A J


    Ocular trauma and disorders that lead to corneal blindness account for over 2 million new cases of monocular blindness every year. A popular ocular surface reconstruction therapy, amniotic membrane transplantation, has been shown to aid corneal wound repair. However, the success rates of the procedure are variable. Here, we proposed to bioengineer a novel synthetic material that would serve as a biomimetic corneal bandage. The PLGA-PEG-PLGA triblock copolymer was synthesised via ring-opening polymerisation. Thermoreversible gelation behaviour was investigated at different polymer concentrations (23%, 30%, 35%, 40%, 45%, w/v) at temperatures ranging between 5 and 60 degrees C. Viscoelastic properties were studied in dynamic mechanical analysis with 1 degrees C/min temperature ramp. Cryo-SEM revealed a porous hydrogel with interconnecting networks. No adverse cytotoxicity was observed with an in vitro scratch-wound assay and in in vivo biocompatibility tests. We have demonstrated that the PLGA-PEG-PLGA hydrogel possessed a suitable gelling profile and, for the first time, the biocompatibility properties for this application as a potential bandage for corneal wound repair.

  7. Corneal infection in Shandong peninsula of China: a 10-year retrospective study on 578 cases

    Directory of Open Access Journals (Sweden)

    Xiao-Jing Pan


    Full Text Available AIM: To determine the epidemiological characteristics, clinical signs, laboratory findings, and outcomes in patients with corneal infection in Shandong peninsula of China. METHODS: The medical records of 578 inpatients (578 eyes with corneal infection were reviewed retrospectively for demographic characteristics, risk factors, seasonal variation, clinical signs, laboratory findings, and treatment strategy. Patient history, ocular examination findings using slit-lamp biomicroscopy, laboratory findings resulted from microbiological cultures, and treatment. RESULTS: Fungal keratitis constituted 58.48% of cases of infectious keratitis among the inpatients, followed by herpes simplex keratitis (20.76%, bacterial keratitis (19.03% and acanthamoeba keratitis (1.73%. The most common risk factor was corneal trauma (71.80%. The direct microscopic examination (338 cases using potassium hydroxide (KOH wet mounts was positive in 296 cases (87.57%. Among the 298 fungal culture-positive cases, Fusarium species were the most common isolates (70.47%. A total of 517 cases (89.45% received surgical intervention, including 255 (44.12% cases of penetrating keratoplasty, 74 (12.80% cases of lamellar keratoplasty which has become increasingly popular, and 77 cases (13.32% of evisceration or enucleation. CONCLUSION: At present, infectious keratitis is a primary corneal disease causing blindness in China. With Fusarium species being the most commonly identified pathogens, fungal keratitis is the leading cause of severe infectious corneal ulcers in Shandong peninsula of China.

  8. Epidemiology and laboratory diagnosis of fungal corneal ulcer in the Sundarban Region of West Bengal, eastern India. (United States)

    Bandyopadhyay, S; Das, D; Mondal, K K; Ghanta, A K; Purkrit, S K; Bhasrar, R


    Corneal ulcers are the second most-common cause of preventable blindness after cataract in tropical developing countries. Fungal corneal ulcers constitute 30 to 62 % of the total microbial culture-positive corneal ulcers. To study the epidemiological characteristics, risk factors and laboratory diagnosis of fungal corneal ulcer in the Sundarban Region, West Bengal, eastern India. A retrospective review of 399 culture-positive, fungal corneal ulcers out of a total 928 corneal ulcer patients attending a tertiary care hospital in Kolkata,eastern India, over a period of four years from February 2007 to January 2011. Males (246; 61.65 %) were more commonly affected than females (P less than .0001).The affected people were mostly (342; 85.71 %) residing in the rural areas (P less than .0001). 196 patients (49.12 %) were involved in agricultural activities (P less than .0001). The younger people of, 21 - 50 years of age, were particularly prone to this disease (269; 67.41 %). Corneal trauma (354; 88.72 %) was the commonest risk factor (P less than .0001) and 261 patients (61.41 %) had a history of trauma with vegetative matter (P less than .0001). The use of topical corticosteroids was implicated in 65 (16.29 %) cases. The incidence of the disease was highest in the monsoon season, between June to September (192; 48.12 %). The aspergillus spp was the most common fungal growth (151; 37.84 %), followed by an Fusarium spp (81; 20.3 %). The fungal corneal ulcers are an important cause of ocular morbidity in people residing in the Sundarban Region. The identification of the etiology and the predisposing factors of corneal ulcers in this region are important for the prevention and early treatment of the disease. © NEPjOPH.

  9. Corneal collagen cross-linking for treatment of non-healing corneal ulcers


    Mitra Zamani; Mahmoodreza Panahi-Bazaz; Mona Assadi


    Purpose: To evaluate the efficacy of corneal collagen cross-linking (CXL) for treatment of corneal ulcers not responding to antimicrobial therapy. Methods: Eight patients with corneal ulcers associated with corneal melting, not responding to conventional antibiotic therapy, were treated with CXL. The procedure was performed according to the standardized protocol for keratoconus. Preoperative medications were continued after CXL in all cases. Microbiological exams revealed Pseudomonas aeru...

  10. Corneal Toxicity Following Exposure to Asclepias Tuberosa

    DEFF Research Database (Denmark)

    Mikkelsen, Lauge Hjorth; Hamoudi, Hassan; Gül, Cigdem Altuntas


    PURPOSE: To present a case of corneal toxicity following exposure to milky plant latex from Asclepias tuberosa. METHODS: A 70-year-old female presented with blurred vision and pain in her left eye after handling an Ascepias tuberosa. Clinical examination revealed a corneal stromal oedema with small...... that inhibit the Na+/ K+-ATPase in the corneal endothelium. The oedema resolved after 96 hours. After nine months the best corrected visual acuity was 20/20. CONCLUSION: Corneal toxicity has previously been reported for plants of the Asclepias family. This is a rare case describing severe corneal toxicity...... caused by exposure to latex from Asclepias tuberosa. Handling of plants of the Asclepias family should be kept as a differential diagnosis in cases of acute corneal toxicity....

  11. Corneal sensation after cataract and refractive surgery. (United States)

    Kohlhaas, M


    Most surgical procedures involving the anterior segment of the eye disrupt the normal organization of corneal innervation. Since denervation of the cornea results in impaired epithelial wound healing, increased epithelial permeability, decreased epithelial metabolic activity, and loss of cytoskeletal structures associated with cellular adhesion, it is important to identify the factors that determine the extent of neural regeneration. Mechanisms of corneal nerve damage and studies of corneal nerve fiber loss and reinnervation after cataract and refractive surgery--epikeratophakia, cryokeratomileusis, keratomileusis in situ, photorefractive keratectomy, laser in situ keratomileusis, and phacoemulsification--are reviewed and the decrease in corneal sensitivity, as a measure of corneal destruction and corneal metabolism, after these surgical procedures is compared.

  12. Topical thrombin-related corneal calcification. (United States)

    Kiratli, Hayyam; Irkeç, Murat; Alaçal, Sibel; Söylemezoğlu, Figen


    To report a highly unusual case of corneal calcification after brief intraoperative use of topical thrombin. A 44-year-old man underwent sclerouvectomy for ciliochoroidal leiomyoma, during which 35 UNIH/mL lyophilized bovine thrombin mixed with 9 mL of diluent containing 1500 mmol/mL calcium chloride was used. From the first postoperative day, corneal and anterior lenticular capsule calcifications developed, and corneal involvement slightly enlarged thereafter. A year later, 2 corneal punch biopsies confirmed calcification mainly in the Bowman layer. Topical treatment with 1.5% ethylenediaminetetraacetic acid significantly restored corneal clarity. Six months later, a standard extracapsular cataract extraction with intraocular lens placement improved visual acuity to 20/60. This case suggests that topical thrombin drops with elevated calcium concentrations may cause acute corneal calcification in Bowman layer and on the anterior lens capsule.


    Directory of Open Access Journals (Sweden)

    Dipak Bhuyan


    Full Text Available BACKGROUND Corneal transplantation or grafting is an operation in which abnormal corneal host tissue is replaced by healthy donor cornea. According to the World Health Organization (WHO, corneal diseases are among the major causes of vision loss and blindness in the world today after cataract and glaucoma. The aim of the study is to- 1. Evaluate the different aetiology of corneal opacity including active infective aetiology as indicated for penetrating keratoplasty. 2. Determine the clinical outcome of penetrating keratoplasty in relation to graft survival, graft rejection and peri-operative complications in different aetiology groups. 3. Determine the final visual outcome. MATERIALS AND METHODS Candidates for keratoplasty were selected from- 1. Eye Bank of Regional Institute of Ophthalmology (R.I.O. 2. R.I.O OPD. The study period was from September 2014 to August 2015. 30 cases were taken in the study. Descriptive statistics were applied to analyse the data wherever necessary. RESULTS 34.6±19.73 yrs. (mean±SD was the mean age at which transplants were done in the study. Out of total 30 cases, 13 (43.33% and 17 (56.66% were male and female, respectively. The different indications for penetrating keratoplasty are- Post ulcer corneal opacity in 14 cases (46.66%, posttraumatic corneal opacity 9 cases (30%, pseudophakic bullous keratopathy 4 cases (13.33%, corneal dystrophy in 2 cases (6.66% and non-healing corneal ulcer in 1 case (3.33%. 16 cases (53.33% showed clear graft till the last follow up while 11 (33.33% cases showed partially clear graft resulting in improved visual outcome while 3 cases (10.00% of the grafts were opaque due to graft failure. CONCLUSION The major indications for penetrating keratoplasty in this part of the world are post ulcer and posttraumatic corneal opacity and majority of them are illiterate agricultural workers who failed to get adequate treatment on time. Graft survival rate is high, which can be attributed to the

  14. Immunoglobulins in granular corneal dystrophy Groenouw type I

    DEFF Research Database (Denmark)

    Møller, H U; Bojsen-Møller, M; Schrøder, H D


    Three patients with granular corneal dystrophy Groenouw type I underwent corneal grafting, and cryostat sections of the corneal buttons were examined immunohistochemically for immunoglobulins. Positive results were obtained for IgG, Kappa-, and Lambda chains with immunofluorescence technique...

  15. Use of bovine pericardium (Tutopatch®) graft for surgical repair of deep melting corneal ulcers in dogs and corneal sequestra in cats. (United States)

    Dulaurent, Thomas; Azoulay, Thierry; Goulle, Frédéric; Dulaurent, Alice; Mentek, Marielle; Peiffer, Robert L; Isard, Pierre-François


    To evaluate the efficacy of bovine pericardium (BP) graft in the treatment of deep melting corneal ulcers in three dogs and corneal sequestra in three cats. Three dogs with keratomalacia affecting the deep third of the stroma and three cats with corneal sequestrum were evaluated and underwent surgery. Following keratectomy, BP material was placed into the keratectomy bed and sutured to the recipient cornea with 9/0 polyglactin suture material. Postoperative treatment with topical and systemic antibiotics, systemic nonsteroidal anti-inflammatory agents, and topical atropine was prescribed. Follow-up examinations were carried out 1, 2 weeks, 1 and 2 months after the surgery and consisted of a complete ophthalmic examination. Optical coherence tomography (OCT) was performed 1 and 2 months after the surgery in one dog and in one cat. At 1 week, corneal neovascularization was present around the BP graft in all cases. Four weeks after the BP graft, in two dogs and in all cats, the vascularization was regressing and the graft was integrated into the cornea, which was regaining transparency. Topical treatment with anti-inflammatory agents was then prescribed for 2 weeks. Two months after the surgery, 5 of 6 corneas in two dogs and three cats had healed with focal corneal scarring. The remaining dog had progression of the keratomalacia involving the deep BP graft that required additional surgery, but became blind. Bovine pericardium graft offers a promising option for surgical reconstruction of the cornea following keratectomy for the management of corneal ulcers and sequestra. © 2013 American College of Veterinary Ophthalmologists.

  16. Corneal hemangiosarcoma in a cat. (United States)

    Cazalot, G; Regnier, A; Deviers, A; Serra, F; Lucas, M N; Etienne, C L; Letron, I Raymond


    A 10 year-old castrated male Domestic Short-hair cat with a history of chronic bilateral keratitis was referred for assessment of a red, elevated mass involving the left cornea. The rapid growth of the mass, over a month period in combination with pronounced vascularization and invasion of the corneal surface suggested an aggressive inflammatory or neoplastic process. Following keratectomy, the lesion was diagnosed histopathologically as a hemangiosarcoma. The tumor recurred locally within 3 weeks and enucleation was performed. Histopathologic examination of the globe confirmed the diagnosis and did not reveal infiltration of the limbus and conjunctiva. No signs of local recurrence or metastatic disease have been observed 18 months following enucleation. To the authors' knowledge this is the first case of primary corneal hemangiosarcoma described in the feline species. © 2011 American College of Veterinary Ophthalmologists.

  17. Clinical research on corneal perforation

    Directory of Open Access Journals (Sweden)

    Cheng-Huan Dong


    Full Text Available AIM: To study the clinical characteristics of corneal perforation(CP.METHODS: A retrospective analysis in July 1995 to July 2010 the First Affiliated Hospital of Fujian Medical University diagnosed CP 72 patients(72 eyes, clinical characteristics of all the patients were analyzed. RESULTS: The incidence of corneal ulcer perforation rised year by year, the morbidity of male and female was 17:7, the onset age focused on 48 years old. Of 23 industrial workers(32%with clear history of trauma, pathogeny identification results: top two: fungal infection and Acanthamoeba keratitis. A using history of glucocorticoid was found in 10 cases. CONCLUSION: There are plenty of primary causes of CP such as traumas, fungal infection, Acanthamoeba keratitis, eroded keratitis, etc. CP happens in middle-aged males in Fujian province, most traumas are the causes, the main pathogenic bacteria is fungal infection.

  18. Evaluation of corneal symmetry after UV corneal crosslinking for keratoconus

    Directory of Open Access Journals (Sweden)

    Mofty H


    Full Text Available Hanan Mofty,1,2 Khaled Alzahrani,2 Fiona Carley,3 Sophie Harper,3 Arun Brahma,3 Leon Au,3 Debbie Morley,3 M Chantal Hillarby2 1Optometry Department, College of Applied Medical Science, King Saud University, Riyadh, Kingdom of Saudi Arabia; 2Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, 3Manchester Royal Eye Hospital, Manchester, UK Purpose: The purpose of this study was to assess UV corneal crosslinking (CXL treatment outcomes for keratoconus by evaluating the corneal regularity in patients through follow-up using the Oculus Pentacam.Patients and methods: A total of 18 eyes from CXL patients with keratoconus were studied before and after CXL treatment, and six eyes from six patients who were not treated with CXL served as controls. Treated patients had Pentacam images taken before CXL treatment and regularly 3 months post treatment up to the 12th month. Controls were imaged during their first appointment and after 12 months. Symmetry and asphericity were evaluated and correlated with both best-corrected visual acuity (BCVA and maximum K-readings.Results: In the CXL-treated group, there was a significant improvement in the index of symmetrical variation (ISV and keratoconus index (KI at 3 months and in the index of height asymmetry (IHA and minimum radius of curvature (Rmin at 9 months post treatment. On the contrary, the untreated group’s indices showed some significant worsening in ISV, KI, central keratoconus index (CKI, and Rmin. A novel finding in our study was a slight positive shift of anterior asphericity in the 6 mm, 7 mm, and 8 mm 3 months after treatment, which had a correlation with BCVA (R2=0.390, p=0.053 and a strong correlation with maximum K-reading (R2=0.690, p=0.005. However, the untreated group had no significant changes after 1 year.Conclusion: The corneal asymmetrical shape is associated with the spherical aberration alteration

  19. Haemophilus influenzae corneal ulcer in a therapeutic contact lens wearer.


    Armstrong, J. R.; Cohen, K. L.; McCarthy, L. R.


    Haemophilus influenzae is an unusual corneal pathogen and an unusual cause of corneal ulcers in Western society. In previous reports corneal complications from H. influenzae have been secondary to a conjunctivitis. The first case of a primary H. influenzae corneal ulcer as a complication of therapeutic contact lens wear is presented. Since other uncommon bacteria have been reported as causes of contact lens related corneal ulcers, the bacteriology of contact lens related corneal ulcers is rev...

  20. Organ transplantation scandal influencing corneal donation rate

    Directory of Open Access Journals (Sweden)

    Tobias Röck


    Full Text Available In the majority of countries, there is a shortage of donor corneas for corneal transplantations. This study investigated the impact of organ transplantation scandals on corneal donation rate at the University Hospital Tübingen. Each deceased patient was considered as a potential corneal donor. An ophthalmic resident handled with stable methods of procedures the corneal donor procurement from 2009 to 2015. The rates of corneal donation were examined and analyzed. Among the 5712 hospital deaths, consent for corneal donation was obtained in 711 cases. The mean annual corneal donation rate was 12.4%. Since 2009, the donation rate per year could be increased with exception of 2013 and 2015. In the end of 2012 and 2014 two huge organ donation scandals were known in Germany. In the following years 2013 and 2015 corneal donation rate decreased significantly (P=0.0181 and P=0.0006. We concluded that transplantation scandals have a significant impact on corneal donation rate. Improving professional's performance through full transparency and honesty is very important to earn trust of potential donors and their families.

  1. Organ transplantation scandal influencing corneal donation rate. (United States)

    Röck, Tobias; Bramkamp, Matthias; Bartz-Schmidt, Karl Ulrich; Röck, Daniel


    In the majority of countries, there is a shortage of donor corneas for corneal transplantations. This study investigated the impact of organ transplantation scandals on corneal donation rate at the University Hospital Tübingen. Each deceased patient was considered as a potential corneal donor. An ophthalmic resident handled with stable methods of procedures the corneal donor procurement from 2009 to 2015. The rates of corneal donation were examined and analyzed. Among the 5712 hospital deaths, consent for corneal donation was obtained in 711 cases. The mean annual corneal donation rate was 12.4%. Since 2009, the donation rate per year could be increased with exception of 2013 and 2015. In the end of 2012 and 2014 two huge organ donation scandals were known in Germany. In the following years 2013 and 2015 corneal donation rate decreased significantly ( P =0.0181 and P =0.0006). We concluded that transplantation scandals have a significant impact on corneal donation rate. Improving professional's performance through full transparency and honesty is very important to earn trust of potential donors and their families.

  2. [Visual impairment and blindness in children in a Malawian school for the blind]. (United States)

    Schulze Schwering, M; Nyrenda, M; Spitzer, M S; Kalua, K


    The aim of this study was to determine the anatomic sites of severe visual impairment and blindness in children in an integrated school for the blind in Malawi, and to compare the results with those of previous Malawian blind school studies. Children attending an integrated school for the blind in Malawi were examined in September 2011 using the standard WHO/PBL eye examination record for children with blindness and low vision. Visual acuity [VA] of the better eye was classified using the standardised WHO reporting form. Fifty-five pupils aged 6 to 19 years were examined, 39 (71 %) males, and 16 (29 %) females. Thirty eight (69%) were blind [BL], 8 (15 %) were severely visually impaired [SVI], 8 (15 %) visually impaired [VI], and 1 (1.8 %) was not visually impaired [NVI]. The major anatomic sites of visual loss were optic nerve (16 %) and retina (16 %), followed by lens/cataract (15 %), cornea (11 %) and lesions of the whole globe (11 %), uveal pathologies (6 %) and cortical blindness (2 %). The exact aetiology of VI or BL could not be determined in most children. Albinism accounted for 13 % (7/55) of the visual impairments. 24 % of the cases were considered to be potentially avoidable: refractive amblyopia among pseudophakic patients and corneal scaring. Optic atrophy, retinal diseases (mostly albinism) and cataracts were the major causes of severe visual impairment and blindness in children in an integrated school for the blind in Malawi. Corneal scarring was now the fourth cause of visual impairment, compared to being the commonest cause 35 years ago. Congenital cataract and its postoperative outcome were the commonest remedial causes of visual impairment. Georg Thieme Verlag KG Stuttgart · New York.

  3. Epidemiology of blindness in children. (United States)

    Solebo, Ameenat Lola; Teoh, Lucinda; Rahi, Jugnoo


    An estimated 14 million of the world's children are blind. A blind child is more likely to live in socioeconomic deprivation, to be more frequently hospitalised during childhood and to die in childhood than a child not living with blindness. This update of a previous review on childhood visual impairment focuses on emerging therapies for children with severe visual disability (severe visual impairment and blindness or SVI/BL).For children in higher income countries, cerebral visual impairment and optic nerve anomalies remain the most common causes of SVI/BL, while retinopathy of prematurity (ROP) and cataract are now the most common avoidable causes. The constellation of causes of childhood blindness in lower income settings is shifting from infective and nutritional corneal opacities and congenital anomalies to more resemble the patterns seen in higher income settings. Improvements in maternal and neonatal health and investment in and maintenance of national ophthalmic care infrastructure are the key to reducing the burden of avoidable blindness. New therapeutic targets are emerging for childhood visual disorders, although the safety and efficacy of novel therapies for diseases such as ROP or retinal dystrophies are not yet clear. Population-based epidemiological research, particularly on cerebral visual impairment and optic nerve hypoplasia, is needed in order to improve understanding of risk factors and to inform and support the development of novel therapies for disorders currently considered 'untreatable'. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  4. Childhood blindness in India: a population based perspective (United States)

    Dandona, R; Dandona, L


    Aim: To estimate the prevalence and causes of blindness in children in the southern Indian state of Andhra Pradesh. Methods: These data were obtained as part of two population based studies in which 6935 children ≤15 years of age participated. Blindness was defined as presenting distance visual acuity <6/60 in the better eye. Results: The prevalence of childhood blindness was 0.17% (95% confidence interval 0.09 to 0.30). Treatable refractive error caused 33.3% of the blindness, followed by 16.6% due to preventable causes (8.3% each due to vitamin A deficiency and amblyopia after cataract surgery). The major causes of the remaining blindness included congenital eye anomalies (16.7%) and retinal degeneration (16.7%). Conclusion: In the context of Vision 2020, the priorities for action to reduce childhood blindness in India are refractive error, cataract related amblyopia, and corneal diseases. PMID:12598433

  5. Surgical technique: coupling of intrastromal corneal ring segments for ectatic corneal disorders in eye bank corneas

    Directory of Open Access Journals (Sweden)

    Moshirfar M


    Full Text Available Majid Moshirfar1 Maylon Hsu1 Yousuf M Khalifa21Moran Eye Center, Salt Lake City, UT, 2Flaum Eye Institute, Rochester, NY, USAAbstract: The management of corneal ectasia is evolving, with intrastromal corneal ring segments playing an important role in delaying or eliminating the need for penetrating keratoplasty. This paper describes a modification in the implantation technique of intrastromal corneal ring segments that allows for coupling of the two segments with suture, affording more structural support.Keywords: intrastromal corneal ring segments, Intacs, keratonconus, corneal ectasia, keratoectasia

  6. Corneal Toxicity Associated With Aquarium Coral Palytoxin. (United States)

    Farooq, Asim V; Gibbons, Allister G; Council, Matthew D; Harocopos, George J; Holland, Simon; Judelson, Jeffrey; Shoss, Bradley L; Schmidt, Eric J; Md Noh, Umi Kalthum; D'Angelo, Alexander; Chundury, Rao V; Judelson, Richard; Perez, Victor L; Huang, Andrew J W


    To report a series of patients who developed corneal toxicity after exposure to aquarium coral palytoxin. Multicenter retrospective case series. Retrospective review. Seven patients presented with corneal findings ranging from superficial punctate epitheliopathy to bilateral corneal melt with subsequent perforation. Among those with mild corneal findings, resolution was achieved with topical steroids and lubrication, whereas some patients who developed progressive corneal melt required therapeutic penetrating keratoplasty. The history in all patients revealed exposure to aquarium zoanthid corals shortly before disease onset. A review of the literature revealed that there are few prior reports of coral-associated corneal toxicity and that some species of coral secrete a substance known as palytoxin, a potent vasoconstrictor that inhibits the membranous sodium-potassium ATPase pump across cell types and can cause rapid death if inhaled or ingested. This is the largest case series to date demonstrating patients with aquarium coral palytoxin-associated corneal toxicity, and is the first to provide details of related histopathologic findings. Similar to other forms of toxic keratoconjunctivitis, a detailed history and careful clinical assessment are required, as well as timely removal of the offending agent from the patients' ocular milieu and environment. Mild ocular surface and corneal disease may be treated effectively with aggressive topical steroid therapy and lubrication. Given the potential severity of ocular as well as systemic adverse effects, there should be increased awareness of this entity among eye care professionals, aquarium enthusiasts, and the general public. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Inhibition of Corneal Neovascularization by Hydrazinocurcumin ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of hydrazinocurcumin on a human vascular endothelial growth factor (VEGF)-induced corneal neovascularization in rabbit model. Methods: Murine corneal neovascularization (CorNV) was induced via two intrastromal implantations of VEGF polymer 2 mm from the limbus.

  8. Corneal staining after treatment with topical tetracycline

    NARCIS (Netherlands)

    Lapid-Gortzak, Ruth; Nieuwendaal, Carla P.; Slomovic, Allan R.; Spanjaard, Lodewijk


    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

  9. Corneal laceration caused by river crab

    Directory of Open Access Journals (Sweden)

    Vinuthinee N


    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


    African Journals Online (AJOL)


    Corneal scraping in corneal ulcerations was done for five children who had not used any medication. These children, with others suspected of having bacterial ulcers that were inadequately treated, were given. *Correspondence: Dr OO Onabolu, Consultant Ophthalmologist, Ophthalmology Department, OACHS, PMB 2027, ...

  11. Serratia corneal ulcers: a retrospective clinical study. (United States)

    Mah-Sadorra, Jeane Haidee; Najjar, Dany M; Rapuano, Christopher J; Laibson, Peter R; Cohen, Elisabeth J


    To study the clinical and microbiological profile of Serratia corneal ulcers at the Cornea Service of the Wills Eye Hospital. This was a retrospective, observational case series. The clinical records of patients with Serratia marcescens corneal ulcers seen at the Cornea Service of the Wills Eye Hospital between January 1, 1998 and December 31, 2002 were reviewed. Twenty-four cases of Serratia keratitis were identified in 21 patients. Two patients (9.5%) had recurrent keratitis, 1 of which recurred twice. Both had corneal graft edema and were on topical steroids and antiglaucoma drops. The Serratia infection in 15 patients (71%) was associated with an abnormal corneal surface. Twelve of these patients (57%) had the ulcer in a corneal graft, 4 (19%) of which were associated with suture infiltrates. Fifteen patients (71%) were on topical medications-15 used corticosteroids and 13 used antiglaucoma drops. Six patients (29%) were contact lens wearers-1 had a concomitant suture infiltrate associated with a corneal graft, and 5 had otherwise healthy corneas. One isolate lacked in vitro susceptibility to ciprofloxacin and ofloxacin but was susceptible to gentamicin and tobramycin. Nineteen patients had a favorable response to medical therapy. Two patients with poor outcome had large corneal ulcers with severe necrosis and thinning associated with delay in treatment. Serratia marcescens keratitis is associated with the presence of an abnormal corneal surface, use of topical medications, and contact lens wear. Prompt medical therapy results in a good clinical response in the majority of cases.

  12. Corneal ectasia after intrastromal presbyopic surgery. (United States)

    Courjaret, Jean-Christophe; Matonti, Frederic; Savoldelli, Michele; D'Hermies, Francois; Legeais, Jean-Marc; Hoffart, Louis


    To report histopathologic findings in a case of bilateral corneal ectasia following intrastromal femtosecond laser presbyopia surgery. Case report. A 56-year-old patient was referred for bilateral corneal ectasia. He was treated for hyperopia using LASIK twice in both eyes. A bilateral femtosecond laser intrastromal presbyopia correction was secondarily performed. The patient complained of progressive loss of distance visual acuity shortly after. Corneal topography showed a bilateral central corneal protrusion. Rigid contact lenses were successfully fitted on the right eye and, because the patient still complained, a deep anterior lamellar keratoplasty was performed in the left eye. Light and electronic microscopy of the corneal button revealed that the inner intrastromal incision crossed the LASIK interface and led to stromal bed dehiscence. This case illustrates that intrastromal refractive surgery should not be recommended in eyes previously treated by lamellar refractive surgery.

  13. Corneal autofluorescence in presence of diabetic retinopathy (United States)

    Rovati, Luigi; Docchio, Franco; Azzolini, Claudio; Van Best, Jaap A.


    Recently corneal autofluorescence has been proposed as an ocular diagnostic tool for diabetic retinopathy. The method is based on the sensible increase of the natural fluorescence of corneal tissue within specific wavelength in presence of early stage of diabetic retinopathy. The main advantages of this method are that the corneal autofluorescence has been demonstrated to be not age-related and that the cornea is readily accessible to be investigated. In this study 47 insulin-dependent diabetes mellitus and 51 non-insulin- dependent diabetes mellitus patients aged 20 - 90 years have been considered. Patients were selected from the Eye Clinic of S. Raffaele Hospital. The modified Airlie House classification was used to grade the diabetic retinopathy. Corneal autofluorescence has been measured by using both a specifically designed instrument and the Fluorotron Master. Corneal autofluorescence mean value for each diabetic retinopathy measured by using both the instruments correlated with the retinopathy grade.

  14. Late onset corneal ectasia after LASIK surgery. (United States)

    Said, Ashraf; Hamade, Issam H; Tabbara, Khalid F


    To report late onset corneal ectasia following myopic LASIK. A retrospective cohort case series. Nineteen patients with late onset corneal ectasia following LASIK procedure were examined at The Eye Center, Riyadh, Saudi Arabia. Patients underwent LASIK for myopia with spherical equivalent ranging from -1.4 to -13.75 diopters. Age and gender, history of systemic or local diseases, and time of onset of corneal ectasia were recorded. Eye examination and corneal topographical analyses were done before and after LASIK surgery. Nineteen patients (29 eyes) with late onset corneal ectasia were identified from 1998 to 2008 in 13 male and six female patients. The mean follow-up period was 108 ± 23 months (range 72-144 months). No patient had pre-operative identifiable risk factors for corneal ectasia and the mean time of onset was 57 ± 24 months (range 24-120 months after LASIK). The pre-operative values included mean central pachymetry 553 ± 25 μm, mean keratometry reading of 42.9 ± 1.5 diopters, average oblique cylinder of 1.4 ± 1.2 diopters, posterior surface elevation of 26 ± 2.1 diopters, corneal flap thickness of 160 μm, mean spherical equivalent of -5.6 ± 3.6 diopters, and calculated residual corneal stromal bed thickness was 288 ± 35 μm. Three (5 eyes) patients developed ectasia after pregnancy. Three (4 eyes) patients developed corneal ectasia following severe adenoviral keratoconjunctivitis and had positive PCR for adenovirus type 8. Corneal ectasia may develop many years after LASIK surgery and symptoms could go undetected for some time. Pregnancy and adenoviral keratoconjunctivitis occurred post-operatively in six patients.

  15. Corneal sensitivity in chronic inflammatory demyelinating polyneuropathy. (United States)

    Bansal, Surbhi; Myneni, Ajay A; Mu, Lina; Myers, Bennett H; Patel, Sangita P


    Neurotrophic keratitis may result from a variety of ocular or systemic diseases. Chronic inflammatory demyelinating polyneuropathy (CIDP) is an autoimmune neuropathy that affects any nerve plexus but with no known association with corneal disease. We observed 2 patients with CIDP and visually compromising neurotrophic corneal ulcers. This study was performed to determine the prevalence of neurotrophic corneas in patients with CIDP to identify a subpopulation of asymptomatic patients who are at risk for vision loss. This is an observational case series of 2 patients with CIDP with visually compromising neurotrophic corneal ulcers and a prospective clinical study comparing corneal sensitivity in 9 patients with CIDP versus 9 age- and sex-matched controls. Corneal sensitivity was tested with an esthesiometer. Statistical analyses were performed to determine patterns or significances in relation to the subject's age, gender, and duration and severity of the disease. The overall median corneal sensitivity was 5.7 for patients with CIDP and 6.0 for controls (P = 0.09). The mean corneal sensitivity was 5.6 ± 0.4 in patients with CIDP compared with 5.8 ± 0.3 in controls. No specific pattern was found with age, gender, or duration and severity of the disease among patients with CIDP. Although the case series demonstrated decreased corneal sensitivity in both patients with CIDP, the prospective study detected reduced corneal sensitivity in patients with CIDP when compared with controls, but did not reach statistical significance. Ophthalmic examinations with measurement of corneal sensitivity should be considered in the management of patients with CIDP.Clinical Trial Registration-URL: Unique identifier: NCT01379833.

  16. Effectiveness of Essence of Chicken in Improving Cognitive Function in Young People Under Work-Related Stress: A Randomized Double-Blind Trial. (United States)

    Chan, Lung; Wang, Hsuan-Min; Chen, Kuan-Yu; Lin, Ying-Chin; Wu, Pei-Jung; Hsieh, Wan-Lin; Chen, Ying-Ru; Liu, Cheung-Pin; Tsai, Han-Yin; Chen, Yun-Ru; Chang, Hsiu-Hui; Hsieh, Yi-Chen; Hu, Chaur-Jong


    Work-related stress (WS) can result in considerable and extensive changes in physiological and psychological performance. WS beyond the optimal levels induces anxiety, confusion, exhaustion, and burnout. Chronic WS affects neurocognitive performance, particularly attention and visuospatial memory. Essence of chicken (EC) has been reported to improve neurocognitive function after mental stress.To investigate the beneficial effects of EC in improving neurocognitive performance under WS, we conducted a randomized, double blind trial. Total 102 young workers in New Taipei City with high WS, evaluated using the Individual Subjective Perception Job Stress Scale scores (>36 for job leaders and 33 for nonleaders) were recruited. Fifty-one participants received 70 mL of EC and 51 received a placebo daily for 2 weeks. Blood tests and neurocognitive assessment were performed before treatment, at the end of treatment, and 2 weeks after treatment.EC improved the performance of participants with high depression scores in the form-color associative memory test, used for assessing short-term memory. Although creatinine and glutamic-pyruvic transaminase (GPT) levels increased in week 2, but the levels returned to the baseline in week 4. Blood urea nitrogen (BUN) levels decreased in week 4.EC significantly improved short-term memory in participants with high WS and concomitant depressive mood, although it slightly increased GPT and creatinine levels and reduced BUN levels. The long-term treatment effects of EC warrant further investigation.

  17. Armodafinil versus Modafinil in Patients of Excessive Sleepiness Associated with Shift Work Sleep Disorder: A Randomized Double Blind Multicentric Clinical Trial

    Directory of Open Access Journals (Sweden)

    D. V. Tembe


    Full Text Available Aim. To compare the efficacy and safety of armodafinil, the R-enantiomer of modafinil, with modafinil in patients of shift work sleep disorder (SWSD. Material and Methods. This was a 12-week, randomized, comparative, double-blind, multicentric, parallel-group study in 211 patients of SWSD, receiving armodafinil (150 mg or modafinil (200 mg one hour prior to the night shift. Outcome Measures. Efficacy was assessed by change in stanford sleepiness score (SSS by at least 2 grades (responder and global assessment for efficacy. Safety was assessed by incidence of adverse events, change in laboratory parameters, ECG, and global assessment of tolerability. Results. Both modafinil and armodafinil significantly improved sleepiness mean grades as compared to baseline (<.0001. Responder rates with armodafinil (72.12% and modafinil (74.29% were comparable (=.76. Adverse event incidences were comparable. Conclusion. Armodafinil was found to be safe and effective in the treatment of SWSD in Indian patients. The study did not demonstrate any difference in efficacy and safety of armodafinil 150 mg and modafinil 200 mg.

  18. Postnatal periodontal ligament as a novel adult stem cell source for regenerative corneal cell therapy. (United States)

    Yam, Gary Hin-Fai; Teo, Ericia Pei-Wen; Setiawan, Melina; Lovatt, Matthew J; Yusoff, Nur Zahirah Binte M; Fuest, Matthias; Goh, Bee-Tin; Mehta, Jodhbir S


    Corneal opacities are a leading cause of global blindness. They are conventionally treated by the transplantation of donor corneal tissue, which is, restricted by a worldwide donor material shortage and allograft rejection. Autologous adult stem cells with a potential to differentiate into corneal stromal keratocytes (CSKs) could offer a suitable choice of cells for regenerative cell therapy. Postnatal periodontal ligament (PDL) contains a population of adult stem cells, which has a similar embryological origin as CSK, that is cranial neural crest. We harvested PDL cells from young adult teeth extracted because of non-functional or orthodontic reason and differentiated them towards CSK phenotype using a two-step protocol with spheroid formation followed by growth factor and cytokine induction in a stromal environment (human amnion stroma and porcine corneal stroma). Our results showed that the PDL-differentiated CSK-like cells expressed CSK markers (CD34, ALDH3A1, keratocan, lumican, CHST6, B3GNT7 and Col8A2) and had minimal expression of genes related to fibrosis and other lineages (vasculogenesis, adipogenesis, myogenesis, epitheliogenesis, neurogenesis and hematogenesis). Introduction of PDL spheroids into the stroma of porcine corneas resulted in extensive migration of cells inside the host stroma after 14-day organ culture. Their quiescent nature and uniform cell distribution resembled to that of mature CSKs inside the native stroma. Our results demonstrated the potential translation of PDL cells for regenerative corneal cell therapy for corneal opacities. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  19. Construction of a human corneal stromal equivalent with non-transfected human corneal stromal cells and acellular porcine corneal stromata. (United States)

    Diao, Jin-Mei; Pang, Xin; Qiu, Yue; Miao, Ying; Yu, Miao-Miao; Fan, Ting-Jun


    A tissue-engineered human corneal stroma (TE-HCS) has been developed as a promising equivalent to the native corneal stroma for replacement therapy. However, there is still a crucial need to improve the current approaches to render the TE-HCS equivalent more favorable for clinical applications. At the present study, we constructed a TE-HCS by incubating non-transfected human corneal stromal (HCS) cells in an acellular porcine corneal stromata (aPCS) scaffold in 20% fetal bovine serum supplemented DMEM/F12 (1:1) medium at 37 °C with 5% CO2in vitro. After 3 days of incubation, the constructed TE-HCS had a suitable tensile strength for transplantation, and a transparency that is comparable to native cornea. The TE-HCS had a normal histological structure which contained regularly aligned collagen fibers and differentiated HCS cells with positive expression of marker and functional proteins, mimicking a native HCS. After transplantation into rabbit models, the TE-HCS reconstructed normal corneal stroma in vivo and function well in maintaining corneal clarity and thickness, indicating that the completely biological TE-HCS could be used as a HCS equivalent. The constructed TE-HCS has promising potentials in regenerative medicine and treatment of diseases caused by corneal stromal disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Intraoperative corneal thickness measurements during corneal collagen cross-linking with isotonic riboflavin solution without dextran in corneal ectasia. (United States)

    Cınar, Yasin; Cingü, Abdullah Kürşat; Sahin, Alparslan; Türkcü, Fatih Mehmet; Yüksel, Harun; Caca, Ihsan


    Abstract Objective: To monitor the changes in corneal thickness during the corneal collagen cross-linking procedure by using isotonic riboflavin solution without dextran in ectatic corneal diseases. The corneal thickness measurements were obtained before epithelial removal, after epithelial removal, following the instillation of isotonic riboflavin solution without dextran for 30 min, and after 10 min of ultraviolet A irradiation. Eleven eyes of eleven patients with progressive keratoconus (n = 10) and iatrogenic corneal ectasia (n = 1) were included in this study. The mean thinnest pachymetric measurements were 391.82 ± 30.34 µm (320-434 µm) after de-epithelialization of the cornea, 435 ± 21.17 µm (402-472 µm) following 30 min instillation of isotonic riboflavin solution without dextran and 431.73 ± 20.64 µm (387-461 µm) following 10 min of ultraviolet A irradiation to the cornea. Performing corneal cross-linking procedure with isotonic riboflavin solution without dextran might not induce corneal thinning but a little swelling throughout the procedure.

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

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    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.

  2. The impact of type 1 diabetes mellitus on corneal epithelial nerve morphology and the corneal epithelium. (United States)

    Cai, Daniel; Zhu, Meifang; Petroll, W Matthew; Koppaka, Vindhya; Robertson, Danielle M


    Diabetic corneal neuropathy can result in chronic, sight-threatening corneal pathology. Although the exact etiology is unknown, it is believed that a reduction in corneal sensitivity and loss of neurotrophic support contributes to corneal disease. Information regarding the relationship between nerve loss and effects on the corneal epithelium is limited. We investigated changes in the corneal epithelium and nerve morphology using three-dimensional imaging in vivo and in situ in a streptozotocin-induced diabetic mouse model. Streptozotocin-treated mice showed increased levels of serum glucose and growth retardation consistent with a severe diabetic state. A reduction in the length of the subbasal nerve plexus was evident after 6 weeks of disease. Loss of the subbasal nerve plexus was associated with corneal epithelial thinning and a reduction in basal epithelial cell density. In contrast, loss of the terminal epithelial nerves was associated with animal age. Importantly, this is the first rodent model of type 1 diabetes that shows characteristics of corneal epithelial thinning and a reduction in basal epithelial cell density, both previously have been documented in humans with diabetic corneal neuropathy. These findings indicate that in type 1 diabetes, nerve fiber damage is evident in the subbasal nerve plexus before terminal epithelial nerve loss and that neurotrophic support from both the subbasal nerve plexus and terminal epithelial nerves is essential for the maintenance of corneal epithelial homeostasis. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  3. High interocular corneal symmetry in average simulated keratometry, central corneal thickness, and posterior elevation. (United States)

    Myrowitz, Elliott H; Kouzis, Anthony C; O'Brien, Terrence P


    The purpose of this study was to assess interocular corneal symmetry in average simulated keratometry, corneal thickness, and posterior corneal elevation. This retrospective analysis included data from scanning slit topography (Orbscan II; Bausch and Lomb, Rochester, NY) on 242 eyes from 121 consecutive patients undergoing standard evaluation for consideration of elective laser vision correction. The symmetry between the right and left eye in average simulated keratometry, minimum central corneal thickness, and posterior corneal elevation was assessed by comparative data analysis. Simulated keratometry ranged from 39.9 to 48.6 D. The interocular difference in average simulated keratometry was 0.47 D (standard deviation [SD] 0.43). The interocular Pearson correlation coefficient for average simulated keratometry was 0.90 (p central corneal thickness was 0.95 (p symmetry in all these parameters was very high in this group of consecutive patients. Asymmetry of these interocular parameters may warrant repeat clinical testing for accuracy and may predict corneal abnormalities. Normative data on posterior cornea elevation is presented. This study points out potentially clinically important high interocular corneal symmetry data in simulated keratometry, corneal thickness, and posterior corneal elevation.

  4. Semi-quantitative assessments of dextran toxicity on corneal endothelium: conceptual design of a predictive algorithm. (United States)

    Filev, Filip; Oezcan, Ceprail; Feuerstacke, Jana; Linke, Stephan J; Wulff, Birgit; Hellwinkel, Olaf J C


    Dextran is added to corneal culture medium for at least 8 h prior to transplantation to ensure that the cornea is osmotically dehydrated. It is presumed that dextran has a certain toxic effect on corneal endothelium but the degree and the kinetics of this effect have not been quantified so far. We consider that such data regarding the toxicity of dextran on the corneal endothelium could have an impact on scheduling and logistics of corneal preparation in eye banking. In retrospective statistic analyses, we compared the progress of corneal endothelium (endothelium cell loss per day) of 1334 organ-cultured corneal explants in media with and without dextran. Also, the influence of donor-age, sex and cause of death on the observed dextran-mediated effect on endothelial cell counts was studied. Corneas cultured in dextran-free medium showed a mean endothelium cell count decrease of 0.7% per day. Dextran supplementation led to a mean endothelium cell loss of 2.01% per day; this reflects an increase by the factor of 2.9. The toxic impact of dextran was found to be time dependent; while the prevailing part of the effect was observed within the first 24 h after dextran-addition. Donor age, sex and cause of death did not seem to have an influence on the dextran-mediated toxicity. Based on these findings, we could design an algorithm which approximately describes the kinetics of dextran-toxicity. We reproduced the previously reported toxic effect of dextran on the corneal endothelium in vitro. Additionally, this is the first work that provides an algorithmic instrument for the semi-quantitative calculation of the putative endothelium cell count decrease in dextran containing medium for a given incubation time and could thus influence the time management and planning of corneal transplantations.

  5. The effects of vortioxetine on cognitive performance in working patients with major depressive disorder: A short-term, randomized, double-blind, exploratory study. (United States)

    Baune, Bernhard T; Sluth, Lasse B; Olsen, Christina K


    Major Depressive Disorder (MDD) is a complex disease characterized by emotional, physical and cognitive symptoms. We explored the efficacy of vortioxetine versus placebo on outcomes of cognition, functioning and mood symptoms in working patients with depression, using paroxetine as an active reference. Gainfully employed patients (18-65 years, N = 152) with MDD were randomized 1:1:1 to 8 weeks' double-blind, parallel treatment either with vortioxetine (10mg/day) or paroxetine (20mg/day), or with placebo. The primary efficacy measure was the Digit Symbol Substitution Test (DSST), analyzed using a mixed model for repeated measurements, and the key secondary efficacy measure was the University of San Diego Performance-based Skills Assessment - Brief (UPSA-B), analyzed using analysis of covariance (last observation carried forward). At week 8, DSST and UPSA-B performance had improved relative to baseline in all treatment groups, with no statistically significant differences between treatment groups. While improvements in mood were comparable for vortioxetine and paroxetine, numerical improvements in cognitive performance (DSST) were larger with vortioxetine. Vortioxetine significantly improved overall cognitive performance and clinician-rated functioning relative to placebo. The majority of adverse events were mild or moderate, with nausea being the most common adverse event for vortioxetine. Small sample sizes implied limited statistical power. This explorative study showed no significant differences versus placebo in DSST or UPSA-B performance at week 8. However, secondary results support vortioxetine as an effective and well-tolerated antidepressant, supporting an added benefit for cognition and functioning, which could have particular therapeutic relevance for the working patient population. Copyright © 2017 H Lundbeck A/S. Published by Elsevier B.V. All rights reserved.

  6. Chapitre 9. How can the rate of avoidable blindness through treatment of trichiasis be evaluated?[Comment évaluer le taux de cécité évitable par cure de trichiasis ?


    Lietman, Thomas


    Although individuals with trachoma may occasionally lose vision from pannus (a superficial fibrovasular proliferation) over the pupil, a more frequent cause of blindness is from a corneal ulcer caused by superinfection with a bacteria or a fungus. These ulcers frequently leave a corneal scar over the pupil and result in markedly decreased vision. People with cicatricial trachoma are at a higher risk for corneal ulcers for several reasons: dry eye from scarred tear glands, recurrent dacryocyst...

  7. Corneal modeling for analysis of photorefractive keratectomy (United States)

    Della Vecchia, Michael A.; Lamkin-Kennard, Kathleen


    Procedurally, excimer photorefractive keratectomy is based on the refractive correction of composite spherical and cylindrical ophthalmic errors of the entire eye. These refractive errors are inputted for correction at the corneal plane and for the properly controlled duration and location of laser energy. Topography is usually taken to correspondingly monitor spherical and cylindrical corneorefractive errors. While a corneal topographer provides surface morphologic information, the keratorefractive photoablation is based on the patient's spherical and cylindrical spectacle correction. Topography is at present not directly part of the procedural deterministic parameters. Examination of how corneal curvature at each of the keratometric reference loci affect the shape of the resultant corneal photoablated surface may enhance the accuracy of the desired correction. The objective of this study was to develop a methodology to utilize corneal topography for construction of models depicting pre- and post-operative keratomorphology for analysis of photorefractive keratectomy. Multiple types of models were developed then recreated in optical design software for examination of focal lengths and other optical characteristics. The corneal models were developed using data extracted from the TMS I corneal modeling system (Computed Anatomy, New York, NY). The TMS I does not allow for manipulation of data or differentiation of pre- and post-operative surfaces within its platform, thus models needed to be created for analysis. The data were imported into Matlab where 3D models, surface meshes, and contour plots were created. The data used to generate the models were pre- and post-operative curvatures, heights from the corneal apes, and x-y positions at 6400 locations on the corneal surface. Outlying non-contributory points were eliminated through statistical operations. Pre- and post- operative models were analyzed to obtain the resultant changes in the corneal surfaces during PRK

  8. [Influence of corneal transparency on the quality of topographies]. (United States)

    Franko Zeitz, P; Kohlhaas, M


    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. Georg Thieme Verlag KG Stuttgart · New York.

  9. Plastic compressed collagen as a novel carrier for expanded human corneal endothelial cells for transplantation.

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    Hannah J Levis

    Full Text Available Current treatments for reversible blindness caused by corneal endothelial cell failure involve replacing the failed endothelium with donor tissue using a one donor-one recipient strategy. Due to the increasing pressure of a worldwide donor cornea shortage there has been considerable interest in developing alternative strategies to treat endothelial disorders using expanded cell replacement therapy. Protocols have been developed which allow successful expansion of endothelial cells in vitro but this approach requires a supporting material that would allow easy transfer of cells to the recipient. We describe the first use of plastic compressed collagen as a highly effective, novel carrier for human corneal endothelial cells. A human corneal endothelial cell line and primary human corneal endothelial cells retained their characteristic cobblestone morphology and expression of tight junction protein ZO-1 and pump protein Na+/K+ ATPase α1 after culture on collagen constructs for up to 14 days. Additionally, ultrastructural analysis suggested a well-integrated endothelial layer with tightly opposed cells and apical microvilli. Plastic compressed collagen is a superior biomaterial in terms of its speed and ease of production and its ability to be manipulated in a clinically relevant manner without breakage. This method provides expanded endothelial cells with a substrate that could be suitable for transplantation allowing one donor cornea to potentially treat multiple patients.

  10. Applications of corneal topography and tomography: a review. (United States)

    Fan, Rachel; Chan, Tommy Cy; Prakash, Gaurav; Jhanji, Vishal


    Corneal imaging is essential for diagnosing and management of a wide variety of ocular diseases. Corneal topography is used to characterize the shape of the cornea, specifically, the anterior surface of the cornea. Most corneal topographical systems are based on Placido disc that analyse rings that are reflected off the corneal surface. The posterior corneal surface cannot be characterized using Placido disc technology. Imaging of the posterior corneal surface is useful for diagnosis of corneal ectasia. Unlike corneal topographers, tomographers generate a three-dimensional recreation of the anterior segment and provide information about the corneal thickness. Scheimpflug imaging is one of the most commonly used techniques for corneal tomography. The cross-sectional images generated by a rotating Scheimpflug camera are used to locate the anterior and posterior corneal surfaces. The clinical uses of corneal topography include, diagnosis of corneal ectasia, assessment of corneal astigmatism, and refractive surgery planning. This review will discuss the applications of corneal topography and tomography in clinical practice. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

  11. Corneal endothelial dysfunction in Pearson syndrome. (United States)

    Kasbekar, Shivani A; Gonzalez-Martin, Jose A; Shafiq, Ayad E; Chandna, Arvind; Willoughby, Colin E


    Mitochondrial disorders are associated with well recognized ocular manifestations. Pearson syndrome is an often fatal, multisystem, mitochondrial disorder that causes variable bone marrow, hepatic, renal and pancreatic exocrine dysfunction. Phenotypic progression of ocular disease in a 12-year-old male with Pearson syndrome is described. This case illustrates phenotypic drift from Pearson syndrome to Kearns-Sayre syndrome given the patient's longevity. Persistent corneal endothelial failure was noted in addition to ptosis, chronic external ophthalmoplegia and mid-peripheral pigmentary retinopathy. We propose that corneal edema resulting from corneal endothelial metabolic pump failure occurs within a spectrum of mitochondrial disorders.

  12. Corneal iron ring after hyperopic photorefractive keratectomy. (United States)

    Bilgihan, K; Akata, F; Gürelik, G; Adigüzel, U; Akpinar, M; Hasanreisoğlu, B


    To report the incidence and course of corneal iron deposition after hyperopic photorefractive keratectomy (PRK). Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey. Between January 1995 and December 1997, 62 eyes had PRK to correct hyperopia. Nine eyes developed corneal iron ring 5 to 8 months (mean 6.25 months +/- 1.3 [SD]) after PRK for hyperopia. The rings persisted during the mean follow-up of 19 +/- 11.09 months. The ring-shaped iron deposition after PRK for hyperopia must be differentiated from the Fleischer ring. Our results suggest that the slitlamp findings of peripheral corneal iron deposition in hyperopic PRK patients correlate with achieved correction.

  13. Should nylon corneal sutures be routinely removed? (United States)

    Jackson, H.; Bosanquet, R.


    Three groups of patients who had undergone cataract extraction through a corneal incision closed with 10/0 nylon sutures one, two, and three years previously were recalled to determine the incidence of suture related complications. Broken corneal sutures were found in 87.5% of patients after two years and 90% after three years and were causing symptoms in over half the patients. It is recommended that 10/0 nylon corneal sutures be routinely removed no later than one year after surgery. Images PMID:1751460

  14. Corneal dermoid in two laboratory beagle dogs. (United States)

    Horikiri, K; Ozaki, K; Maeda, H; Narama, I


    Two male laboratory beagle dogs used in toxicity studies, one 7 months old and the other 9 months old, showed the evidence of corneal dermoid. Grossly, the dermoid was observed in both cases as hair growth from the cornea. In one case, the hairs had been removed from the cornea, but regrowth was observed about 70 days later. Histopathologically, melanocytes, melanin granules, hairs, hair bulbs, adipose tissue and sebaceous and sweat glands were observed in the corneal epithelium and propria. According to the information obtained from 4 breeders, the incidence of corneal dermoid was extremely rare in laboratory beagle dogs.

  15. Post-LASIK ectasia treated with intrastromal corneal ring segments and corneal crosslinking


    Lam, Kay; Rootman, Dan B.; Lichtinger,, Alejandro; Rootman, David S.


    Corneal ectasia is a serious complication of laser in situ keratomileusis (LASIK). We report the case of a 29-year-old man who underwent LASIK in both eyes and in whom corneal ectasia developed in the left eye 3 years after surgery. He was treated sequentially with intraocular pressure–lowering medication, intrastromal corneal ring segment (ICRS) implants, and collagen cross-linking. Vision improved and the ectasia stabilized following treatment. Combined ICRS implantation and collagen cross-...

  16. Correlation of both corneal surfaces in corneal ectasia after myopic LASIK. (United States)

    Peinado, Teresa Fernández; Piñero, David P; López, Ignacio Alcaraz; Alio, Jorge L


    We report a case of corneal ectasia in a 25-year-old man after myopic laser in situ keratomileusis in which a complete characterization of the corneal structure was performed by means of a Scheimpflug photography-based system. The patient presented in the ectatic eye with a subjective refraction of +0.50 to 6.00 × 100°, which with correction gave a visual acuity of 20/25. With the topographic analysis, corneal shapes from both corneal surfaces at the four different quadrants were found to be complementary, maintaining the meniscus-shaped profile of the cornea. This correlation between the anterior and posterior corneal surfaces was also confirmed with an optical tomography evaluation. Corneal biomechanics was also evaluated by means of the Ocular Response Analyzer (Reichert), which confirmed the biomechanical alteration. In summary, biomechanical changes leading to corneal ectasia in this case affected the global corneal structure, inducing alterations in the shape of both anterior and posterior corneal surfaces.

  17. Repair of corneal ulcer or perforation using the corneal stromal lenticule

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    Xiao-Feng Hao


    Full Text Available AIM: To describe the outcomes of corneal stromal lenticules in repairing of corneal ulcer and/or perforation. METHODS: This was a retrospective chart review of 6 eyes of 6 patients from January to June 2017,who underwent corneal ulcer repair with the corneal, stromal lenticules harvested from femtosecond laser refractive surgery and kept in pure glycerin for use. Three cases of infectious corneal ulcers were bacterial, fungal, and infection with foreign bodies in corneal deep layer, one each. The other 3 were corneal ulcer perforation. Making sure no air bubble between donor graft and Descemet membrane. The mean follow-up time was 3.71±1.56mo(range 1-6mo. RESULTS: All eyes were successfully treated under control of infection without intra-operative complications, and early postoperative evaluation showed a clear graft in all cases. The last follow-up visit showed the mean best corrected visual acuity(VAsignificantly improved after surgery. There was significant difference from 0.48±0.12 to 1.50±0.08(PCONCLUSION: The preliminary results suggest that the use of corneal stromal lenticules may be a safe and effective surgical alternative for corneal ulcer, even though the long-term outcome of the graft needs to be further observed.

  18. New Trends in Quantitative Assessment of the Corneal Barrier Function

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    Anton Guimerà


    Full Text Available The cornea is a very particular tissue due to its transparency and its barrier function as it has to resist against the daily insults of the external environment. In addition, maintenance of this barrier function is of crucial importance to ensure a correct corneal homeostasis. Here, the corneal epithelial permeability has been assessed in vivo by means of non-invasive tetrapolar impedance measurements, taking advantage of the huge impact of the ion fluxes in the passive electrical properties of living tissues. This has been possible by using a flexible sensor based in SU-8 photoresist. In this work, a further analysis focused on the validation of the presented sensor is performed by monitoring the healing process of corneas that were previously wounded. The obtained impedance measurements have been compared with the damaged area observed in corneal fluorescein staining images. The successful results confirm the feasibility of this novel method, as it represents a more sensitive in vivo and non-invasive test to assess low alterations of the epithelial permeability. Then, it could be used as an excellent complement to the fluorescein staining image evaluation.

  19. Protective Effects of Trehalose on the Corneal Epithelial Cells

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    Pasquale Aragona


    Full Text Available Purpose. Aim of the present work was to evaluate the effects of the trehalose on the corneal epithelium undergoing alcohol delamination. Methods. Twelve patients undergoing laser subepithelial keratomileusis (LASEK were consecutively included in the study. The right eyes were pretreated with 3% trehalose eye drops, whilst left eyes were used as control. Epithelial specimens were processed for cells vitality assessment, apoptosis, and light and transmission electron microscopy; a morphometric analysis was performed in both groups. Results. In both trehalose-untreated eyes (TUE and trehalose-treated eyes (TTE, the percentage of vital cells was similar and no apoptotic cells were observed. In TUE, the corneal epithelium showed superficial cells with reduced microfolds, wing cells with vesicles and dilated intercellular spaces, and dark basal cells with vesicles and wide clefts. In TTE, superficial and wing cells were better preserved, and basal cells were generally clear with intracytoplasmatic vesicles. The morphometric analysis showed statistically significant differences between the two groups: the TTE epithelial height was higher, the basal cells showed larger area and clearer cytoplasm. The distribution of desmosomes and hemidesmosomes was significantly different between the groups. Conclusions. Trehalose administration better preserved morphological and morphometric features of alcohol-treated corneal epithelium, when compared to controls.

  20. Genetics Home Reference: congenital stromal corneal dystrophy (United States)

    ... the cornea appears cloudy and may have an irregular surface. These corneal changes lead to visual impairment, ... IGF I) epitopes recognized by monoclonal and polyclonal antibodies to IGF I. Endocrinology. 1990 Jun;126(6): ...

  1. Conjunctival intraepithelial neoplasia with corneal furrow degeneration

    Directory of Open Access Journals (Sweden)

    Pukhraj Rishi


    Full Text Available A 68-year-old man presented with redness of left eye since six months. Examination revealed bilateral corneal furrow degeneration. Left eye lesion was suggestive of conjunctival squamous cell carcinoma, encroaching on to cornea. Anterior segment optical coherence tomography (AS-OCT confirmed peripheral corneal thinning. Fluorescein angiography confirmed intrinsic vascularity of lesion. Patient was managed with "no touch" surgical excision, dry keratectomy without alcohol, cryotherapy, and primary closure. Pathologic examination of removed tissue confirmed clinical diagnosis. Management of this particular case required modification of standard treatment protocol. Unlike the alcohol-assisted technique of tumor dissection described, ethyl alcohol was not used for risk of corneal perforation due to underlying peripheral corneal thinning. Likewise, topical steroids were withheld in the post-operative period. Three weeks post-operatively, left eye was healing well. Hence, per-operative usage of absolute alcohol and post-operative use of topical steroids may be best avoided in such eyes.

  2. [Nanostructured bioplastic material for traumatic corneal injuries]. (United States)

    Kanyukov, V N; Stadnikov, A A; Trubina, O M; Yakhina, O M


    To substantiate the use of nanostructured bioplastic material for the treatment of traumatic eye injuries. The study enrolled 96 eyes of 48 rabbits and was carried out in 3 series of experiments, different in the type of induced corneal trauma: mechanical erosion, alkaline or acid burn. The animals were clinically monitored and sacrificed for morphological investigation at days 3, 7, 14, 30, and 90. The size of mechanical corneal erosions was repeatedly evaluated with fluorescein eye stain test. In the experimental group, Hyamatrix biomaterial was topically administered according to an original technique. In the controls, soft contact lenses were inserted and sutured. Complete closure of the epithelial defect with no impact on corneal properties was achieved in 3 days in the experimental group and in4 days in the control group. As for alkaline and acid corneal burns, experimental and control groups received Hyamatrix biomaterial and Solcoseryl eye gel correspondingly. In the experimental group of alkaline burn the defect closed by day 7, in the controls--by day 10-11. Acid-induced corneal edema also resolved by day 7 in the experimental group and by day 14 in the control group. 1. The results of this experimental and morphological study prove the hyaluronic acid-derived nanostructured bioplastic material effective in accelerating corneal re-epithelialization after mechanical erosions as compared with the controls. 2. Topical application of the hyaluronic acid-derived nanostructured bioplastic material shortens the exudative phase of inflammation, promotes corneal defect closure with formation of a more subtle opacification, and stimulates corneal restoration after chemical burns.

  3. Risk factors for corneal ectasia after LASIK. (United States)

    Tabbara, Khalid F; Kotb, Amgad A


    To establish a grading system that helps identify high-risk individuals who may experience corneal ectasia after LASIK. Retrospective, comparative, interventional case series. One hundred forty-eight consecutive patients (148 eyes) were included in this study. Thirty-seven patients who underwent LASIK at other refractive centers experienced corneal ectasia in 1 eye after LASIK. One hundred eleven eyes of 111 patients who underwent successful LASIK during the same period were age and gender matched and served as controls. All patients underwent preoperative and postoperative topographic analysis of the cornea. The follow-up period in both groups of patients ranged from 2 to 5 years, with a mean follow-up of 3.6 years. All patients underwent LASIK for myopia (spherical equivalent, -4.00 to -8.00 diopters). Corneal keratometry, oblique cylinder, pachymetry, posterior surface elevation, difference between the inferior and superior corneal diopteric power, and posterior best sphere fit (BSF) over anterior BSF were given a grade of 1 to 3 each. An ectasia grading system was established, and the cumulative risk score was assessed. Patients who had a grade of 7 or less showed no evidence of corneal ectasia, whereas 16 (59%) of 27 patients who had a grade of 8 to 12 had corneal ectasia. Twenty-one (100%) of 21 patients with a grade of more than 12 had corneal ectasia after LASIK (P<0.0001). A risk score may help in the prediction of patients who are at risk of experiencing corneal ectasia after LASIK. A prospective clinical study is needed to assess the validity of these risk factors.

  4. Corneal elastosis within lattice dystrophy lesions. (United States)

    Pe'er, J; Fine, B S; Dixon, A; Rothberg, D S


    Corneal buttons of two patients with lattice corneal dystrophy were studied by light and electron microscopy. They showed elastotic degeneration within the amyloid deposits. The amyloid deposits displayed characteristic staining; the elastotic material (elastin) within the deposits stained positive with Verhoeff-van Gieson and Movat pentachrome stains and showed autofluorescence. The characteristic ultrastructural findings of amyloid and elastotic material were also demonstrated. The possibility of the associations of these two materials in the cornea is discussed. Images PMID:3258531

  5. Effects of axial length and corneal curvature on corneal biomechanics in elderly population

    Directory of Open Access Journals (Sweden)

    Sha-Sha Song


    Full Text Available AIM:To explore the corneal biomechanical properties of the elderly with different axial length(ALand corneal curvature by corneal visualization Scheimpflug Technology(Corvis ST. METHODS: Cross-sectional study. A total of 161 patients(297 eyesundergoing phacoemulsification were collected in this study. They were divided into 22-24mm, 24-26mm, more than 26mm groups according to axial length(190 eyes, 54 eyes and 53 eyes, respectively. Those of whom axial length was 22-24mm and the corneal curvature was 42-44D were divided into male and female groups(44 eyes and 49 eyes, respectively. Those of whom axial length was 22-24mm were divided into 42-44D group, more than 44D group according to corneal curvature(88 eyes, 102 eyes, respectively. Corvis ST was used to measure the biomechanical parameters of the cornea. The differences in the parameters between different groups were analyzed using the independent-samples t test or one-way analysis of variance and correlation analyses were performed using Pearson correlation analysis. RESULTS: When comparing the corneal biomechanical parameters, no statistically significant differences were found between male and female groups(P>0.05. The first applanation length and second applanation length among different corneal curvatures were statistically significant(PPr=0.429, 0.278; Pr=-0.291, -0.415; PCONCLUSION: The corneal curvature and ocular axial length may be the factors affecting the corneal biomechanical characteristics. The longer axial length, the thinner corneal thickness, the more easily the corneal is deformed, and with the increase of the axial length, intraocular pressure also increases.

  6. Collagen Cross-Linking Using Riboflavin and Ultraviolet-A for Corneal Thinning Disorders (United States)

    Pron, G; Ieraci, L; Kaulback, K


    , watching television or reading, difficult to perform. Keratoconus is the most common form of corneal thinning disorder and involves a noninflammatory chronic disease process of progressive corneal thinning. Although the specific cause for the biomechanical alterations in the corneal stroma is unknown, there is a growing body of evidence suggesting that genetic factors may play an important role. Keratoconus is a rare disease (corneal transplants as a last option when they can no longer tolerate contact lenses or when lenses no longer provide adequate vision. Keratoconus is one of the leading indications for corneal transplants and has been so for the last 3 decades. Despite the high success rate of corneal transplants (up to 20 years) there are reasons to defer it as long as possible. Patients with keratoconus are generally young and a longer-term graft survival of at least 30 or 40 years may be necessary. The surgery itself involves lengthy time off work and postsurgery, while potential complications include long-term steroid use, secondary cataracts, and glaucoma. After a corneal transplant, keratoconus may recur resulting in a need for subsequent interventions. Residual refractive errors and astigmatism can remain challenges after transplantation, and high refractive surgery and regraft rates in KC patients have been reported. Visual rehabilitation or recovery of visual acuity after transplant may be slow and/or unsatisfactory to patients. Description of Technology/Therapy Corneal cross-linking involves the use of riboflavin (vitamin B2) and ultraviolet-A (UVA) radiation. A UVA irradiation device known as the CXL® device (license number 77989) by ACCUTECH Medical Technologies Inc. has been licensed by Health Canada as a Class II device since September 19, 2008. An illumination device that emits homogeneous UVA, in combination with any generic form of riboflavin, is licensed by Health Canada for the indication to slow or stop the progression of corneal thinning caused

  7. Intracorneal Ring Segments Implantation for Corneal Ectasia. (United States)

    Giacomin, Natalia T; Mello, Glauco R; Medeiros, Carla S; Kiliç, Alyin; Serpe, Cristine C; Almeida, Hirlana G; Kara-Junior, Newton; Santhiago, Marcony R


    To provide an overview of the predictability, safety, and efficacy of intrastromal corneal ring segment (ICRS) implantation as a tool to improve visual acuity and its association with other techniques such as corneal collagen cross-linking (CXL), addressing biomechanical outcomes, models, surgical planning and technique, indications, contraindications, and complications in ectatic corneas. Literature review. ICRSs have been used to regularize the corneal shape and reduce corneal astigmatism and higher order aberrations, improve visual acuity to acceptable limits, and delay, or eventually prevent, a corneal keratoplasty in keratoconic eyes. Changes in ICRS thickness and size, combination of techniques, and the addition of femtosecond lasers to dissect more foreseeable channels represent an improvement toward more predictable results. Several studies have shown, over time, the long-term efficacy and safety of ICRS treatment for keratoconus, with variable predictability, maintaining the early satisfactory outcomes regarding visual acuity, keratometry, and corneal thickness. It is just as important to ensure that the disease will not progress as it is to improve the visual acuity. Therefore, many studies have shown combined techniques using ICRS implantation and CXL. Also, further limitations of ICRS implantation can be addressed when associated with phakic intraocular lens implantation and photorefractive keratectomy. ICRS implantation has shown effectiveness and safety in most cases, including combined procedures. In properly selected eyes, it can improve both refraction and vision in patients with keratoconus. [J Refract Surg. 2016;32(12):829-839.]. Copyright 2016, SLACK Incorporated.

  8. Corneal crystals: a precursor to cancer. (United States)

    Chou, Janel L; Sink, Makesha L


    Corneal crystalline deposits are a sign of a limited number of conditions that can often be differentiated based on the appearance and pattern of the deposits. Although, there are limited treatment options available to reduce the appearance or effects of corneal crystals, it is important to identify the correct etiology of these deposits. There are several associated systemic conditions, some of which are life threatening, for which treatments are available. A 51-year-old black male presented to the clinic with the complaint of "glare at night due to crystals on [the] cornea." Slitlamp findings revealed diffuse subepithelial and anterior stromal crystals across both corneas. The patient had a medical history of renal insufficiency and arthralgia. Through systemic testing, the patient was found to have monoclonal gammopathy of undetermined significance (MGUS), and subsequent follow-up of this patient revealed a conversion of MGUS to multiple myeloma. Corneal crystals can appear diffusely through the cornea secondary to corneal dystrophies, gammopathies, cystinosis, or other rare systemic conditions. In this case report, these crystals are secondary to MGUS, which progressed to multiple myeloma. These crystals consist of immunoglobulin, primarily IgG, and excessive kappa light chains. It is important to obtain laboratory tests and make appropriate referrals to determine whether corneal crystal deposits are associated with a serious systemic disease or merely a corneal dystrophy.

  9. p53 protein expression in corneal squamous cell carcinomas of dogs

    Directory of Open Access Journals (Sweden)

    Lucas Bahdour Cossi


    Full Text Available Ocular tumors play an increasing concern in veterinary ophthalmology. Corneal squamous cell carcinoma is unfrequent in dogs, and by this way it has little studies. Studies that investigated the carcinogenesis mechanisms wich could help to the development of ocular squamous cell carcinoma (SCC in dog are rare. The aim of this work was to identify by immunohistochemical techniques, the p53 protein expression in the spontaneous dog corneal SCC. For this work, were used five cases of corneal SCC and one case of actinic keratitis. The sections were obtained from paraffin-wax blocks and submitted to histopathological and immunohistochemical analysis. All the six samples showed immunolabeling to cytokeratin and p53 protein. These results support the conclusions that the immunoreactivity of p53 protein by immunohistochemistry is present in canine corneal SCC suppporting its role in carcinogenesis of this tumor, but not provides prognostic indicators in cases of SCC corneal in dog; and can be a association of exposure to solar radiation with the possible mutation of the TP53 gene.

  10. Therapy of corneal erosions and 'dry eye' with Solcoseryl and Vitasic eye drops. (United States)

    Krannig, H M; Rohde-Germann, H; Straub, W


    A comparative study of Solcoseryl eye drops versus Vitasic eye drops has been carried out under controlled conditions (randomized and double-blind) on a total of 94 patients. 52 had corneal erosion, 30 had dry eye syndrome, 8 cases could not be evaluated. In addition, 2 eyes with photophthalmia were treated with Vitasic and 2 showing keratitis with Solcoseryl. There were no adverse reactions other than 2 instances of stinging with Solcoseryl and 1 case of severe irritation after Vitasic. The patients were examined on days 0, 1, 3 and 7. Results showed a consistent superiority of Solcoseryl eye drops in respect to speed of healing of corneal erosions and moistening of the cornea in the 'dry eye' syndrome which reached statistical significance in some parameters.

  11. Reshaping procedures for the surgical management of corneal ectasia. (United States)

    Ziaei, Mohammed; Barsam, Allon; Shamie, Neda; Vroman, David; Kim, Terry; Donnenfeld, Eric D; Holland, Edward J; Kanellopoulos, John; Mah, Francis S; Randleman, J Bradley; Daya, Sheraz; Güell, Jose


    Corneal ectasia is a progressive, degenerative, and noninflammatory thinning disorder of the cornea. Recently developed corneal reshaping techniques have expanded the treatment armamentarium available to the corneal specialist by offering effective nontransplant options. This review summarizes the current evidence base for corneal collagen crosslinking, topography-guided photorefractive keratectomy, and intrastromal corneal ring segment implantation for the treatment of corneal ectasia by analyzing the data published between the years 2000 and 2014. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  12. Penetrating keratoplasty for perforated corneal ulcers: preservation of iris by corneal debulking. (United States)

    Vajpayee, Rasik B; Singhvi, Arun; Sharma, Namrata; Sinha, Rajesh


    This study was designed to study an alternative technique of lamellar separation of corneal layers for therapeutic keratoplasty in place of an en bloc removal of host corneal button in eyes with perforated corneal ulcers with pseudocornea. Twelve eyes with perforated corneal ulcers with pseudocornea in which therapeutic keratoplasty was planned were included in the study. A new technique was used in which the host corneal tissue was removed in layers by lamellar dissection started peripherally and proceeding centripetally with care taken to prevent perforation at the site of iris incarceration. After injection of viscoelastic into the anterior chamber with a 26-gauge needle entered tangentially, the deeper layer of the cornea was then gently dissected and peeled away from the iris tissue, with care not to avulse the fragile iris and the overlying fibrotic membrane. Adjunctive procedures were performed, and the donor tissue was secured over the host bed. A complete separation of the iris tissue from corneal button and the fibrous membrane was achieved in 9 eyes. In 3 eyes, iris was partly trimmed along with the fibrous membrane, because the membrane was totally adherent to the iris tissue. Eight patients required pupilloplasty. Apart from minimal bleeding, no other complication was encountered. At the end of 3 months, 9 of 12 grafts remained clear. Debulking and layer-by-layer removal of host corneal tissue is effective in preservation of iris while performing therapeutic keratoplasty in eyes with perforated corneal ulcers with pseudocornea.

  13. The receptor for advanced glycation end products RAGE is involved in corneal healing. (United States)

    Nass, Norbert; Trau, Stefanie; Paulsen, Friedrich; Kaiser, Delia; Kalinski, Thomas; Sel, Saadettin


    Impaired corneal healing is still a major cause of blindness. As RAGE (receptor for advanced glycation endproducts) is involved in inflammation and wound healing in other tissues, we here investigated its relevance for corneal wound healing. Corneal re-epithelialization after alkaline injury was analysed in an ex-vivo approach with cultured, enucleated eyes from mice either of the C57Bl/6 NChR genotype (RAGE+/+) and mice of the same strain lacking the RAGE gene (RAGE-/-). The wound area was determined time dependently by fluorescence imaging using fluorescein staining. The eyes of RAGE-/- mice showed a significantly slower re-epithelialization than eyes of the RAGE+/- and the RAGE+/+ genotype. In immunohistochemistry, RAGE expression was increased in wounded corneas whereas the abundance of the RAGE ligand HMGB1 was unaffected, but an increase in S100b-like proteins was revealed upon injury. However, neither the addition of the RAGE agonist HMGB1 or an HMGB1 antagonising antibody nor bovine S100b protein to the culture medium of the wounded eyes had an effect on corneal wound closure in ex-vivo. Further gene expression analysis by RT-PCR demonstrated an increase in RAGE expression on the mRNA level, no significant regulation of HMGB1 and a differential regulation of the S100 gene family after alkaline burn of the cornea. In conclusion, RAGE is clearly involved in corneal re-epithelialization most probably mediated by signalling via S100 proteins. Copyright © 2017 Elsevier GmbH. All rights reserved.

  14. Causes and temporal trends of childhood blindness in Indonesia: study at schools for the blind in Java. (United States)

    Sitorus, R S; Abidin, M Sulaiman; Prihartono, Joedo


    To ascertain the causes of blindness and severe visual impairment (BL/SVI) in schools for the blind in Java, to identify preventable and treatable causes and to evaluate temporal trends in the major causes. From a total of 504 students, 479 were examined. Data was collected using a modified World Heath Organization Prevention of Blindness (WHO/PBL) eye examination record for children. The majority of the students (95%) were blind and 4.6% were severely visually impaired. The major anatomical site of BL/SVI was whole globe in 35.9%, retina in 18.9%, lens in 16.4% and cornea in 16.1%. The major underlying aetiology of BL/SVI was undetermined/unknown in 32.7% (mainly microphthalmia, anterior segment dysgenesis and cataract), hereditary factors 31.9% (mainly retinal dystrophies), and childhood disorders 28.5%. Avoidable causes of BL/SVI accounted for 59.9% of the total students, whereas measles blindness was the underlying condition for 23.1% of the preventable causes; cataract and glaucoma accounted for 15.5% and 8.2% of the treatable causes, respectively. Exploration on trends of SVI/BL among two different age groups or = 16 years suggested that childhood disorders and corneal factors have declined, while hereditary disorders have increased. Optic nerve disorder, although not counted as a major cause of blindness, seems to be on the increase. More than half of the BL/SVI causes are potentially avoidable. Cataract and corneal disorders related to measles or vitamin A deficiency were the major treatable and preventable causes. Declining proportions of childhood factors and corneal disorders over a period of 10-20 years could reflect improved vitamin A supplementation and measles vaccination coverage in Indonesia. This finding, and the increased proportion of hereditary disease causes, could suggest improving levels of socioeconomic development and health care services.

  15. Visual impairment and blindness among the students of blind schools in Allahabad and its vicinity: A causal assessment. (United States)

    Bhalerao, Sushank Ashok; Tandon, Mahesh; Singh, Satyaprakash; Dwivedi, Shraddha; Kumar, Santosh; Rana, Jagriti


    Information on eye diseases in blind school children in Allahabad is rare and sketchy. A cross-sectional study was performed to identify causes of blindness (BL) in blind school children with an aim to gather information on ocular morbidity in the blind schools in Allahabad and in its vicinity. A cross-sectional study was carried out in all the four blind schools in Allahabad and its vicinity. The students in the blind schools visited were included in the study and informed consents from parents were obtained. Relevant ocular history and basic ocular examinations were carried out on the students of the blind schools. A total of 90 students were examined in four schools of the blind in Allahabad and in the vicinity. The main causes of severe visual impairment and BL in the better eye of students were microphthalmos (34.44%), corneal scar (22.23%), anophthalmos (14.45%), pseudophakia (6.67%), optic nerve atrophy (6.67%), buphthalmos/glaucoma (3.33%), cryptophthalmos (2.22%), staphyloma (2.22%), cataract (2.22%), retinal dystrophy (2.22%), aphakia (1.11%), coloboma (1.11%), retinal detachment (1.11%), etc. Of these, 22 (24.44%) students had preventable causes of BL and another 12 (13.33%) students had treatable causes of BL. It was found that hereditary diseases, corneal scar, glaucoma and cataract were the prominent causes of BL among the students of blind schools. Almost 38% of the students had preventable or treatable causes, indicating the need of genetical counseling and focused intervention.

  16. Visual impairment and blindness among the students of blind schools in Allahabad and its vicinity: A causal assessment

    Directory of Open Access Journals (Sweden)

    Sushank Ashok Bhalerao


    Full Text Available Background/Aims: Information on eye diseases in blind school children in Allahabad is rare and sketchy. A cross-sectional study was performed to identify causes of blindness (BL in blind school children with an aim to gather information on ocular morbidity in the blind schools in Allahabad and in its vicinity. Study Design and Setting: A cross-sectional study was carried out in all the four blind schools in Allahabad and its vicinity. Materials and Methods: The students in the blind schools visited were included in the study and informed consents from parents were obtained. Relevant ocular history and basic ocular examinations were carried out on the students of the blind schools. Results: A total of 90 students were examined in four schools of the blind in Allahabad and in the vicinity. The main causes of severe visual impairment and BL in the better eye of students were microphthalmos (34.44%, corneal scar (22.23%, anophthalmos (14.45%, pseudophakia (6.67%, optic nerve atrophy (6.67%, buphthalmos/glaucoma (3.33%, cryptophthalmos (2.22%, staphyloma (2.22%, cataract (2.22%, retinal dystrophy (2.22%, aphakia (1.11%, coloboma (1.11%, retinal detachment (1.11%, etc. Of these, 22 (24.44% students had preventable causes of BL and another 12 (13.33% students had treatable causes of BL. Conclusion: It was found that hereditary diseases, corneal scar, glaucoma and cataract were the prominent causes of BL among the students of blind schools. Almost 38% of the students had preventable or treatable causes, indicating the need of genetical counseling and focused intervention.

  17. Post-Ocular Trauma Corneal Staphyloma in a Child Living in an Underdeveloped Region of Eastern Indonesia


    Ratna Sitompul; Gladys Kusumowidagdo; Eiko B. Matiur; Julie D. Barliana; Rita S. Sitorus; Saleha Sungkar


    Ocular trauma occurring in children often leads to visual impairment or blindness when it is not properly managed. This often occurs in underdeveloped regions with difficult access to professional care at local health facilities. We report a case of post-trauma corneal staphyloma in an underdeveloped region of eastern Indonesia to illustrate the importance of proper management of ocular trauma in areas lacking such expertise and where patients have difficulty accessing even basic health care....

  18. [Corneal protection in contact lens users]. (United States)

    Egorova, G B; Mitichkina, T S; Shamsudinova, A R


    To evaluate the efficacy of corneoprotective agents (Corneregel and Solcoseryl) in contact lens users. A total of 66 long-term contact lens wearers with dry eye symptoms and varying degrees of corneal epitheliopathy were monitored. All patients used artificial tears, which, however, were not effective enough to suppress manifestations of corneal epitheliopathy and to release the associated discomfort. The therapy was supplemented with Corneregel. The following examination methods were applied: biomicroscopy with fluorescent staining, Norn test, Schirmer's test, advanced tearscopy with digital image analysis of the precorneal tear film lipid layer, corneal confocal microscopy. In all cases the assessment was performed prior to starting Corneregel and repeated in 7 days, 14 days and 1 month. Complete corneal re-epithelization and restoration of the most superficial layer of the epithelium were achieved within 7-14 days. In case of severe initial epitheliopathy the effect of Corneregel was not sufficient and epithelium defects remained. These patients additionally received Solcoseryl Eye Gel. After the treatment course the condition of corneal epithelium ameliorated and contact lens wearing comfort increased. A longer precorneal tear film break-up time indicated an increase of tear film stability. The total tear production did not change significantly. The moistening effect of Corneregel and low-viscosity artificial tears together with intensive regeneration of corneal epithelium enables structural recovery of the epithelial membrane and considerable improvement of the anterior corneal stroma. At the first stage of corneoprotective treatment it is appropriate to use preservative-free artificial tears of low and high viscosity. If the effect of tear substitutive therapy is unsatisfactory it is recommended to prescribe Corneregel and Solcoseryl. The regimen is to be adjusted individually.

  19. Blind Compressed Sensing


    Gleichman, Sivan; Eldar, Yonina C.


    The fundamental principle underlying compressed sensing is that a signal, which is sparse under some basis representation, can be recovered from a small number of linear measurements. However, prior knowledge of the sparsity basis is essential for the recovery process. This work introduces the concept of blind compressed sensing, which avoids the need to know the sparsity basis in both the sampling and the recovery process. We suggest three possible constraints on the sparsity basis that can ...

  20. Optical coherence elastography assessment of corneal viscoelasticity with a modified Rayleigh-Lamb wave model. (United States)

    Han, Zhaolong; Li, Jiasong; Singh, Manmohan; Wu, Chen; Liu, Chih-Hao; Raghunathan, Raksha; Aglyamov, Salavat R; Vantipalli, Srilatha; Twa, Michael D; Larin, Kirill V


    The biomechanical properties of the cornea play a critical role in forming vision. Diseases such as keratoconus can structurally degenerate the cornea causing a pathological loss in visual acuity. UV-A/riboflavin corneal collagen crosslinking (CXL) is a clinically available treatment to stiffen the cornea and restore its healthy shape and function. However, current CXL techniques do not account for pre-existing biomechanical properties of the cornea nor the effects of the CXL treatment itself. In addition to the inherent corneal structure, the intraocular pressure (IOP) can also dramatically affect the measured biomechanical properties of the cornea. In this work, we present the details and development of a modified Rayleigh-Lamb frequency equation model for quantifying corneal biomechanical properties. After comparison with finite element modeling, the model was utilized to quantify the viscoelasticity of in situ porcine corneas in the whole eye-globe configuration before and after CXL based on noncontact optical coherence elastography measurements. Moreover, the viscoelasticity of the untreated and CXL-treated eyes was quantified at various IOPs. The results showed that the stiffness of the cornea increased after CXL and that corneal stiffness is close to linear as a function of IOP. These results show that the modified Rayleigh-Lamb wave model can provide an accurate assessment of corneal viscoelasticity, which could be used for customized CXL therapies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Riboflavin for corneal cross-linking. (United States)

    O'Brart, D P S


    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. Copyright 2016 Prous Science, S.A.U. or its licensors. All rights reserved.

  2. MicroRNA-184 Regulates Corneal Lymphangiogenesis. (United States)

    Grimaldo, Sammy; Yuen, Don; Theis, Jaci; Ng, Melissa; Ecoiffier, Tatiana; Chen, Lu


    MicroRNAs are a class of small noncoding RNAs that negatively regulate gene expression by binding to complimentary sequences of target messenger RNA. Their roles in corneal lymphangiogenesis are largely unknown. This study was to investigate the specific role of microRNA-184 (mir-184) in corneal lymphangiogenesis (LG) in vivo and lymphatic endothelial cells (LECs) in vitro. Standard murine suture placement model was used to study the expressional change of mir-184 in corneal inflammatory LG and the effect of synthetic mir-184 mimic on this process. Additionally, a human LEC culture system was used to assess the effect of mir-184 overexpression on cell functions in vitro. Expression of mir-184 was significantly downregulated in corneal LG and, accordingly, its synthetic mimic suppressed corneal lymphatic growth in vivo. Furthermore, mir-184 overexpression in LECs inhibited their functions of adhesion, migration, and tube formation in vitro. These novel findings indicate that mir-184 is involved critically in LG and potentially could be used as an inhibitor of the process. Further investigation holds the promise for divulging new therapies for LG disorders, which occur inside and outside the eye.

  3. Primary central corneal hemangiosarcoma in a dog. (United States)

    Haeussler, David J; Rodríguez, Laura Muñoz; Wilkie, David A; Premanandan, Chris


    To report a case of primary central corneal hemangiosarcoma in the dog. An 11-year-old, neutered, female, German shepherd mixed breed dog was referred to the Hospital Veterinario Sierra de Madrid (Spain) for evaluation of an enlarging corneal mass of the left eye (OS). The dog was predominantly housed outdoors and was diagnosed with a history of chronic superficial keratitis of both eyes (OU) by the referring veterinarian. The corneal mass was resected by routine superficial keratectomy and submitted for histopathology and Factor VIII immunohistochemical staining. The mass was diagnosed as a corneal hemangiosarcoma with complete excision. Postoperatively, the keratectomy site healed without complication and there was no evidence of recurrence three and a half months postoperatively. Complete systemic evaluation, including abdominal ultrasound and CT scan of the head and thorax, indicated no other detectable neoplasia in the dog. Outdoor housing and ultraviolet exposure, breed, and chronic superficial keratitis were all suspected as contributing factors to the development of a primary corneal hemangiosarcoma. Surgical removal and postoperative treatment for chronic superficial keratitis provided effective therapy. © 2011 American College of Veterinary Ophthalmologists.

  4. Bilateral coexistence of keratoconus and macular corneal dystrophy

    Directory of Open Access Journals (Sweden)

    Ghazi Al-Hamdan


    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.

  5. Recent advances in the treatment of corneal ectasia with intrastromal corneal ring segments. (United States)

    Poulsen, David M; Kang, Joann J


    To review the recent advances and reported outcomes in the use of intrastromal corneal ring segments (ICRS) for the treatment of corneal ectasia. ICRS are a well-tolerated and effective treatment for patients with corneal ectasia, particularly keratoconus, offering long-term improvement in visual, refractive, and keratometric measures. ICRS do not consistently decrease corneal aberrations. Patients with mild-to-moderate keratoconus, known to have less predictable outcomes with ICRS, may be better selected and treated with the use of customized nomograms, accounting for factors such as internal astigmatism. Corneal collagen cross-linking performed after ICRS implantation is an important complementary treatment in preventing the progression of ectasia, whereas subsequent treatment with either photorefractive keratectomy or toric intraocular lens implantation offers a significantly improved visual and refractive result. ICRS are an important component to the treatment of corneal ectasia. Knowledge of outcomes among specific groups of patients should improve treatment planning and nomograms. Combined treatments with ICRS allow for notable improvements in corneal stability and refractive error, in addition to the improvement in irregular astigmatism seen with ICRS.

  6. Keratocyte apoptosis and corneal antioxidant enzyme activities after refractive corneal surgery. (United States)

    Bilgihan, K; Bilgihan, A; Adiguzel, U; Sezer, C; Yis, O; Akyol, G; Hasanreisoglu, B


    Refractive corneal surgery induces keratocyte apoptosis and generates reactive oxygen radicals (ROS) in the cornea. The purpose of the present study is to evaluate the correlation between keratocyte apoptosis and corneal antioxidant enzyme activities after different refractive surgical procedures in rabbits. Rabbits were divided into six groups. All groups were compared with the control group (Group 1), after epithelial scraping (Group 2), epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK: Group 3), transepithelial PRK (Group 4), creation of a corneal flap with microkeratome (Group 5) and laser-assisted in situ keratomileusis (LASIK, Group 6). Terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay (to detect DNA fragmentation in situ) and light microscopy were used to detect apoptosis in rabbit eyes. Glutathione peroxidase (Gpx) and superoxide dismutase (SOD) activities of the corneal tissues were measured with spectrophotometric methods. Corneal Gpx and SOD activities decreased significantly in all groups when compared with the control group (P<0.05) and groups 2, 3 and 6 showed a significantly higher amount of keratocyte apoptosis (P<0.05). Not only a negative correlation was observed between corneal SOD activity and keratocyte apoptosis (cc: -0.3648) but Gpx activity also showed negative correlation with keratocyte apoptosis (cc: -0.3587). The present study illustrates the negative correlation between keratocyte apoptosis and corneal antioxidant enzyme activities. This finding suggests that ROS may be partly responsible for keratocyte apoptosis after refractive surgery.

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

    Directory of Open Access Journals (Sweden)

    Ozdemir Ozdemir


    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.

  8. Therapy of canine corneal pannus with strontium-90

    International Nuclear Information System (INIS)

    Hoecht, S.; Nausner, M.; Hinkelbein, W.; Gruening, G.; Allgoewer, I.; Brunnberg, L.


    Background: Corneal pannus is a disease which, if untreated, nearly always is progressive and may lead to blindness of the affected dog. A therapeutic standard is yet to be defined. Beta-ray irradiation with Sr-90 is often recommended on a casuistic basis, but systematic studies are sparse. The aim of the present study was to evaluate efficacy and to document side effects of radiotherapy with Sr-90. Material and Methods: 17 animals were treated. 13 of them received treatment of 15 Gy surface dose twice within 2 days with additional medical therapy with ciclosporin and prednisolon. Only the more affected eye was treated with radiation which was applied with an eye-applicator, the other eye served as control. Four animals with already advanced impairment of vision received keratectomy, afterwards radiation was applied on both sides. Results: Medical treatment alone led to deterioration in vascularization and spread of pigmentation in eleven of 13 (85%) of the control-eyes, density of pigmentation increased in eight of 13 (62%). After radiation therapy, almost all animals showed a marked initial improvement. Even if progressive disease occurred later on, further worsening as it happened in the control-eyes could be stopped in nine resp. ten of 13 eyes (69% and 77%). All animals with keratectomy and radiotherapy regained and preserved adequate vision. Besides short-term blepharospasm, no side effects were recorded. Conclusion: Corneal pannus is responsive to radiation therapy with Sr-90 and long-term benefit can be achieved. Side effects are minimal. Optimal sequencing of therapy and dosage still have to be examined. (orig.) [de

  9. Detection of aldehyde dehydrogenase activity in human corneal extracts

    NARCIS (Netherlands)

    Gondhowiardjo, T. D.; van Haeringen, N. J.; Hoekzema, R.; Pels, L.; Kijlstra, A.


    The major soluble protein in bovine corneal epithelial extracts is a 54 kD protein (BCP 54) which has recently been identified as the corneal aldehyde dehydrogenase. Although ALDH activity has been reported in human corneal extracts it was not yet clear whether this was identical with the 54 kD

  10. A fibrin sealant for perforated and preperforated corneal ulcers.


    Lagoutte, F M; Gauthier, L; Comte, P R


    Fibrin sealant is used to close perforated or preperforated corneal ulcers. In addition to the usual advantages of cyanoacrylates it is degraded physiologically and provides a good support for corneal healing. Corneal grafting can be avoided when contraindicated or postponed when conditions allow. This technique has been successful in nine eyes of eight patients.

  11. Post-LASIK ectasia treated with intrastromal corneal ring segments and corneal crosslinking. (United States)

    Lam, Kay; Rootman, Dan B; Lichtinger, Alejandro; Rootman, David S


    Corneal ectasia is a serious complication of laser in situ keratomileusis (LASIK). We report the case of a 29-year-old man who underwent LASIK in both eyes and in whom corneal ectasia developed in the left eye 3 years after surgery. He was treated sequentially with intraocular pressure-lowering medication, intrastromal corneal ring segment (ICRS) implants, and collagen cross-linking. Vision improved and the ectasia stabilized following treatment. Combined ICRS implantation and collagen cross-linking should be considered early in the management of post-LASIK ectasia.

  12. [The effect of Solcoseryl eye gel in combination with neomycin and bacitracin on the healing of corneal lesions after foreign body removal]. (United States)

    Haydon, P


    The effect of Solcoseryl on the healing rate of corneal lesions after foreign body removal was assessed in a double-blind study. Solcoseryl is a protein-free hemodialysate which is widely used to stimulate tissue repair processes. The healing rate was determined by means of photodocumentation which was complete in 82 out of 92 cases. The Solcoseryl group showed in significantly faster healing rate and a lower tendency to development of corneal opacities than the control group. No side-effects were observed which could be attributed to either of the drugs used in the study.

  13. Corneal versus ocular aberrations after overnight orthokeratology. (United States)

    Gifford, Paul; Li, Melanie; Lu, Helen; Miu, Jonathan; Panjaya, Monica; Swarbrick, Helen A


    To investigate relationships between changes to corneal and ocular aberrations induced by orthokeratology (OK) and their influence on visual function. Eighteen subjects (aged 20 to 23 years) were fitted with OK lenses (BE Enterprises Pty Ltd, Australia), manufactured in Boston XO material (Bausch & Lomb Boston, Wilmington, MA), and worn overnight for seven nights. Corneal and ocular aberrations were simultaneously captured (Discovery, Innovative Visual Systems, Elmhurst, IL), and contrast sensitivity function was measured on days 1 and 7, within 2 and 8 hours after lens removal on waking. Data from the eye achieving the higher myopic correction were analyzed for changes over time. There was a significant refractive effect at all visits. Orthokeratology induced an increase in corneal and ocular root mean square higher order aberrations (HOAs) and a positive shift in spherical aberration (SA) on day 1, with further increases by day 7. Increases in root mean square coma became significant by day 7. Changes to corneal and ocular SA were similar on day 1; however, by day 7, there was a greater increase in corneal than ocular SA, indicating a change in internal SA. Orthokeratology led to an overall decrease in contrast sensitivity function, which was isolated to spatial frequency changes on day 1 at 1 cycle per degree and on day 7 at 1 and 8 cycles per degree. A greater positive shift in corneal compared with ocular SA on day 7 suggests a negative shift in internal SA, which would be consistent with an increased accommodative response. Lack of any difference on day 1 indicates that this may be an ocular adaptation response toward neutralizing induced positive SA, rather than a direct effect of SA changes on the accommodation mechanism.

  14. Corneal nerve microstructure in Parkinson's disease. (United States)

    Misra, Stuti L; Kersten, Hannah M; Roxburgh, Richard H; Danesh-Meyer, Helen V; McGhee, Charles N J


    Ocular surface changes and blink abnormalities are well-established in Parkinson's disease. Blink rate may be influenced by corneal sub-basal nerve density, however, this relationship has not yet been investigated in Parkinson's disease. This case-control study examined the ocular surface in patients with moderately severe Parkinson's disease, including confocal microscopy of the cornea. Fifteen patients with moderately severe Parkinson's disease (modified Hoehn and Yahr grade 3 or 4) and fifteen control participants were recruited. Ophthalmic assessment included slit-lamp examination, blink rate assessment, central corneal aesthesiometry and in vivo corneal confocal microscopy. The effect of disease laterality was also investigated. Of the 15 patients with Parkinson's disease, ten were male and the mean age was 65.5±8.6years. The corneal sub-basal nerve plexus density was markedly reduced in patients with Parkinson's disease (7.56±2.4mm/mm 2 ) compared with controls (15.91±2.6mm/mm 2 ) (pParkinson's disease (0.79±1.2mBAR) and the control group (0.26±0.35mBAR), p=0.12. Sub-basal nerve density was not significantly different between the eye ipsilateral to the side of the body with most-severe motor symptoms, and the contralateral eye. There was a significant positive correlation between ACE-R scores and sub-basal corneal nerve density (R 2 =0.66, p=0.02). This is the first study to report a significant reduction in corneal sub-basal nerve density in Parkinson's disease and demonstrate an association with cognitive dysfunction. These results provide further evidence to support the involvement of the peripheral nervous system in Parkinson's disease, previously thought to be a central nervous system disorder. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Corneal epithelial inclusion cyst in a dog

    Directory of Open Access Journals (Sweden)

    Campos Carla de Freitas


    Full Text Available An unilateral corneal epithelial inclusion cyst in a 7-year-old male Boxer dog is reported. The cyst had been observed for thirty days, was unique, not congenital and only one eye was involved. Seven months prior to the referral the dog had manifested indolent corneal ulcer treated with grade keratotomy and third eyelid flap. The cyst was removed by superficial keratectomy followed by a conjunctival pedicle graft. Recovery was uncomplicated and there wasn?t recurrence seven months after the surgery.

  16. Corneal collagen crosslinking for keratoconus. A review

    Directory of Open Access Journals (Sweden)

    M. M. Bikbov


    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

  17. The corneal stroma during contact lens wear. (United States)

    Jalbert, Isabelle; Stapleton, Fiona


    Recent technological advances have lead to novel descriptions of the microanatomy of the corneal stroma. In the first section of this review, these findings and the role they play in the maintenance of vital properties such as corneal transparency, mechanical strength, homeostasis, wound-healing response and metabolism are described. In the second part, contact lens induced stromal alterations such as acidosis, oedema, striae, thinning and opacities are reviewed as well as the more recently described phenomenon of microdot deposits and keratocyte loss with an emphasis on how lens wearing stromal effects can be minimised.

  18. Unilateral Keratectasia Treated with Femtosecond Fashioned Intrastromal Corneal Inlay (United States)

    Jadidi, Khosrow; Hasanpour, Hossein


    Purpose: In this case report, we describe the surgical procedure of corneal inlay preparation and corneal pocket creation using a femtosecond laser system. Case Report: A 7-year-old girl who presented with unilateral paracentral corneal thinning underwent the surgical procedure of corneal inlay. Preoperatively, the refraction was +10.00-6.00 × 170. One month after the procedure, astigmatism and hyperopia were decreased and the refraction was +5.00-1.25 × 110. Conclusion: Femtosecond laser–assisted pocket creation for the implantation of corneal inlays offers accuracy of pocket parameters, enhancing predictability, resulting in better final outcomes, and improving the safety of the procedure. PMID:28791068

  19. Current status of accelerated corneal cross-linking

    Directory of Open Access Journals (Sweden)

    Michael Mrochen


    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.

  20. Corneal-Wavefront guided transepithelial photorefractive keratectomy after corneal collagen cross linking in keratoconus

    Directory of Open Access Journals (Sweden)

    Massimo Camellin


    Conclusions: Corneal-Wavefront guided transepithelial PRK ablation profiles after conventional CXL yields to good visual, optical, and refractive results. These treatments are safe and efficacious for the correction of refracto-therapeutic problems in keratoconic patients.

  1. Corneal collagen crosslinking for keratoconus or corneal ectasia without epithelial debridement. (United States)

    Hirji, N; Sykakis, E; Lam, F C; Petrarca, R; Hamada, S; Lake, D


    Corneal collagen crosslinking (CXL) is a relatively new technique to reduce the progression of keratoconus. The technique can be performed with or without complete debridement of the corneal epithelium. We describe a novel intermediate technique involving mechanical disruption of the epithelium, and evaluate its safety and efficacy. The case notes of 128 eyes with progressive keratoconus or iatrogenic corneal ectasia who had undergone CXL using the epithelial disruption technique were retrospectively reviewed. Thin corneas were treated with hypotonic riboflavin. All others were treated with an isotonic solution. Note was made of preoperative and postoperative parameters, including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, endothelial cell count, and corneal tomography. Occurrence of procedure-related complications was recorded. Statistical analyses were performed using the paired sample t-test and Wilcoxon signed-rank test, with a level of Pcorneal ectasia, and may be better tolerated by patients than the epithelium-off technique.

  2. Relationship between Central Corneal Thickness, Vitreous ...

    African Journals Online (AJOL)

    Navarro R. The Optical Design of the Human Eye: a Critical Review J Optom. 2009; 2(1): 3–18. 2. David B, Fabrice M, Arthur H, Noel Z, Alexandre M. R, Rakhi J, Adriana A, ..... Mohamed H, Jorge LA, Pascual C, Walid HA, Juan JP. Relationship between Anterior Chamber Depth, Refractive State, Corneal Diameter, and Axial ...

  3. Corneal topography measurements for biometric applications (United States)

    Lewis, Nathan D.

    The term biometrics is used to describe the process of analyzing biological and behavioral traits that are unique to an individual in order to confirm or determine his or her identity. Many biometric modalities are currently being researched and implemented including, fingerprints, hand and facial geometry, iris recognition, vein structure recognition, gait, voice recognition, etc... This project explores the possibility of using corneal topography measurements as a trait for biometric identification. Two new corneal topographers were developed for this study. The first was designed to function as an operator-free device that will allow a user to approach the device and have his or her corneal topography measured. Human subject topography data were collected with this device and compared to measurements made with the commercially available Keratron Piccolo topographer (Optikon, Rome, Italy). A third topographer that departs from the standard Placido disk technology allows for arbitrary pattern illumination through the use of LCD monitors. This topographer was built and tested to be used in future research studies. Topography data was collected from 59 subjects and modeled using Zernike polynomials, which provide for a simple method of compressing topography data and comparing one topographical measurement with a database for biometric identification. The data were analyzed to determine the biometric error rates associated with corneal topography measurements. Reasonably accurate results, between three to eight percent simultaneous false match and false non-match rates, were achieved.

  4. Serological profile of candidates for corneal donation

    Directory of Open Access Journals (Sweden)

    Adroaldo Lunardelli


    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.

  5. Relationship between Central Corneal Thickness, Vitreous ...

    African Journals Online (AJOL)

    The central corneal thickness (CCT), Vitreous chamber depth (VCD) and axial length (AL) are important ocular parameters used in the assessment of ocular health in relation to some ocular morbidities. Determining the differences in these parameters in relation to each other is fundamental to understanding the general eye ...

  6. Inhibition of Corneal Neovascularization by Hydrazinocurcumin

    African Journals Online (AJOL)

    This article previously published in Volume 15 Issue 2 of this journal in February 2016 has been retracted in line with the guidelines from the Committee on Publication Ethics (COPE, Retracted: Zhan W, Zhu J, Zhang Y. Inhibition of corneal neovascularization by ...

  7. Mathematical analysis of corneal oxygenation | Avtar | International ...

    African Journals Online (AJOL)

    Purpose: To develop a quasi steady state model for the time course concentration profile describing the oxygen diffusion and consumption in a multilayered corneal tissue and investigate the effect of various model parameters on the oxygen concentration for open and closed eyes. Method: A simple mathematical model for ...

  8. Retracted: Inhibition of Corneal Neovascularization by ...

    African Journals Online (AJOL)

    This article previously published in Volume 15 Issue 2 of this journal in February 2016 has been retracted in line with the guidelines from the Committee on Publication Ethics (COPE, Retracted: Zhan W, Zhu J, Zhang Y. Inhibition of corneal neovascularization by ...

  9. Ultraviolet induced lysosome activity in corneal epithelium

    International Nuclear Information System (INIS)

    Cullen, A.P.


    A 5.000 W Xe-Hg high pressure lamp and a double monochromator were used to produce a 3.3 nm half-bandpass ultraviolet radiation at 295 nm. Pigmented rabbit eyes were irradiated with radiant exposures from 140 Jm -2 to 10.000 Jm -2 and evaluated by slit-lamp biomicroscopy, light and electron microscopy. Corneal threshold (Hsub(c) was 200 Jm -2 and lens threshold (Hsub(L)) was 7.500 Jm -2 . The most repeatable and reliable corneal response to these levels of UV was the development of corneal epithelial granules. Histological changes included a loss of superficial epithelial cells and selective UV induced autolysis of the wing cells. It is suggested that the biomicroscopically observed granules are the clinical manifestation of the secondary lysosomes revealed by light and electron microscopy. It is proposed that UV breaks down the primary lysosome membranes to release hydrolytic enzymes which in turn form the secondary lysosomes during autolysis. Extreme levels of radiant exposure at 295 nm result in indiscriminate destruction of all layers of the corneal epithelium, but the posterior cornea was spared. (orig.) [de

  10. Management of Corneal Bee Sting Injuries. (United States)

    Rai, Ruju R; Gonzalez-Gonzalez, Luis A; Papakostas, Thanos D; Siracuse-Lee, Donna; Dunphy, Robert; Fanciullo, Lisa; Cakiner-Egilmez, Tulay; Daly, Mary K


    To review the management of keratitis after corneal bee stings and to report a case of deep stromal corneal infiltrate secondary to a retained bee stinger managed conservatively in a patient who presented three days after unsanitary manipulation of the stinger apparatus. Case report and review of literature. A 57-year-old male beekeeper was evaluated for pain, blurry vision, and photosensitivity after a corneal bee sting. Of note, the venom sac had been removed with dirty tweezers three days prior to his visit. On exam, a focal infiltrate with diffuse edema was seen surrounding a retained bee stinger in the peripheral cornea. Trace cells in the anterior chamber were also noted. Based on a high suspicion for infectious keratitis, a conservative treatment strategy was elected. Administration of broad-spectrum topical antibiotics with concomitant abstention of corticosteroids led to rapid resolution of the symptoms. Over 16 months of follow-up, the stinger has remained in situ without migration and the patient has maintained 20/20 visual acuity without complications. There is debate on the preferred method for the management of corneal injury secondary to bee stings, especially when it is associated with a retained stinger. We herein present our findings in our appraisal of reported cases. In the aftermath of an ocular bee sting, close surveillance for inflammation and infection is essential. Individual manifestations of these injuries vary in timing, type, and severity; therefore, the accessibility of the stinger and the evolving clinical picture should guide therapeutic decisions.

  11. Corneal Intelligence | Murdoch | Nigerian Journal of Ophthalmology

    African Journals Online (AJOL)

    Nigerian Journal of Ophthalmology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 19, No 1 (2011) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Corneal Intelligence. I Murdoch. Abstract. No Abstract.

  12. The Relationship between Central Corneal Thickness and ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the relationship between central corneal thickness (CCT) and intraocular pressure (IOP) in a predominantly black population. A total of eighty-five subjects (right eyes) with mean age 44.7 ± 15.1 years consisting of 49 males and 36 females were recruited for this study. The central ...

  13. [Purulent corneal ulcers: etiology, pathogenesis, classification]. (United States)

    Kasparova, Evg A; Kasparova, Evg A


    Advanced purulent corneal ulcer, as well as abscess, is a serious vision-threatening condition notable for its fulminant course and possible loss of the eye due to endophthalmitis. Its leading causes, pathogenesis, and classifications are described and analyzed in this paper.

  14. Polysaccharide coating of human corneal endothelium

    DEFF Research Database (Denmark)

    Schroder, H D; Sperling, S


    Electron microscopy revealed the presence of a 600-1500 A thick layer of polysaccharide on the surface of human corneal endothelial cells. The surface layer was visualized by combined fixation and staining in a mixture of ruthenium red and osmium tetroxide. The coating material was stable...

  15. Corneal ulcers: For the general practitioner

    African Journals Online (AJOL)

    may be important predisposing factors and give clues as to the aetiology. Contact lens use is a very common cause of corneal ulcers. Tools for examination. In general practice it is presumed that a slit-lamp and other specialised equipment is unavailable. It would be reasonable to have the following ophthalmic tools at one's ...

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

    Directory of Open Access Journals (Sweden)

    Alexandra X Crawford


    Full Text Available This review highlights many of the fundamental concepts and events in the development of corneal transplantation - from ancient times to modern. Tales of eye, limb, and even heart transplantation appear in ancient and medieval texts; however, in the scientific sense, the original concepts of corneal surgery date back to the Greek physician Galen (130-200 AD. Although proposals to provide improved corneal clarity by surgical interventions, including keratoprostheses, were better developed by the 17 th and 18 th centuries, true scientific and surgical experimentation in this field did not begin until the 19 th century. Indeed, the success of contemporary corneal transplantation is largely the result of a culmination of pivotal ideas, experimentation, and perseverance by inspired individuals over the last 200 years. Franz Reisinger initiated experimental animal corneal transplantation in 1818, coining the term "keratoplasty". Subsequently, Wilhelmus Thorne created the term corneal transplant and 3 years later Samuel Bigger, 1837, reported successful corneal transplantation in a gazelle. The first recorded therapeutic corneal xenograft on a human was reported shortly thereafter in 1838-unsurprisingly this was unsuccessful. Further progress in corneal transplantation was significantly hindered by limited understanding of antiseptic principles, anesthesiology, surgical technique, and immunology. There ensued an extremely prolonged period of debate and experimentation upon the utility of animal compared to human tissue, and lamellar versus penetrating keratoplasty. Indeed, the first successful human corneal transplant was not performed by Eduard Zirm until 1905. Since that first successful corneal transplant, innumerable ophthalmologists have contributed to the development and refinement of corneal transplantation aided by the development of surgical microscopes, refined suture materials, the development of eye banks, and the introduction of

  17. Research on mouse model of grade II corneal alkali burn

    Directory of Open Access Journals (Sweden)

    Jun-Qiang Bai


    Full Text Available AIM: To choose appropriate concentration of sodium hydroxide (NaOH solution to establish a stable and consistent corneal alkali burn mouse model in grade II. METHODS: The mice (n=60 were randomly divided into four groups and 15 mice each group. Corneal alkali burns were induced by placing circle filter paper soaked with NaOH solutions on the right central cornea for 30s. The concentrations of NaOH solutions of groups A, B, C, and D were 0.1 mol/L, 0.15 mol/L , 0.2 mol/L, and 1.0 mol/L respectively. Then these corneas were irrigated with 20 mL physiological saline (0.9% NaCl. On day 7 postburn, slit lamp microscope was used to observe corneal opacity, corneal epithelial sodium fluorescein staining positive rate, incidence of corneal ulcer and corneal neovascularization, meanwhile pictures of the anterior eyes were taken. Cirrus spectral domain optical coherence tomography was used to scan cornea to observe corneal epithelial defect and corneal ulcer. RESULTS: Corneal opacity scores ( were not significantly different between the group A and group B (P=0.097. Incidence of corneal ulcer in group B was significantly higher than that in group A (P=0.035. Incidence of corneal ulcer and perforation rate in group B was lower than that in group C. Group C and D had corneal neovascularization, and incidence of corneal neovascularization in group D was significantly higher than that in group C (P=0.000. CONCLUSION: Using 0.15 mol/L NaOH can establish grade II mouse model of corneal alkali burns.

  18. Outcome of corneal transplantation in a private institution in Saudi Arabia. (United States)

    Omar, Nazri; Bou Chacra, Charbel T; Tabbara, Khalid F


    The aim of this work was to describe the indications, complications, and outcomes of penetrating keratoplasty (PKP) in Saudi Arabia. In a retrospective, noncomparative interventional case series, the medical records of patients who underwent PKP from January 2000 to December 2008 and had a minimum follow-up of 6 months were reviewed. All corneas were obtained from eye banks in the US. Indications, complications, and outcomes of surgery were recorded. This study was approved by the institutional review board. Eighty-five consecutive eyes were included in this study. There were 52 (61.2%) males and 33 (38.8%) females. The median age was 35.0 years (range 3-85 years), and the median follow-up period was 24 months (range 6-108 months). The indications for PKP were keratoconus, bullous keratopathy, corneal scars, corneal dystrophy, and corneal regraft. The overall graft survival time was 88.9 months ± 4.9 months (mean ± standard error of mean, 95% confidence interval [CI] 79.4 months -98.4 months) while the 3-year and 5-year cumulative survival rates were 90.7% and 84.3%, respectively. Surgical indication (P = 0.038), immune rejection (P < 0.001), preoperative corneal vascularization (P = 0.022), and perioperative high intraocular pressure (P = 0.032) were associated significantly with corneal graft failure in univariate analysis. Multivariate analysis reduced these significant associations to rejection (P < 0.001) and vascularization (P = 0.009). Relative risk for failure in rejected cornea was 16.22 (95% CI 4.99-52.69) and in vascularized cornea was 3.89 (95% CI 1.36-11.09). At last visit following PKP, 34 (40%) eyes had best spectacle-corrected visual acuity of 20/40 or better, and 51 (60.0%) eyes had 20/80 or better. Best spectacle-corrected visual acuity was worse than 20/400 in 15 (17.6%) eyes. The overall corneal graft survival in a private setting in Saudi Arabia can be excellent. Thorough preoperative evaluation and comprehensive postoperative management are

  19. New corneal findings in chromosome 10 deletion syndrome: report of two cases of corneal ectasia of varying severity. (United States)

    Lim, Lik Thai; Rehman, Ajmal; Masoud, Mohammad Tahir; Jaiya, Amrita; Tan, Peng Yi; Scott, J Angus


    To describe corneal changes associated with chromosome 10 terminal deletion (chromosome 10, monosomy 10qter) syndrome. Report of two cases of bilateral corneal ectasia with literature review. Corneal pathology has not previously been reported in the limited number of case reports on 10qter syndrome. However, Rodrigues et al.(1) have reported sclerocornea in 10q translocation. Ophthalmic manifestations of 10qter syndrome include strabismus, lid, and facial anomalies. We present two cases of corneal ectasia of varying severity. Possible etiologies include the following: secondary to genetic factors, acquired corneal exposure during sleep, or possible intrinsic immunocompromise exacerbating ocular surface infections. Corneal ectasia with specific histological changes is a feature of various genetic disorders (e.g., Down's, Ehler's Danlos, and Marfan's syndromes). It is unknown whether genetics plays a role in the development of corneal changes in 10qter syndrome. Management of inflammation and visual rehabilitation in these patients poses a therapeutic challenge.

  20. Biodegradable and biocompatible poly(ethylene glycol)-based hydrogel films for the regeneration of corneal endothelium. (United States)

    Ozcelik, Berkay; Brown, Karl D; Blencowe, Anton; Ladewig, Katharina; Stevens, Geoffrey W; Scheerlinck, Jean-Pierre Y; Abberton, Keren; Daniell, Mark; Qiao, Greg G


    Corneal endothelial cells (CECs) are responsible for maintaining the transparency of the human cornea. Loss of CECs results in blindness, requiring corneal transplantation. In this study, fabrication of biocompatible and biodegradable poly(ethylene glycol) (PEG)-based hydrogel films (PHFs) for the regeneration and transplantation of CECs is described. The 50-μm thin hydrogel films have similar or greater tensile strengths to human corneal tissue. Light transmission studies reveal that the films are >98% optically transparent, while in vitro degradation studies demonstrate their biodegradation characteristics. Cell culture studies demonstrate the regeneration of sheep corneal endothelium on the PHFs. Although sheep CECs do not regenerate in vivo, these cells proliferate on the films with natural morphology and become 100% confluent within 7 d. Implantation of the PHFs into live sheep corneas demonstrates the robustness of the films for surgical purposes. Regular slit lamp examinations and histology of the cornea after 28 d following surgery reveal minimal inflammatory responses and no toxicity, indicating that the films are benign. The results of this study suggest that PHFs are excellent candidates as platforms for the regeneration and transplantation of CECs as a result of their favorable biocompatibility, degradability, mechanical, and optical properties. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Necessity to identify the causative agent for appropriate treatment in fungal corneal ulcer: an in vitro study. (United States)

    Gupta, M K; Chandra, A; Prakash, P; Tilak, R


    Fungal corneal ulcers are a major cause of preventable blindness. Different antifungal agents as natamycin, nystatin, fluconazole, itraconazole, voriconazole are used to treat these ulcers. Among these, natamycin is most widely used as a treatment modality. In natamycin non-responding cases, other drugs especially voriconazole is used. This study was done to assess the use of antifungal drugs in the treatment of fungal corneal ulcer by determining the minimum inhibitory concentration against common fungal pathogens. Minimum inhibitory concentration of fluconazole, itraconazole, voriconazole, nystatin and natamycin was assessed against the 61 isolated corneal fungal pathogens as per CLSI guidelines. MIC value of different antifungal agents varies as per fungal strains. Voriconazole showed the lowest MIC against the isolated fungi, in comparison to fluconazole and itraconazole. In comparison to other fungi, higher natamycin MIC was observed against Aspergillus species. Itraconazole is poorly effective against Fusarium sp. Identification of causative fungi is necessary before antifungal treatment. Lowest voriconazole MIC promotes its use as 1st line drug. Comparative higher natamycin MIC, especially against Aspergillus species, warns clinician to have MIC in each case of a non-responding fungal corneal ulcer. Copyright © 2017. Published by Elsevier Masson SAS.

  2. A Locus for Posterior Polymorphous Corneal Dystrophy (PPCD3) Maps to Chromosome 10 (United States)

    Shimizu, Satoko; Krafchak, Charles; Fuse, Nobuo; Epstein, Michael P.; Schteingart, Miriam T.; Sugar, Alan; Eibschitz-Tsimhoni, Maya; Downs, Catherine A.; Rozsa, Frank; Trager, Edward H.; Reed, David M.; Boehnke, Michael; Moroi, Sayoko E.; Richards, Julia E.


    Posterior polymorphous corneal dystrophy (PPCD) is an autosomal dominant disorder characterized by corneal endothelial abnormalities, which can lead to blindness due to loss of corneal transparency and sometimes glaucoma. We mapped a new locus responsible for PPCD in a family in which we excluded the previously reported PPCD locus on 20q11, and the region containing COL8A2 on chromosome 1. Results of a 317-marker genome scan provided significant evidence of linkage of PPCD to markers on chromosome 10, with single-point LOD scores of 2.63, 1.63, and 3.19 for markers D10S208 (at θ^=0.03), D10S1780 (at θ^=0.00), and D10S578 (at θ^=0.06). A maximum multi-point LOD score of 4.35 was found at marker D10S1780. Affected family members shared a haplotype in an 8.55 cM critical interval that was bounded by markers D10S213 and D10S578. Our finding of another PPCD locus, PPCD3, on chromosome 10 indicates that PPCD is genetically heterogeneous. Guttae, a common corneal finding sometimes observed along with PPCD, were found among both affected and unaffected members of the proband’s sib ship, but were absent in the younger generations of the family. Evaluation of phenotypic differences between family members sharing the same affected haplotype raises questions about whether differences in disease severity, including differences in response to surgical interventions, could be due to genetic background or other factors independent of the PPCD3 locus. PMID:15384081

  3. [Cell-based therapies - an innovative therapeutic option in ophthalmology: Treating corneal diseases with stem cells]. (United States)

    Bakker, Ann-Christin; Langer, Barbara


    Pathological changes and disorders of the cornea are a major cause of severe visual impairment and blindness. Replacement of a pathologically altered cornea with healthy corneal tissue from the eye of a suitable donor is among the most common and successful transplantation procedures in medicine. In Germany, approximately 5000-6000 corneal transplantations are performed each year, but the total demand per year is estimated to be twice as high. With a success rate of 90%, the outcome of cornea transplantation is very favourable. However, long-term maintenance and regeneration of a healthy new cornea requires tissue-specific corneal stem cells residing at the basal layer of the limbus, which is the annular transition zone between the cornea and sclera. When this important limbal stem cell population is destroyed or dysfunctional, a pathological condition known as limbal stem cell deficiency (LSCD) manifests. Limbal stem cell deficiency describes conditions associated with impaired corneal wound healing and regeneration. In this situation, transplantation of healthy limbal stem cells is the only curative treatment approach for restoration of an intact and functional ocular surface. To date, treatment of LSCD presents a great challenge for ophthalmologists. However, innovative, cell-therapeutic approaches may open new, promising treatment perspectives. In February 2015, the European Commission granted marketing authorization to the first stem cell-based treatment in the European Union. The product named Holoclar® is an advanced therapy medicinal product (ATMP) for the treatment of moderate to severe LSCD due to physical and chemical burns in adults. Further cell-based treatment approaches are in clinical development.

  4. Mimicking corneal stroma using keratocyte-loaded photopolymerizable methacrylated gelatin hydrogels. (United States)

    Kilic Bektas, Cemile; Hasirci, Vasif


    Cell-laden methacrylated gelatin (GelMA) hydrogels with high (approximately 90%) transparency were prepared to mimic the natural form and function of corneal stroma. They were synthesized from GelMA with a methacrylation degree of 70% as determined by nuclear magnetic resonance. Hydrogels were strong enough to withstand handling. Stability studies showed that 87% of the GelMA hydrogels remained after 21 days in phosphate buffered saline (PBS). Cell viability in the first 2 days was over 90% for the human keratocytes loaded in the gels as determined with the live-dead analysis. Cells in the hydrogel elongated and connected to each other as observed by confocal laser scanning microscopy (CLSM) images and scanning electron microscope analysis after 3 weeks in the culture medium and cells were seen to be distributed throughout the hydrogel bulk. Cells were found to synthesize collagen Types I and V, decorin, and biglycan (representative collagens and proteoglycans of human corneal stroma, respectively) showing that keratocytes maintained their functions and preserved their phenotypes in the hydrogels. Transparency of cell-loaded and cell-free hydrogels after 21 days was found to be over 90% at all time points in the visible light range and was comparable to the transparency of the native cornea. The corneal stroma equivalent produced in this study that has cells entrapped in it leads to a product with homogenous distribution of cells. It was transparent at the very beginning and is expected to allow better vision than nontransparent substrates. It, therefore, has a significant potential to be used as an alternative to the current products used to treat corneal blindness. Copyright © 2017 John Wiley & Sons, Ltd.

  5. [Corneal ulcers in systemic autoimmunologic diseases]. (United States)

    Augsten, R; Dawczynski, J; Voigt, U; Oelzner, P; Schulze, E; Königsdörffer, E


    Keratolysis is a rare severe complication following systemic autoimmunologic diseases. Despite of complex therapeutic treatments, the prognosis is very poor. Ten eyes from seven patients with corneal ulcers were reported (age 45 - 73 years, mean 63 years; 6 women, 1 man). The corneal ulcer was perforated in 7 eyes. Five patients suffered from rheumatoid arthritis, and one patient developed a Sjögren's syndrome. Besides, one patient had shown both autoimmunologic diseases. After clinical attendance, visual acuity in the eyes with nonperforated ulcers was between 0.1 and 0.4, and in the eyes with perforated ulcers between light perception and 0.2. In 7 eyes with perforated corneal ulcers an emergency tectonic conjunctival plasty and, 1 - 2 days later, a keratoplasty had been performed. Postoperatively, local therapies had been initiated with antibiotic and immunosuppressive eyedrops as well as with conventional drops for dry-eye symptoms. Because of the autoimmunologic diseases of the patients, a systemic immunosuppressive therapy had been arranged. Follow-up period had been between 4 weeks and 3,5 years (mean 16 months). In the three eyes with nonperforated ulcers which received an antibiotic and immunosuppressive treatment, visual acuity was found at 1 / 20 and 0.4. However, in spite of stabilized findings in the 5 eyes with perforated ulcers, the visual acuity was in this case only between light perception and 0.05. One patient with a perforated ulcer and one patient with a recurrent corneal perforation after keratoplasty refused further operative procedures. Finally, both eyes had to undergo evisceration. Despite of intensive local and systemic immunosuppressive as well as operative therapies, corneal ulcers associated with autoimmunologic diseases (rheumatoid arthritis, Sjögren's syndrome) may cause a marked decrease of visual acuity or the loss of an eye. With regard to the healthy eye, an immunosuppressive therapy for life is most important.

  6. What is Color Blindness? (United States)

    ... Stories Español Eye Health / Eye Health A-Z Color Blindness Sections What Is Color Blindness? What Are ... Treatment How Color Blindness Is Tested What Is Color Blindness? Leer en Español: ¿Qué es el daltonismo? ...

  7. Bilateral corneal ulceration in ocular graft-versus-host disease. (United States)

    Stevenson, William; Shikari, Hasanain; Saboo, Ujwala S; Amparo, Francisco; Dana, Reza


    To report on corneal ulceration in ocular graft-versus-host disease (GVHD). This was a retrospective, observational case series investigating corneal ulceration and perforation in a cohort of ocular GVHD patients seen between June 2007 and October 2012. Four of 243 ocular GVHD patients developed corneal ulcerations attributable to ocular GVHD, and all four cases involved bilateral corneal ulceration. The median length of time from the diagnosis of ocular GVHD to the diagnosis of the first corneal ulceration was 317 days (range 168-434). The median length of time between the diagnosis of corneal ulceration in each patient's first and second eye was 248 days (range 9-645). Outcomes varied from complete resolution with medical treatment to corneal perforation necessitating penetrating keratoplasty. In cases of corneal perforation, the median length of time from the diagnosis of corneal ulceration to perforation was 10 days (range 0-20). Common clinical features included: centrally or paracentrally located ulcerations and perforations, concomitant dry eye, and the use of topical or systemic corticosteroids. Frequent follow-up and bilateral monitoring are highly recommended in cases of ocular GVHD-associated stromal thinning, as bilateral involvement or rapid progression to corneal perforation can occur.

  8. Corneal neurotization: a novel technique for the anesthetic cornea. (United States)

    Terzis, Julia K; Dryer, Marylou M; Bodner, Bruce I


    This report describes and evaluates the efficacy of a novel procedure, direct corneal neurotization using contralateral, supraorbital, and supratrochlear nerves in patients with unilateral facial palsy and corneal anesthesia. The charts of 6 patients were thoroughly reviewed. Evaluated outcome parameters included corneal sensibility, improvement in best-corrected visual acuity, blink reflex, donor deficit, synesthesia, long-term corneal health, several psychosocial measures, and overall patient satisfaction. The mean age at time of surgery in our study was 41.7 +/- 9.07 years. Average time from denervation to surgery was 7.00 +/- 8.56 years with an average follow-up time of 16.3 +/- 2.42 years. After surgery, all 6 eyes showed improvement of corneal sensibility, visual acuity, and corneal health and remained free of ulcers without adjunctive surgical treatment. Average time to sensibility was 2.80 +/- 2.17 years, and average corneal sensibility improved from 2.00 +/- 4.47 mm before surgery to 27.8 +/- 22.6 mm after corneal neurotization (P corneal sensibility in patients with unilateral facial palsy and anesthetic cornea. This procedure preserves ocular anatomy and cosmesis while restoring function by improving corneal health and visual acuity and by reestablishing the blink reflex.

  9. Cytopathic effect of Acanthamoeba on human corneal fibroblasts (United States)

    Takaoka-Sugihara, Noriko; Yokoo, Seiichi; Matsubara, Masao; Yagita, Kenji


    Purpose Acanthamoeba keratitis is associated with keratocyte depletion in humans. We investigated how Acanthamoebae isolated from corneas affected by Acanthamoeba keratitis interacted with human corneal stromal cells in vitro. Methods Acanthamoebae were isolated from 6 patients with Acanthamoeba keratitis and genotyping was done. Whether the isolated Acanthamoebae could invade the corneal stroma was assessed with denuded corneal stroma ex vivo. The cytopathic effect of Acanthamoeba on cultured corneal fibroblasts from donor corneas was quantitatively evaluated by the MTT assay after culture under various conditions. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and Annexin V staining were employed to detect apoptotic cells among the corneal fibroblasts co-cultured with Acanthamoebae. Results All 6 Acanthamoebae isolated from the patients with Acanthamoeba keratitis were shown to have the T4 genotype by 18S rDNA sequence analysis. Acanthamoebae invaded the denuded corneal stroma in the ex vivo experiments and had a cytopathic effect on human corneal fibroblasts after direct adhesion, but not via chemical mediators. A cytopathic effect was detected with all 6 Acanthamoebae and corneal fibroblasts mainly died by apoptosis, as evidenced by Annexin V staining. Conclusions Acanthamoebae isolated from patients with Acanthamoeba keratitis had a cytopathic effect on human corneal fibroblasts, mainly via induction of apoptosis after direct adhesion. Our findings may provide some clues to the pathophysiology of corneal keratocyte depletion in patients with Acanthamoeba keratitis. PMID:22933834

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

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    Federico Saenz-Frances


    Full Text Available 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 logistic regressions for MC and PC.CONCLUSION: MT was typically located at the inferior-temporal quadrant of the cornea and its distance to the corneal apex tended to decrease with the increment of corneal volume.

  11. Corneal biomechanical features in patients with ankylosing spondylitis. (United States)

    Cabuk, Kubra Serefoglu; Üstün, Emine Isil; Atalay, Kursat; Kirgiz, Ahmet; Aydin, Rukiye


    To evaluate the corneal biomechanical features and central corneal thickness in ankylosing spondylitis patients and to evaluate correlations of these parameters with disease activity. The study included 51 patients diagnosed with ankylosing spondylitis (mean age, 40.80 ± 13.15 years; range, 18-72 years) and 34 age- and sex-matched healthy controls (mean age, 42.00 ± 12.32 years; range, 18-60 years). All underwent a complete ophthalmological and physical examination, including visual acuity testing and biomicroscopic anterior and posterior segment examinations. Corneal hysteresis, corneal resistance factor, Goldmann-correlated intraocular pressure, and corneal compensated intraocular pressure were evaluated with an ocular response analyzer, and the central corneal thickness was measured with Sirius® corneal tomography. The Bath Ankylosing Spondylitis Disease Activity Index, Functional Index, and Metrology Index scores were recorded. In the ankylosing spondylitis patients, the mean disease duration was 7.73 ± 6.05 (range, 1-30) years. There was no statistically significant difference between the patients and controls in the corneal biomechanical features. The Goldmann-correlated intraocular pressure and corneal compensated intraocular pressure both showed positive correlations with age (p=0.003 and p=0.001, res-pectively). There was a negative correlation between corneal hysteresis and disease duration (p=0.002), and between central corneal thickness and the Bath Ankylosing Spondylitis Metrology Index score (p=0.003). This study demonstrated a significant negative correlation between corneal hysteresis and disease duration in ankylosing spondylitis patients. Furthermore, the central corneal thickness value decreased with an increase in Bath Ankylosing Spondylitis Metrology Index score, which may result in an underestimate of intraocular pressure readings and thus an inaccurate risk assessment of glaucoma.

  12. Corneal collagen cross-linking to stop corneal ectasia exacerbated by radial keratotomy. (United States)

    Mazzotta, Cosimo; Baiocchi, Stefano; Denaro, Rosario; Tosi, Gian Marco; Caporossi, Tomaso


    To assess the efficacy of riboflavin ultraviolet A (UV-A) corneal collagen cross-linking in the management of keratoconic corneal ectasia exacerbated by radial keratotomy (RK). A patient with progressive corneal ectasia and hyperopic shift, occurring 10 years after RK performed in the left eye, was treated with riboflavin UV-A corneal collagen cross-linking according to the Siena protocol: Pilocarpin 0.1% drop (1 hour before), lidocaine 4% drops 15 minutes before, mechanical scraping of epithelium (9-mm-diameter area), preirradiation stromal soaking for 10 minutes in riboflavin 0.1%-dextrane 20% (Ricrolin; Sooft Italy) applied every 2 minutes, and 30 minutes of total exposure (6 steps of 5 minutes) to solid-state UV-A illuminator (Caporossi, Baiocchi, Mazzotta Vega X linker; CSO Opthalmics, Florence, Italy), energy delivered 3 mW/cm, and irradiated area 9 mm in diameter. After the operation, uncorrected visual acuity and best spectacle-corrected visual acuity improved from 0.2 to 0.6 and from 0.3 to 0.8 Snellen lines, respectively, in a 12-month follow-up. Improved topographical K readings and corneal symmetry index were also recorded starting from the first postoperative month and continuing thereafter. No adverse effects were recorded after treatment. Riboflavin UV-A-induced corneal cross-linking seems to be a promising surgical option in the management of unstable corneal ectasia exacerbated by RK, particularly in eyes with preexisting keratoconus. A large cohort and longer follow-up are needed to determine its long-term efficacy in this clinical setting.

  13. Adipose Derived Stem Cells for Corneal Wound Healing after Laser Induced Corneal Lesions in Mice

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    Marco Zeppieri


    Full Text Available The aim of our study was to assess the clinical effectiveness of topical adipose derived stem cell (ADSC treatment in laser induced corneal wounds in mice by comparing epithelial repair, inflammation, and histological analysis between treatment arms. Corneal lesions were performed on both eyes of 40 mice by laser induced photorefractive keratectomy. All eyes were treated with topical azythromycin bid for three days. Mice were divided in three treatment groups (n = 20, which included: control, stem cells and basic serum; which received topical treatment three times daily for five consecutive days. Biomicroscope assessments and digital imaging were performed by two masked graders at 30, 54, 78, 100, and 172 h to analyze extent of fluorescein positive epithelial defect, corneal inflammation, etc. Immunohistochemical techniques were used in fixed eyes to assess corneal repair markers Ki67, α Smooth Muscle Actin (α-SMA and E-Cadherin. The fluorescein positive corneal lesion areas were significantly smaller in the stem cells group on days 1 (p < 0.05, 2 (p < 0.02 and 3. The stem cell treated group had slightly better and faster re-epithelization than the serum treated group in the initial phases. Comparative histological data showed signs of earlier and better corneal repair in epithelium and stromal layers in stem cell treated eyes, which showed more epithelial layers and enhanced wound healing performance of Ki67, E-Cadherin, and α-SMA. Our study shows the potential clinical and histological advantages in the topical ADSC treatment for corneal lesions in mice.

  14. Access to Mathematics by Blind Students: A Global Problem

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    Arthur I. Karshmer


    Full Text Available The issue of blindness and legally blind is becoming a global issue. Based on the last statistics from American Foundation for the blind, there are approximately 10 million blind and visually impaired people in the United States alone. Over 45 million people around the world are completely blind. 180 million more people are legally blind, and approximately 7 million people are diagnosed as blind or legally blind every year. One of the greatest stumbling blocks in the ability of the blind to enter careers in science, technology, engineering or mathematics is the paucity of tools to help them read and write equations. Over the years there have been numerous projects around the world with the goal of building special tools to help the visually impaired student read and write equations. In the current work, we describe some of the most interesting work in this domain and then attempt to make recommendations and/or predictions about the future.

  15. Rapid assessment of avoidable blindness in Western Rwanda: blindness in a postconflict setting.

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    Wanjiku Mathenge


    Full Text Available The World Health Organization estimates that there were 37 million blind people in 2002 and that the prevalence of blindness was 9% among adults in Africa aged 50 years or older. Recent surveys indicate that this figure may be overestimated, while a survey from southern Sudan suggested that postconflict areas are particularly vulnerable to blindness. The aim of this study was to conduct a Rapid Assessment for Avoidable Blindness to estimate the magnitude and causes of visual impairment in people aged > or = 50 y in the postconflict area of the Western Province of Rwanda, which includes one-quarter of the population of Rwanda.Clusters of 50 people aged > or = 50 y were selected through probability proportionate to size sampling. Households within clusters were selected through compact segment sampling. Visual acuity (VA was measured with a tumbling "E" chart, and those with VA below 6/18 in either eye were examined by an ophthalmologist. The teams examined 2,206 people (response rate 98.0%. The unadjusted prevalence of bilateral blindness was 1.8% (95% confidence interval [CI] 1.2%-2.4%, 1.3% (0.8%-1.7% for severe visual impairment, and 5.3% (4.2%-6.4% for visual impairment. Most bilateral blindness (65% was due to cataract. Overall, the vast majority of cases of blindness (80.0%, severe visual impairment (67.9%, and visual impairment (87.2% were avoidable (i.e.. due to cataract, refractive error, aphakia, trachoma, or corneal scar. The cataract surgical coverage was moderate; 47% of people with bilateral cataract blindness (VA < 3/60 had undergone surgery. Of the 29 eyes that had undergone cataract surgery, nine (31% had a best-corrected poor outcome (i.e., VA < 6/60. Extrapolating these estimates to Rwanda's Western Province, among the people aged 50 years or above 2,565 are expected to be blind, 1,824 to have severe visual impairment, and 8,055 to have visual impairment.The prevalence of blindness and visual impairment in this postconflict

  16. Unilateral corneal leukoplakia without limbal involvement

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    Hirano K


    Full Text Available Koji Hirano,1 Mihoko Koide,2 Yoshikazu Mizoguchi,3 Yasuhiro Osakabe,4 Kaoru-Araki Sasaki5 1Department of Ophthalmology, Ban Buntane Hotokukai Hospital, School of Medicine, Fujita Health University, Nagoya, Japan; 2Koide Internal Medicine and Eye Clinic, Nagoya, Japan; 3Department of Pathology, Ban Buntane Hotokukai Hospital, School of Medicine, Fujita Health University, Nagoya, Japan; 4Department of Molecular Pathology, Tokyo Medical University, Tokyo, Japan; 5Department of Ophthalmology, Japan Health Care Organization, Hoshigaoka Medical Center, Hirakata, Japan Purpose: Leukoplakia is the term given to a white patch or plaque that is found mainly on the oral mucus membrane. It can occasionally be seen on the corneal surface. We report our clinical and histopathological findings in a case of unilateral corneal leukoplakia. Methods: A 26-year-old woman was referred to our hospital because of a white patch on her right cornea that continued to expand. She first noticed the white patch when she was 20 years old, and the white patch had expanded to cover the pupillary area affecting her vision. After plastic surgery on both eyelids for bilateral entropion to alleviate the pain caused by the eyelashes rubbing the cornea, the white corneal patch decreased in size. Because of this reduction, we performed surgery to remove the patch with microforceps under topical anesthesia. The plaque was removed easily and completely, and submitted for histopathological examination. Results: Histopathological examination showed that the specimen had characteristics of epidermis with a basal cell layer, spinous cell layer, granular cell layer, and horny layer with hyperkeratosis. She was diagnosed with leukoplakia of the corneal surface. The basic structure of the squamous cell layer was preserved, and there were no signs of metaplasia. Six months after the removal of the leukoplakia, no recurrence was seen and her corrected decimal visual acuity recovered to 1

  17. Outcome of corneal transplantation in a private institution in Saudi Arabia

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    Omar N


    Full Text Available Nazri Omar,1,2 Charbel T Bou Chacra,1 Khalid F Tabbara1,3,4 1The Eye Center and The Eye Foundation for Research in Ophthalmology, Riyadh, Saudi Arabia; 2Department of Ophthalmology, Universiti Putra Malaysia, Serdang, Malaysia; 3Department of Ophthalmology, King Saud University, Riyadh, Saudi Arabia; 4The Wilmer Ophthalmological Institute of Johns Hopkins University School of Medicine, Baltimore, MD, USA Background: The aim of this work was to describe the indications, complications, and outcomes of penetrating keratoplasty (PKP in Saudi Arabia. Methods: In a retrospective, noncomparative interventional case series, the medical records of patients who underwent PKP from January 2000 to December 2008 and had a minimum follow-up of 6 months were reviewed. All corneas were obtained from eye banks in the US. Indications, complications, and outcomes of surgery were recorded. This study was approved by the institutional review board. Results: Eighty-five consecutive eyes were included in this study. There were 52 (61.2% males and 33 (38.8% females. The median age was 35.0 years (range 3–85 years, and the median follow-up period was 24 months (range 6–108 months. The indications for PKP were keratoconus, bullous keratopathy, corneal scars, corneal dystrophy, and corneal regraft. The overall graft survival time was 88.9 months ± 4.9 months (mean ± standard error of mean, 95% confidence interval [CI] 79.4 months -98.4 months while the 3-year and 5-year cumulative survival rates were 90.7% and 84.3%, respectively. Surgical indication (P = 0.038, immune rejection (P < 0.001, preoperative corneal vascularization (P = 0.022, and perioperative high intraocular pressure (P = 0.032 were associated significantly with corneal graft failure in univariate analysis. Multivariate analysis reduced these significant associations to rejection (P < 0.001 and vascularization (P = 0.009. Relative risk for failure in rejected cornea was 16.22 (95% CI 4.99–52.69 and

  18. Corneal tissue ablation using 6.1 μm quantum cascade laser (United States)

    Huang, Yong; Kang, Jin U.


    High absorption property of tissues in the IR range (λ> 2 μm) results in effective tissue ablation, especially near 3 μm. In the mid-infrared range, wavelengths of 6.1 μm and 6.45 μm fall into the absorption bands of the amide protein groups Amide-I and Amide-II, respectively. They also coincide with the deformation mode of water, which has an absorption peak at 6.1 μm. This coincidence makes 6.1 μm laser a better ablation tool that has promising effectiveness and minimum collateral damages than 3 μm lasers. In this work, we performed bovine corneal ablation test in-vitro using high-power 6.1μm quantum cascade laser (QCL) operated at pulse mode. Quantum cascade laser has the advantages of low cost, compact size and tunable wavelength, which makes it great alternative Mid-IR light source to conventional tunable free-electron lasers (FEL) for medical applications. Preliminary results show that effective corneal stroma craters were achieved with much less collateral damage in corneal tissue that contains less water. Future study will focus on optimizing the control parameters of QCL to attain neat and precise ablation of corneal tissue and development of high peak power QCL.

  19. Ciliary neurotrophic factor promotes the activation of corneal epithelial stem/progenitor cells and accelerates corneal epithelial wound healing. (United States)

    Zhou, Qingjun; Chen, Peng; Di, Guohu; Zhang, Yangyang; Wang, Yao; Qi, Xia; Duan, Haoyun; Xie, Lixin


    Ciliary neurotrophic factor (CNTF), a well-known neuroprotective cytokine, has been found to play an important role in neurogenesis and functional regulations of neural stem cells. As one of the most innervated tissue, however, the role of CNTF in cornea epithelium remains unclear. This study was to explore the roles and mechanisms of CNTF in the activation of corneal epithelial stem/progenitor cells and wound healing of both normal and diabetic mouse corneal epithelium. In mice subjecting to mechanical removal of corneal epithelium, the corneal epithelial stem/progenitor cell activation and wound healing were promoted by exogenous CNTF application, while delayed by CNTF neutralizing antibody. In cultured corneal epithelial stem/progenitor cells, CNTF enhanced the colony-forming efficiency, stimulated the mitogenic proliferation, and upregulated the expression levels of corneal epithelial stem/progenitor cell-associated transcription factors. Furthermore, the promotion of CNTF on the corneal epithelial stem/progenitor cell activation and wound healing was mediated by the activation of STAT3. Moreover, in diabetic mice, the content of CNTF in corneal epithelium decreased significantly when compared with that of normal mice, and the supplement of CNTF promoted the diabetic corneal epithelial wound healing, accompanied with the advanced activation of corneal epithelial stem/progenitor cells and the regeneration of corneal nerve fibers. Thus, the capability of expanding corneal epithelial stem/progenitor cells and promoting corneal epithelial wound healing and nerve regeneration indicates the potential application of CNTF in ameliorating limbal stem cell deficiency and treating diabetic keratopathy. © 2014 AlphaMed Press.

  20. Plasma polymer-coated contact lenses for the culture and transfer of corneal epithelial cells in the treatment of limbal stem cell deficiency. (United States)

    Brown, Karl David; Low, Suet; Mariappan, Indumathi; Abberton, Keren Maree; Short, Robert; Zhang, Hong; Maddileti, Savitri; Sangwan, Virender; Steele, David; Daniell, Mark


    Extensive damage to the limbal region of the cornea leads to a severe form of corneal blindness termed as limbal stem cell deficiency (LSCD). Whereas most cases of corneal opacity can be treated with full thickness corneal transplants, LSCD requires stem cell transplantation for successful ocular surface reconstruction. Current treatments for LSCD using limbal stem cell transplantation involve the use of murine NIH 3T3 cells and human amniotic membranes as culture substrates, which pose the threat of transmission of animal-derived pathogens and donor tissue-derived cryptic infections. In this study, we aimed to produce surface modified therapeutic contact lenses for the culture and delivery of corneal epithelial cells for the treatment of LSCD. This approach avoids the possibility of suture-related complications and is completely synthetic. We used plasma polymerization to deposit acid functional groups onto the lenses at various concentrations. Each surface was tested for its suitability to promote corneal epithelial cell adhesion, proliferation, retention of stem cells, and differentiation and found that acid-based chemistries promoted better cell adhesion and proliferation. We also found that the lenses coated with a higher percentage of acid functional groups resulted in a higher number of cells transferred onto the corneal wound bed in rabbit models of LSCD. Immunohistochemistry of the recipient cornea confirmed the presence of autologous, transplanted 5-bromo-2'-deoxyuridine (BrdU)-labeled cells. Hematoxylin staining has also revealed the presence of a stratified epithelium at 26 days post-transplantation. This study provides the first evidence for in vivo transfer and survival of cells transplanted from a contact lens to the wounded corneal surface. It also proposes the possibility of using plasma polymer-coated contact lenses with high acid functional groups as substrates for the culture and transfer of limbal cells in the treatment of LSCD.

  1. Factores de riesgo en pacientes con sospecha de úlcera corneal micótica en Pinar del Río Risk factors found in patients with possible diagnosis of mycotic corneal ulcer in Pinar del Río province

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    Janet González Sotero


    patients suspected of mycotic corneal ulcer in Pinar del Río province. METHODS: An observational and analytical case-control study was conducted. Data were collected from the medical histories of those patients with possible diagnosis of mycotic corneal ulcer, who had been admitted at the Ophthalmology Service of "Abel Santamaría Cuadrado" clinical and surgical hospital from January 1st, 2004 to November 30th, 2007. The variables such as age, sex, occupation, kind of residence place, recent history of corneal trauma caused by vegetable matter, corneal trauma, use of contact lenses, use of topical steroids, immunosuppressive systemic diseases, previous eye surgery and and ocular surface chronic illness were all used . The frequency and association measures were also used. RESULTS: It was determined that occupation, kind of residence place and recent history of corneal trauma with vegetable matter are possible risk factors of mycotic corneal ulcer in the province. The frequency of mycotic corneal ulcer was 27 % of the total number of patients admitted and diagnosed with that disease. Males were the most affected and the 38-57 y age group as well. CONCLUSIONS: The recent history of corneal trauma caused by the vegetable material, rural place of residence and direct handling of plants at work were those risk factors in the studied patients. The frequency of mycotic corneal ulcer in this study matched that of the pattern seen in those countries with warm and humid climate, particularly near the Equator. Mycotic corneal ulcer is more common in men at working age.

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

    Directory of Open Access Journals (Sweden)

    Marcello Colombo-Barboza


    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.

  3. Effect of central corneal thickness, corneal curvature, and axial length on applanation tonometry. (United States)

    Kohlhaas, Markus; Boehm, Andreas G; Spoerl, Eberhard; Pürsten, Antje; Grein, Hans J; Pillunat, Lutz E


    To evaluate the effect of central corneal thickness (CCT), corneal curvature, and axial length on applanation tonometry in an in vivo study. In a masked, prospective clinical trial, we examined 125 eyes of 125 patients scheduled for cataract surgery. Corneal curvature was measured by means of keratometry and axial length by A-scan ultrasonography. By cannulating the anterior chamber before surgery, intraocular pressure (IOP) was set to 20, 35, and 50 mm Hg in a closed system by means of a water column. After measuring thickness, the IOP was measured with an applanation tonometer. Pearson product moment correlations and multiple linear regression analyses were performed, and significance levels were evaluated by the paired, 2-tailed t test. The difference between measured and real IOP was significantly dependent (P < .001) on CCT. The associations between IOP and corneal curvature or IOP and axial length were not statistically significant (P = .31). The association between IOP reading and CCT is shown in the "Dresdner correction table," which illustrates an approximately 1-mm Hg correction for every 25-microm deviation from a CCT of 550 microm. The correction values were positive as thickness decreased and negative as thickness increased. Central corneal thickness significantly affects IOP readings obtained by applanation tonometry according to the Goldmann principle. A correction of IOP readings by considering CCT according to the Dresdner correction table might be helpful for determining an accurate IOP value.

  4. Corneal Shape, Volume, and Interocular Symmetry: Parameters to Optimize the Design of Biosynthetic Corneal Substitutes. (United States)

    Durr, Georges M; Auvinet, Edouard; Ong, Jeb; Meunier, Jean; Brunette, Isabelle


    To characterize the three-dimensional (3D) shape, volume distribution, and mirror symmetry of the right and left corneas at the scale of a large population, based on the integrated analysis of 3D corneal shape average maps and topography parameters. A total of 7670 Orbscan II corneal topographies from 3835 consenting subjects with no history of ocular disease were studied. Average topography maps were created using the right and left corneal topographies of all subjects. To quantify symmetry, left eye topographies were flipped horizontally into "right eye" topographies and statistics maps were generated, including difference and intraclass correlation coefficient (ICC) maps. The standard deviation of the anterior and posterior average elevation maps in the 3-mm radius central zone of the right and left corneas ranged within ± 8 μm and ± 44 μm, respectively. The ICC maps showed almost perfect interocular agreement for anterior elevation, posterior elevation, and pachymetry (all ICCs > 0.96). All studied shape parameters also showed excellent agreement (ICCs ≥ 0.80). Mirror symmetry was not affected by age, sex, or spherical equivalent. We also showed that this horizontal reflection (flip) of the right and left corneal shapes could not be replaced by a simple rotation. These results indicate that in normal eyes, the anterior elevation, posterior elevation, and pachymetry of the right and left corneas show remarkable symmetry. This comprehensive analysis was achieved with the purpose of guiding the development of future biosynthetic corneal substitutes.

  5. Epidemiological characteristics, predisposing factors and microbiological profiles of infectious corneal ulcers: the Portsmouth corneal ulcer study. (United States)

    Ibrahim, Y W; Boase, D L; Cree, I A


    The aim of the study was to identify the epidemiological characteristics, predisposing factors, and the clinical and microbiological diagnosis of infectious corneal ulcers in a population based in southern England. A retrospective review was undertaken of the medical records of patients presenting with infectious corneal ulcers at the eye casualty department of Queen Alexandra Hospital, Portsmouth, UK, between January 1997 and December 2003. A total of 1786 patients presented with infectious corneal ulcers, with a mean age of 45 years and female predominance (54.5%). Contact lens wear was the main predisposing factor in 554 patients (31%). Corneal scrapes from 1254 patients grew positive cultures in 800 patients. Gram-positive bacteria accounted for 696 (71.1%) of the total 979 bacterial isolates, while Gram-negative bacteria accounted for 283 (28.9%) with the predominance of Pseudomonas aeruginosa. Nine out of 11 patients with Acanthamoeba keratitis were contact lens wearers. The majority of patients 1728 (96.8%) sought medical help more than once and 34 patients (1.9%) had poor visual outcome. Follow-up was completed in 1633 patients (91.4%) with an average of 11.5 days. Wearing contact lenses remains the most important risk factor for infectious corneal ulcers. Reduction of the rate and severity of infectious keratitis requires continuous education of patients, and of professionals.

  6. The molecular mechanisms of action of PPAR-γ agonists in the treatment of corneal alkali burns (Review) (United States)

    Zhou, Hongyan; Zhang, Wensong; Bi, Miaomiao; Wu, Jie


    Corneal alkali burns (CAB) are characterized by injury-induced inflammation, fibrosis and neovascularization (NV), and may lead to blindness. This review evaluates the current knowledge of the molecular mechanisms responsible for CAB. The processes of cytokine production, chemotaxis, inflammatory responses, immune response, cell signal transduction, matrix metalloproteinase production and vascular factors in CAB are discussed. Previous evidence indicates that peroxisome proliferator-activated receptor γ (PPAR-γ) agonists suppress immune responses, inflammation, corneal fibrosis and NV. This review also discusses the role of PPAR-γ as an anti-inflammatory, anti-fibrotic and anti-angiogenic agent in the treatment of CAB, as well as the potential role of PPAR-γ in the pathological process of CAB. There have been numerous studies evaluating the clinical profiles of CAB, and the aim of this systematic review was to summarize the evidence regarding the treatment of CAB with PPAR-γ agonists. PMID:27499172

  7. [Peripheral corneal melting syndrome in psoriatic arthritis treated with adalimumab]. (United States)

    Restrepo, Juan Pablo; Medina, Luis Fernando; Molina, María del Pilar


    Peripheral corneal melting syndrome is a rare immune condition characterized by marginal corneal thinning and sometimes perforation. It is associated with rheumatic and non-rheumatic diseases. Few cases of peripheral corneal melting have been reported in patients with psoriasis. The pathogenesis is not fully understood but metalloproteinases may play a pathogenic role. Anti-TNF therapy has shown to decrease skin and serum metalloproteinases levels in psoriasis. We report a 61-year-old man with peripheral corneal melting syndrome associated with psoriatic arthritis who received Adalimumab to control skin and ocular inflammation. To our knowledge, this is the first case report of peripheral corneal melting syndrome in psoriatic arthritis treated with Adalimumab showing resolution of skin lesions and complete healing of corneal perforation in three months. Copyright © 2013 Elsevier Editora Ltda. All rights reserved.

  8. Relationship between central and peripheral corneal astigmatism in elderly patients (United States)

    Kawamorita, Takushi; Shimizu, Kimiya; Hoshikawa, Rie; Kamiya, Kazutaka; Shoji, Nobuyuki


    Abstract Purpose We investigated the relationship between central and peripheral corneal astigmatism in elderly patients. Methods Seventy-six eyes of 76 elderly subjects (mean age = 72.6 ± 3.0 years) were included in the study. Corneal shape was evaluated using the Pentacam HR (Oculus, Wetzlark, Germany), which is comprised of a rotating Scheimpflug camera and a short-wavelength slit light. The power distribution map was selected and corneal astigmatism was calculated using front K-Readings in zones centered on the pupil. Analyzed zones were 2.0-6.0 mm in diameter. Results Corneal astigmatism decreased as diameter increased, similar to what was observed in eyes with with-the-rule astigmatism and against-the-rule astigmatism (ANOVA, p axis of corneal astigmatism (ANOVA, p = 0.98). Conclusion These results suggest that the relationship between central and peripheral corneal astigmatism should be taken into consideration to optimize vision when astigmatic correction is needed.

  9. [Corneal neurotrophic ulcers--clinical and etiopathogenic aspects]. (United States)

    Damian, Carmen; Craitoiu, Stefania; Preda, Mirela; Manescu, Rodica; Irimia, Anca; Marinescu, Florentina


    The aim of this paper is to observe the corneal neurotrophic ulcers in patients with ophthalmic and systemic diseases associated with impairment of the sensory innervation of the cornea. We have performed a retrospective study using a lot of patients with corneal neurotrophic ulcers, admitted in Ophthalmology Clinic in 2003-2006. We have analyzed the etiopathogenic factors that have determined the corneal trophic ulcers, the treatment and the complications occurred. The study spot-lighted two main causes responsible for the corneal trophic ulcers: ocular and systemic disorders. For many patients the etiopathogenic factor is multiple. 1. Corneal neurotrophic ulcer is a severe complication of an ophthalmic or a systemic disorder. 2. The moderate outcome of ophthalmic complications require early treatment, adjusted for each patient. 3. Prevention of the corneal neurotrophic ulcers is the best method of treatment.

  10. Systemic immunomodulatory strategies in high-risk corneal transplantation

    Directory of Open Access Journals (Sweden)

    Tulio B Abud


    Full Text Available The cornea is the most commonly transplanted tissue in the body. Although corneal grafts generally have high success rates, transplantation onto inflamed and vascularized host beds, or so-called high-risk corneal transplantation, has a high rate of graft rejection. The management of this high-risk corneal transplantation is challenging and involves numerous measures. One of the key measures to prevent graft rejection in these cases is the use of systemic immunosuppressive agents. In this article, we will review the systemic immunosuppressive agents most commonly used for high-risk corneal transplantation, which include corticosteroids, cysclosporine A, tacrolimus, mycophenolate mofetil, and rapamycin. Benefits, risks, and published data on the use of these medications for high-risk corneal transplantation will be detailed. We will also summarize novel immunoregulatory approaches that may be used to prevent graft rejection in high-risk corneal transplantation.

  11. Blind Quantum Computation

    DEFF Research Database (Denmark)

    Salvail, Louis; Arrighi, Pablo


    We investigate the possibility of "having someone carry out the work of executing a function for you, but without letting him learn anything about your input". Say Alice wants Bob to compute some known function f upon her input x, but wants to prevent Bob from learning anything about x. The situa......We investigate the possibility of "having someone carry out the work of executing a function for you, but without letting him learn anything about your input". Say Alice wants Bob to compute some known function f upon her input x, but wants to prevent Bob from learning anything about x....... The situation arises for instance if client Alice has limited computational resources in comparison with mistrusted server Bob, or if x is an inherently mobile piece of data. Could there be a protocol whereby Bob is forced to compute f(x) "blindly", i.e. without observing x? We provide such a blind computation...... protocol for the class of functions which admit an efficient procedure to generate random input-output pairs, e.g. factorization. The cheat-sensitive security achieved relies only upon quantum theory being true. The security analysis carried out assumes the eavesdropper performs individual attacks....

  12. Representing vision and blindness. (United States)

    Ray, Patrick L; Cox, Alexander P; Jensen, Mark; Allen, Travis; Duncan, William; Diehl, Alexander D


    There have been relatively few attempts to represent vision or blindness ontologically. This is unsurprising as the related phenomena of sight and blindness are difficult to represent ontologically for a variety of reasons. Blindness has escaped ontological capture at least in part because: blindness or the employment of the term 'blindness' seems to vary from context to context, blindness can present in a myriad of types and degrees, and there is no precedent for representing complex phenomena such as blindness. We explore current attempts to represent vision or blindness, and show how these attempts fail at representing subtypes of blindness (viz., color blindness, flash blindness, and inattentional blindness). We examine the results found through a review of current attempts and identify where they have failed. By analyzing our test cases of different types of blindness along with the strengths and weaknesses of previous attempts, we have identified the general features of blindness and vision. We propose an ontological solution to represent vision and blindness, which capitalizes on resources afforded to one who utilizes the Basic Formal Ontology as an upper-level ontology. The solution we propose here involves specifying the trigger conditions of a disposition as well as the processes that realize that disposition. Once these are specified we can characterize vision as a function that is realized by certain (in this case) biological processes under a range of triggering conditions. When the range of conditions under which the processes can be realized are reduced beyond a certain threshold, we are able to say that blindness is present. We characterize vision as a function that is realized as a seeing process and blindness as a reduction in the conditions under which the sight function is realized. This solution is desirable because it leverages current features of a major upper-level ontology, accurately captures the phenomenon of blindness, and can be

  13. Corneal cross-linking treatment of keratoconus

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    Mahgol Farjadnia


    Full Text Available Keratoconus as the most common cause of ectasia is one of the leading cause of corneal transplants worldwide. The current available therapies do not modify the underlying pathogenesis of the disease, and none of the available approaches but corneal transplant hinder the ongoing ectasia. Several studies document Crosslink defect between collagen fibrils in the pathogenesis of keratoconus. Collagen cross link is a relatively new approach that with the application of the riboflavin and ultraviolet A, new covalent bands reform. Subjective and objective results following this method seem to be promising. Endothelial damage besides other deep structural injury, which is the major concern of this technique have not yet been reported, when applying the standard method.

  14. [Morphologic Corneal Changes after Crosslinking for Keratoconus]. (United States)

    Müller, P L; Löffler, K U; Kohlhaas, M; Holz, F G; Herwig-Carl, M C


    Keratoconus is a relatively common (1 : 2000) bilateral disease leading to a change in biochemical and biomechanical corneal structure as well as thinning and ectasia. For more than 10 years, crosslinking has been a therapeutic option in cases of progression. Using riboflavin and UVA-radiation, the anterior corneal stroma (300 µm) gets stiffened by crosslinking of collagen fibers. When protocols and limitations are adhered, the procedure is described to be effective and of low-risk. This review gives an overview about physiologic and pathologic changes in keratoconic corneas before and after crosslinking. Based on histopathologic examination, the current knowledge in published literature is reviewed and is complemented by our own investigations. Georg Thieme Verlag KG Stuttgart · New York.

  15. Corneal Chromoblastomycosis Caused by Fonsecaea pedrosoi

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    Winai Chaidaroon


    Full Text Available Purpose: To report 2 unusual cases of fungal keratitis due to Fonsecaea pedrosoi. Methods: Two patients were diagnosed with Fonsecaea pedrosoi keratitis. Their files were reviewed for predisposing factors, clinical characteristics, microbiological study, treatment, and outcome. Results: Two consecutive patients presented with brownish pigmented corneal ulcers in their eyes after sustaining eye trauma from vegetative matter. In both cases, corneal scrapings were collected for microscopic examination and culture. Dematiaceous hyphae were seen on the smears, and dark pigmented colonies grew on the culture media, identified as F. pedrosoi. Both patients were treated and cured with combined topical antifungal agents and oral itraconazole. The first patient required an amniotic membrane patch, while the second received an intracameral amphotericin B injection. Conclusions: Pigmented infiltrates can be an important diagnostic clue, but a microscopic evaluation and culture are required to obtain an accurate diagnosis of Fonsecaea keratitis. The prompt diagnosis and combined antifungal treatment can prevent morbidity associated with this fungal infection.

  16. Corneal biomechanics in asymmetrical normal-tension glaucoma

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    Helmy H


    Full Text Available Hazem Helmy,1 Mahmoud Leila,2 Ahmed Atef Zaki3 1Department of Glaucoma and Optic Nerve Diseases, 2Retina Department, 3Corneal Diseases Department, Research Institute of Ophthalmology, Cairo, Egypt Purpose: We aimed to assess corneal biomechanics using the ocular response analyzer in patients with normal-tension glaucoma (NTG, and to evaluate the relationship between corneal biomechanics and visual field loss. Methods: This was a prospective observational case series including patients with bilateral asymmetric NTG. For all patients, corneal hysteresis (CH, corneal resistance factor (CRF, CH - CRF difference, and central corneal thickness values were matched against the mean deviation (MD of the visual field and the cup/disc ratio. For paired-eye comparison in each patient, both eyes were categorized into a better-eyes group and a worse-eyes group according to lower and higher corneal-compensated intraocular pressure readings, respectively. Statistical analysis was carried out with the independent-samples Student’s t-test, and the level of statistical significance was set at 0.05. Correlation was assessed using Pearson’s correlation coefficient. Results: The study included 240 eyes of 120 patients. CH was inversely proportional to the MD in the visual field (P=0.01. CRF in both eyes was inversely proportional to the MD of the visual field (P=0.01. CH - CRF difference was directly proportional to the MD of the visual field (P=0.01. For paired-eye comparison, lower corneal-compensated intraocular pressure was associated with higher CH, higher CRF, smaller cup/disc ratio, and less deterioration of MD of visual field. Conclusion: CH, CRF, and CH - CRF are more powerful predictors of NTG progression than central corneal thickness. Keywords: corneal-compensated intraocular pressure, corneal hysteresis, corneal resistance factor

  17. Participatory ergonomic intervention versus strength training on chronic pain and work disability in slaughterhouse workers: study protocol for a single-blind, randomized controlled trial. (United States)

    Sundstrup, Emil; Jakobsen, Markus D; Andersen, Christoffer H; Jay, Kenneth; Persson, Roger; Aagaard, Per; Andersen, Lars L


    The prevalence of musculoskeletal pain in the shoulder, arm and hand is high among slaughterhouse workers, allegedly due to the highly repetitive and forceful exposure of these body regions during work. Work disability is a common consequence of these pains. Lowering the physical exposure through ergonomics intervention is the traditional strategy to reduce the workload. An alternative strategy could be to increase physical capacity of the worker through strength training. This study investigates the effect of two contrasting interventions, participatory ergonomics versus strength training on pain and work disability in slaughterhouse workers with chronic pain. 66 slaughterhouse workers were allocated to 10 weeks of (1) strength training of the shoulder, arm and hand muscles for 3 x 10 minutes per week, or (2) participatory ergonomics involving counseling on workstation adjustment and optimal use of work tools (~usual care control group). Inclusion criteria were (1) working at a slaughterhouse for at least 30 hours per week, (2) pain intensity in the shoulder, elbow/forearm, or hand/wrist of at least 3 on a 0-10 VAS scale during the last three months, (3) pain lasting for more than 3 months, (4) frequent pain (at least 3 days per week) (5) at least moderate work disability, (6) no strength training during the last year, (7) no ergonomics instruction during the last year.Perceived pain intensity (VAS scale 0-10) of the shoulder, elbow/forearm and hand/wrist (primary outcome) and Disability of the Arm, Shoulder and Hand (Work module, DASH questionnaire) were measured at baseline and 10-week follow-up. Further, total muscle tenderness score and muscle function were assessed during clinical examination at baseline and follow-up. This RCT study will provide experimental evidence of the effectiveness of contrasting work-site interventions aiming at reducing chronic pain and work disability among employees engaged in repetitive and forceful work. Clinical


    Directory of Open Access Journals (Sweden)

    S. V. Trufanov


    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

  19. Subconjunctival injection of antagomir-21 alleviates corneal neovascularization in a mouse model of alkali-burned cornea. (United States)

    Zhang, Yun; Zhang, Ting; Ma, Xiaoyun; Zou, Jun


    Corneal neovascularization may result in loss of corneal transparency and blindness. However, developing successful and inexpensive medical treatments for corneal neovascularization remains an unresolved issue. Recently, several studies have implicated miRNA functions in the regulation of cornea homeostasis. This study aimed to identify the miRNA expression profile in the neovascularized cornea after an alkali burn and to investigate the related underlying mechanisms. Here, alkali-burned corneas and matched normal tissues were pooled to perform miRNA sequencing. MiR-21 in alkali-burned cornea showed the greatest increment of abundance at 4 and 7 d after injury compared to the healthy cornea. The miR-21 expression was positively correlated with both the mRNA and protein level of key angiogenic factors including vascular endothelial growth factor (VEGF)-A and hypoxia-inducible factor-1α (HIF-1α). At 2 and 8 d after alkali burn, the mice received subconjunctival injections of antagomir-21 (1 or 5 nmol per injection). The injection of antagomir-21 (5 nmol) inactivated miR-21 and attenuated neovascularization progression by inhibiting the expression of VEGF-A and HIF-1α. Western blot analysis of the corneas demonstrated that antagomir-21 restored Sprouty 2/4 expression and silenced p-ERK activation. Therefore, these data reveal that antagomir-21 ameliorates the progression of corneal neovascularization likely via Sprouty 2/4-mediated inactivation of p-ERK. Delivery of antagomir-21 might be a potential therapeutic approach to prevent or treat visual loss caused by corneal neovascularization.

  20. Various factors affecting the bacterial corneal ulcer healing: a 4-years study in referral tertiary eye hospital in Indonesia

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    Muhammad Asroruddin


    Full Text Available Background: Corneal ulcer is one of the most common causes of visual acuity impairment and blindness all over the world. The aim of the study was to evaluate various factors affecting the bacterial corneal ulcers healing, including the predisposing factors, causative organisms, antibiotic sensitivity, as well as the treatment outcomes.Methods: All data were taken retrospectively from medical records of patients who underwent corneal scraping for Gram examination and/or culture over a-4-year period (2008-2011 at the Cipto Mangunkusumo Hospital Jakarta. Treatment outcome were analyzed using Chi-square test, one-way ANOVA, and post-hoc analysis. Mean time required for complete epithelial healing was also investigated.Results: 220 cases of bacterial corneal ulcers in 216 patients were included. The most common risk factors were ocular trauma (45.8%. Gram-positive coccus were found in 65.7% cases other than other microbes. Pseudomonas sp. (25,0% and Staphylococcus epidermidis (18.4% were the most common isolates, sensitive to almost all kinds of antibiotics. About 83.0% (106 cases were improved with antibiotics only, the rest were not improved and worsened. Mean time for complete epithelial healing was 17.5 ± 8.9 days with mild ulcer had the most rapid recovery. Eyes treated with fluoroquinolone eyedrops were healed in 14 days, faster than other regiments.Conclusion: Ocular trauma was the most common risk factor for corneal ulcer, and the most commonly isolated organism was Pseudomonas sp. Most cases were improved with antibiotics, and fluoroquinolone showed faster healing. Complete epithelial healing occurred in about 17.5 days.

  1. Biomechanics of corneal ectasia and biomechanical treatments. (United States)

    Roberts, Cynthia J; Dupps, William J


    Many algorithms exist for the topographic/tomographic detection of corneas at risk for post-refractive surgery ectasia. It is proposed that the reason for the difficulty in finding a universal screening tool based on corneal morphologic features is that curvature, elevation, and pachymetric changes are all secondary signs of keratoconus and post-refractive surgery ectasia and that the primary abnormality is in the biomechanical properties. It is further proposed that the biomechanical modification is focal in nature, rather than a uniform generalized weakening, and that the focal reduction in elastic modulus precipitates a cycle of biomechanical decompensation that is driven by asymmetry in the biomechanical properties. This initiates a repeating cycle of increased strain, stress redistribution, and subsequent focal steepening and thinning. Various interventions are described in terms of how this cycle of biomechanical decompensation is interrupted, such as intrastromal corneal ring segments, which redistribute the corneal stress, and collagen crosslinking, which modifies the basic structural properties. Proprietary or commercial disclosures are listed after the references. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  2. Decreased central corneal thickness in ankylosing spondylitis. (United States)

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


    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. Study on phototherapeutic keratotomy for bacterial corneal lesions in rabbit

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    Xin Zhou


    Full Text Available AIM: To study the effect of phototherapeutic keratectomy(PTKon rabbit bacterial corneal ulcer model and explore the clinical potential of this method. METHODS: Totally 48 eyes from all the 24 New Zealand rabbits were inoculated with Staphylococcus aureus and bacterial corneal ulcer model was established successfully. At 1d after inoculation, 48 eyes were given levofloxacin eye drops when corneal ulcer was confirmed. Then slit lamp inspection and optical coherence tomography(OCTwere performed to measure the central corneal ulcer depth. All the rabbits right eyes were treated with PTK, as an observation group, left eyes were not treated as a control group. The eye section were observed by slit lamp and central thickness of corneal ulcer was measured by OCT at 3 and 7d after this operation. Rabbits were sacrificed and the cornea was removed for pathological section 7d later. RESULTS: The corneal ulcers in both groups had a tendency to heal, showing a decrease in ulcer area and smoothness of the surface. There was no significant difference in the depth of corneal ulcer between the observation group and the control group before PTK(t=0.706, P=0.484. The difference between the two groups of eyes at 3 and 7d after PTK was obviously(PCONCLUSION: PTK can effectively cure rabbit Staphylococcus aureus corneal ulcer and promote ulcer wound healing, which may be used for clinical treatment of patients with bacterial corneal lesions.

  4. [Management of corneal hydrops using air and micro-punctures]. (United States)

    Campos Polo, R; Chacón Iglesias, J; Gamazo Carrasco, M; Mencía Bartolomé, J M; Solana Fajardo, J; García Guisado, D; Fernández Miranda, C; Bueno Álvarez-Arenas, J; Sánchez Trancón, Á; García Ardoy, E


    A 22-year- old woman with an acute hydrops and Descemet membrane detachment was managed by intracameral air injection combined with multiple corneal stromal venting incisions for the drainage of intrastromal fluid. No intraoperative complications were encountered, and the intrastromal fluid was resolved over 2 weeks. Acute corneal hydrops is a significant complication of keratoconus. If not treated, resolution usually occurs over a period of 2-4 months. The persistent oedema can cause complications, such as corneal neovascularisation, infection and corneal perforation. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  5. Histopathological features of equine superficial, nonhealing, corneal ulcers. (United States)

    Hempstead, Julie E; Clode, Alison B; Borst, Luke B; Gilger, Brian C


    To evaluate corneal changes associated with chronic, nonhealing, superficial, corneal ulcers in horses via common histopathological stains. Retrospective study. Twenty-four horses diagnosed with chronic, nonhealing, superficial, corneal ulceration. The medical records of horses evaluated at North Carolina State University's Veterinary Teaching Hospital (NCSU-VTH) from 2005 to 2011, diagnosed with a chronic, nonhealing, superficial, corneal ulcer and treated with superficial keratectomy (SK) were reviewed. Inclusion criteria were superficial corneal ulceration, no cellular infiltration via slit-lamp biomicroscopy, no microorganisms evident on corneal cytology, and acquisition of samples for aerobic bacterial and common fungal cultures. Corneal tissue samples were evaluated histopathologically for the presence or absence of a nonadherent epithelial 'lip', epithelial dysmaturity, intraepithelial inflammatory cells, an acellular hyaline zone in the anterior stroma, and stromal inflammatory cells, fibrosis and vascularization. In the majority of analyzed samples, epithelial cells adjacent to the ulcerated site showed nonadherence to the basement membrane and dysmaturity. Intraepithelial inflammatory cell infiltration was uncommon. Histopathological features of an anterior stromal hyaline zone, intrastromal inflammation, fibrosis and vascularization were variably present. The most consistent histopathological characteristics of equine chronic, nonhealing, superficial, corneal ulcers include epithelial nonadherence, epithelial dysmaturity and mild to moderate stromal inflammation; however, one set of histopathological characteristics does not definitively define this syndrome in horses. Additionally, the anterior stromal acellular hyaline zone commonly cited in canine spontaneous chronic corneal epithelial defects (SCCED) is not a consistent finding in equine corneas. © 2013 American College of Veterinary Ophthalmologists.

  6. Corneal collagen cross-linking (CXL) combined with refractive procedures for the treatment of corneal ectatic disorders: CXL plus. (United States)

    Kymionis, George D; Grentzelos, Michael A; Portaliou, Dimitra M; Kankariya, Vardhaman P; Randleman, J Bradley


    To discuss current combined corneal collagen cross-linking (CXL) and refractive surgical techniques (herein termed "CXL plus") for the treatment of corneal ectatic disorders to improve functional visual acuity in addition to corneal stability from CXL alone. Literature review. Efficacious combined treatments with CXL include: photorefractive keratectomy, transepithelial phototherapeutic keratectomy, intrastromal corneal ring segments implantation, phakic intraocular lens implantation, and multiple combined procedures. Some uncertainty remains as to the optimal strategies for each patient. A decision tree is proposed to facilitate optimal patient management. With multiple adjuvant techniques, CXL plus is likely to benefit many patients with corneal ectatic disorders. The appropriate combined procedure will depend on multiple factors, such as refraction, corneal thickness, and degree of irregular astigmatism. Copyright 2014, SLACK Incorporated.

  7. Causes of childhood blindness in Malaysia: results from a national study of blind school students. (United States)

    Reddy, S C; Tan, B C


    A national study was conducted in children attending six schools for the blind in Malaysia to identify the anatomical site and underlying causes of blindness (BL) and severe visual impairment (SVI), with a view to determine the potentially preventable and treatable causes so that appropriate control measures can be implemented in the future. The standardized clinical examination of eyes was performed and the findings were recorded on the WHO Prevention of Blindness Programme eye examination record form for children with blindness and low vision. A total of 358 children aged between 7 and 17 years were examined, of whom 332 (92.7%) were blind or severely visually impaired. The results relate to these 332 children. Lens was the major anatomical site (22.3%) of visual loss followed by retina (20.8%), whole globe (17.2%), cornea (15.1%), optic nerve (8.7%) and uvea (5.1%). Glaucoma was responsible for BL/SVI in 7.2% and others in 3.6% of cases. Hereditary diseases were responsible for visual loss in 29.5%, intrauterine factors in 4.5%, perinatal factors in 9% and childhood factors in 7.8% of cases. However, the aetiology was unknown in 49.1% of cases which included congenital anomalies of the globe. Childhood cataract and corneal scarring are major treatable causes of BL/SVI that can benefit from future intervention strategies. Perinatal screening for intrauterine factors and hereditary eye diseases, and appropriate interventional therapy will help in reducing the prevalence of childhood blindness.

  8. Corneal Tomographic Changes After UV Cross-Linking for Corneal Ectasia (1-Year Results). (United States)

    Baksoellah, Zainab; Lavy, Itay; Baydoun, Lamis; Hooijmaijers, Hilde C M; van Dijk, Korine; Melles, Gerrit R J


    To evaluate changes in maximum keratometry (Kmax), corneal higher-order aberrations (HOAs), and densitometry (backscattered light) up to 1 year after UV cross-linking and their possible relation with changes in the visual outcome. Retrospective cohort study on 18 eyes of 16 patients, who underwent UV cross-linking after the Dresden protocol for progressive keratoconus or ectasia after laser-assisted in situ keratomileusis. Corrected distance visual acuity (CDVA), Scheimpflug-based corneal tomography, mean image brightness (corneal densitometry) from the anterior 120 μm of the midcornea, and posterior 60 μm of the central 6 mm of the cornea, and HOAs were evaluated. Kmax at 1 month (59.7 ± 6.0D) after UV cross-linking resembled preoperative Kmax (59.3 ± 6.4D, P = 0.368), decreased until 3 months postoperatively (58.3 ± 6.3D, P = 0.002), and stabilized thereafter (P > 0.227). All postoperative corneal densitometry values were higher than preoperative values in all measured depths (P corneal HOAs (4.28 ± 1.64 μm and 3.87 ± 1.62 μm, respectively) resembled preoperative values (4.10 ± 1.70 μm and 3.67 ± 1.62 μm, respectively; P > 0.221) and then decreased until 12 months postoperatively (3.86 ± 1.84 μm and 3.40 ± 1.80 μm, respectively; P 0.345 and P > 0.257, respectively). No relations were found between CDVA and the evaluated parameters (P > 0.05). One year after UV cross-linking, the observation of stable CDVA and thinnest point thickness, together with reduced Kmax suggests no ectasia progression within the study period in these cases. Although HOAs showed a trend toward improvement, corneal densitometry remained elevated.

  9. Participatory ergonomic intervention versus strength training on chronic pain and work disability in slaughterhouse workers: study protocol for a single-blind, randomized controlled trial


    Sundstrup, Emil; Jakobsen, Markus D; Andersen, Christoffer H; Jay, Kenneth; Persson, Roger; Aagaard, Per; Andersen, Lars L


    Background The prevalence of musculoskeletal pain in the shoulder, arm and hand is high among slaughterhouse workers, allegedly due to the highly repetitive and forceful exposure of these body regions during work. Work disability is a common consequence of these pains. Lowering the physical exposure through ergonomics intervention is the traditional strategy to reduce the workload. An alternative strategy could be to increase physical capacity of the worker through strength training. This stu...

  10. Influence of Apical Clearance on Mini-Scleral Lens Settling, Clinical Performance, and Corneal Thickness Changes. (United States)

    Esen, Fehim; Toker, Ebru


    The purpose of this work was to define the timing and magnitude of scleral contact lens settling, the factors influencing settling, and to examine whether the amount of apical clearance has an impact on clinical performance or is associated with hypoxia-induced corneal changes. Eleven patients (22 eyes) with keratoconus were fitted with a mini-scleral lens (Esclera, Brazil). Three different lenses with successively greater sagittal depths were applied to achieve 3 levels of initial apical clearance: 100 to 200 μm (low), 200 to 300 μm (medium), and greater than 300 μm (high). Corneal apical clearance was measured at 15 min, 1, 2, 4, 6, and 8 hr with optical coherence tomography (OCT). Central corneal thickness was measured with OCT and Pentacam, in the morning and immediately after removal of the contact lens. Mean settling was 26.8±18.8 μm (42.7%) at 1 hr, 39.5±26.5 μm (62.9%) at 2 hr, 50.7±31.6 μm (80.8%) at 4 hr, 57.4±34.6 μm (91.4%) at 6 hr, and 62.8±38.4 μm (100%) at 8 hr. Settling rate was significantly lower in low apical clearance group (P=0.01). The smaller diameter lenses settled more (P=0.03). There was a slight statistically significant increase of 1.3% in central corneal thickness measured with OCT (P=0.03). Central corneal thickness measured with Pentacam at three locations increased slightly (P=0.001). Settling showed significant intrasubject and intersubject variations. The amount of corneal swelling and comfort scores did not differ significantly according to apical clearance. The average amount of settling was 62.8 μm after 8 hr, 80% of which occurred during the first 4 hr. Slight corneal swelling (1.3%) occurred after 8 hr of wear.

  11. Effects of single-segment Intacs implantation on visual acuity and corneal topographic indices of keratoconus

    Directory of Open Access Journals (Sweden)

    Kazem Amanzadeh


    Conclusion: Intacs implantation in keratoconic eyes increased visual acuity and made corneal shape less irregular. However, the improvements of visual acuity and corneal shape were not strongly correlated.

  12. Blindness and cataract in children in developing countries

    Directory of Open Access Journals (Sweden)

    Parikshit Gogate


    Full Text Available Blindness in children is considered a priority area for VISION 2020, as visually impaired children have a lifetime of blindness ahead of them. Various studies across the globe show that one-third to half of childhood blindness is either preventable or treatable1 and that cataract is the leading treatable cause of blindness in children.The 8th General Assembly of the International Agency for the Prevention of Blindness (IAPB provided an opportunity to be acquainted with recent research and programme development work in the prevention of childhood blindness.

  13. Keratoconus: A biomechanical perspective on loss of corneal stiffness

    Directory of Open Access Journals (Sweden)

    Abhijit Sinha Roy


    Full Text Available Keratoconus (KC is progressive disease of corneal thinning, steepening and collagen degradation. Biomechanics of the cornea is maintained by the intricate collagen network, which is responsible for its unique shape and function. With the disruption of this collagen network, the cornea loses its shape and function, resulting in progressive visual degradation. While KC is essentially a stromal disease, there is evidence that the epithelium undergoes significant thinning similar to the stroma. Several topographical approaches have been developed to detect KC early. However, it is now hypothesized that biomechanical destabilization of the cornea may precede topographic evidence of KC. Biomechanics of KC has been investigated only to a limited extent due to lack of in vivo measurement techniques and/or devices. In this review, we focus on recent work performed to characterize the biomechanical characteristics of KC.

  14. Blind Quantum Signature with Blind Quantum Computation (United States)

    Li, Wei; Shi, Ronghua; Guo, Ying


    Blind quantum computation allows a client without quantum abilities to interact with a quantum server to perform a unconditional secure computing protocol, while protecting client's privacy. Motivated by confidentiality of blind quantum computation, a blind quantum signature scheme is designed with laconic structure. Different from the traditional signature schemes, the signing and verifying operations are performed through measurement-based quantum computation. Inputs of blind quantum computation are securely controlled with multi-qubit entangled states. The unique signature of the transmitted message is generated by the signer without leaking information in imperfect channels. Whereas, the receiver can verify the validity of the signature using the quantum matching algorithm. The security is guaranteed by entanglement of quantum system for blind quantum computation. It provides a potential practical application for e-commerce in the cloud computing and first-generation quantum computation.

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


    J. Zarranz-Ventura; E. De Nova; J. Moreno-Montañés


    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, hematológi...

  16. Corneal layer plate removal with Fluconazole injected corneal stroma and autologous conjunctival transplantation for keratomycosis

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    Li-Dong Yang


    Full Text Available AIM: To investigate the clinical effect of corneal layer plate removal with Fluconazole injected corneal stroma and autologous conjunctival transplantation for keratomycosis.METHODS: There were 168 cases suffered keratomycosis that the focus located shallow of the cornea and was not obvious to drug, who registered in our hospital from March 2005 to June 2010. In surgery we removed plate layer to cormea clear, the region was greater than focus for 0.5mm,then we injected fluconazole which is 2g/L density in corneal stroma to make the edema area greater than Removal of area for 0.5mm. At last we took pedicle conjunctival flap to cover the plant bed by continuous suture. Postoperative day use drug to drop eye and to observe that whether recurrent of the keratomycosis and how was the edema degrade, the blood supply of conjunctival graft pieces, how about the stimulating signs of the surgery eye, the vision.RESULTS: The improvement rate was 96.2% after surgery for seven days and the cure rate was 95.5% after surgery for one months. We found in 157 eyes accepted trigeminy surgery there were 6 eyes recurrence and the recurrence rate was 3.8%. The mean time of corneal stromal edema faded away was 13.4 hours. After surgery for one month there were 39 eyes(24.8%whose vision removed than preoperative, there were 91 eyes(58.0%whose vision were same as preoperative and there were 27 eyes(17.2%whose vision lower than preoperative. In these operations the loss ratio of corneal endothelium was from 0%-8%, the mean was 2.9%. The irritative symptoms postoperative were mild for 87%, moderate for 10% and severe for 3%. By this surgery the mean length of stay was 7.3 days so the mean hospitalization expenses only were 2160 RMB. Three months after surgery, 4 cases were slight corneal ectasia.CONCLUSION: This operation combined corneal layer plate removal, Fluconazole injected corneal stroma and autologous conjunctival transplantation for keratomycosis which was in

  17. Participatory ergonomic intervention versus strength training on chronic pain and work disability in slaughterhouse workers: study protocol for a single-blind, randomized controlled trial (United States)


    Background The prevalence of musculoskeletal pain in the shoulder, arm and hand is high among slaughterhouse workers, allegedly due to the highly repetitive and forceful exposure of these body regions during work. Work disability is a common consequence of these pains. Lowering the physical exposure through ergonomics intervention is the traditional strategy to reduce the workload. An alternative strategy could be to increase physical capacity of the worker through strength training. This study investigates the effect of two contrasting interventions, participatory ergonomics versus strength training on pain and work disability in slaughterhouse workers with chronic pain. Methods/design 66 slaughterhouse workers were allocated to 10 weeks of (1) strength training of the shoulder, arm and hand muscles for 3 x 10 minutes per week, or (2) participatory ergonomics involving counseling on workstation adjustment and optimal use of work tools (~usual care control group). Inclusion criteria were (1) working at a slaughterhouse for at least 30 hours per week, (2) pain intensity in the shoulder, elbow/forearm, or hand/wrist of at least 3 on a 0–10 VAS scale during the last three months, (3) pain lasting for more than 3 months, (4) frequent pain (at least 3 days per week) (5) at least moderate work disability, (6) no strength training during the last year, (7) no ergonomics instruction during the last year. Perceived pain intensity (VAS scale 0–10) of the shoulder, elbow/forearm and hand/wrist (primary outcome) and Disability of the Arm, Shoulder and Hand (Work module, DASH questionnaire) were measured at baseline and 10-week follow-up. Further, total muscle tenderness score and muscle function were assessed during clinical examination at baseline and follow-up. Discussion This RCT study will provide experimental evidence of the effectiveness of contrasting work-site interventions aiming at reducing chronic pain and work disability among employees engaged in

  18. Causes of severe visual impairment and blindness in students in schools for the blind in Northwest Ethiopia. (United States)

    Asferaw, Mulusew; Woodruff, Geoffrey; Gilbert, Clare


    To determine the causes of severe visual impairment and blindness (SVI/BL) among students in schools for the blind in Northwest Ethiopia and to identify preventable and treatable causes. Students attending nine schools for the blind in Northwest Ethiopia were examined and causes assigned using the standard WHO record form for children with blindness and low vision in May and June 2015. 383 students were examined, 357 (93%) of whom were severely visually impaired or blind (students aged visual loss among those 0-15 years was cornea/phthisis (47.1%), usually due to measles and vitamin A deficiency, followed by whole globe (22.1%), lens (9.6%) and uvea (8.7%). Among students aged 16 years and above, corneal/phthisis (76.3%) was the major anatomical cause, followed by lens (6.3%), whole globe (4.7%), uvea (3.6%) and optic nerve (3.2%). The leading underlying aetiology among students aged students in schools for the blind are potentially avoidable, with measles/vitamin A deficiency and cataract being the leading causes.

  19. The first rapid assessment of avoidable blindness (RAAB in Thailand.

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    Saichin Isipradit

    Full Text Available BACKGROUND: The majority of vision loss is preventable or treatable. Population surveys are crucial for planning, implementation, and monitoring policies and interventions to eliminate avoidable blindness and visual impairments. This is the first rapid assessment of avoidable blindness (RAAB study in Thailand. METHODS: A cross-sectional study of a population in Thailand age 50 years old or over aimed to assess the prevalence and causes of blindness and visual impairments. Using the Thailand National Census 2010 as the sampling frame, a stratified four-stage cluster sampling based on a probability proportional to size was conducted in 176 enumeration areas from 11 provinces. Participants received comprehensive eye examination by ophthalmologists. RESULTS: The age and sex adjusted prevalence of blindness (presenting visual acuity (VA <20/400, severe visual impairment (VA <20/200 but ≥20/400, and moderate visual impairment (VA <20/70 but ≥20/200 were 0.6% (95% CI: 0.5-0.8, 1.3% (95% CI: 1.0-1.6, 12.6% (95% CI: 10.8-14.5. There was no significant difference among the four regions of Thailand. Cataract was the main cause of vision loss accounted for 69.7% of blindness. Cataract surgical coverage in persons was 95.1% for cut off VA of 20/400. Refractive errors, diabetic retinopathy, glaucoma, and corneal opacities were responsible for 6.0%, 5.1%, 4.0%, and 2.0% of blindness respectively. CONCLUSION: Thailand is on track to achieve the goal of VISION 2020. However, there is still much room for improvement. Policy refinements and innovative interventions are recommended to alleviate blindness and visual impairments especially regarding the backlog of blinding cataract, management of non-communicative, chronic, age-related eye diseases such as glaucoma, age-related macular degeneration, and diabetic retinopathy, prevention of childhood blindness, and establishment of a robust eye health information system.

  20. Vision - night blindness (United States)

    ... this page: // Vision - night blindness To use the sharing features on ... page, please enable JavaScript. Night blindness is poor vision at night or in dim light. Considerations Night ...

  1. Leading Causes of Blindness (United States)

    ... Home Current Issue Past Issues Feature: Vision Leading Causes of Blindness Past Issues / Summer 2008 Table of ... million Americans have cataracts. They are the leading cause of blindness in the world. By age 80, ...

  2. Ocular morbidity patterns among children in schools for the blind in Chennai. (United States)

    Prakash, M Vs; Sivakumar, S; Dayal, Ashutosh; Chitra, A; Subramaniam, Sudharshini


    To identify the morbidity patterns causing blindness in children attending schools for the blind in Chennai and comparing our data with similar studies done previously. A cross-sectional prevalence study was carried out in two schools for the blind in Chennai. Blind schools were visited by a team of ophthalmologists and optometrists. Students with best-corrected visual acuity (BCVA) worse than 3/60 in the better eye were included and relevant history was noted. Every student underwent anterior segment evaluation and detailed fundus examination. Morbidity of the better eye was taken as cause of blindness. Health records maintained by the school were referred to wherever available. The anatomical causes of blindness include optic nerve disorders in 75 (24.8%) cases, retinal disorders in 55 (18.2%), corneal disorders in 47 (15.6%), lens-related disorders in 39 (12.9%), congenital anomalies in 11 (3.6%), and congenital glaucoma in 20 (6.6%) cases. The whole globe was involved in six cases (1.99%). Among conditions causing blindness, optic atrophy seen in 73 (24.17%) cases was the most common, followed by retinal dystrophy in 44 (14.56%), corneal scarring in 35 (11.59%), cataract in 22 (7.28%), and congenital glaucoma in 20 (6.6%) cases. It was found that avoidable causes of blindness were seen in 31% of cases and incurable causes in 45%. Optic nerve atrophy and retinal dystrophy are the emerging causes of blindness, underlining the need for genetic counseling and low vision rehabilitation centers, along with a targeted approach for avoidable causes of blindness.

  3. Toxic corneal ulcer: a frequent and sight-threatening disease. (United States)

    Sacchetti, Marta; Lambiase, Alessandro; Coassin, Marco; Bonini, Sergio; Bonini, Stefano


    Overtreatment with topical ophthalmic preparations can lead to toxic corneal ulcer development. This study aimed to investigate the clinical and visual impact of toxic corneal ulcers and the management and risk factors for their development and outcomes. Clinical records of 226 consecutive patients with corneal ulcers referred to our tertiary care center were retrospectively evaluated. Frequency, clinical features, and management of toxic corneal ulcers are described. The relationship between clinical severity and outcomes (healing time, corneal transparency, and visual acuity) of toxic corneal ulcers and the number and classes of topical drugs, the number of daily instillations, and the duration of treatment were statistically evaluated. Toxic corneal ulcer was diagnosed in 9% (21/226) of all patients. After topical treatment discontinuation, the cornea spontaneously healed in all patients in 2 to 21 days. A longer healing time was related to a greater number of topical drugs used (p=0.029), a greater frequency of daily instillations (p=0.042), and a longer duration of treatment (p=0.048). The specific drugs used did not significantly influence healing time. After resolution, 16 out of 21 patients showed corneal scarring and impairment of visual function. The severity of corneal haze was related to the number of drugs used (p=0.023), to the frequency of daily instillations (p=0.031), and to the healing time (p=0.008). Toxic corneal ulcer is a frequent disease that can potentially lead to permanent visual impairment. A high-dose regimen is the major risk factor for corneal toxic ulcer development and poor visual outcomes.

  4. The learning effects of different presentations of worked examples on medical students' breaking-bad-news skills: A randomized and blinded field trial. (United States)

    Schmitz, Felix Michael; Schnabel, Kai Philipp; Bauer, Daniel; Bachmann, Cadja; Woermann, Ulrich; Guttormsen, Sissel


    Effective instructional approaches are needed to enable undergraduates to optimally prepare for the limited training time they receive with simulated patients (SPs). This study examines the learning effects of different presentation formats of a worked example on student SP communication. Sixty-seven fourth-year medical students attending a mandatory communication course participated in this randomized field trial. Prior to the course, they worked through an e-learning module that introduced the SPIKES protocol for delivering bad news to patients. In this module, a single worked example was presented to one group of students in a text version, to a second group in a video version, and to a third group in a video version enriched with text hints denoting the SPIKES steps. The video-with-hints group broke bad news to SPs significantly more appropriately than either of the other groups. Although no further condition-related effects were revealed, students who learned from the text version most frequently (although non-significantly) ignored unpleasant emotions (standardised emotional cues and concerns) expressed by the SPs. The learning effect was strongest when the video-based worked example was accompanied by hints. Video-related learning approaches that embed attention-guiding hints can effectively prepare undergraduates for SP encounters. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Working memory training in children with neuropsychiatric disorders and mild to borderline intellectual functioning, the role of coaching; a double-blind randomized controlled trial

    NARCIS (Netherlands)

    Roording-Ragetlie, S.; Klip, H.; Buitelaar, J.K.; Slaats-Willemse, D.I.E.


    BACKGROUND: Working memory training (WMT) has been shown to offer therapeutic benefits to both patients with Attention-Deficit Hyperactivity Disorder (ADHD) and patients with mild to borderline Intellectual Disabilities (MBID; 60 < IQ < 85). However, robust evidence for transfer effects and

  6. Effectiveness of executive function training on mental set shifting, working memory and inhibition in healthy older adults: A double-blind randomized controlled trials. (United States)

    Chiu, Huei-Ling; Chan, Pi-Tuan; Kao, Ching-Chiu; Chu, Hsin; Chang, Pi-Chen; Hsiao, Shu-Tai Sheen; Liu, Doresses; Chang, Wen-Chi; Chou, Kuei-Ru


    The aim of this study was to evaluate the effectiveness of executive function training on mental set shifting, working memory and inhibition for healthy older adults. Executive functions control and guide individuals' behaviours through a top-down cognitive model and have been regarded as the exhibition and integration of various high-level cognitive functions. However, prior studies have rarely focused on the subcomponent indicators of executive function, such as mental set shifting, working memory and inhibition in healthy older adults. Randomized controlled trial. A total of 62 participants were recruited between January 2015 - March 2017, with both groups attending a 30-min training session three times per week for 8 weeks. Executive function training group received the training content that focused on the mental set shifting, working memory and inhibition. Active control group engaged in passive information activities. The primary outcome was mental set shifting, measured by the Wisconsin card sort test. The secondary outcomes were working memory measured by digit span and inhibition measured by the Stroop color word test. The executive function training group had statistically significant higher scores of mental set shifting and working memory at immediate follow-up and that its effect on mental set shifting could be maintained for 3-6 months. However, this training did not have any statistically significant results on inhibition. The executive function training may be an effective preventive intervention for healthy older adults. Future studies are recommended to include a broader range of participants with different levels of cognitive function. © 2017 John Wiley & Sons Ltd.

  7. Blind image deconvolution methods and convergence

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    Chaudhuri, Subhasis; Rameshan, Renu


    Blind deconvolution is a classical image processing problem which has been investigated by a large number of researchers over the last four decades. The purpose of this monograph is not to propose yet another method for blind image restoration. Rather the basic issue of deconvolvability has been explored from a theoretical view point. Some authors claim very good results while quite a few claim that blind restoration does not work. The authors clearly detail when such methods are expected to work and when they will not. In order to avoid the assumptions needed for convergence analysis in the

  8. [Frequency and causes of blindness and visual impairment in schools for the blind in Yaoundé (Cameroon)]. (United States)

    Noche, Christelle Domngang; Bella, Assumpta Lucienne


    To determine the causes of blindness and visual impairment in students attending schools for the blind in Yaounde (Cameroon) and to estimate their frequencies. This study examined all 56 students at three schools for the blind in Yaoundé from September 15 through October 15, 2006. We collected data about their age, sex, medical and surgical history. Visual acuity was measured to determine their vision status according to the World Health Organization categories for blindness and visual impairment. All subjects underwent an ocular examination. Epi Info 3.5.1. was used for the statistical analysis of age, sex, visual acuity, causes of blindness and visual impairment, and etiologies. Fifty six people were examined: 37 men (66.1%) and 19 women (33.9%). Their mean age was 21.57 ± 10.53 years (min-max: 5-49), and 48.2% were in the 10-19 years age group (n = 27). In all, 87.5% were blind, 7.14% severely visually impaired, and 1.78% moderately visually impaired. The main causes of blindness and visual impairment in our sample were corneal disease (32.14%), optic nerve lesions (26.78%), cataract and its surgical complications (19.64%), retinal disorders (10.71%), glaucoma (8.92%, and malformations of the eyeball (1.78%). Their etiologies included congenital cataracts (19.64%), meningitis/fever (8.92%), glaucoma (7.14%), measles (5.35%), ocular trauma (5.35%), albinism (3.57%), Lyell syndrome (1.8%), and alcohol ingestion (1.8%). Etiology was unknown in 46.42%. Fifty per cent of these causes of blindness and visual impairment were treatable and/or preventable. Corneal lesions were the main cause of blindness and visual impairment in our sample. Fifty per cent of the causes found were treatable and/or preventable. Thus, substantial efforts are required to ensure access to better quality specialist ocular care. Furthermore, local authorities should create more centers specialised in the rehabilitation of the visual handicapped.

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

    Directory of Open Access Journals (Sweden)

    R Bassily


    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

  10. Corneal Ectasia After LASIK Combined With Prophylactic Corneal Cross-linking. (United States)

    Taneri, Suphi; Kiessler, Saskia; Rost, Anika; Dick, H Burkhard


    To report a case of unilateral corneal ectasia following LASIK surgery combined with prophylactic corneal cross-linking (CXL) in a young patient. Case report. Preoperative topography was unremarkable in both eyes with a minimum corneal thickness of 554 μm in the right eye and 546 μm in the left eye. Preoperative corrected distance visual acuity (CDVA) was 1.0 (20/20 Snellen) in both eyes with a refraction of +1.25 -2.75 × 10 in the right eye and +0.50 -2.00 × 163 in the left eye. LASIK combined with CXL was uneventful. After 12 months, postoperative topography was unremarkable with an uncorrected distance visual acuity (UDVA) of 1.0 in both eyes. Two years after surgery, the patient presented with a loss of vision (UDVA 0.25) and an inferior steepening on topography in the left eye. Standard CXL was performed to arrest further progression. This report illustrates that the currently used prophylactic CXL protocol in combination with LASIK may not be effectively preventing corneal ectasia in every case. [J Refract Surg. 2017;33(1):50-52.]. Copyright 2017, SLACK Incorporated.

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

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    Ying Wu


    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.

  12. The Effects of High-Frequency Transcutaneous Electrical Nerve Stimulation for Dental Professionals with Work-Related Musculoskeletal Disorders: A Single-Blind Randomized Placebo-Controlled Trial

    Directory of Open Access Journals (Sweden)

    Hye Rim Suh


    Full Text Available Work-related musculoskeletal symptom disorders (WMSDs have a significant issue for dental professionals. This study investigated the effects of high-frequency transcutaneous electrical nerve stimulation (TENS on work-related pain, fatigue, and the active range of motion in dental professionals. Among recruited 47 dental professionals with WMSDs, 24 subjects received high-frequency TENS (the TENS group, while 23 subjects received placebo stimulation (the placebo group. TENS was applied to the muscle trigger points of the levator scapulae and upper trapezius, while placebo-TENS was administered without electrical stimulation during 60 min. Pain and fatigue at rest and during movement were assessed using the visual analog scale (VAS, pain pressure threshold (PPT, and active range of motion (AROM of horizontal head rotation at six time points: prelabor, postlabor, post-TENS, and at 1 h, 3 h, and 1 day after TENS application. Both groups showed significantly increased pain and fatigue and decreased PPT and AROM after completing a work task. The TENS group showed significantly greater improvements in VAS score, fatigue, PPT, and AROM at post-TENS and at 1 h and 3 h after application (all P < 0.05 as compared to the placebo group. A single session high-frequency TENS may immediately reduce symptoms related to WMSDs in dental professionals.

  13. Work of Breathing into Snow in the Presence versus Absence of an Artificial Air Pocket Affects Hypoxia and Hypercapnia of a Victim Covered with Avalanche Snow: A Randomized Double Blind Crossover Study.

    Directory of Open Access Journals (Sweden)

    Karel Roubík

    Full Text Available Presence of an air pocket and its size play an important role in survival of victims buried in the avalanche snow. Even small air pockets facilitate breathing. We hypothesize that the size of the air pocket significantly affects the airflow resistance and work of breathing. The aims of the study are (1 to investigate the effect of the presence of an air pocket on gas exchange and work of breathing in subjects breathing into the simulated avalanche snow and (2 to test whether it is possible to breathe with no air pocket. The prospective interventional double-blinded study involved 12 male volunteers, from which 10 completed the whole protocol. Each volunteer underwent two phases of the experiment in a random order: phase "AP"--breathing into the snow with a one-liter air pocket, and phase "NP"--breathing into the snow with no air pocket. Physiological parameters, fractions of oxygen and carbon dioxide in the airways and work of breathing expressed as pressure-time product were recorded continuously. The main finding of the study is that it is possible to breath in the avalanche snow even with no air pocket (0 L volume, but breathing under this condition is associated with significantly increased work of breathing. The significant differences were initially observed for end-tidal values of the respiratory gases (EtO2 and EtCO2 and peripheral oxygen saturation (SpO2 between AP and NP phases, whereas significant differences in inspiratory fractions occurred much later (for FIO2 or never (for FICO2. The limiting factor in no air pocket conditions is excessive increase in work of breathing that induces increase in metabolism accompanied by higher oxygen consumption and carbon dioxide production. The presence of even a small air pocket reduces significantly the work of breathing.

  14. Work of Breathing into Snow in the Presence versus Absence of an Artificial Air Pocket Affects Hypoxia and Hypercapnia of a Victim Covered with Avalanche Snow: A Randomized Double Blind Crossover Study (United States)


    Presence of an air pocket and its size play an important role in survival of victims buried in the avalanche snow. Even small air pockets facilitate breathing. We hypothesize that the size of the air pocket significantly affects the airflow resistance and work of breathing. The aims of the study are (1) to investigate the effect of the presence of an air pocket on gas exchange and work of breathing in subjects breathing into the simulated avalanche snow and (2) to test whether it is possible to breathe with no air pocket. The prospective interventional double-blinded study involved 12 male volunteers, from which 10 completed the whole protocol. Each volunteer underwent two phases of the experiment in a random order: phase “AP”—breathing into the snow with a one-liter air pocket, and phase “NP”—breathing into the snow with no air pocket. Physiological parameters, fractions of oxygen and carbon dioxide in the airways and work of breathing expressed as pressure-time product were recorded continuously. The main finding of the study is that it is possible to breath in the avalanche snow even with no air pocket (0 L volume), but breathing under this condition is associated with significantly increased work of breathing. The significant differences were initially observed for end-tidal values of the respiratory gases (EtO2 and EtCO2) and peripheral oxygen saturation (SpO2) between AP and NP phases, whereas significant differences in inspiratory fractions occurred much later (for FIO2) or never (for FICO2). The limiting factor in no air pocket conditions is excessive increase in work of breathing that induces increase in metabolism accompanied by higher oxygen consumption and carbon dioxide production. The presence of even a small air pocket reduces significantly the work of breathing. PMID:26666523

  15. Genomics of corneal wound healing: a review of the literature. (United States)

    Maycock, Nick J R; Marshall, John


    Corneal wound healing is a complex process: its mechanisms and the underlying genetic control are not fully understood. It involves the integrated actions of multiple growth factors, cytokines and proteases produced by epithelial cells, stromal keratocytes, inflammatory cells and lacrimal gland cells. Following an epithelial insult, multiple cytokines are released triggering a cascade of events that leads to repair the epithelial defect and remodelling of the stroma to minimize the loss of transparency and function. In this review, we examine the literature surrounding the genomics of corneal wound healing with respect to the following topics: epithelial and stromal wound healing (including inhibition); corneal neovascularisation; the role of corneal nerves in wound healing; the endothelium; the role of aquaporins and aptamers. We also examine the effect of ectasia on corneal wound healing with regard to keratoconus and following corneal surgery. A better understanding of the cellular and molecular changes that occur during repair of corneal wounds will provide the opportunity to design treatments that selectively modulate key phases of the healing process resulting in scars that more closely resemble normal corneal architecture. © 2013 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  16. Effects of genipin corneal crosslinking in rabbit corneas. (United States)

    Avila, Marcel Y; Narvaez, Mauricio; Castañeda, Juan P


    To evaluate the effect of genipin, a natural crosslinking agent, in rabbit eyes. Department of Ophthalmology, Universidad Nacional de Colombia Centro de Tecnologia Oftalmica, Bogotá, Colombia. Experimental study. Ex vivo rabbit eyes (16; 8 rabbits) were treated with genipin 1.00%, 0.50%, and 0.25% for 5 minutes with a vacuum device to increase corneal permeability. Penetration was evaluated using Scheimpflug pachymetry (Pentacam). In the in vivo model (20 rabbits; 1 eye treated, 1 eye with vehicle), corneas were crosslinked with genipin as described. Corneal curvature, corneal pachymetry, and intraocular pressure (IOP) assessments as well as slitlamp examinations were performed 0, 7, 30, and 60 days after treatment. In the ex vivo model, Scheimpflug pachymetry showed deep penetration in the rabbit corneas with an increase in corneal density and a dose-dependent relationship. Corneal flattening was observed in treated eyes (mean 4.4 diopters ± 0.5 [SD]) compared with the control eyes. Pachymetry and IOP were stable in all evaluations. No eye showed toxicity in the anterior chamber or in the lens. Corneal crosslinking induced by genipin produced significant flattening of the cornea with no toxicity in rabbit eyes. This crosslinking could be useful in the treatment of corneal ectasia and in the modification of corneal curvature. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  17. Complications Following Corneal Cross-Linking Treatment in Keratectasia

    Directory of Open Access Journals (Sweden)

    Faik Oruçoğlu


    Full Text Available Pur po se: To report complications of corneal cross-linking treatment in keratoconus and secondary ectatic eyes. Ma te ri al and Met hod: Cases that were treated between February 2007 and February 2011, had a minimum follow-up of one month, and developed complications following corneal cross-linking were retrospectively evaluated. Re sults: Complication data were present in eight cases. Scar formation developed in three cases. Scar density has decreased in one patient during long-term follow-up. Keratometric flattening was observed associated with scar development. Cross-linking was performed on the second eye of the affected patient, and no scar development was observed. Corneal clouding was observed in one patient three days after treatment. Corneal clouding has decreased in the following days. Local corneal edema has developed in one patient, and improvement was achieved in the following days. Uveitis has developed in one case with total improvement after adding topical steroids. Post-LASIK ectasia eye showed deep lamellar keratitis after cross-linking. In one patient, epithelization was completed in 14 days. Dis cus si on: Corneal scars, corneal clouding and edema, uveitis, and late epithelization are possible complications after corneal cross-linking. Scar density was decreased, while other complications showed total improvement. (Turk J Ophthalmol 2013; 43: 1-6

  18. Corneal Biomechanical Changes and Tissue Remodeling After SMILE and LASIK. (United States)

    Shetty, Rohit; Francis, Mathew; Shroff, Rushad; Pahuja, Natasha; Khamar, Pooja; Girrish, Molleti; Nuijts, Rudy M M A; Sinha Roy, Abhijit


    To evaluate transient corneal tissue healing and biomechanical changes between laser in situ keratomileusis (LASIK) and small incision lenticule extraction (SMILE) eyes. In each patient, one eye underwent LASIK and the other underwent SMILE. Optical coherence tomography (OCT) and dynamic Scheimpflug imaging (Corvis-ST) was used to assess tissue healing and biomechanics, respectively. Analyses of OCT scans yielded corneal speckle distribution (CSD) and Bowman's roughness index (BRI). Waveform analyses of deformation amplitude yielded corneal stiffness. Further, corneal force versus corneal deformation data helped compare the two procedures. BRI increased and then decreased transiently after both treatments (P < 0.05). However, SMILE eyes had BRI similar to that of their preoperative state compared to LASIK eyes at 6-month follow-up. CSD indicated a marked increase in the number of bright pixels and a decrease in the number of dark pixels after SMILE (1-month follow-up) and LASIK eyes (3-month follow-up), respectively. CSD returned to near preoperative state thereafter, respectively. Corneal stiffness change from preoperative state was similar between LASIK and SMILE eyes. However, deformation at discrete values of corneal force indicated some recovery of biomechanical strength after SMILE, but not in LASIK eyes. BRI and CSD indicated earlier tissue healing in SMILE eyes than in LASIK. CSD results may indicate delayed cell death in LASIK eyes and increased light scatter due to interface fluid in SMILE eyes. Corneal biomechanical strength remodeled better in SMILE. This may indicate some hydration-related recovery.

  19. Crosslinking and corneal cryotherapy in acanthamoeba keratitis -- a histological study. (United States)

    Hager, Tobias; Hasenfus, A; Stachon, T; Seitz, B; Szentmáry, N


    Acanthamoeba keratitis is rare, but difficult to treat. Penetrating keratoplasty is performed in therapy-resistant cases. Nevertheless, subsequent recurrences occur in 40 % of the cases. In addition to triple-topical therapy (polyhexamid, propamidinisoethionat, neomycin), treatment alternatives are corneal cryotherapy and/or crosslinking (CXL). The aim of our present histological study was to analyze the persistence of acanthamoebatrophozoites and cysts, the persistence of bacteria, and activation of keratocytes in corneas of acanthamoeba keratitis patients following corneal cryotherapy and/or CXL. We analyzed histologically corneal buttons (from penetrating keratoplasties) of nine patients with acanthamoeba keratitis, following corneal cryotherapy (two patients) or a combination of crosslinking and corneal cryotherapy (seven patients), using haematoxilin–eosin, periodic acid Schiff (PAS), Gram and alpha-smooth muscle actin (alpha-SMA) stainings. Acanthamoeba trophozoites persisted in three corneas after cryotherapy and CXL. Cysts persisted in one of two corneas following corneal cryotherapy and in six of seven corneas after a combination of CXL and cryotherapy. One cornea showed positive Gram staining, but there were no alpha-SMA positive keratocytes in any of the corneas. Crosslinking and corneal cryotherapy have only limited impact on killing of acanthamoeba trophozoites, cysts, or bacteria. Corneal cryotherapy and CXL did not stimulate myofibroblastic transformation of keratocytes.

  20. Changes of Corneal Optical Properties after UVB Irradiation Investigated Spectrophotometrically

    Czech Academy of Sciences Publication Activity Database

    Čejka, Čestmír; Pláteník, J.; Širc, Jakub; Ardan, Taras; Michálek, Jiří; Brůnová, B.; Čejková, Jitka


    Roč. 59, č. 4 (2010), s. 591-597 ISSN 0862-8408 Grant - others:GA MŠk(CZ) 1M0538 Program:1M Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z40500505 Keywords : corneal hydration * corneal light absorption * absorption coefficients Subject RIV: FF - HEENT, Dentistry Impact factor: 1.646, year: 2010

  1. Corneal reshaping and wavefront aberrations during overnight orthokeratology. (United States)

    Lian, Yan; Shen, Meixiao; Huang, Shenghai; Yuan, Yimin; Wang, Yaozeng; Zhu, Dexi; Jiang, Jun; Mao, Xinjie; Wang, Jianhua; Lu, Fan


    To investigate changes of corneal thickness at the vertical and horizontal meridians and of wavefront aberrations (WA) over a 30-day period of overnight myopia orthokeratology (OK) lens wear. Sixteen subjects (11 women, 5 men, 26.3±3.2 years) were enrolled and fitted for OK lenses. Long scan depth optical coherence tomography was used to measure corneal thickness profiles at both horizontal and vertical meridians at baseline and on days 1, 7, and 30 days. Corneal and ocular WA of a 6-mm pupil were measured and the root-mean-square (RMS) of the astigmatism, coma, spherical aberration (SA), and total higher-order aberrations (HOAs) were determined. During the 30-day period, the central cornea thinned in the horizontal and vertical meridians, whereas corneal thickening occurred in the temporal, nasal, and inferior mid-peripheries. In contrast, the cornea thinned in the mid-peripheral superior. There were significant increases in RMS for astigmatism, SA, coma, and positive horizontal coma during the study period. After OK, there were significant positive correlations between the midperipheral-central thickness change difference and the changes in corneal and ocular RMS of total HOAs and SA (r range: 0.281 to 0.492, POK caused unique changes in corneal thickness profiles at the vertical and horizontal meridians and increased corneal and ocular HOAs related to corneal reshaping.

  2. Prevalence of corneal ulcer among contact lens wearers in Nigeria ...

    African Journals Online (AJOL)

    Corneal Ulceration has been described as the most serious complication of contact lens wear worldwide. The incidence of corneal ulceration in contact lens wearers in Nigeria was determined retrospectively. 1759 case notes of patients who had worn contact lenses for at least one year were obtained from eye clinics in ...

  3. Matrix Regeneration Therapy: A Case Series of Corneal Neurotrophic Ulcers. (United States)

    Arvola, Riku P J; Robciuc, Alexandra; Holopainen, Juha M


    Treating corneal neurotrophic ulcers is challenging. Topical application of matrix regeneration therapy (RGTA), which is a dextran derivative polymer and heparan sulfate analog, is a promising regenerative therapy and an alternative or additional therapeutic regimen when corneal healing is compromised. The aim of this study was to evaluate the efficacy of RGTA (Cacicol) in the treatment of 6 patients with severe neurotrophic ulcers. We present an uncontrolled prospective case series of 6 patients (6 eyes) with severe corneal neurotrophic ulcers. Patients were treated with topical RGTA at a dose of 1 drop every second day. The main outcome measure was complete corneal epithelialization. We measured corneal thickness by anterior segment swept-source optical coherence tomography. Two patients (33%) showed complete corneal healing, one at 6 weeks and the other at 10 weeks. Treatment was considered failure in 4 patients (67%), and 1 patient had corneal perforation. None of the patients showed improvement in best-corrected visual acuity. There were no RGTA-related local or systemic side effects. Based on previous studies, RGTA seems to be a promising therapeutic agent for controlling ocular surface inflammation and promoting corneal healing. In this study, the efficacy of RGTA did not match the encouraging results from previous reports.

  4. Case Report: Corneal Pyogenic Granuloma: Rare Complication of ...

    African Journals Online (AJOL)

    Slit lamp examination showed vascularized central corneal mass with surrounding stromal infiltrates. The mass was excised, and histopathological examination confirmed pyogenic granuloma of the cornea. Conclusion: Corneal pyogenic granuloma could be a rare complication of infectious keratitis. Therefore, it should be ...

  5. Terahertz sensing in corneal tissues


    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.


    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% a...

  6. Blind MuseumTourer: A System for Self-Guided Tours in Museums and Blind Indoor Navigation


    Apostolos Meliones; Demetrios Sampson


    Notably valuable efforts have focused on helping people with special needs. In this work, we build upon the experience from the BlindHelper smartphone outdoor pedestrian navigation app and present Blind MuseumTourer, a system for indoor interactive autonomous navigation for blind and visually impaired persons and groups (e.g., pupils), which has primarily addressed blind or visually impaired (BVI) accessibility and self-guided tours in museums. A pilot prototype has been developed and is curr...

  7. Distributed scanning volumetric SDOCT for motion corrected corneal biometry. (United States)

    McNabb, Ryan P; Larocca, Francesco; Farsiu, Sina; Kuo, Anthony N; Izatt, Joseph A


    We present a method, termed distributed scanning OCT (DSOCT), which reduces the effects of patient motion on corneal biometry utilizing current-generation clinically available spectral domain optical coherence tomography (SDOCT) systems. We first performed a pilot study of the power spectrum of normal patient axial eye motion based on repeated (M-mode) SDOCT. Using DSOCT to reduce the effects of patient motion, we conducted a preliminary patient study comparing the measured anterior and posterior corneal curvatures and the calculated corneal power to both corneal topography and Scheimpflug photography in normal subjects. The repeatability for the measured radius of curvature of both anterior and posterior surfaces as well as calculated corneal refractive power using DSOCT was comparable to those of both topography and Scheimpflug photography.

  8. Usefulness of corneal esthesiometry for screening diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Lênio Souza Alvarenga


    Full Text Available OBJECTIVE: To assess the usefulness of corneal esthesiometry for screening diabetic retinopathy. METHODS: A cross-sectional study was carried out comprising 575 patients attending a diabetic retinopathy-screening program in the city of São Paulo. Corneal esthesiometry was assessed with the Cochet-Bonnet esthesiometer. The presence of diabetic retinopathy was detected with indirect fundoscopy. The validity of corneal esthesiometry in identifying diabetic retinopathy was evaluated by the Receiver Operating Characteristic (ROC curve. RESULTS: Sensitivity and specificity analyses of the corneal esthesiometry for detecting the stages of diabetic retinopathy using different cut-offs showed values less than 80%. The best indices (72.2% sensitivity and 57.4% specificity were obtained for the identification of patients with proliferative diabetic retinopathy. CONCLUSIONS: In the study series, corneal esthesiometry was not a good indicator of diabetic retinopathy.

  9. Corneal ectasia secondary to LASIK after arcuate keratotomy. (United States)

    Ghanem, Ramon C; Ghanem, Marcielle A; Bogoni, Ayla; Ghanem, Vinícius C


    To present a case of corneal ectasia after LASIK in a patient with previous arcuate keratotomy. Case report. The patient underwent arcuate keratotomy in both eyes in 1997 for with-the-rule regular hyperopic astigmatism and uneventful bilateral LASIK for residual astigmatism 5 years later. Visual acuity and refraction remained stable for 5 years, when the patient noticed worsening visual acuity. Corneal topography showed progressive inferior steepening, confirming the diagnosis of ectasia. Corneal high-resolution optical coherence tomography revealed a normal LASIK flap. The patient had no risk factors for corneal ectasia other than previous incisional surgery. This case suggests that isolated arcuate keratotomy can be a significant risk factor for the development of corneal ectasia after LASIK. Copyright 2013, SLACK Incorporated.

  10. Bioactive self-assembled peptide nanofibers for corneal stroma regeneration. (United States)

    Uzunalli, G; Soran, Z; Erkal, T S; Dagdas, Y S; Dinc, E; Hondur, A M; Bilgihan, K; Aydin, B; Guler, M O; Tekinay, A B


    Defects in the corneal stroma caused by trauma or diseases such as macular corneal dystrophy and keratoconus can be detrimental for vision. Development of therapeutic methods to enhance corneal regeneration is essential for treatment of these defects. This paper describes a bioactive peptide nanofiber scaffold system for corneal tissue regeneration. These nanofibers are formed by self-assembling peptide amphiphile molecules containing laminin and fibronectin inspired sequences. Human corneal keratocyte cells cultured on laminin-mimetic peptide nanofibers retained their characteristic morphology, and their proliferation was enhanced compared with cells cultured on fibronectin-mimetic nanofibers. When these nanofibers were used for damaged rabbit corneas, laminin-mimetic peptide nanofibers increased keratocyte migration and supported stroma regeneration. These results suggest that laminin-mimetic peptide nanofibers provide a promising injectable, synthetic scaffold system for cornea stroma regeneration. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  11. Use of Topical Insulin to Treat Refractory Neurotrophic Corneal Ulcers. (United States)

    Wang, Angeline L; Weinlander, Eric; Metcalf, Brandon M; Barney, Neal P; Gamm, David M; Nehls, Sarah M; Struck, Michael C


    To report the clinical course of 6 patients with refractory neurotrophic corneal ulcers that were treated with topical insulin drops. Retrospective chart review of patients who had neurotrophic corneal ulcers or epithelial defects refractory to standard medical and surgical treatment. Insulin drops, prepared by mixing regular insulin in artificial tears with a polyethylene glycol and propylene glycol base at a concentration of 1 unit per milliliter, were prescribed 2 to 3 times daily. Six patients, aged 2 to 73 years, developed neurotrophic corneal ulcers refractory to a range of medical and surgical treatments, including bandage contact lens, amniotic membrane grafting, and permanent tarsorrhaphy. Each patient was administered topical insulin drops with complete corneal reepithelialization within 7 to 25 days. Topical insulin may be a simple and effective treatment for refractory neurotrophic corneal ulcers. Further study is required to determine the clinical efficacy and side effect profile of insulin drops.

  12. Intacs with or without same-day corneal collagen cross-linking to treat corneal ectasia. (United States)

    Legare, Marie Eve; Iovieno, Alfonso; Yeung, Sonia N; Lichtinger, Alejandro; Kim, Peter; Hollands, Simon; Slomovic, Allan R; Rootman, David S


    To compare combined intrastromal corneal ring segment implantation with same-day ultraviolet-A/riboflavin corneal collagen cross-linking (ICRS-CXL) versus ICRS implantation alone in patients with corneal ectasia. Retrospective comparative study. Sixty-six eyes from 54 patients with corneal ectasia were included in the study. The groups were composed of 32 eyes from 27 patients and 34 eyes from 27 patients for the ICRS-CXL and ICRS groups, respectively. We reviewed the charts of all patients who underwent these procedures from November 2008 to February 2011 for preoperative and for up to 1 year postoperative uncorrected (UDVA) and best corrected distance visual acuity (BDVA), refraction, topographical analysis (mean and steepest keratometry [K]), as well as root mean-square (RMS) of higher-order aberrations (HOAs). Overall, a significant improvement was seen in both groups for UDVA, BDVA, sphere, cylinder, mean refractive spherical equivalent (MRSE), mean and steepest K, coma, spherical and total HOA at 12 months. Trefoil did not improve, and higher-order astigmatism worsened in the ICRS group (p = 0.0466). There was no statistically significant difference between the 2 groups for visual acuity, sphere, cylinder, coma, trefoil, and spherical HOA. Outcomes were significantly more improved in the ICRS group for MRSE (p = 0.0082), mean K (p = 0.0021), steepest K (p = 0.0152), and total HOAs (p = 0.0208). No complications were observed. ICRS-CXL and ICRS alone were both safe and effective in treating corneal ectasia. The ICRS alone group demonstrated better outcomes of MRSE, mean and steepest K, as well as total HOA. Copyright © 2013 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  13. Mycotic corneal ulcers in upper Assam

    Directory of Open Access Journals (Sweden)

    Reema Nath


    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.

  14. Mycotic corneal ulcers in upper Assam. (United States)

    Nath, Reema; Baruah, Syamanta; Saikia, Lahari; Devi, Bhanu; Borthakur, A K; Mahanta, J


    To study the association of various risk factors and epidemiological variables of mycotic keratitis treated at a tertiary referral hospital of upper Assam. 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. 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. 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.

  15. Corneal surface reconstruction - a short review

    Directory of Open Access Journals (Sweden)

    Madhavan H N


    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

  16. Finite element modeling of corneal strip extensometry

    CSIR Research Space (South Africa)

    Botha, N


    Full Text Available Donnell, ?Corneal tensile strength in fully healed radial keratotomy wounds.? Investigative Ophthalmology & Visual Science, vol. 35, no. 7, pp. 3022 ?3031, Jun. 1994. [Online]. Available: [12] A. Elsheikh, M. Brown...- timization process, are listed in Table I for two different age groups [12]. Note that the incompressibility parameter, D1, c SACAM 2012 26 is fixed at 0.004, which ensures the incompressibility of the material model. The corresponding extensometry test...

  17. User-centered Technologies For Blind Children

    Directory of Open Access Journals (Sweden)

    Jaime Sánchez


    Full Text Available The purpose of this paper is to review, summarize, and illustrate research work involving four audio-based games created within a user-centered design methodology through successive usability tasks and evaluations. These games were designed by considering the mental model of blind children and their styles of interaction to perceive and process data and information. The goal of these games was to enhance the cognitive development of spatial structures, memory, haptic perception, mathematical skills, navigation and orientation, and problem solving of blind children. Findings indicate significant improvements in learning and cognition from using audio-based tools specially tailored for the blind. That is, technologies for blind children, carefully tailored through user-centered design approaches, can make a significant contribution to cognitive development of these children. This paper contributes new insight into the design and implementation of audio-based virtual environments to facilitate learning and cognition in blind children.

  18. Characteristics of corneal ectasia after LASIK for myopia. (United States)

    Twa, Michael D; Nichols, Jason J; Joslin, Charlotte E; Kollbaum, Pete S; Edrington, Timothy B; Bullimore, Mark A; Mitchell, G Lynn; Cruickshanks, Karen J; Schanzlin, David J


    There are numerous reports of corneal ectasia after laser in situ keratomileusis (LASIK) for myopia without a consistent definition of this condition or a definitive etiology. We conducted a retrospective analysis of published case reports to describe common characteristics of this postoperative event and compared them with findings from a group of successful LASIK patients. A MEDLINE search for "LASIK" and "ectasia" yielded 21 relevant articles published before May 2003 (n = 86 eyes, 59 patients). A comparison group (n = 103 eyes, 63 patients) was selected from a clinic-based sample of successful LASIK patients with 12 months of follow-up after treatment. Descriptive statistics are reported as median and interquartile range. Comparisons were performed using the Wilcoxon rank sum, Wilcoxon signed rank, and chi-square tests. Time to diagnosis of ectasia after LASIK was 13 months (6 to 20 months). Residual myopia in the ectasia group was -3.69 D (-6.00 to -2.13 D) and was significantly greater than the comparison group, -0.38 D (-0.75 to 0.00 D), P ectasia had increased corneal toricity 2.87 D (2.00 to 4.9 D) with increased oblique astigmatism 1.3 D (0.23 to 2.89 D) relative to eyes in the comparison group 0.00 D (0.00 to 0.08 D), and a loss of 2 lines (-0.5 to -6 lines) of best spectacle-corrected visual acuity (all P corneal transplantation. Preoperative characteristics of corneal ectasia include worse visual acuity, less corneal thickness, greater residual myopia, and greater corneal toricity than nonectatic eyes. Treatment factors associated with corneal ectasia after LASIK are greater stromal ablation and less residual stromal bed thickness. Postoperative characteristics of corneal ectasia are myopic refractive error with increased astigmatism, worse spectacle-corrected visual acuity, increased corneal toricity with topographic abnormality, and progressive corneal thinning.

  19. Utilización del bevacizumab en la neovascularización corneal Use of Bevacizumab in corneal neovascularization

    Directory of Open Access Journals (Sweden)

    Taimi Cárdenas Díaz


    Full Text Available La neovascularización corneal es causa de pérdida de su transparencia y también es un factor de riesgo para el rechazo secundario de trasplantes en esa estructura. El bevacizumab es un anticuerpo monoclonal humanizado que bloquea selectivamente la cascada de formación del VEGF y con esto disminuye la formación de vasos sanguíneos. Se presentan tres casos con neovascularización corneal por diferentes causas, a los cuales se le administró tres dosis subconjuntival de 2,5 mg de bevacizumab, con una frecuencia mensual. En los ojos tratados se observó una regresión parcial de la neovascularización corneal y fue más visible en el paciente con antecedente de quemadura corneal.Neovascularization of the cornea is a cause of loss of transparency of the same and is also a risk factor for secondary rejection corneal transplants. Bevacizumab is a humanized monoclonal antibody that selectively blocks the formation of the VEGF cascade and, with this, decreases the formation of blood vessels. Three cases with corneal neovascularization from different causes were presented, which were given three doses of 2.5 mg subconjunctival bevacizumab once a month. A partial regression of corneal neovascularization was observed in the treated eyes, being more visible in the patient with a history of corneal burn.

  20. Applanation optical coherence elastography: noncontact measurement of intraocular pressure, corneal biomechanical properties, and corneal geometry with a single instrument (United States)

    Singh, Manmohan; Han, Zhaolong; Nair, Achuth; Schill, Alexander; Twa, Michael D.; Larin, Kirill V.


    Current clinical tools provide critical information about ocular health such as intraocular pressure (IOP). However, they lack the ability to quantify tissue material properties, which are potent markers for ocular tissue health and integrity. We describe a single instrument to measure the eye-globe IOP, quantify corneal biomechanical properties, and measure corneal geometry with a technique termed applanation optical coherence elastography (Appl-OCE). An ultrafast OCT system enabled visualization of corneal dynamics during noncontact applanation tonometry and direct measurement of micro air-pulse induced elastic wave propagation. Our preliminary results show that the proposed Appl-OCE system can be used to quantify IOP, corneal biomechanical properties, and corneal geometry, which builds a solid foundation for a unique device that can provide a more complete picture of ocular health.

  1. Dangerous reef aquaristics: Palytoxin of a brown encrusting anemone causes toxic corneal reactions. (United States)

    Ruiz, Yasmin; Fuchs, Joan; Beuschel, Ralf; Tschopp, Markus; Goldblum, David


    Although frequently observed in domestic saltwater aquariums, literature on exposure to palytoxin (PTX) of encrusting anemones (Zoanthidea) kept in aquariums is rare. Handling these animals for propagation purposes or during cleaning work can lead to dermal, ocular or respiratory contact with the PTX generated by some Zoanthids. The present study describes a case of ocular exposure to liquid from a Zoanthid, which led to corneal ulcers. The patient also suffered from systemic symptoms of dyspnea and shivering and a suspected rhabdomyolysis, which required monitoring in the Intensive Care Unit. After symptomatic treatment provided insufficient results, the corneal ulcers improved with an amniotic membrane transplantation. A review of the literature regarding ocular exposures to this diverse order of Hexacorallia reveals that severe and systemic symptoms can develop with minimal contact. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Spatial and spectral analysis of corneal epithelium injury using hyperspectral images (United States)

    Md Noor, Siti Salwa; Michael, Kaleena; Marshall, Stephen; Ren, Jinchang


    Eye assessment is essential in preventing blindness. Currently, the existing methods to assess corneal epithelium injury are complex and require expert knowledge. Hence, we have introduced a non-invasive technique using hyperspectral imaging (HSI) and an image analysis algorithm of corneal epithelium injury. Three groups of images were compared and analyzed, namely healthy eyes, injured eyes, and injured eyes with stain. Dimensionality reduction using principal component analysis (PCA) was applied to reduce massive data and redundancies. The first 10 principal components (PCs) were selected for further processing. The mean vector of 10 PCs with 45 pairs of all combinations was computed and sent to two classifiers. A quadratic Bayes normal classifier (QDC) and a support vector classifier (SVC) were used in this study to discriminate the eleven eyes into three groups. As a result, the combined classifier of QDC and SVC showed optimal performance with 2D PCA features (2DPCA-QDSVC) and was utilized to classify normal and abnormal tissues, using color image segmentation. The result was compared with human segmentation. The outcome showed that the proposed algorithm produced extremely promising results to assist the clinician in quantifying a cornea injury.

  3. Corneal topographer based on the Hartmann test. (United States)

    Mejía, Yobani; Galeano, Janneth C


    The purpose of this article is to show the performance of a topographer based on the Hartmann test for convex surfaces of F/# approximately 1. This topographer, called "Hartmann Test topographer (HT topographer)," is a prototype developed in the Physics Department of the Universidad Nacional de Colombia. From the Hartmann pattern generated by the surface under test, and by the Fourier analysis and the optical aberration theory we obtain the sagitta (elevation map) of the surface. Then, taking the first and the second derivatives of the sagitta in the radial direction we obtain the meridional curvature map. The method is illustrated with an example. To check the performance of the HT topographer a toric surface, a revolution aspherical surface, and two human corneas were measured. Our results are compared with those obtained with a Placido ring topographer (Tomey TMS-4 videokeratoscope), and we show that our curvature maps are similar to those obtained with the Placido ring topographer. The HT topographer is able to reconstruct the corneal topography potentially eradicating the skew ray problem, therefore, corneal defects can be visualized more. The results are presented by elevation and meridional curvature maps.

  4. Corneal collagen denaturation in laser thermokeratoplasty (United States)

    Brinkmann, Ralf; Kampmeier, Juergen; Grotehusmann, Ulf; Vogel, Alfred; Koop, Norbert; Asiyo-Vogel, Mary; Birngruber, Reginald


    In laserthermokeratoplasty (LTK) thermal denaturation and shrinkage of corneal collagen is used to correct hyperopia and astigmatism. In order to optimize dosimetry, the temperature at which maximal shrinkage of collagen fibrils occurs is of major interest. Since the exposure time in clinical LTK-treatment is limited to a few seconds, the kinetics of collagen denaturation as a rate process has to be considered, thus the time of exposure is of critical importance for threshold and shrinkage temperatures. We investigated the time-temperature correlation for corneal collagen denaturation within different time domains by turbidimetry of scattered HeNe laser probe light using a temperature controlled water bath and pulsed IR laser irradiation. In the temperature range of 60 degree(s)C to 95 degree(s)C we found an exponential relation between the denaturation time and temperature. For the typical LTK-treatment time of 2 s, a temperature of 95 degree(s)C is needed to induce thermal damage. Use of pulsed Holmium laser radiation gave significant scattering of HeNe laser probe light at calculated temperatures of around 100 degree(s)DC. Rate parameters according to the formalism of Arrhenius were fitted to these results. Force measurements showed the simultaneous onset of light scattering and collagen shrinkage.

  5. Coefficient of Friction of Human Corneal Tissue. (United States)

    Wilson, Tawnya; Aeschlimann, Rudolf; Tosatti, Samuele; Toubouti, Youssef; Kakkassery, Joseph; Osborn Lorenz, Katherine


    A novel property evaluation methodology was used to determine the elusive value for the human corneal coefficient of friction (CoF). Using a microtribometer on 28 fresh human donor corneas with intact epithelia, the CoF was determined in 4 test solutions (≥5 corneas/solution): tear-mimicking solution (TMS) in borate-buffered saline (TMS-PS), TMS in phosphate-buffered saline (TMS-PBS), TMS with HEPES-buffered saline (TMS-HEPES), and tear-like fluid in PBS (TLF-PBS). Mean (SD) CoF values ranged from 0.006 to 0.015 and were 0.013 (0.010) in TMS-PS, 0.006 (0.003) in TMS-PBS, 0.014 (0.005) in TMS-HEPES, and 0.015 (0.009) in TLF-PBS. Statistically significant differences were shown for TMS-PBS versus TLF (P = 0.0424) and TMS-PBS versus TMS-HEPES (P = 0.0179), but not for TMS-PBS versus TMS-PS (P = 0.2389). Successful measurement of the fresh human corneal tissue CoF was demonstrated, with values differing in the evaluated buffer solutions, within this limited sample size.

  6. Clinical utility of the KAMRA corneal inlay (United States)

    Naroo, Shehzad Anjam; Bilkhu, Paramdeep Singh


    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. Percent tissue altered and corneal ectasia. (United States)

    Santhiago, Marcony R


    This article reviews the association of a novel metric, percentage tissue altered (PTA), with the occurrence of ectasia after laser in-situ keratomileusis in eyes with normal corneal topography, and analyses the influence of the variables that comprise it, and its role on eyes with suspicious topography. PTA is derived from [PTA = (FT + AD)/CCT] where FT = flap thickness, AD = ablation depth, and CCT = preoperative central corneal thickness. Our studies revealed that there is a robust relationship between high PTA and ectasia risk in eyes with normal preoperative topography. PTA higher or equal to 40% presented the highest odds ratio and highest predictive capabilities for ectasia risk than each of the variables that comprise it, residual stromal bed or age. Average thicker flaps alone were insufficient to create ectasia unless coupled with greater ablation depths, meaning a high PTA. In eyes with suspicious topography, even low PTA value is sufficient to induce ectasia. This new metric, PTA, should be taken into account when screening patients for refractive surgery. Patients with normal topography or tomography, presenting a PTA higher or equal to 40% should be considered at higher risk for post laser in-situ keratomileusis ectasia.

  8. Bilateral Keratectasia 34 Years after Corneal Transplant

    Directory of Open Access Journals (Sweden)

    Xavier Valldeperas


    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. [New stimulants of corneal reparative regeneration]. (United States)

    Egorov, E A; Kalinin, N I; Kiiasov, A P


    The efficacy of corneregel, a drug containing pantothenic acid, a component of coenzyme A, in healing of corneal wounds has been evaluated. The study was carried out on 19 rabbits (38 eyes) with standard corneal defect made with a 5-mm trephine for lamellar transplantation of the cornea, divided into 2 groups: 1) instillations of corneregel (10 eyes) and 0.25% levomycetin solution (10 eyes) and 2) 20% solcoseryl gel (9 eyes) and 0.25% levomycetin (9 eyes). Time course of changes were evaluated by biomicroscopy (fluorescent test), histologically (hematoxylin-eosin staining), and immunohistochemically after 1, 2, 4, 7, 30, and 90 days. Proliferative activity was studied by expression of the proliferating cell nuclear antigen and the migration capacity of cells by expression of alpha-smooth muscle actin. The terms of epithelialization were as follows: corneregel 10 +/- 7 h, 20% solcoseryl gel 108 +/- 10 h, levomycetin 124 +/- 6.93 h. Earlier epithelialization in the corneregel group was apparently due to increased expression of alpha-smooth muscle actin and increase in the cell migration capacity. Hence, corneregel is recommended for practical use as a stimulant of reparative regeneration of the cornea.

  10. Corneal endothelial glutathione after photodynamic change

    International Nuclear Information System (INIS)

    Hull, D.S.; Riley, M.V.; Csukas, S.; Green, K.


    Rabbit corneal endothelial cells perfused with 5 X 10(-6)M rose bengal and exposed to incandescent light demonstrated no alteration of either total of or percent oxidized glutathione after 1 hr. Addition of 5400 U/ml catalase to the perfusing solution had no effect on total glutathione levels but caused a marked reduction in percent oxidized glutathione in corneas exposed to light as well as in those not exposed to light. Substitution of sucrose for glucose in the perfusing solution had no effect on total or percent oxidized glutathione. Perfusion of rabbit corneal endothelium with 0.5 mM chlorpromazine and exposure to ultraviolet (UV) light resulted in no change in total glutathione content. A marked reduction in percent oxidized glutathione occurred, however, in corneas perfused with 0.5 mM chlorpromazine both in the presence and absence of UV light. It is concluded that photodynamically induced swelling of corneas is not the result of a failure of the glutathione redox system

  11. Femtosecond laser's application in the corneal surgery

    Directory of Open Access Journals (Sweden)

    Shu-Liang Wang


    Full Text Available With the rapid development over the past two decades,femtosecond(10-15slasers(FShas become a new application in ophthalmic surgery. As laser power is defined as energy delivered per unit time, decreasing the pulse duration to femtosecond level(100fsnot only increases the power delivered but also decreases the fluence threshold for laser induced optical breakdown. In ablating tissue, FS has an edge over nanosecond lasers as there is minimal collateral damage from shock waves and heat conduction during surgical ablation. Thus, application of FS has been widely spread, from flap creation for laser-assisted in situ keratomileusis(LASIKsurgery, cutting of donor and recipient corneas in keratoplasty, creation of pockets for intracorneal ring implantation. FS applied in keratoplasty is mainly used in making graft and recipient bed, and can exactly cut different tissue of keratopathy. FS can also cut partial tissue of cornea, even if it is under the moderate corneal macula and corneal edema condition.

  12. Topographic corneal changes after collagen cross-linking in patients with corneal keratoconus

    Directory of Open Access Journals (Sweden)

    Hasan Razmjoo


    Full Text Available Background: Corneal collagen cross-linking with riboflavin, also known as collagen cross-linking (CXL, involves the application of riboflavin solution to the eye that is activated by illumination with ultraviolet A (UVA light. We survey here the topographic corneal changes one year after CXL in patients with corneal keratoconus. Materials and Methods: This prospective randomized clinical trial study comprised 66 patients with progression of keratoconus during one year who were enrolled at Feiz University Referral Eye Center in Isfahan. Before and after the operation, patients were examined with slit lamp and funduscopic examinations and measurement of uncorrected visual acuity (UCVA, and best spectacle-corrected visual acuity (BSCVA was done with a logarithm of minimal angle of resolution (logMAR scale. Corneal topographic and pachymetry values were derived from Orbscan II. The paired t-test test was used for statistical analyses with SPSS software version 20 (SPSS Inc., Chicago, IL, USA. Results: All 66 patients completed postoperative follow-up at 12 months. The mean age of the patients was 22.4 ± 5.4 years (range: 18-29 years. Thirty-six (54.55% subjects were men and 30 (45.45% were women. The mean preoperative sphere was −2.66 ± 2.14 diopter (D, the mean cylinder was −3.97 ± 2.29, and the mean spherical equivalent (SE was −4.64 ± 2.56. Postoperatively, the mean sphere was −2.22 ± 2.57 D, the mean cylinder was −3.60 ± 2.40 D, and SE was −4.02 ± 2.93 D (P = 0.037. SE also demonstrated a mean difference of 0.62 ± 0.37 D significantly (P = 0.006.The mean diameter of preoperative posterior best-fit sphere (BFS was 6.33 ± 0.35mm (range: 5.51-7.73 mm before operation, and it improved to 6.28 ± 0.34mm (range: 4.36-6.13 mm after operation; the difference was significant (P = 0.039. Conclusion: Our study showed a significant improvement in topographic corneal changes and refractive results in patients with corneal ectasia after

  13. Corneal power evaluation after myopic corneal refractive surgery using artificial neural networks. (United States)

    Koprowski, Robert; Lanza, Michele; Irregolare, Carlo


    Efficacy and high availability of surgery techniques for refractive defect correction increase the number of patients who undergo to this type of surgery. Regardless of that, with increasing age, more and more patients must undergo cataract surgery. Accurate evaluation of corneal power is an extremely important element affecting the precision of intraocular lens (IOL) power calculation and errors in this procedure could affect quality of life of patients and satisfaction with the service provided. The available device able to measure corneal power have been tested to be not reliable after myopic refractive surgery. Artificial neural networks with error backpropagation and one hidden layer were proposed for corneal power prediction. The article analysed the features acquired from the Pentacam HR tomograph, which was necessary to measure the corneal power. Additionally, several billion iterations of artificial neural networks were conducted for several hundred simulations of different network configurations and different features derived from the Pentacam HR. The analysis was performed on a PC with Intel ® Xeon ® X5680 3.33 GHz CPU in Matlab ® Version (R2010b) with Signal Processing Toolbox Version 7.1 (R2010b), Neural Network Toolbox 7.0 (R2010b) and Statistics Toolbox (R2010b). A total corneal power prediction error was obtained for 172 patients (113 patients forming the training set and 59 patients in the test set) with an average age of 32 ± 9.4 years, including 67% of men. The error was at an average level of 0.16 ± 0.14 diopters and its maximum value did not exceed 0.75 dioptres. The Pentacam parameters (measurement results) providing the above result are tangential anterial/posterior. The corneal net power and equivalent k-reading power. The analysis time for a single patient (a single eye) did not exceed 0.1 s, whereas the time of network training was about 3 s for 1000 iterations (the number of neurons in the hidden layer was 400).

  14. [Urgent therapeutic penetrating autokeratoplasty for a purulent corneal ulcer in the only functional eye]. (United States)

    Onishchenko, A L; Kolbasko, A V; Tatarnikova, G N; Mamontova, É G


    The article presents a case of severe purulent corneal ulcer in the only functional eye of a young patient with Frank-Kamenetsky glaucoma and high-degree myopia. Combination therapy was ineffective and the patient developed a descemetocele. Due to the absence of cadaver corneas and small size of the only available conserved Alloplant cornea, the contralateral cornea (of the blind eye, which was enucleated under general anesthesia) was used for urgent therapeutic penetrating autokeratoplasty. Postoperative period was complicated with ocular hypertension, which was surgically resolved. To overcome the critical situation around keratoplasty, with results from Russian regulation gaps, the authors suggest creating interregional eye banks in large cities that would provide sampling, conservation and storage control of donor material in accordance with the existing legislation.

  15. The blindness of John Milton. (United States)

    Bartley, G B


    John Milton (1608-1674) often has been regarded as the greatest poet of his time, yet he did not compose his most famous work, Paradise Lost, until after he had become blind in both eyes. On the basis of clues in Milton's writings, several possible diagnoses have been advanced to explain his loss of vision. The evidence for and against each theory is presented.

  16. Postictal blindness in adults.


    Sadeh, M; Goldhammer, Y; Kuritsky, A


    Cortical blindness following grand mal seizures occurred in five adult patients. The causes of seizures included idiopathic epilepsy, vascular accident, brain cyst, acute encephalitis and chronic encephalitis. Blindness was permanent in one patients, but the others recovered within several days. Since most of the patients were either unaware of or denied their blindness, it is possible that this event often goes unrecognised. Cerebral hypoxia is considered the most likely mechanism.

  17. Rapid assessment of avoidable blindness in Negros Island and Antique District, Philippines. (United States)

    Eusebio, Cristina; Kuper, Hannah; Polack, Sarah; Enconado, John; Tongson, Noel; Dionio, Donald; Dumdum, Anne; Limburg, Hans; Foster, Allen


    To conduct rapid assessments of avoidable blindness to estimate the magnitude and causes of blindness in people aged >/=50 years in Negros Island and Antique district, Philippines. Clusters of 50 people aged >/=50 years were sampled with probability proportionate to size. Households within clusters were selected through compact segment sampling. Visual acuity (VA) was measured with a tumbling "E" chart. Ophthalmologists examined people with VA/=6/60). Most of the cases of blindness (67% in Negros, 82% in Antique) and visual impairment (94% in Negros, 95% in Antique) were avoidable (ie, operated and unoperated cataract, refractive error and corneal scar). In Negros, 23% of eyes had a poor outcome after cataract surgery, and 13% in Antique. The prevalence of blindness in two areas in the Philippines was relatively low. Since most cases were avoidable, further reductions are possible.

  18. Punctiform and Polychromatophilic Dominant Pre-Descemet Corneal Dystrophy. (United States)

    Lagrou, Lisa; Midgley, Julian; Romanchuk, Kenneth Gerald


    To describe the slit-lamp appearance and corneal confocal microscopy of autosomal dominant punctiform and polychromatophilic pre-Descemet corneal dystrophy in 3 members of the same family. Slit-lamp examination of a 9-year-old boy showed bilateral polychromatophilic corneal opacities in a pre-Descemet membrane location evenly deposited limbus to limbus, both horizontally and vertically, with an intervening clear cornea. The corneal endothelium was normal on corneal confocal microscopy, with hyperreflective opacities of various sizes located pre-Descemet membrane. Slit-lamp examination of the patient's father and brother revealed identical crystalline deposition in the pre-Descemet corneal stroma. The remainders of the eye examinations were otherwise normal in all 3 individuals, and all were asymptomatic. The general physical examination and laboratory investigations of the patient were all normal, as were the laboratory investigations of the other 2 family members. There was no progression in the corneal findings over 6 months of follow-up. These patients likely illustrate a rare autosomal dominant pre-Descemet crystalline keratopathy that has been reported only once previously.

  19. Corneal Higher-Order Aberrations in Infectious Keratitis. (United States)

    Shimizu, Eisuke; Yamaguchi, Takefumi; Yagi-Yaguchi, Yukari; Dogru, Murat; Satake, Yoshiyuki; Tsubota, Kazuo; Shimazaki, Jun


    To characterize the corneal higher-order aberrations (HOAs) in eyes with Acanthamoeba keratitis (AK), bacterial keratitis (BK), and fungal keratitis (FK). Retrospective consecutive case series. This retrospective study includes 18 normal subjects and 63 eyes of 62 consecutive patients with corneal scarring due to AK (20 eyes), BK (35 eyes), and FK (8 eyes) from 2010 to 2016. HOAs of the anterior and posterior surfaces and the total cornea were analyzed by anterior segment optical coherence tomography. Corneal HOA patterns were assigned on the basis of corneal topography maps. Corneal opacity grading was assigned on the basis of slit-lamp examinations. We evaluated corneal HOAs, corneal opacity grading, and their correlation with visual acuity. HOAs of the total cornea within a 4-mm diameter were significantly larger in eyes with infectious keratitis (AK, 1.15 ± 2.06 μm; BK, 0.91 ± 0.88 μm; FK, 1.39 ± 1.46 μm) compared with normal controls (0.09 ± 0.01 μm, all, P keratitis were associated with poorer visual acuity values. Asymmetric pattern was the most common topographic pattern in infectious keratitis. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Corneal Biomechanics in Ectatic Diseases: Refractive Surgery Implications (United States)

    Ambrósio, Jr, Renato; Correia, Fernando Faria; Lopes, Bernardo; Salomão, Marcella Q.; Luz, Allan; Dawson, Daniel G.; Elsheikh, Ahmed; Vinciguerra, Riccardo; Vinciguerra, Paolo; Roberts, Cynthia J.


    Background: Ectasia development occurs due to a chronic corneal biomechanical decompensation or weakness, resulting in stromal thinning and corneal protrusion. This leads to corneal steepening, increase in astigmatism, and irregularity. In corneal refractive surgery, the detection of mild forms of ectasia pre-operatively is essential to avoid post-operative progressive ectasia, which also depends on the impact of the procedure on the cornea. Method: The advent of 3D tomography is proven as a significant advancement to further characterize corneal shape beyond front surface topography, which is still relevant. While screening tests for ectasia had been limited to corneal shape (geometry) assessment, clinical biomechanical assessment has been possible since the introduction of the Ocular Response Analyzer (Reichert Ophthalmic Instruments, Buffalo, USA) in 2005 and the Corvis ST (Oculus Optikgeräte GmbH, Wetzlar, Germany) in 2010. Direct clinical biomechanical evaluation is recognized as paramount, especially in detection of mild ectatic cases and characterization of the susceptibility for ectasia progression for any cornea. Conclusions: The purpose of this review is to describe the current state of clinical evaluation of corneal biomechanics, focusing on the most recent advances of commercially available instruments and also on future developments, such as Brillouin microscopy. PMID:28932334

  1. Intrastromal corneal ring segment implantation for ectasia after refractive surgery. (United States)

    Torquetti, Leonardo; Ferrara, Paulo


    To evaluate the clinical outcomes of implantation of Ferrara intrastromal corneal ring segments (ICRS) in patients with corneal ectasia after refractive surgery. Private clinic, Belo Horizonte, Brazil. Charts of patients with corneal ectasia after refractive surgery were retrospectively reviewed. The following parameters were studied: uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometry, corneal asphericity, and pachymetry. All patients were evaluated by Scheimpflug scanning-slit tomography (Pentacam). Twenty-five eyes (20 patients) with corneal ectasia (20 after laser in situ keratomileusis, 4 after radial keratotomy, 1 after photorefractive keratectomy) were evaluated. Postoperatively, the mean UDVA increased from 20/185 to 20/66 (P = .005) and the mean CDVA, from 20/125 to 20/40 (P = .008). The mean asphericity decreased from -0.95 preoperatively to -0.23 postoperatively (P = .006). The mean pachymetry at the apex of the cornea increased from 457.7 microm +/- 48.7 (SD) preoperatively to 466.2 +/- 49.8 mum postoperatively (P = .025) and the mean pachymetry at the thinnest point, from 436.3 +/- 46.2 microm to 453.9 +/- 49.3 microm (P = .000). The mean keratometry decreased from 45.41 +/- 5.63 diopters (D) to 42.88 +/- 4.44 D, respectively; the decrease was statistically significant (P = .000). Intrastromal corneal ring segment implantation significantly improved UDVA and CDVA in patients with corneal ectasia. (c) 2010. Published by Elsevier Inc.

  2. Topical ranibizumab as a treatment of corneal neovascularization. (United States)

    Ferrari, Giulio; Dastjerdi, Mohammad H; Okanobo, Andre; Cheng, Sheng-Fu; Amparo, Francisco; Nallasamy, Nambi; Dana, Reza


    To examine the effect of topical ranibizumab on clinically stable corneal neovascularization (NV). This was a prospective, open-label, monocentric, uncontrolled noncomparative study. Ten eyes of 9 patients with corneal NV received topical ranibizumab (1%) 4 times a day for 3 weeks with a follow-up period of 16 weeks. The main corneal NV outcome measures were: neovascular area, the area occupied by the corneal neovessels; vessel caliber (VC), the mean diameter of the corneal neovessels; and invasion area (IA), the fraction of the total cornea area covered by the vessels. This study was conducted at the Massachusetts Eye and Ear Infirmary, Boston, MA. Statistically significant decreases in neovascular area (55.3%, P < 0.001), which lasted through 16 weeks, and VC (59%, P < 0.001), which continued to improve up to week 16, were observed after treatment. No significant decrease was observed in IA (12.3%, P = 0.49). There was no statistically significant change in visual acuity or intraocular pressure. No adverse events ascribed to the treatment were noted. Topical application of ranibizumab is effective in reducing the severity of corneal NV in the context of established corneal NV, mostly through decrease in VC rather than IA.

  3. Impact of Hydration Media on Ex Vivo Corneal Elasticity Measurements. (United States)

    Dias, Janice; Ziebarth, Noël M


    To determine the effect of hydration media on ex vivo corneal elasticity. Experiments were conducted on 40 porcine eyes retrieved from an abattoir (10 eyes each for phosphate-buffered saline (PBS), balanced salt solution, Optisol, 15% dextran). The epithelium was removed, and the cornea was excised with an intact scleral rim and placed in 20% dextran overnight to restore its physiological thickness. For each hydration media, corneas were evenly divided into two groups: one with an intact scleral rim and the other without. Corneas were mounted onto a custom chamber and immersed in a hydration medium for elasticity testing. Although in each medium, corneal elasticity measurements were performed for 2 hr: at 5-min intervals for the first 30 min and then 15-min intervals for the remaining 90 min. Elasticity testing was performed using nanoindentation with spherical indenters, and Young modulus was calculated using the Hertz model. Thickness measurements were taken before and after elasticity testing. The percentage change in corneal thickness and elasticity was calculated for each hydration media group. Balanced salt solution, PBS, and Optisol showed an increase in thickness and Young moduli for corneas with and without an intact scleral rim. Fifteen percent dextran exhibited a dehydrating effect on corneal thickness and provided stable maintenance of corneal elasticity for both groups. Hydration media affects the stability of corneal thickness and elasticity measurements over time. Fifteen percent dextran was most effective in maintaining corneal hydration and elasticity, followed by Optisol.

  4. Topical Ranibizumab as a Treatment of Corneal Neovascularization (United States)

    Ferrari, Giulio; Dastjerdi, Mohammad H.; Okanobo, Andre; Cheng, Sheng-Fu; Amparo, Francisco; Nallasamy, Nambi; Dana, Reza


    Purpose To examine the effect of topical ranibizumab on clinically stable corneal neovascularization (NV). Methods This was a prospective, open-label, monocentric, uncontrolled, non-comparative study. Ten eyes of 9 patients with corneal NV received topical ranibizumab (1%) 4 times a day for 3 weeks with a follow-up of 16 weeks. The main corneal neovascularization outcome measures were: neovascular area (NA), the area occupied by the corneal neovessels; vessel caliber (VC), the mean diameter of the corneal neovessels; and invasion area (IA), the fraction of the total cornea area covered by the vessels. This study was conducted at the Massachusetts Eye and Ear Infirmary, Boston, MA, USA. Results Statistically significant decreases in NA (55.3%, P<0.001), which lasted through 16 weeks, and VC (59%, P<0.001), which continued to improve up to week 16, were observed after treatment. No significant decrease was observed in IA (12.3%, P=0.49). There was no statistically significant change in visual acuity or intraocular pressure. No adverse events ascribed to the treatment were noted. Conclusions Topical application of ranibizumab is effective in reducing the severity of corneal NV in the context of established corneal NV, mostly through decrease in VC rather than IA. PMID:23407316

  5. Corneal ectasia secondary to peripheral endotheliopathy in a patient with classic pars planitis


    Arellanes-Garcia, Lourdes; Preciado-Delgadillo, Maricarmen; Hernandez-Quintela, Everardo; Garza-Leon, Manuel


    Purpose To report a case of corneal ectasia secondary to pars planitis corneal endotheliopathy Methods Clinical case description and proposed hypothesis regarding development of corneal ectasia Results Eight-year-old male presented with 360° peripheral corneal endotheliopathy and edema, granulomatous keratic precipitates, and mild iritis OD. A progressive corneal ectasia then developed. Twenty months later, OS presented similarly and anterior chamber inflammatory cells, vitreous snowballs, an...

  6. Ten years left to eliminate blinding trachoma

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    Haddad D.


    Full Text Available n 1997, the World Health Organization formed the Global Alliance to Eliminate Blinding Trachoma by 2020 (GET 2020, a coalition of governmental, non-governmental, research, and pharmaceutical partners. In 1998, the World Health Assembly urged member states to map blinding trachoma in endemic areas, implement the SAFE strategy (which stands for surgery for trichiasis, antibiotics, facial-cleanliness and environmental change, such as clean water and latrines and collaborate with the global alliance in its work to eliminate blinding trachoma.

  7. Blepharokeratoconjunctivitis in childhood: corneal involvement and visual outcome. (United States)

    Rodríguez-García, A; González-Godínez, S; López-Rubio, S


    The main objective of this study is to describe the prevalence, degree and risk of corneal involvement, and visual impact in a pediatric population with blepharokeratoconjunctivitis (BKC). Retrospective, observational, case-control study. Clinical records of patients ≤16 years old with BKC seen between 2006 and 2012 were reviewed. The prevalence and relative risk of corneal involvement was evaluated between patients with and without corneal affection through a univariate and multivariate analysis with logistic regression. Visual acuity at presentation and at last follow-up visit was also analyzed. One hundred and fourteen children with BKC, with a male-to-female ratio of 1 : 1 and a mean age at diagnosis of 9.13 years. The mean follow-up time was 26.4 (±25) months. Corneal involvement was present in 39.5% of patients, varying from superficial punctate keratitis to perforation. Corneal changes were not seen in children under 4 years old. The risk of corneal affection was greater in patients with photophobia, hordeolum, female gender and asymmetric disease (OR of 2.69, 11.6, 2.35 and 2.77, respectively). The mean best-corrected visual acuity at presentation was 0.20 (corneal affected group), compared to 0.11 (unaffected group; P=0.02). Our study showed an older age at time of diagnosis and a worse visual outcome in patients with BKC and corneal disease compared with previous reports. Early diagnosis and detection of risk factors for corneal involvement, as well as adequate treatment, is mandatory to prevent serious long-term visual repercussions in children with BKC.

  8. Using corneal topography design personalized cataract surgery programs

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    Jin-Ou Huang


    Full Text Available AIM:To investigate how to design personalized cataract surgery programs to achieve surgical correction of preoperative corneal astigmatism with surgical astigmatism under the guidance of corneal topography, improve postoperative visual quality and reduce the cost of treatment. METHODS: Totally 202 cases(226 eyescataract patients were divided into randomized treatment group and individualized treatment group. According to the method and location of the incision, randomized treatment group were divided into 8 groups. Surgical astigmatism after different incision were calculated with the use of preoperative and postoperative corneal astigmatism through vector analysis method. Individualized treatment groups were designed personably for surgical method with reference of every surgically induced astigmatism, the surgical method chooses the type of surgical incision based on close link between preoperative corneal astigmatism and surgically induced astigmatism, and the incision was located in the steep meridian. The postoperative corneal astigmatism of individualized treatment group was observed. RESULTS: Postoperative corneal astigmatism of individualized treatment group were lower than that of 3.0mm clear corneal tunnel incision in the randomized treatment group, there were statistically significance difference, while with 3.0mm sclera tunnel incision group there were no statistically significance difference. After 55.8% of patients with the use of individualized surgical plan could undergo the operation of extracapsular cataract extraction with relatively low cost and rigid intraocular lens implantation, the per capita cost of treatment could be reduced. CONCLUSION: Personalized cataract surgery programs are designed to achieve surgical correction of preoperative corneal astigmatism under the use of corneal topography, improve postoperative visual quality and reduce the cost of treatment.

  9. Development of a novel ex vivo equine corneal model. (United States)

    Marlo, Todd L; Giuliano, Elizabeth A; Sharma, Ajay; Mohan, Rajiv R


    To develop an ex vivo equine corneal organ culture model. Specifically, to assess the equine cornea's extracellular matrix and cellularity after 7 days using two different culture techniques: either (i) immersion system or (ii) air/liquid interface system, to determine the best ex vivo equine corneal model. Fourteen healthy equine corneas of various breeds. Equine corneas with 2 mm of perilimbal sclera were freshly harvested from 7 horses undergoing humane euthanasia. One corneal-scleral ring (CSR) from each horse was randomly placed in the (i) immersion condition organ culture system (IC), with the contralateral CSR being placed in the (ii) air/liquid interface organ culture system (ALC) for 7 days. All corneas were evaluated using serial daily gross photography, histology, qPCR, and TUNEL assay. corneal-scleral rings placed in the IC (i) had complete loss of corneal transparency on gross photography by 7 days, showed a significant level of corneal stromal disorganization, significantly increased α-SMA levels on qPCR, and apoptosis on TUNEL assay compared to controls. The ALC (ii) had weak stromal disorganization on histopathologic examination and was not significantly different from normal equine corneal controls on all other evaluated parameters. The air-liquid interface organ culture system maintains the equine cornea's extracellular matrix and preserves corneal transparency, while the immersion condition results in near complete degradation of normal equine corneal architecture after 7 days in culture. The air-liquid organ culture is a viable option to maintain a healthy equine cornea in an ex vivo setting for wound healing studies. © 2016 American College of Veterinary Ophthalmologists.

  10. Pharmacologic strategies in the prevention and treatment of corneal transplant rejection. (United States)

    Tabbara, Khalid F


    Corneal transplantation remains one of the most successful organ transplantation procedures in humans. The unique structure of the cornea, with its absence of blood vessels and corneal lymphatic, allows the survival of corneal allograft. Recent advances in sutures, storage media, microsurgical instrumentation, and new pharmacological strategies have greatly improved the success of corneal transplantation and the prevention of corneal allograft rejection. Our strategies in the management and prevention of corneal graft rejection can modify and improve the survival of corneal allografts. Preoperative evaluation, understanding the risk factors, and management of ocular surface disorders may greatly improve the survival of the corneal transplant. Early recognition of corneal allograft rejection and aggressive treatment may improve the survival of the corneal graft. Furthermore, patients who undergo corneal transplantation should be maintained under close ophthalmic surveillance and patients should be informed to report immediately whenever symptoms of corneal graft rejection occur. The mainstay of therapy is topical corticosteroids. In severe cases, periocular, intravenous, and oral corticosteroids therapy can be rendered. New therapeutic modalities such as cyclosporine, tacrolimus, daclizumab, mycophenolate mofetil, leflunomide, rapamycin, and others may prove to be of help in the prevention and treatment of corneal graft rejection. Early recognition of corneal graft rejection and prompt treatment are mandatory for the successful survival of the corneal allograft.

  11. Methylene blue-related corneal edema and iris discoloration. (United States)

    Timucin, Ozgur Bulent; Karadag, Mehmet Fatih; Aslanci, Mehmet Emin; Baykara, Mehmet


    We report the case of a 70-year-old female patient who developed corneal edema and iris discoloration following the inadvertent use of 1% methylene blue instead of 0.025% trypan blue to stain the anterior capsule during cataract phacoemulsification surgery. Copious irrigation was performed upon realization of incorrect dye use. Corneal edema and iris discoloration developed during the early postoperative period and persisted at 24-months follow-up. However, keratoplasty was not required. The intracameral use of 1% methylene blue has a cytotoxic effect on the corneal endothelium and iris epithelium. Copious irrigation for at least 30 min using an anterior chamber maintainer may improve outcomes.

  12. Pseudomonas-induced corneal ulcers associated with contaminated eye mascaras. (United States)

    Wilson, L A; Ahearn, D G


    Seven Pseudomonas-induced corneal ulcers were associated with the use of four brands of mascara contaminated with P. aeruginosa. In laboratory studies, preservative systems of three of the four brands were inadequate in comparison with a control mascara of known antimicrobial activity. If the corneal epithelium is scratched during the application of mascara, particularly if the applicator is old, the cornea should be treated immediately and the mascara cultured to detect Pseudomonas. The high incidence of recurrent corneal ulceration in cases of Pseudomonas-induced keratitis indicates that initial chemotherapy should be intensive and maintained until the lesion stabilizes.

  13. Corneal perforation secondary to UV radiation from a tanning lamp. (United States)

    Funnell, Charlotte; Watson, Keith; Stewart, Owen; Dua, Gurcharan


    To report the case of a patient with keratoconus who developed a corneal perforation secondary to UV radiation from a tanning lamp. We believe this to be the first case of a corneal perforation secondary to UV radiation. The presentation and management of the patient and the pathophysiology of UV keratitis are discussed. Our patient developed a full-thickness corneal perforation after 30 minutes of tanning lamp exposure without eye protection. The cornea was temporized with cyanoacrylate tissue adhesive until penetrating keratoplasty could be performed. With an increased understanding of the pathophysiology of UV damage, treatment should be aimed at modulating the disease to reduce the likelihood of a poor outcome.

  14. Corneal endothelial cell density and morphology in healthy Turkish eyes. (United States)

    Arıcı, Ceyhun; Arslan, Osman Sevki; Dikkaya, Funda


    Purpose. To describe the normative values of corneal endothelial cell density, morphology, and central corneal thickness in healthy Turkish eyes. Methods. Specular microscopy was performed in 252 eyes of 126 healthy volunteers (M : F, 42 : 84). Parameters studied included mean endothelial cell density (MCD), mean cell area (MCA), coefficient of variation (CV) in cell size, percentage of hexagonal cells, and central corneal thickness (CCT). Results. The mean age of volunteers was 44.3 ± 13.5 (range, 20 to 70) years. There was a statistically significant decrease in MCD (P Filipino eyes and higher than that described in Indian, Thai, and Iranian eyes.

  15. Repositioning of pedicle conjunctival flap performed for refractory corneal ulcer. (United States)

    Sharma, Ashok; Mohan, Kanwar; Sharma, Rajan; Nirankari, Verinder S


    A 50-year-old male was referred with a previous history of conjunctival flap (CF) for a nonhealing fungal corneal ulcer with extreme corneal thinning in the right eye. The peritomy for the CF extended from 6:30 to 9:30 clock h on the cornea. The CF was disengaged, peritomy area deepithelialized, and CF was repositioned. He later underwent penetrating keratoplasty and achieved 20/40 best corrected visual acuity. The authors present a new concept for surgically repositioning CF s to the original site immediately after healing of the corneal ulcer.

  16. Causes of childhood blindness in the northeastern states of India

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    Bhattacharjee Harsha


    Full Text Available Background: The northeastern region (NER of India is geographically isolated and ethno-culturally different from the rest of the country. There is lacuna regarding the data on causes of blindness and severe visual impairment in children from this region. Aim: To determine the causes of severe visual impairment and blindness amongst children from schools for the blind in the four states of NER of India. Design and Setting: Survey of children attending special education schools for the blind in the NER. Materials and Methods: Blind and severely visually impaired children (best corrected visual acuity < 20/200 in the better eye, aged up to 16 years underwent visual acuity estimation, external ocular examination, retinoscopy and fundoscopy. Refraction and low vision workup was done where indicated. World Health Organization′s reporting form was used to code anatomical and etiological causes of visual loss. Statistical Analysis: Microsoft Excel Windows software with SPSS. Results: A total of 376 students were examined of whom 258 fulfilled the eligibility criteria. The major anatomical causes of visual loss amongst the 258 were congenital anomalies (anophthalmos, microphthalmos 93 (36.1%; corneal conditions (scarring, vitamin A deficiency 94 (36.7%; cataract or aphakia 28 (10.9%, retinal disorders 15 (5.8% and optic atrophy 14 (5.3%. Nearly half of the children were blind from conditions which were either preventable or treatable (48.5%. Conclusion: Nearly half the childhood blindness in the NER states of India is avoidable and Vitamin A deficiency forms an important component unlike other Indian states. More research and multisectorial effort is needed to tackle congenital anomalies.

  17. Infiltrados corneales asociados al uso de lentes de contacto Corneal infiltrates associated with contact lens wear

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    Vivian Padrón Álvarez


    Full Text Available Se estudiaron 15 pacientes que usan lentes de contacto rígidas, permeables al gas (LCRPG y lentes de contacto blandas (LCB que presentaron infiltrados corneales. Se realizó estudio microbiológico de las lesiones y seguimiento clínico de estos casos. En 3 de los casos estudiados el cultivo fue positivo a estafilococo aureus, el resto de los estudios microbiológicos fueron negativos. Todos los pacientes respondieron rápidamente al retirar la lente de contacto y al tratamiento con antibióticos tópicos y ninguno tuvo afectación permanente de la agudeza visual. El diagnóstico exacto y el manejo apropiado de los infiltrados corneales en pacientes que usan lentes de contacto es de gran importancia por la posibilidad de infección o de secuela visual permanente.15 patients wearing gas permeable rigid contact lenses (GPRCL and soft contanct lenses (SCL that presented corneal infiltrates were studied. A microbiological study of the injuries and a clinical follow-up of these cases were conducted. In 3 of the studied cases the culture was positive to Staphyloccocus aureus. The rest of the mircobiological studies were negative. All the patients responded rapidly to the contact lens removal and to the treatment with topical antibiotics. None of them had permanent affection of visual acuity. The accurate diagnosis and the appropiate management of the corneal infiltrates in patients wearing contact lenses is very important due to the possibility of infection or of permanent visual sequela.

  18. Corneal stromal demarcation line after collagen cross-linking in corneal ectatic diseases: a review of the literature

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    Spadea L


    Full Text Available Leopoldo Spadea, Emanuele Tonti, Enzo Maria Vingolo Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy Abstract: Collagen cross-linking (CXL is a relatively new conservative approach for progressive corneal ectasia, which is able to strengthen corneal tissue reforming new covalent bonds. Subjective and objective results following this method seem to be promising. In recent years, newer CXL protocols have been developed to perform more effective and less invasive procedures. The increasing diffusion of CXL in the corneal ectatic disease has increased the need to have actual indices regarding the efficacy of the treatment. Evaluation of demarcation line (DL, a transition zone between the cross-linked anterior corneal stroma and the untreated posterior corneal stroma, is considered a measurement of the depth of CXL treatment into the stroma. Some evidence in the literature emphasize that DL could be a measure of effectiveness of the CXL. On the contrary, some authors believe that the “the deeper, the better” principle is rather a simplistic approach for interpreting the clinical importance of the corneal stromal DL. Keywords: corneal cross-linking, demarcation line, keratoconus, ultraviolet A

  19. U.S. Multicenter Clinical Trial of Corneal Collagen Crosslinking for Treatment of Corneal Ectasia after Refractive Surgery. (United States)

    Hersh, Peter S; Stulting, R Doyle; Muller, David; Durrie, Daniel S; Rajpal, Rajesh K


    To evaluate the safety and efficacy of corneal collagen crosslinking (CXL) for the treatment of corneal ectasia after laser refractive surgery. Prospective, randomized, multicenter, controlled clinical trial. One hundred seventy-nine subjects with corneal ectasia after previous refractive surgery. The treatment group underwent standard CXL, and the sham control group received riboflavin alone without removal of the epithelium. The primary efficacy criterion was the change over 1 year of topography-derived maximum keratometry (K), comparing treatment with control groups. Secondary outcomes evaluated were corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent, endothelial cell count, and adverse events. In the crosslinking treatment group, the maximum K value decreased by 0.7 diopters (D) from baseline to 1 year, whereas there was continued progression in the control group (1.3 D difference between treatment and control, P Corneal haze was the most frequently reported crosslinking-related adverse finding. Corneal collagen crosslinking was effective in improving the maximum K value, CDVA, and UDVA in eyes with corneal ectasia 1 year after treatment, with an excellent safety profile. CXL is the first approved procedure to diminish progression of this ectatic corneal process. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

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

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    Mehmet Balcı


    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.

  1. Evolution in the use of intrastromal corneal ring segments for corneal ectasia. (United States)

    Park, Jennifer; Gritz, David C


    To report the recent advances in the use of intrastromal corneal ring segments (ICRS) for treating patients with corneal ectasia. ICRS improve visual, refractive, and keratometric parameters in patients with keratoconus and postlaser in-situ keratomileusis ectasia. ICRS have been made safer, quicker, and more precise with the use of femtosecond lasers for ring insertion. ICRS produce better visual outcomes in patients with poor preoperative corrected distance visual acuity compared with patients with less preoperative visual impairment. Standard ICRS do not improve vision in patients with stage 3-4 keratoconus (Amsler-Krumeich classification), but newer models of ICRS, such as Intacs SK, appear promising for these patients. ICRS have been successfully combined with treatments such as corneal collagen cross-linking (CXL), penetrating keratoplasty, and photorefractive keratectomy. ICRS variably improve visual acuity. Numerous questions concerning ICRS remain, including the duration of the effects of ICRS and the changes that ICRS induce on a biomechanical level. The optimal method for combined CXL and ICRS placement has not yet been determined. Further well-designed randomized controlled studies with long-term follow-up are needed for clarification.

  2. Depósitos corneales de ciprofloxacino Corneal deposits of ciprofloxacin

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    Taimi Cárdenas Díaz


    Full Text Available Las fluoroquinolonas son ampliamente utilizadas para el tratamiento de infecciones oculares bacterianas, ya que tienen actividad tanto para grampositivos, como para gramnegativos. Son fármacos seguros, pero se han descrito depósitos blancos cristalinianos en pacientes con administración frecuente y prolongada;en la mayoría de los casos, ellos resuelven de forma lenta al interrumpir el tratamiento. Si esto no ocurre, los depósitos se deben desbridar. Se ilustran 3 casos operados de catarata que llevaron tratamiento con ciprofloxacino en el posoperatorio, en los cuales se presentaron depósitos corneales y aunque disminuyó la agudeza visual, esta se recuperó después de la queratectomía.Fluoroquinolones are broadly used for the treatment of bacterial ocular infections, since they can act upon both grampositive and gramnegative bacteria. They are safe drugs, but white corneal deposits have been described in patients who frequently take this drug for a long period of time. In most of the cases, the deposits disappear slowly after the treatment is interrupted. If this does not happen, the deposits should be eliminated. Three cases operated on from cataract were presented, who had been taken ciprofloxacin in the postoperative stage and had corneal deposits. Although their visual acuity decreased, it recovered after keratectomy.

  3. Validation of Na,K-ATPase pump function of corneal endothelial cells for corneal regenerative medicine. (United States)

    Hatou, Shin; Higa, Kazunari; Inagaki, Emi; Yoshida, Satoru; Kimura, Erika; Hayashi, Ryuhei; Tsujikawa, Motokazu; Tsubota, Kazuo; Nishida, Kohji; Shimmura, Shigeto


    Tissue-engineering approaches to cultivate corneal endothelial cells (CECs) or induce CECs from stem cells are under investigation for the treatment of endothelial dysfunction. Before clinical application, a validation method to determine the quality of these cells is required. In this study, we quantified the endothelial pump function required for maintaining the corneal thickness using rabbit CECs (RCECs) and a human CEC line (B4G12). The potential difference of RCECs cultured on a permeable polyester membrane (Snapwell), B4G12 cells on Snapwell, or B4G12 cells on a collagen membrane (CM6) was measured by an Ussing chamber system, and the effect of different concentrations of ouabain (Na,K-ATPase specific inhibitor) was obtained. A mathematical equation derived from the concentration curve revealed that 2 mM ouabain decreases pump function of RCECs to 1.0 mV, and 0.6 mM ouabain decreases pump function of B4G12 on CM6 to 1.0 mV. Ouabain injection into the anterior chamber of rabbit eyes at a concentration of pump function >1.0 mV is required to maintain the corneal thickness. These results can be used for standardization of CEC pump function and validation of tissue-engineered CEC sheets for clinical use.

  4. Generation of corneal epithelial cells from induced pluripotent stem cells derived from human dermal fibroblast and corneal limbal epithelium.

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    Ryuhei Hayashi

    Full Text Available Induced pluripotent stem (iPS cells can be established from somatic cells. However, there is currently no established strategy to generate corneal epithelial cells from iPS cells. In this study, we investigated whether corneal epithelial cells could be differentiated from iPS cells. We tested 2 distinct sources: human adult dermal fibroblast (HDF-derived iPS cells (253G1 and human adult corneal limbal epithelial cells (HLEC-derived iPS cells (L1B41. We first established iPS cells from HLEC by introducing the Yamanaka 4 factors. Corneal epithelial cells were successfully induced from the iPS cells by the stromal cell-derived inducing activity (SDIA differentiation method, as Pax6(+/K12(+ corneal epithelial colonies were observed after prolonged differentiation culture (12 weeks or later in both the L1B41 and 253G1 iPS cells following retinal pigment epithelial and lens cell induction. Interestingly, the corneal epithelial differentiation efficiency was higher in L1B41 than in 253G1. DNA methylation analysis revealed that a small proportion of differentially methylated regions still existed between L1B41 and 253G1 iPS cells even though no significant difference in methylation status was detected in the specific corneal epithelium-related genes such as K12, K3, and Pax6. The present study is the first to demonstrate a strategy for corneal epithelial cell differentiation from human iPS cells, and further suggests that the epigenomic status is associated with the propensity of iPS cells to differentiate into corneal epithelial cells.

  5. Inflammatory cytokine TNF-α promotes corneal endothelium apoptosis via upregulating TIPE2 transcription during corneal graft rejection. (United States)

    Wang, Qun; Wei, Chao; Ma, Li; Wang, Xin; Li, Lin; Zhou, Qingjun; Shi, Weiyun


    Endothelial dysfunction accounts for 50% of total corneal transplantation failures, suggesting that corneal endothelial damage is the leading cause of graft failure. Tumor necrosis factor-α (TNF-α) is known to contribute to the negative regulation of corneal transplantation, but how it does so remains unclear. Here, we report a regulatory loop involving TNF-α, TNF-α-induced protein 8 like 2 (TNFAIP8L2 or TIPE2), and apoptosis during corneal graft rejection. We established mice models of penetrating keratoplasty to verify whether the quantification of TNF-α in allogeneic corneas is enhanced through ELISA assay and immunofluorescence staining. In cornea tissues, we obtained corneal endothelium and measured apoptosis of the removed cells. Meanwhile, quantitative real-time PCR and Western blotting were used to detect the mRNA and protein expression of TIPE2. In human corneal endothelial cells, we verified the conclusions through some experiments. By specifically knocking down TIPE2, we detected the importance of TIPE2 in TNF-α-triggered apoptosis. In mice models, TNF-α was higher in the cornea and aqueous humor in allograft group and TNF-α elevation increased the apoptosis of the corneal endothelium. In addition, high levels of TIPE2 were found in allograft rejection models following TNF-α elevation. In human corneal endothelial cells (HCECs), TNF-α clearly augments TIPE2 expression and promotes cell apoptosis through upregulating TIPE2 transcription. Knocking down markedly decreased cell apoptosis. Our study identifies the molecular mechanisms underlying the interplay of TNF-α, TIPE2, and apoptosis during allograft rejection, and it suggests that both TNF-α and TIPE2 might be potential targets for the successfully grafted corneal endothelium.

  6. Self-Complementary Adeno-Associated Virus Vectors Improve Transduction Efficiency of Corneal Endothelial Cells.

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    Anja K Gruenert

    Full Text Available Transplantation of a donor cornea to restore vision is the most frequently performed transplantation in the world. Corneal endothelial cells (CEC are crucial for the outcome of a graft as they maintain corneal transparency and avoid graft failure due to corneal opaqueness. Given the characteristic of being a monolayer and in direct contact with culture medium during cultivation in eye banks, CEC are specifically suitable for gene therapeutic approaches prior to transplantation. Recombinant adeno-associated virus 2 (rAAV2 vectors represent a promising tool for gene therapy of CEC. However, high vector titers are needed to achieve sufficient gene expression. One of the rate-limiting steps for transgene expression is the conversion of single-stranded (ss- DNA vector genome into double-stranded (ds- DNA. This step can be bypassed by using self-complementary (sc- AAV2 vectors. Aim of this study was to compare for the first time transduction efficiencies of ss- and scAAV2 vectors in CEC. For this purpose AAV2 vectors containing enhanced green fluorescent protein (GFP as transgene were used. Both in CEC and in donor corneas, transduction with scAAV2 resulted in significantly higher transgene expression compared to ssAAV2. The difference in transduction efficiency decreased with increasing vector titer. In most cases, only half the vector titer of scAAV2 was required for equal or higher gene expression rates than those of ssAAV2. In human donor corneas, GFP expression was 64.7±11.3% (scAAV and 38.0±8.6% (ssAAV (p<0.001, respectively. Furthermore, transduced cells maintained their viability and showed regular morphology. Working together with regulatory authorities, a translation of AAV2 vector-mediated gene therapy to achieve a temporary protection of corneal allografts during cultivation and transplantation could therefore become more realistic.

  7. Prevalence and causes of functional low vision and implications for services: the Pakistan National Blindness and Visual Impairment Survey. (United States)

    Shah, Shaheen P; Minto, Hasan; Jadoon, Mohammad Z; Bourne, Rupert R A; Dineen, Brendan; Gilbert, Clare E; Khan, Mohammad D


    To determine the prevalence and causes of functional low vision (FLV) and total blindness and to estimate the assessment needs for low-vision services in Pakistan. Multistage, cluster random sampling was used to select a nationally representative sample of adults (age, > or =30 years). Participants underwent visual acuity measurement and detailed ophthalmic examination. Functional low vision was defined as a corrected visual acuity in the better eye of less than 6/18 to more than no perception of light (NPL) in individuals with untreatable causes of visual loss. Total blindness was defined as NPL in both eyes. Needs assessments were categorized into three groups: optical services, nonoptical/environmental interventions, and rehabilitation. A sample of 16,507 adults (95.3% response rate) was examined. The standardized prevalence of FLV and total blindness were 1.7% (95% CI: 1.5%-1.9%) and 0.2% (95% CI: 0.1%-0.2%), respectively. More than 90% of those with FLV were illiterate and 35.3% were of working age (i.e., Pakistan had FLV. Retinal conditions were the commonest cause in urban populations (39.8% vs. 26.5% rural) compared with corneal opacity in rural areas (38.0% vs. 25.5% urban). It was estimated that 565,000 adults require assessment for optical services, 735,000 for nonoptical interventions, and 424,000 for rehabilitation. As VISION 2020 enters its second 5-year phase, the provision of low-vision services and their integration into national eyecare programs is a priority. In Pakistan, planning must take account of the magnitude along with the demographic and educational characteristics of those affected.

  8. Static analysis for blinding

    DEFF Research Database (Denmark)

    Nielsen, Christoffer Rosenkilde; Nielson, Hanne Riis


    operation blinding. In this paper we study the theoretical foundations for one of the successful approaches to validating cryptographic protocols and we extend it to handle the blinding primitive. Our static analysis approach is based on Flow Logic; this gives us a clean separation between the specification...

  9. Corneal sensation in scleritis and episcleritis. (United States)

    Lyne, A. J.


    A series of 59 patients were examined for loss of corneal sensitivity. Thirty-five of them suffered from scleritis and 24 suffered from episcleritis. There was a difference between the 2 conditions in that significantly more patients with scleritis were affected than patients with episcleritis. It was also found that among the scleritis patients there was a close relationship between the number of quadrants affected and decrease in sensitivity. Five patients had necrotising scleritis, and they all showed marked loss of sensitivity. Sensitivity returned to normal when the scleritis resolved except when a large area of scleral ectasia resulted. The test is of importance because it is one of the easiest methods of detecting the onset of necrotising scleritis in its earliest stages. Images PMID:588518

  10. Morphological evaluation of normal human corneal epithelium.

    DEFF Research Database (Denmark)

    Ehlers, Niels; Heegaard, Steffen; Hjortdal, Jesper Østergaard


    of corneas from 100 consecutively selected paraffin-embedded eyes were stained with hematoxylin-eosin and Periodic Acid-Schiff (PAS). All specimens were evaluated by light microscopy. The eyes were enucleated from patients with choroidal melanoma. Corneas were considered to be normal. RESULTS: Ninety of 100...... eyes were evaluated. The central epithelial, stromal and total corneal thickness was measured as 36.0 µm, 618 µm and 651µm, respectively, with a variation coefficient from 0.21 to 0.22. Pathological appearances were found in 27% of corneas, including thickened basement membrane and alterations....... The high number of pathological observations suggests that 'normal' eyes harbour and potentially accumulate considerable pathology....

  11. Another Risk From Cigarette Smoking: Corneal Burn

    Directory of Open Access Journals (Sweden)

    Volkan Hürmeriç


    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

  12. Higher-order aberrations after corneal collagen crosslinking for keratoconus and corneal ectasia. (United States)

    Greenstein, Steven A; Fry, Kristen L; Hersh, Matthew J; Hersh, Peter S


    To determine changes in higher-order aberrations (HOAs) after corneal collagen crosslinking (CXL). Cornea and refractive surgery practice. Prospective randomized controlled clinical trial. Corneal and ocular HOAs were measured and analyzed using the Pentacam device and Ladarwave aberrometer, respectively, at baseline and 12 months after CXL. Ninety-six eyes (64 keratoconus, 32 ectasia) of 73 patients had CXL. A fellow-eye control group comprised 42 eyes. The mean preoperative total anterior corneal HOAs, total coma, 3rd-order coma, and vertical coma were 4.68 μm ± 2.33 (SD), 4.40 ± 2.32 μm, 4.36 ± 2.30 μm, and 4.04 ± 2.27 μm, respectively. At 1 year, the mean values decreased significantly to 4.27 ± 2.25 μm, 4.01 ± 2.29 μm, 3.96 ± 2.27 μm, and 3.66 ± 2.22 μm, respectively (all Pcorneal HOAs. The mean preoperative total ocular HOAs, total coma, 3rd-order coma, trefoil, and spherical aberration were 2.80 ± 1.0 μm, 2.60 ± 1.03 μm, 2.57 ± 1.03 μm, 0.98 ± 0.46 μm, and 0.90 ± 0.42 μm, respectively. At 1 year, the mean values decreased significantly to 2.59 ± 1.06 μm, 2.42 ± 1.07 μm, 2.39 ± 1.07 μm, 0.88 ± 0.49 μm, and 0.83 ± 0.38 μm, respectively (all P=.01). After CXL, HOAs were significantly improved compared with the control group. Changes in HOAs were not statistically associated with an improvement in visual acuity or most subjective visual symptoms, however. Corneal and ocular HOAs decreased after CXL, suggesting an improvement in corneal shape. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  13. Stereoacuity after small aperture corneal inlay implantation

    Directory of Open Access Journals (Sweden)

    Linn SH


    Full Text Available Steven H Linn,1 David F Skanchy,2 Tyler S Quist,3 Jordan D Desautels,4 Majid Moshirfar1,5 1Department of Clinical Research, HDR Research Center, Hoopes Vision, Draper, UT, 2McGovern Medical School, The University of Texas Health Science Center at Houston, TX, 3University of Utah School of Medicine, Salt Lake City, UT, 4Tufts University School of Medicine, Boston, MA, 5John A Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, USA Purpose: The aim of this study was to compare stereoacuity before and after KAMRA corneal inlay implantation for the correction of presbyopia.Patients and methods: This is a prospective study of 60 patients who underwent KAMRA inlay implantation. Patients were examined before and 6 months after surgery for stereoacuity, uncorrected distance visual acuity (UDVA, and uncorrected near visual acuity (UNVA.Results: The mean stereoacuity before surgery was 29.5±28.1 arcsec (range: 20–200 and at 6 months was 29.8±26.4 arcsec (range: 20–200. The decline in stereoacuity was not statistically significant. At 6 months follow-up, UDVA was 20/25 or better in all 60 patients and UNVA was J2 (20/25 or better in 51 (85% patients.Conclusion: There is no significant change in stereoacuity following KAMRA inlay implantation. The KAMRA inlay is a good treatment option for improving near vision in presbyopic patients while preserving stereoacuity and distance vision. Keywords: KAMRA, corneal inlay, AcuFocus, stereoacuity, presbyopia 

  14. Clinical utility of the KAMRA corneal inlay

    Directory of Open Access Journals (Sweden)

    Naroo SA


    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

  15. Tear Mediators in Corneal Ectatic Disorders.

    Directory of Open Access Journals (Sweden)

    Dorottya Pásztor

    Full Text Available To compare the concentrations of 11 tear mediators in order to reveal the biochemical difference between pellucid marginal degeneration (PMD and keratoconus (KC.We have designed a cross-sectional study in which patients with corneal ectasia based on slit-lamp biomicroscopy and Pentacam HR (keratometry values (K1, K2, Kmax, astigmatism, minimal radius of curvature (Rmin, corneal thickness (Apex and Min, indices (surface variation, vertical asymmetry, keratoconus, central keratoconus, height asymmetry and decentration were enrolled. Eyes of keratoconic patients were similar to the PMD patients in age and severity (K2, Kmax and Rmin. Non-stimulated tear samples were collected from nine eyes of seven PMD patients, 55 eyes of 55 KC patients and 24 eyes of 24 healthy controls. The mediators' (interleukin -6, -10, chemokine ligand 5, -8, -10, matrix metalloproteinase (MMP -9, -13, tissue inhibitor of metalloproteinases (TIMP-1, tissue plasminogen activator, plasminogen activator inhibitor, nerve growth factor concentrations were measured using Cytometric Bead Array.MMP-9 was the only mediator which presented relevant variances between the two patient groups (p = 0.005. The ratios of MMP-9 and TIMP-1 were 2.45, 0.40 and 0.23 in PMD, KC and the controls, respectively.As far as we are aware, this is the first study that aims to reveal the biochemical differences between PMD and KC. Further studies of biomarkers to investigate the precise role of these mediators need to be defined, and it is important to confirm the observed changes in a larger study to gain further insights into the molecular alterations in PMD.

  16. Blinded by Irrelevance: Pure Irrelevance Induced "Blindness" (United States)

    Eitam, Baruch; Yeshurun, Yaffa; Hassan, Kinneret


    To what degree does our representation of the immediate world depend solely on its relevance to what we are currently doing? We examined whether relevance per se can cause "blindness," even when there is no resource limitation. In a novel paradigm, people looked at a colored circle surrounded by a differently colored ring--the task relevance of…

  17. Comparison of scleral and corneal Tono-Pen readings. (United States)

    Kolin, Talia; Wedemeyer, Linda L; Kolin, Elliot; Braun, Yosi


    To compare scleral Tono-Pen (Medtronic Solan, Jacksonville, FL) readings to corneal Tono-Pen readings. Intraocular pressure (IOP) was measured prospectively in 72 eyes of 37 adult patients and in 10 eyes of 5 children. Measurements were taken on the central cornea and on the sclera. Recorded measurements were within 5% confidence levels by Tono-Pen. Corneal IOP ranged from 10 to 28 mm Hg (mean +/- standard deviation, 17.0 +/- 3.8 mm Hg). Scleral measurements ranged from 4 to 99 mm Hg (40.4 +/- 23.0 mm Hg). Scleral measurements ranged from 11 mm Hg lower to 76 mm Hg higher than corneal measurements. Tono-Pen readings obtained from sclera are of no clinical value and should not be used to approximate corneal IOP.

  18. Unilateral keratectasia treated with femtosecond fashioned intrastromal corneal inlay

    Directory of Open Access Journals (Sweden)

    Khosrow Jadidi


    conclusion: Femtosecond laser–assisted pocket creation for the implantation of corneal inlays offers accuracy of pocket parameters, enhancing predictability, resulting in better final outcomes, and improving the safety of the procedure.

  19. Corneal epithelium and UV-protection of the eye. (United States)

    Ringvold, A


    To study UV-absorption and UV-induced fluorescence in the bovine corneal epithelium. Spectrophotometry and spectrofluorimetry. The corneal epithelium absorbs UV-B radiation mainly owing to its content of protein, RNA, and ascorbate. Some of the absorbed energy is transformed to the less biotoxic UV-A radiation by fluorescence. RNA and ascorbate reduce tissue fluorescence. The corneal epithelium acts as a UV-filter, protecting internal eye structures through three different mechanisms: (1) Absorption of UV-B roughly below 310 nm wavelength. (2) Fluorescence-mediated ray transformation to longer wavelengths. (3) Fluorescence reduction. The extremely high ascorbate concentration in the corneal epithelium has a key role in two of these processes.

  20. Excimer laser corneal surgery and free oxygen radicals. (United States)

    Bilgihan, K; Bilgihan, A; Akata, F; Hasanreisoğlu, B; Türközkan, N


    Corneal photoablation with 193 nm argon fluoride excimer laser is a new technique for the treatment of refractive errors and for removing corneal opacities and irregularities. Ultraviolet radiation and thermal injury induce free radical formation in the tissues. The aim of this study was to confirm the production of free radicals by excimer laser photoablation in rabbits. The thermal changes of the posterior corneal surface were recorded during excimer laser photoablation. The lipid peroxide (LPO) levels and superoxide dismutase (SOD) activities of aqueous humour were measured after excimer laser keratectomy. The aqueous LPO levels were not changed after excimer laser ablation, but both the thermal increase in the cornea during the photoablation and the decreased aqueous SOD activities suggest that free radicals are formed in the cornea during excimer laser keratectomy, and that they may be responsible for some of the complications of excimer laser corneal surgery.

  1. Corneal ulcers: For the general practitioner | Ballim | Continuing ...

    African Journals Online (AJOL)

    Abstract. A corneal ulcer is a defect in the epithelial layer of the cornea. e general practitioner may play an important role in early management and appropriate referral. Incidence varies and depends on aetiology.

  2. Cataract Surgery with a Refractive Corneal Inlay in Place


    Stojanovic, N. R.; Panagopoulou, S. I.; Pallikaris, I. G.


    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 bot...

  3. [Diagnostic value of confocal microscopy in primary corneal ectasia]. (United States)

    Egorova, G B; Rogova, A Ia; Mitichkina, T S


    Diagnostic value of confocal microscopy in subclinical corneal ectasia is analysed. Morphological changes were revealed in 71.2% of cases with subclinical keratoconus. Results of the study let us reveal typical morphological abnormalities in subclinical keratoconus, although these changes are not specific for this condition. The method is also not informative for detecting of early signs of pellucid marginal degeneration. Confocal microscopy may be considered an additional specifying method in diagnostic algorithm of subclinical corneal ectasia.

  4. [The use of iontophoresis in corneal crosslinking technique]. (United States)

    Stanca, Horia T; Tabacaru, Bogdana


    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. Serum zinc in corneal ulcer-A preliminary report

    Directory of Open Access Journals (Sweden)

    Pati Santanu


    Full Text Available In recent times zinc is emerging as a nutrient of clinical importance and had been found to be low in serum in various disease conditions. In the current study 11 control cases and 22 corneal ulcer cases were taken. Their serum zinc level was measured by atomic absorption spectrophotometer. Serum zinc level in recalcitrant corneal ulcer cases was found to be below normal.

  6. Second-hand cigarette smoke inhibits wound healing of the cornea by stimulating inflammation that delays corneal reepithelialization. (United States)

    Ma, Chongze; Martins-Green, Manuela


    Corneal reepithelialization is a key process in preventing abnormal cornea healing and impaired vision. To gain insight into the mechanisms of cigarette smoke-induced corneal epithelial damage, we injured the cornea of mice and exposed the wounds during the healing process to cigarette smoke in a system that mimics second-hand cigarette smoking by humans. Immunolabeling studies showed that in the mice exposed to smoke, fibronectin, an extracellular matrix molecule critical for epithelial cell migration, is not present in the wounded area and that there is an accumulation of neutrophils in the stroma beneath the wound. Furthermore, inflammatory cytokines, such as interleukin-1alpha, increase after injury in the second-hand-smoke-exposed mice. Localized treatment of the wounds with dexamethasone, an anti-inflammatory agent, resulted in improved healing and infiltration of fewer neutrophils into the wounded area. Depletion of neutrophils with nitrogen mustard or treatment of the wounds with proteinase inhibitors have similar effects to those of dexamethasone. In conclusion, the work presented here shows that second-hand cigarette smoke delays corneal reepithelialization and healing by stimulating both neutrophil attraction to the wound site and degradation of extracellular matrix and adhesion molecules that are important for corneal epithelial cell adhesion and migration.

  7. Clinical effects of conjunctival sac flushing using different concentration of povidoneiodine on corneal epithelium before cataract surgeries

    Directory of Open Access Journals (Sweden)

    Xue-Lian Gu


    Full Text Available AIM:To determine the most optimal concentration of the safe usage of povidone-iodine(PVP-Iin the flushing to disinfect the conjunctive sac before cataract surgeries, in order to provide a scientific basis for clinical eye surgery work.METHODS:Sixty-two patients with phacoemulsification and intraocular lens implantation in our hospital from October 2012 to October 2014 were randomly divided into 0.25g/L PVP-I group(Ⅰand 5g/L PVP-I group(Ⅱ. Sterilizing effect and the complications postoperative were analyzed.RESULTS:The sterilizing effects of the two groups after flushing conjunctiva sac using different concentrations of PVP-I were both remarkable, but the difference between the two groups was not statistically significant(P>0.05. No endophthalmitis occurred in the two groups. Observing the corneal condition after rinsing, no severe conjunctival hyperemia, corneal edema and other serious complications occurred. There was slightly punctate corneal epithelial shedding in groupⅡ, and the difference was statistically significant(PPCONCLUSION:Using 0.25g/L PVP-I in the conjunctiva sac rinsing before surgeries can inhibit the growth of bacteria in the conjunctival sac, reduce the impact on the corneal epithelium thereby reducing the incidence of postoperative complications and the positive rate of bacterial culture, increasing the comfort degree of patients, bringing a better area for the surgeries.

  8. Decreased corneal sensation as an initial feature of Acanthamoeba keratitis. (United States)

    Perry, H D; Donnenfeld, E D; Foulks, G N; Moadel, K; Kanellopoulos, A J


    Herpes simplex keratitis is the most common misdiagnosis in patients with Acanthamoeba keratitis, which is increasing in frequency and is associated with daily wear soft contact lenses. Both entities usually present as unilateral keratitis. The manifestations of superficial Acanthamoeba keratitis (i.e., unilaterality, dendriform appearance, positive response to antivirals, and decreased corneal sensation) increase the opportunity for misdiagnosis as herpes simplex keratitis. The authors have encountered six patients with Acanthamoeba keratitis in whom the correct diagnosis was delayed from 2 weeks to 3 months. All six patients underwent testing with the Cochet-Bonnet esthesiometer and extensive pharmacologic treatment for herpes simplex keratitis. Corneal scrapings were taken between 2 and 6 weeks after the initial examination. In all six patients, corneal sensation was decreased significantly. Drug therapy was ineffective. Cultures were positive for Acanthamoeba. Five of six patients underwent penetrating keratoplasty. Decreased corneal sensation has contributed to the misdiagnosis of Acanthamoeba as herpes simplex keratitis. Misdiagnosis results in delayed treatment and worse outcome. The authors found that significantly decreased corneal sensation is a frequent finding in early Acanthamoeba keratitis. Therefore, physicians should consider Acanthamoeba keratitis as an alternative diagnosis in patients with presumed herpes simplex keratitis with decreased corneal sensation.

  9. Unilateral corneal ectasia following small-incision lenticule extraction. (United States)

    Sachdev, Gitansha; Sachdev, Mahipal S; Sachdev, Ritika; Gupta, Hemlata


    We describe a case of unilateral corneal ectasia in a 26-year-old man following small-incision lenticule extraction. The preoperative corneal topography was normal, with a minimum corneal thickness of 511 μm and 513 μm in the right eye and left eye, respectively. Lenticules of 85 μm and 82 μm were fashioned to offer a refractive correction of -3.75 -1.50 × 180 and -3.50 -1.50 × 165 in the right eye and left eye, respectively. Twelve months after small-incision lenticule extraction, the patient presented with early signs of ectasia in the left eye on corneal topography, which had worsened at the 18-month examination. Intrastromal corneal ring segment implantation with corneal collagen crosslinking was performed to arrest further progression and to improve uncorrected distance visual acuity. On the last examination, the corrected distance visual acuity was 20/20(-2). Dr. Mahipal S. Sachdev receives travel grants from Carl Zeiss Meditec AG. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  10. Congenital Corneal Anesthesia and Neurotrophic Keratitis: Diagnosis and Management

    Directory of Open Access Journals (Sweden)

    Flavio Mantelli


    Full Text Available Neurotrophic keratitis (NK is a rare degenerative disease of the cornea caused by an impairment of corneal sensory innervation, characterized by decreased or absent corneal sensitivity resulting in epithelial keratopathy, ulceration, and perforation. The aetiopathogenesis of corneal sensory innervation impairment in children recognizes the same range of causes as adults, although they are much less frequent in the pediatric population. Some extremely rare congenital diseases could be considered in the aetiopathogenesis of NK in children. Congenital corneal anesthesia is an extremely rare condition that carries considerable diagnostic and therapeutic problems. Typically the onset is up to 3 years of age and the cornea may be affected in isolation or the sensory deficit may exist as a component of a congenital syndrome, or it may be associated with systemic somatic anomalies. Accurate diagnosis and recognition of risk factors is important for lessening long-term sequelae of this condition. Treatment should include frequent topical lubrication and bandage corneal or scleral contact lenses. Surgery may be needed in refractory cases. The purpose of this review is to summarize and update data available on congenital causes and treatment of corneal hypo/anesthesia and, in turn, on congenital NK.

  11. Effects of two different incision phacoemulsification on corneal astigmatism

    Directory of Open Access Journals (Sweden)

    Lu Huo


    Full Text Available AIM:To compare the effect of different incision in corneal astigmatism after phacoemulsification. METHODS: Totally 88 cases(122 eyeswith pure cataract were randomly divided into two groups. Forty cases(60 eyeswere clarity corneal incision in group A, and 48 cases(62 eyeswere sclera tunnel incision in group B. Mean corneal astigmatism, surgically induced astigmatism(SIA, uncorrected visual acuity(UCVAand best correct vision acuity(BCVAwere observed in pre- and post-operation at 1d; 1wk; 1mo.RESULTS: The mean astigmatism had statistically significant difference between two groups at 1d; 1wk; 1mo after operation(PPP>0.05. UCVA≥0.5 and BCVA≥0.8 had statistically significant difference at 1d; 1wk(PP>0.05.CONCLUSION: Phacoemulsification with scleral tunnel incision remove combined intraocular lens(IOLimplantation has small changes to corneal astigmatism. By selecting personalized corneal incision according to the corneal topography might be more beneficial.

  12. Inhibition of Corneal Neovascularization by Topical and Subconjunctival Tigecycline

    Directory of Open Access Journals (Sweden)

    Sertan Goktas


    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.

  13. Acacia honey accelerates in vitro corneal ulcer wound healing model. (United States)

    Abd Ghafar, Norzana; Ker-Woon, Choy; Hui, Chua Kien; Mohd Yusof, Yasmin Anum; Wan Ngah, Wan Zurinah


    The study aimed to evaluate the effects of Acacia honey (AH) on the migration, differentiation and healing properties of the cultured rabbit corneal fibroblasts. Stromal derived corneal fibroblasts from New Zealand White rabbit (n = 6) were isolated and cultured until passage 1. In vitro corneal ulcer was created using a 4 mm corneal trephine onto confluent cultures and treated with basal medium (FD), medium containing serum (FDS), with and without 0.025 % AH. Wound areas were recorded at day 0, 3 and 6 post wound creation. Genes and proteins associated with wound healing and differentiation such as aldehyde dehydrogenase (ALDH), vimentin, alpha-smooth muscle actin (α-SMA), collagen type I, lumican and matrix metalloproteinase 12 (MMP12) were evaluated using qRT-PCR and immunocytochemistry respectively. Cells cultured with AH-enriched FDS media achieved complete wound closure at day 6 post wound creation. The cells cultured in AH-enriched FDS media increased the expression of vimentin, collagen type I and lumican genes and decreased the ALDH, α-SMA and MMP12 gene expressions. Protein expression of ALDH, vimentin and α-SMA were in accordance with the gene expression analyses. These results demonstrated AH accelerate corneal fibroblasts migration and differentiation of the in vitro corneal ulcer model while increasing the genes and proteins associated with stromal wound healing.

  14. Corneal Cross-linking to Halt the Progression of Keratoconus and Corneal Ectasia: Seven-Year Follow-up. (United States)

    O'Brart, David P S; Patel, Parul; Lascaratos, Gerassimos; Wagh, Vijay K; Tam, Connan; Lee, Jennifer; O'Brart, Naomi A


    To determine long-term efficacy and safety of riboflavin/ultraviolet A corneal cross-linking (CXL). Prospective cohort study. Thirty-six patients (36 eyes) who underwent epithelium-off CXL at a University Hospital (Guy's and St Thomas' National Health Service Foundation Trust) 6-8 years previously were examined. The main outcome measures were refractive error, visual acuity, corneal topographic keratometry, ultrasonic pachymetry, and topography-derived corneal wavefront. At 7 years compared to preoperative values, mean spherical equivalent refractive error (SEQ) increased by +0.78 diopter (D) (P corneal cross-linking, improvements in topographic and wavefront parameters evident at 1 year were seen to continue to improve at 5 years and were maintained at 7 years. No treated eyes progressed over the 7-year follow-up period. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Iterated Gate Teleportation and Blind Quantum Computation. (United States)

    Pérez-Delgado, Carlos A; Fitzsimons, Joseph F


    Blind quantum computation allows a user to delegate a computation to an untrusted server while keeping the computation hidden. A number of recent works have sought to establish bounds on the communication requirements necessary to implement blind computation, and a bound based on the no-programming theorem of Nielsen and Chuang has emerged as a natural limiting factor. Here we show that this constraint only holds in limited scenarios, and show how to overcome it using a novel method of iterated gate teleportations. This technique enables drastic reductions in the communication required for distributed quantum protocols, extending beyond the blind computation setting. Applied to blind quantum computation, this technique offers significant efficiency improvements, and in some scenarios offers an exponential reduction in communication requirements.

  16. Evaluation of subbasal nerve morphology and corneal sensation after accelerated corneal collagen cross-linking treatment on keratoconus. (United States)

    Ozgurhan, Engin Bilge; Celik, Ugur; Bozkurt, Ercument; Demirok, Ahmet


    The aim of this study was to report on the evaluation of corneal nerve fiber density and corneal sensation after accelerated corneal collagen cross-linking on keratoconus patients. The study was performed on 30 keratoconus eyes (30 participants: 16 M, 14 F; 17-32 years old) treated with accelerated collagen cross-linking for disease stabilization. Mean outcome measures were corneal sensation evaluation by Cochet-Bonnet esthesiometry and subbasal nerve fiber density assessment by corneal in vivo confocal microscopy. All corneal measurements were performed using scanning slit confocal microscopy (ConfoScan 4, Nidek Technologies, Padova, Italy). The accelerated corneal collagen cross-linking procedure was performed on 30 eyes of 30 patients (19 right, 63.3%; 11 left, 27.7%). The mean age was 23.93 ± 4. The preoperative mean keratometry, apex keratometry and pachymetry values were 47.19 ± 2.82 D, 56.79 ± 5.39 and 426.1 ± 25.6 μm, respectively. Preoperative mean corneal sensation was 56.3 ± 5.4 mm (with a range from 40 to 60 mm), it was significantly decreased at 1st and 3rd month visit and increased to preoperative values after 6th month visit. Preoperative mean of subbasal nerve fiber density measurements was 22.8 ± 9.7 nerve fiber/mm(2) (with a range of 5-45 mm), it was not still at the preoperative values at 6th month (p = 0.0001), however reached to the preoperative values at 12th month (p = 0.914). Subbasal nerve fibers could reach the preoperative values at the 12th month after accelerated corneal collagen cross-linking treatment although the corneal sensation was improved at 6th month. These findings imply that the subjective healing process is faster than the objective evaluation of the keratoconus patients' cornea treated with accelerated corneal collagen cross-linking.

  17. Construction of Anterior Hemi-Corneal Equivalents Using Nontransfected Human Corneal Cells and Transplantation in Dog Models. (United States)

    Xu, Bin; Song, Zhan; Fan, Tingjun


    Tissue-engineered human anterior hemi-cornea (TE-aHC) is a promising equivalent for treating anterior lamellar keratopathy to surmount the severe shortage of donated corneas. This study was intended to construct a functional TE-aHC with nontransfected human corneal stromal (ntHCS) and epithelial (ntHCEP) cells using acellular porcine corneal stromata (aPCS) as a carrier scaffold, and evaluate its biological functions in a dog model. To construct a TE-aHC, ntHCS cells were injected into an aPCS scaffold and cultured for 3 days; then, ntHCEP cells were inoculated onto the Bowman's membrane of the scaffold and cultured for 5 days under air-liquid interface condition. After its morphology and histological structure were characterized, the constructed TE-aHC was transplanted into dog eyes via lamellar keratoplasty. The corneal transparency, thickness, intraocular pressure, epithelial integrity, and corneal regeneration were monitored in vivo, and the histological structure and histochemical property were examined ex vivo 360 days after surgery, respectively. The results showed that the constructed TE-aHC was highly transparent and composed of a corneal epithelium of 7-8 layer ntHCEP cells and a corneal stroma of regularly aligned collagen fibers and well-preserved glycosaminoglycans with sparsely distributed ntHCS cells, mimicking a normal anterior hemi-cornea (aHC). Moreover, both ntHCEP and ntHCS cells maintained positive expression of their marker and functional proteins. After transplantation into dog eyes, the constructed TE-aHC acted naturally in terms of morphology, structure and inherent property, and functioned well in maintaining corneal clarity, thickness, normal histological structure, and composition in dog models by reconstructing a normal aHC, which could be used as a promising aHC equivalent in corneal regenerative medicine and aHC disorder therapy. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  18. Explore the full thick layer of corneal transplantation in the treatment of pseudomonas aeruginosa corneal ulcer infection

    Directory of Open Access Journals (Sweden)

    Xin Wang


    Full Text Available AIM: To explore the feasibility, safety and effect of the full-thickness lamellar keratoplasty for the treatment of pseudomonas aeruginosa corneal ulcer. METHODS: Based on a retrospective non-controlled study, 25 patients were given the full-thickness lamellar keratoplasty for clinical diagnosis of pseudomonas aeruginosa infection and corneal ulcer medication conventional anti-gram-negative bacteria. Routine follow-up were carried out at postoperative 1wk; 1, 3, 6, 12, 18mo to observe the situation of corneal epithelial healing, recurrent infection, immune rejection, graft transparency and best corrected visual acuity, etc. At the 6 and 12mo postoperative, corneal endothelial cell density was reexamined.RESULTS: No patients because of Descemet's membrane rupture underwent penetrating keratoplasty surgery: One only in cases of bacterial infection after 1mo, once again did not cultivate a culture of bacteria pseudomonas aeruginosa, and the remaining 24 cases average follow-up 14±6mo, corneal graft were transparent, the cure rate was 96%. At the sixth month after surgery, there were 16 cases of eye surgery best corrected visual acuity ≥4.5, of which 3 cases ≥4.8. At the sixth month after surgery, the average corneal endothelial cell density 2 425±278/mm2; At 12mo postoperatively, it was 2 257± 326/mm2.CONCLUSION: Full-thickness lamellar keratoplasty is an effective method of pseudomonas aeruginosa infection in the treatment of corneal ulcers, corneal drying material glycerol can be achieved by visual effects.

  19. Generation of Femtosecond Laser-Cut Decellularized Corneal Lenticule Using Hypotonic Trypsin-EDTA Solution for Corneal Tissue Engineering


    Huh, Man-Il; Lee, Kyoung-Pil; Kim, Jeongho; Yi, Soojin; Park, Byeong-Ung; Kim, Hong Kyun


    Purpose. To establish an optimized and standardized protocol for the development of optimal scaffold for bioengineering corneal substitutes, we used femtosecond laser to process human corneal tissue into stromal lenticules and studied to find the most efficient decellularization method among various reagents with different tonicities. Methods. The decellularization efficacy of several agents (0.1%, 0.25%, and 0.5% of Triton X-100, SDS, and trypsin-EDTA (TE), resp.) with different tonicities w...

  20. Excimer laser-assisted anterior lamellar keratoplasty for keratoconus, corneal problems after laser in situ keratomileusis, and corneal stromal opacities. (United States)

    Bilgihan, Kamil; Ozdek, Sengül C; Sari, Ayça; Hasanreisoğlu, Berati


    To evaluate excimer laser-assisted anterior lamellar keratoplasty to augment thin corneas as in keratoconus ( .05). This technique presents a different modality for the treatment of keratoconus, post-LASIK corneal problems, and other corneal stromal opacities with anterior lamellar keratoplasty. Additional studies with more patients and longer follow-up will help determine the role of this technique as a substitute for penetrating keratoplasty in these patients.

  1. Blindness and Visual Impairment in an Urban West African Population: The Tema Eye Survey (United States)

    Budenz, Donald L.; Bandi, Jagadeesh R.; Barton, Keith; Nolan, Winifred; Herndon, Leon; Whiteside-de Vos, Julia; Hay-Smith, Graham; Kim, Hanna; Tielsch, James


    Objective To determine the prevalence, etiologies, and risk factors of blindness and visual impairment among persons age 40 years and older residing in an urban West African location. Design Population-based cross-sectional study. Participants Five thousand six hundred and three participants residing in Tema, Ghana. Methods Proportionate random cluster sampling was used to select participants age 40 and over living in the city of Tema. Presenting distance visual acuity was measured at 4 and 1 meters using a reduced Logarithm of the Minimum Angle of Resolution (logMAR) tumbling E chart and then with trial frame based on autorefraction. A screening examination was performed in the field on all participants. Complete clinical examination by an ophthalmologist was performed on participants with best corrected visual acuity visual acuity in the better eye of visual impairment (visual acuity in the better eye of visual impairment was 17.1% and blindness was 1.2%. After refraction and spectacle correction, the prevalence of visual impairment and blindness decreased to 6.7% and 0.75% respectively, suggesting that refractive error is the major correctable etiology of visual impairment and blindness in this population. Of 65 subjects having visual acuity visual impairment, and one to normal. The remaining 43 (66%) had underlying pathology (19 cataract, 9 glaucoma, 3 non-glaucomatous optic neuropathy, 3 corneal opacities, 3 retinal disease, 5 undetermined) that prevented refractive correction. Increased age was a significant risk factor for blindness and visual impairment. Conclusions There is a high prevalence of blindness and visual impairment among those aged ≥40 years in Tema, Ghana, West Africa. Refractive error is a major cause of blindness and visual impairment in this population, followed by cataract, glaucoma, and corneal disease. PMID:22677425

  2. Models for the blind

    DEFF Research Database (Denmark)

    Olsén, Jan-Eric


    When displayed in museum cabinets, tactile objects that were once used in the education of blind and visually impaired people, appear to us, sighted visitors, as anything but tactile. We cannot touch them due to museum policies and we can hardly imagine what it would have been like for a blind...... person to touch them in their historical context. And yet these objects are all about touch, from the concrete act of touching something to the norms that assigned touch a specific pedagogical role in nineteenth-century blind schools. The aim of this article is twofold. First, I provide a historical...

  3. Blindness and visual impairment in the Americas and the Caribbean. (United States)

    Muñoz, B; West, S K


    To summarise available data on the prevalence and causes of visual impairment and blindness in the Americas and the Caribbean. The published literature was searched in Medline and LILACS using the following key words: blindness, visual impairment, prevalence. Articles were reviewed, and the references of the articles were also searched for relevant articles, which were also reviewed. Using the mortality in children under the age of 5 as an indicator, the overall prevalence of childhood blindness (in the under age 15 group) for the region was estimated at 0.45/1000, with the majority (67%) living in countries with mortality of children under age 5 above 30/1000 live births. Corneal opacities were more common in countries where the under 5 year mortality are above 30/1000 live births and retinopathy of prematurity (ROP) was an important cause in countries with intermediate death rates. For adults, overall blindness rates were not estimated because of the social, economic, and ethnic diversity in the region. The primary causes of visual loss in adults in the Americas were age related eye diseases, notably cataract and glaucoma in the African-American and Hispanic populations, and age related macular degeneration in the white population. Uncorrected refractive error was a significant cause of decreased vision across ages, ethnic groups, and countries. More data are needed on the magnitude and causes of visual loss for the Caribbean and Latin American countries. Rates of blindness and visual loss from available data within these countries are widely disparate. Prevention and control of avoidable blindness needs to be an ongoing focus in this region.

  4. Clinical characterization of corneal ectasia after myopic laser in situ keratomileusis based on anterior corneal aberrations and internal astigmatism. (United States)

    Piñero, David P; Alió, Jorge L; Barraquer, Rafael I; Uceda-Montanes, Antonio; Murta, Joaquim


    To evaluate and characterize the clinical features of corneal ectasia after myopic laser in situ keratomileusis (LASIK) considering internal astigmatism and corneal aberrations and their correlation with other clinical data. Vissum-Instituto de Oftalmológico de Alicante, Alicante, Spain. Retrospective comparative case series. In this multicenter study, eyes were divided into 2 groups. The study group comprised eyes that had corneal ectasia after myopic LASIK. The control group comprised eyes that had successful LASIK to correct high myopia. The clinical outcomes were analyzed and compared. Internal astigmatism was calculated using vectorial analysis. The study enrolled 91 eyes (48 study group; 40 control group) of 81 patients (age 18 to 67 years). Uncorrected and corrected (CDVA) distance visual acuities and the refractive status were significantly worse in the study group (P ≤ .01). Corneas in the study group had a significantly higher steepest keratometry (K) reading and a more negative central asphericity (P corneal aberrations were also significantly higher in the study group (P corneal aberrations leading to a visual deterioration were present in eyes with corneal ectasia after myopic LASIK. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  5. Natural history of corneal haze after collagen crosslinking for keratoconus and corneal ectasia: Scheimpflug and biomicroscopic analysis. (United States)

    Greenstein, Steven A; Fry, Kristen L; Bhatt, Jalpa; Hersh, Peter S


    To determine the natural history of collagen crosslinking (CXL)-associated corneal haze measured by Scheimpflug imagery and slitlamp biomicroscopy in patients with keratoconus or ectasia after laser in situ keratomileusis. Cornea and refractive surgery subpecialty practice, United States. Prospective randomized controlled clinical trial. The treatment group received ultraviolet-A/riboflavin CXL therapy. The control group received riboflavin alone without epithelial debridement. To objectively measure CXL-associated corneal haze, corneal densitometry using Scheimpflug imagery was measured and the changes in haze were analyzed over time. A similar analysis was performed using clinician-determined slitlamp haze. Correlation of CXL-associated corneal haze with postoperative outcomes was analyzed. The mean preoperative corneal densitometry was 14.9 ± 1.93 (SD) (Pentacam Scheimpflug densitometry units). Densitometry peaked at 1 month (mean 23.4 ± 4.40; Pectasia group (16.1 ± 2.41; P = .15). The postoperative course of slitlamp haze was similar to objective densitometry measurements. Increased haze, measured by densitometry, did not correlate with postoperative clinical outcomes. The time course of corneal haze after CXL was objectively quantified; it was greatest at 1 month, plateaued at 3 months, and was significantly decreased between 3 months and 12 months. Changes in haze did not correlate with postoperative clinical outcomes. Copyright © 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  6. Collagen based film with well epithelial and stromal regeneration as corneal repair materials: Improving mechanical property by crosslinking with citric acid

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xuan; Liu, Yang; Li, Weichang; Long, Kai; Wang, Lin; Liu, Sa; Wang, Yingjun [School of Materials Science and Engineering, South China University of Technology, Guangzhou (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou (China); Ren, Li, E-mail: [School of Materials Science and Engineering, South China University of Technology, Guangzhou (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou (China)


    Corneal disease can lead to vision loss. It has become the second greatest cause of blindness in the world, and keratoplasty is considered as an effective treatment method. This paper presents the crosslinked collagen (Col)–citric acid (CA) films developed by making use of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The results showed that the Col–CA films had necessary optical performance, water content. The collagenase resistance of CA crosslinked films was superior to that of EDC crosslinked films. And CA5 film (Col:CA:EDC:NHS = 60:3:10:10) had the best mechanical properties. Cell experiments showed that CA5 film was non-cytotoxic and human corneal epithelial cells could proliferate well on the films. Lamellar keratoplasty showed that the CA5 film could be sutured in the rabbit eyes and was epithelialized completely in about 10 days, and the transparency was restored quickly in 30 ± 5 days. No inflammation and corneal neovascularization were observed at 6 months. Corneal stroma had been repaired; stromal cells and neo-stroma could be seen in the area of operation from the hematoxylin–eosin stained histologic sections and anterior segment optical coherence tomography images. These results indicated that Col–CA films were highly promising biomaterials that could be used in corneal tissue engineering and a variety of other tissue engineering applications. - Highlights: • Adding different amounts of citric acid could change the properties of films. • The crosslinked films had better mechanical property than non-modified films. • Crosslinked collagen–citric acid films could tolerate suture during operation. • The films showed good ability of epithelial and stromal repair.

  7. Prevalence and determinants of corneal blindness in a Semi-Urban ...

    African Journals Online (AJOL)

    Ocular examinations of the anterior and posterior segments of the participants were performed using pen touch, magnifying loupe, slit lamp and direct ophthalmoscope. The data collected were analyzed using the Statistical Package for Social Sciences software version 22. Summary statistics was presented using frequency ...

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

    Directory of Open Access Journals (Sweden)

    Jie Hou


    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.

  9. Blind Loop Syndrome (United States)

    ... of tissue that protrude through the intestinal wall (diverticulosis) Certain medical conditions, including Crohn's disease, radiation enteritis, ... History of radiation therapy to the abdomen Diabetes Diverticulosis of the small intestine Complications A blind loop ...

  10. Blindness and vision loss (United States)

    ... life. Alternative Names Loss of vision; No light perception (NLP); Low vision; Vision loss and blindness Images ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  11. The blind hens’ challenge

    DEFF Research Database (Denmark)

    Sandøe, Peter; Hocking, Paul M.; Forkman, Björn


    about breeding blind hens. But we also argue that alternative views, which (for example) claim that it is important to respect the telos or rights of an animal, do not offer a more convincing solution to questions raised by the possibility of disenhancing animals for their own benefit.......Animal ethicists have recently debated the ethical questions raised by disenhancing animals to improve their welfare. Here, we focus on the particular case of breeding blind hens for commercial egg-laying systems, in order to benefit their welfare. Many people find breeding blind hens intuitively...... repellent, yet 'welfare-only' positions appear to be committed to endorsing this possibility if it produces welfare gains. We call this the 'Blind Hens' Challenge'. In this paper, we argue that there are both empirical and theoretical reasons why even those adopting 'welfare-only' views should be concerned...

  12. Issues in Traumatic Blindness. (United States)

    Dale, B.


    This article discusses factors related to individuals with sudden blindness, focusing on the visually impaired client's readiness for rehabilitation, the reactions of family members and friends, and personality variables. Two cases illustrate the adjustment process and eventual rehabilitation. (DB)

  13. Hemangiossarcoma corneal em cão

    Directory of Open Access Journals (Sweden)

    Ú.C. Guberman


    Full Text Available O hemangiossarcoma é uma neoplasia maligna e sua apresentação corneal é rara em cães. Relata-se um caso de hemangiossarcoma corneal primário, em uma fêmea canina, sem raça definida, de 20kg, nove anos de idade e com histórico de crescimento progressivo de massa em bulbo ocular direito há dois meses. Ao exame oftálmico do olho direito, foram observados blefarospasmo, hiperemia conjuntival moderada e presença de nódulo avermelhado, irregular em região dorsal de córnea direita, ocupando cerca de 60% dela. A ultrassonografia ocular foi realizada, e constatou-se que a neoplasia acometia apenas a córnea. Por meio do exame citológico, foi diagnosticada neoplasia mesenquimal maligna. O paciente foi submetido à ceratectomia seguida de flap de terceira pálpebra. Encaminhou-se o material excisado para análise histopatológica, e foi diagnosticado hemangiossarcoma. Após 15 dias, o flap de terceira pálpebra foi retirado, e, ao exame oftálmico, notou-se a recidiva da neoplasia, que recobria toda a córnea e parte da conjuntiva bulbar, procedendo-se à enucleação. O paciente foi submetido à ultrassonografia abdominal e à radiografia torácica sem nenhuma alteração evidente, o que caracterizou o caráter primário da afecção. Após dois anos do procedimento cirúrgico, o paciente encontra-se bem clinicamente, sem qualquer sinal de recidiva ou metástase. Apesar da exérese cirúrgica da neoplasia com margens limpas, em casos de hemangiossarcoma com comportamento agressivo, a enucleação deve ser considerada uma opção viável para um protocolo terapêutico de sucesso e melhor prognóstico do paciente.

  14. The effects of chalazion excision on corneal surface aberrations. (United States)

    Park, Young Min; Lee, Jong Soo


    This study is the first to consider the effects of chalazion on corneal surface aberrations taking into account of corneal zones, and to establish the size standard for the excision of chalazion. Twenty three eyes from 23 patients with central upper eyelid chalazion larger than 3mm were recruited in this prospective study. The participants were classified into two groups, depending on size of the lesion: Group 1 with lesion size 3-5mm and Group 2 with lesion size >5mm Chalazion was excised by standard transconjunctival vertical incision. Corneal surface aberrations were measured using a Galilei™ analyzer and an auto-refractometer before and 2 months after the excision. Corneal astigmatism in all patients decreased significantly in both auto refractometer (P=0.012) and Galilei™ (P=0.020) measurements after chalazion excision. RMS of total HOAs decreased significantly in 6mm (P=0.043) and 3mm zone (P=0.051). The RMS of Zernike orders in the vertical and horizontal trefoil decreased significantly in 6mm (P=0.035) and 3mm (P=0.041) zone. Group 2 showed a significant decrease in corneal astigmatism in both auto refractometer (P=0.040) and Galilei™ (P=0.017) parameters after chalazion excision. Group 1 showed an insignificant decrease in corneal astigmatism. Unlike Group 1, the RMS of total HOAs and vertical and horizontal trefoil in 6mm zone decreased significantly in Group 2 (Pchalazion increases astigmatism and HOAs, especially at the peripheral cornea. Significantly induced astigmatism and HOAs are caused by chalazion >5mm in size. Thus, we recommend the surgical excision of chalazion >5mm in size to reduce corneal surface aberrations. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  15. Childhood blindness at a school for the blind in Riyadh, Saudi Arabia. (United States)

    Kotb, Amgad A; Hammouda, Ehab F; Tabbara, Khalid F


    To determine the major causes of eye diseases leading to visual loss and blindness among children attending a school for the blind in Riyadh, Saudi Arabia. A total of 217 school children with visual disabilities attending a school for the blind in Riyadh were included. All children were brought to The Eye Center, Riyadh, and had complete ophthalmologic examinations including visual acuity testing, biomicroscopy, ophthalmoscopy, tonometry and laboratory investigations. In addition, some patients were subjected to electroretinography (ERG), electrooculography (EOG), measurement of visual evoked potentials (VEP), and laboratory work-up for congenital disorders. There were 117 male students with an age range of 6-19 years and a mean age of 16 years. In addition, there were 100 females with an age range of 6-18 years and a mean age of 12 years. Of the 217 children, 194 (89%) were blind from genetically determined diseases or congenital disorders and 23 (11%) were blind from acquired diseases. The major causes of bilateral blindness in children were retinal degeneration, congenital glaucoma, and optic atrophy. The most common acquired causes of childhood blindness were infections and trauma. The etiological pattern of childhood blindness in Saudi Arabia has changed from microbial keratitis to genetically determined diseases of the retina and optic nerve. Currently, the most common causes of childhood blindness are genetically determined causes. Consanguineous marriages may account for the autosomal recessive disorders. Public education programs should include information for the prevention of trauma and genetic counseling. Eye examinations for preschool and school children are mandatory for the prevention and cure of blinding disorders.

  16. Change blindness, aging, and cognition (United States)

    Rizzo, Matthew; Sparks, JonDavid; McEvoy, Sean; Viamonte, Sarah; Kellison, Ida; Vecera, Shaun P.


    Change blindness (CB), the inability to detect changes in visual scenes, may increase with age and early Alzheimer’s disease (AD). To test this hypothesis, participants were asked to localize changes in natural scenes. Dependent measures were response time (RT), hit rate, false positives (FP), and true sensitivity (d′). Increased age correlated with increased sensitivity and RT; AD predicted even slower RT. Accuracy and RT were negatively correlated. Differences in FP were nonsignificant. CB correlated with impaired attention, working memory, and executive function. Advanced age and AD were associated with increased CB, perhaps due to declining memory and attention. CB could affect real-world tasks, like automobile driving. PMID:19051127

  17. Corneal ring infiltration in contact lens wearers

    Directory of Open Access Journals (Sweden)

    Seyed Ali Tabatabaei


    Full Text Available To report a case of atypical sterile ring infiltrates during wearing soft silicone hydrogel contact lens due to poor lens care. A 29-year-old woman presented with complaints of pain, redness, and morning discharge. She was wearing soft silicone hydrogel contact lens previously; her current symptoms began 1 week before presentation. On examination, best-corrected visual acuity was 20/40 in that eye. Slit-lamp examination revealed dense, ring-shaped infiltrate involving both the superficial and deep stromal layers with lucid interval to the limbus, edema of the epithelium, epithelial defect, and vascularization of the superior limbus. Cornea-specific in vivo laser confocal microscopy (Heidelberg Retina Tomograph 2 Rostock Cornea Module, HRT 2-RCM, Heidelberg Engineering GmbH, Dossenheim, Germany revealed Langerhans cells and no sign of Acanthamoeba or fungal features, using lid scraping and anti-inflammatory drops; her vision completely recovered. We reported an atypical case of a sterile corneal ring infiltrate associated with soft contact lens wearing; smear, culture, and confocal microscopy confirmed a sterile inflammatory reaction.

  18. Evaluation of the effects of resveratrol and bevacizumab on experimental corneal alkali burn. (United States)

    Doganay, Selim; Firat, Penpe Gul; Cankaya, Cem; Kirimlioglu, Hale


    To evaluate the effects of resveratrol and bevacizumab on experimental corneal neovascularization. A corneal alkali burn was performed in 62 eyes of 31 male white Vienna rabbits. Resveratrol (group 1), dimethyl sulfoxide (group 2), bevacizumab (group 3) and 0.9% NaCl (group 4) were administered to both eyes of the rabbits by subconjunctival injection for 7 days. Corneal photos were taken at 15 days after alkali injury. Inflammatory index scores and neovascularization areas were calculated. In bevacizumab group both inflammatory index scores and the calculation of the corneal neovascularization area was significantly less than the groups. The subconjunctival administration of bevacizumab inhibits corneal neovascularization effectively in the rabbit corneal alkali burn model. No effect of resveratrol to the corneal neovascularization on experimental model of the corneal alkali burn was seen at the doses of usage. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  19. Tectonic deep anterior lamellar keratoplasty in impending corneal perforation using cryopreserved cornea. (United States)

    Jang, Ji Hye; Chang, Sung Dong


    We report a case of tectonic corneal transplantation for impending corneal perforation to preserve anatomic integrity using cryopreserved donor tissue. An 82-year-old woman exhibiting impending corneal perforation suffered from moderate ocular pain in the left eye for one week. After abnormal tissues around the impending perforation area were carefully peeled away using a Crescent blade and Vannas scissors, the patient received tectonic deep anterior lamellar keratoplasty using a cryopreserved cornea stored in Optisol GS® solution at -70℃ for four weeks. At six months after surgery, the cornea remained transparent and restored the normal corneal thickness. There were no complications such as corneal haze or scars, graft rejection, recurrent corneal ulcer, and postoperative rise of intraocular pressure. Cryopreserved donor lamellar tissue is an effective substitute in emergency tectonic lamellar keratoplasty, such as impending corneal perforation and severe necrotic corneal keratitis. © 2011 The Korean Ophthalmological Society

  20. Blind Analysis in Particle Physics


    Roodman, Aaron


    A review of the blind analysis technique, as used in particle physics measurements, is presented. The history of blind analyses in physics is briefly discussed. Next the dangers of "experimenter's bias" and the advantages of a blind analysis are described. Three distinct kinds of blind analysis in particle physics are presented in detail. Finally, the BABAR collaboration's experience with the blind analysis technique is discussed.

  1. Corneal sensation after corneal refractive surgery with small incision lenticule extraction. (United States)

    Demirok, Ahmet; Ozgurhan, Engin Bilge; Agca, Alper; Kara, Necip; Bozkurt, Ercument; Cankaya, Kadir Ilker; Yilmaz, Omer Faruk


    To compare effects of small-incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (F-LASIK) on corneal sensation and dry eye parameters. In this prospective, randomized, contralateral-eye study, 28 patients with myopia or myopic astigmatism in both eyes were enrolled. One eye of each patient was treated by SMILE, and the fellow eye was treated by F-LASIK. Mean outcome measures Cochet-Bonnet esthesiometry, Schirmer test with anesthesia, tear breakup time, and tear film osmolarity were evaluated preoperatively as well as 1 week, 1 month, 3 months, and 6 months after surgery. Corneal sensation was reduced after both SMILE and F-LASIK surgeries 1 week, 1 month, and 3 months after surgery (p sensation was significantly lower after F-LASIK than after SMILE at postoperative 1 week, 1 month, and 3 months (p sensation 1 week, 1 month, and 3 months after surgery, they did not affect the dry eye parameters at any point.

  2. Transepithelial Riboflavin Absorption in an Ex Vivo Rabbit Corneal Model. (United States)

    Gore, Daniel M; O'Brart, David; French, Paul; Dunsby, Chris; Allan, Bruce D


    To measure depth-specific riboflavin concentrations in corneal stroma using two-photon fluorescence microscopy and compare commercially available transepithelial corneal collagen cross-linking (CXL) protocols. Transepithelial CXL riboflavin preparations--MedioCross TE, Ribocross TE, Paracel plus VibeX Xtra, and iontophoresis with Ricrolin+--were applied to the corneal surface of fresh postmortem rabbit eyes in accordance with manufacturers' recommendations for clinical use. Riboflavin 0.1% (VibeX Rapid) was applied after corneal epithelial debridement as a positive control. After riboflavin application, eyes were snap frozen in liquid nitrogen. Corneal cross sections 35-μm thick were cut on a cryostat, mounted on a slide, and imaged by two-photon fluorescence microscopy. Mean (SD) concentrations were calculated from five globes tested for each protocol. Peak riboflavin concentration of 0.09% (± 0.01) was observed within the most superficial stroma (stromal depth 0-10 μm) in positive controls (epithelium-off). At the same depth, peak stromal riboflavin concentrations for MedioCross TE, Ricrolin+, Paracel/Xtra, and Ribocross TE were 0.054% (± 0.01), 0.031% (0.003), 0.021% (± 0.001), and 0.015% (± 0.004), respectively. At a depth of 300 μm (within the demarcation zone commonly seen after corneal cross-linking), the stromal concentration in epithelium-off positive controls was 0.075% (± 0.006), while at the same depth MedioCross TE and Ricrolin+ achieved 0.018% (± 0.006) and 0.016% (0.002), respectively. None of the remaining transepithelial protocols achieved concentrations above 0.005% at this same 300-μm depth. Overall, MedioCross TE was the best-performing transepithelial formulation. Corneal epithelium is a significant barrier to riboflavin absorption into the stroma. Existing commercial transepithelial CXL protocols achieve relatively low riboflavin concentrations in the anterior corneal stroma when compared to gold standard epithelium-off absorption

  3. A new multiple noncontinuous puncture (pointage technique for corneal tattooing

    Directory of Open Access Journals (Sweden)

    Jin Hyoung Park


    Full Text Available AIM:To assess the safety and cosmetic efficacy of a new multiple noncontinuous transepithelial puncture technique for tattooing a decompensated cornea.METHODS:It was anon-comparative clinical case series study.The study examines 33 eyes in 33 patients with total corneal opacity due to corneal decompensation, which developed following intraocular surgery.Corneal tattooing was performed using the multiple noncontinuous transepithelial puncture technique (i.e. pointage. The safety of this new surgical strategy was assessed by occurrence of adverse events for the follow-up period. The cosmetic efficacy was determined by the patient’s cosmetic satisfaction and independent observer’s opinion about patient appearance.RESULTS:Seven women and 26 men were included in the study. The mean age was 46.4±17.5y (range:7-67. In total, 30 of 33 patients (91% reported cosmetic satisfaction within the follow-up period. Only 3 patients (9% required additional tattooing due to cosmetic unsatisfaction. Cosmetic outcomes were analyzed and classified as excellent or good in 13 (39% and 17 (52% patients, respectively. No serious adverse events developed, except delayed epithelial healing in 3 cases.CONCLUSION:The cosmetic outcomes of the multiple noncontinuous transepithelial puncture technique for corneal tattooing were good. The safety of this method is higher than conventional procedures. This new procedure also provides improved cost-effectiveness and safety over current corneal tattooing techniques.

  4. Temporary corneal stem cell dysfunction after radiation therapy

    International Nuclear Information System (INIS)

    Hiroshi, Fujishima; Kazuo, Tsubota


    Radiation therapy can cause corneal and conjuctival abnormalities that sometimes require surgical treatment. Corneal stem cell dysfunction is described, which recovered after the cessation of radiation. Methods - A 44-year-old man developed a corneal epithelial abnormality associated with conjuctival and corneal inflammation following radiation therapy for maxillary cancer. Examination of brush cytology samples showed goblet cells in the upper and lower parts of the cornea, which showed increased fluorescein permeability, and intraepithelial lymphocytes. Impression cytology showed goblet cells in the same part of the cornea. Specular microscopy revealed spindle type epithelial cells. Patient follow up included artificial tears and an antibiotic ophthalmic ointment. The corneal abnormalities resolved after 4 months with improved visual acuity without any surgical intervention, but the disappearance of the palisades of Vogt did not recover at 1 year after radiation. Radiation therapy in this patient caused temporary stem cell dysfunction which resulted in conjunctivalisation in a part of the cornea. Although limbal stem cell function did not fully recover, this rare case suggested that medical options should be considered before surgery. (Author)

  5. Bioactive Antimicrobial Peptides as Therapeutics for Corneal Wounds and Infections. (United States)

    Griffith, Gina L; Kasus-Jacobi, Anne; Pereira, H Anne


    Significance: More than 2 million eye injuries and infections occur each year in the United States that leave civilians and military members with reduced or complete vision loss due to the lack of effective therapeutics. Severe ocular injuries and infections occur in varied settings including the home, workplace, and battlefields. In this review, we discuss the potential of developing antimicrobial peptides (AMPs) as therapeutics for the treatment of corneal wounds and infections for which the current treatment options are inadequate. Recent Advances: Standard-of-care employs the use of fluorescein dye for the diagnosis of ocular defects and is followed by the use of antibiotics and/or steroids to treat the infection and reduce inflammation. Recent advances for treating corneal wounds include the development of amniotic membrane therapies, wound chambers, and drug-loaded hydrogels. In this review, we will discuss an innovative approach using AMPs with the dual effect of promoting corneal wound healing and clearing infections. Critical Issues: An important aspect of treating ocular injuries is that treatments need to be effective and administered expeditiously. This is especially important for injuries that occur during combat and in individuals who demonstrate delayed wound healing. To overcome gaps in current treatment modalities, bioactive peptides based on naturally occurring cationic antimicrobial proteins are being investigated as new therapeutics. Future Directions: The development of new therapeutics that can treat ocular infections and promote corneal wound healing, including the healing of persistent corneal epithelial defects, would be of great clinical benefit.

  6. Experimental study on cryotherapy for fungal corneal ulcer. (United States)

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


    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. Rabbit models of cornea infection were established using a combined method of intrastromal injection and keratoplasty. After treatment with cryotherapy and anti-fungal agents, scanning electron microscopy, transmission electron microscopy, and confocal microscopy were conducted to observe changes in microstructure in the rabbits. Periodic acid Schiff A and hematoxylin and eosin staining were used for detection of histological changes. Continuous scanning electron microscopy and transmission electron microscopy observations showed that cryothermal treatment inhibited growth of fungal mycelium by destroying fungal cellular structures. Typical cryotherapy was effective in curing fungal corneal ulcer. Different fungi showed different susceptibilities to treatment. The curative effect of Candida albicans was the best, while that of Aspergillus fumigates was the worst. Our study provides a novel method of a combination of cryotherapy and anti-fungal agents for treatment of fungal corneal ulcer. This treatment could help facilitate the practice of fungal keratitis treatment in the future.

  7. Determination of corneal elasticity coefficient using the ORA database. (United States)

    Avetisov, Sergei E; Novikov, Ivan A; Bubnova, Irina A; Antonov, Alexei A; Siplivyi, Vladimir I


    To propose a new approach for the study of corneal biomechanics using the Reichert Ocular Response Analyzer (ORA) database, which is based on changes in velocity retardation in the central cornea at the peak of flattening. The ORA applanation curve was analyzed using a mathematical technique, which allowed calculation of the elasticity coefficient (Ke), which is primarily characteristic of the elastic properties of the cornea. Elasticity coefficient values were obtained in patients with presumably different biomechanical properties of the cornea: "normal" cornea (71 eyes, normal group), keratoconus (34 eyes, keratoconus group), LASIK (36 eyes, LASIK group), and glaucoma with elevated and compensated intraocular pressure (lOP) (38 eyes, glaucoma group). The mean Ke value in the normal group was 11.05 +/- 1.6, and the corneal thickness correlation coefficient r2 was 0.48. In the keratoconus group, the mean Ke value was 4.91 +/- 1.87 and the corneal thickness correlation coefficient r2 was 0.47. In the LASIK group, Ke and r2 were 5.99 +/- 1.18 and 0.39, respectively. In the glaucoma group, the same eyes that experienced a two-fold reduction in lOP developed a statistically significant reduction in the Ke (1.06 times lower), whereas their corneal hysteresis value increased 1.25 times. The elasticity coefficient calculated using the ORA applanation curve can be used in the evaluation of corneal biomechanical properties.

  8. Blind distributed estimation algorithms for adaptive networks (United States)

    Bin Saeed, Muhammad O.; Zerguine, Azzedine; Zummo, Salam A.


    Until recently, a lot of work has been done to develop algorithms that utilize the distributed structure of an ad hoc wireless sensor network to estimate a certain parameter of interest. However, all these algorithms assume that the input regressor data is available to the sensors, but this data is not always available to the sensors. In such cases, blind estimation of the required parameter is needed. This work formulates two newly developed blind block-recursive algorithms based on singular value decomposition (SVD) and Cholesky factorization-based techniques. These adaptive algorithms are then used for blind estimation in a wireless sensor network using diffusion of data among cooperative sensors. Simulation results show that the performance greatly improves over the case where no cooperation among sensors is involved.

  9. In vivo corneal neovascularization imaging by optical-resolution photoacoustic microscopy


    Liu, Wenzhong; Schultz, Kathryn M.; Zhang, Kevin; Sasman, Amy; Gao, Fengli; Kume, Tsutomu; Zhang, Hao F.


    Corneal neovascularization leads to blurred vision, thus in vivo visualization is essential for pathological studies in animal models. Photoacoustic (PA) imaging can delineate microvasculature and hemodynamics noninvasively, which is suitable for investigating corneal neovascularization. In this study, we demonstrate in vivo imaging of corneal neovascularization in the mouse eye by optical-resolution photoacoustic microscopy (OR-PAM), where corneal neovascularization is induced by deliberate ...

  10. Effect of central corneal thickness and radius of the corneal curvature on intraocular pressure measured with the Tono-Pen and noncontact tonometer in healthy schoolchildren. (United States)

    Yildirim, Nilgun; Sahin, Afsun; Basmak, Hikmet; Bal, Cengiz


    To determine the effect of central corneal thickness and radius of the corneal curvature on intraocular pressure (IOP) measurements using the Tono-Pen and a noncontact tonometer in healthy Turkish schoolchildren. IOP was measured with the Tono-Pen and a noncontact tonometer in 602 eyes of 602 healthy schoolchildren with a mean age of 10.1 +/- 1.6 years. Central corneal thickness was measured using an ultrasonic pachymeter after all IOP determinations had been made. The effect of central corneal thickness, radius of the corneal curvature, and sex on measured IOP was explored by linear regression analysis. The mean central corneal thickness was found to be 564.92 +/- 32 microm. The mean IOP readings were 17.9 +/- 2 mm Hg using the Tono-Pen, and 16.7 +/- 2 mm Hg using a noncontact tonometer. The Tono-Pen measured IOP values slightly greater than the noncontact tonometer (P < .0001). A significant association between measured IOP and central corneal thickness was found with each device. The IOP increased 2.1 and 4.2 mm Hg with every 100-microm increase in central corneal thickness for the Tono-Pen and the noncontact tonometer, respectively. The dependence of IOP on central corneal thickness did not differ between boys and girls. There was a significant association between the Tono-Pen and noncontact tonometer differences and central corneal thickness; the noncontact tonometer tended to overestimate IOP in eyes with thicker corneas. The Tono-Pen readings appeared to be less affected by corneal thickness than those of the noncontact tonometer. The corneal radius of curvature had no significant effect on measured IOP with each device. Because the Tono-Pen was relatively easy to use and less affected by corneal thickness, it may be an alternative method for measuring IOP in children.

  11. Downregulation of PTEN at Corneal Wound Sites Accelerates Wound Healing through Increased Cell Migration


    Cao, Lin; Graue-Hernandez, Enrique O.; Tran, Vu; Reid, Brian; Pu, Jin; Mannis, Mark J.; Zhao, Min


    Wounding downregulates PTEN and activates the PI3 kinase/Akt pathway. Pharmacologic inhibition of PTEN stimulates the motility of corneal epithelial cells and corneal wound healing. These results imply that the inhibition of PTEN may be a plausible approach for corneal wounds.

  12. 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; Forrest, Alistair R. R.; Rehli, Michael; Baillie, J. Kenneth; de Hoon, Michiel J. L.; Haberle, Vanja; Lassmann, Timo; Kulakovskiy, Ivan V.; Lizio, Marina; Andersson, Robin; Mungall, Christopher J.; Meehan, Terrence F.; Schmeier, Sebastian; Bertin, Nicolas; Jørgensen, Mette; Dimont, Emmanuel; Arner, Erik; Schmidl, Christian; Schaefer, Ulf; Medvedeva, Yulia A.; Plessy, Charles; Vitezic, Morana; Severin, Jessica; Semple, Colin A.; Ishizu, Yuri; Francescatto, Margherita; Alam, Intikhab; Albanese, Davide; Altschuler, Gabriel M.; Archer, John A. C.; Arner, Peter; Babina, Magda; Baker, Sarah; Balwierz, Piotr J.; Beckhouse, Anthony G.; Pradhan-Bhatt, Swati; Blake, Judith A.; Blumenthal, Antje; Bodega, Beatrice; Bonetti, Alessandro; Briggs, James; Brombacher, Frank; Burroughs, A. Maxwell; Califano, Andrea; Cannistraci, Carlo V.; Carbajo, Daniel; Chen, Yun; Chierici, Marco; Ciani, Yari; Clevers, Hans C.; Dalla, Emiliano; Davis, Carrie A.; Detmar, Michael; Diehl, Alexander D.; Dohi, Taeko; Drabløs, Finn; Edge, Albert S. B.; Edinger, Matthias; Ekwall, Karl; Endoh, Mitsuhiro; Enomoto, Hideki; Fagiolini, Michela; Fairbairn, Lynsey; Fang, Hai; Farach-Carson, Mary C.; Faulkner, Geoffrey J.; Favorov, Alexander V.; Fisher, Malcolm E.; Frith, Martin C.; Fujita, Rie; Fukuda, Shiro; Furlanello, Cesare; Furuno, Masaaki; Furusawa, Jun-ichi; Geijtenbeek, Teunis B.; Gibson, Andrew; Gingeras, Thomas; Goldowitz, Daniel; Gough, Julian; Guhl, Sven; Guler, Reto; Gustincich, Stefano; Ha, Thomas J.; Hamaguchi, Masahide; Hara, Mitsuko; Harbers, Matthias; Harshbarger, Jayson; Hasegawa, Akira; Hasegawa, Yuki; Hashimoto, Takehiro; Herlyn, Meenhard; Hitchens, Kelly J.; Ho Sui, Shannan J.; Hofmann, Oliver M.; Hoof, Ilka; Hori, Fumi; Huminiecki, Lukasz; Iida, Kei; Ikawa, Tomokatsu; Jankovic, Boris R.; Jia, Hui; Joshi, Anagha; Jurman, Giuseppe; Kaczkowski, Bogumil; Kai, Chieko; Kaida, Kaoru; Kaiho, Ai; Kajiyama, Kazuhiro; Kanamori-Katayama, Mutsumi; Kasianov, Artem S.; Kasukawa, Takeya; Katayama, Shintaro; Kato, Sachi; Kawaguchi, Shuji; Kawamoto, Hiroshi; Kawamura, Yuki I.; Kawashima, Tsugumi; Kempfle, Judith S.; Kenna, Tony J.; Kere, Juha; Khachigian, Levon M.; Kitamura, Toshio; Klinken, S. Peter; Knox, Alan J.; Kojima, Miki; Kojima, Soichi; Kondo, Naoto; Koseki, Haruhiko; Koyasu, Shigeo; Krampitz, Sarah; Kubosaki, Atsutaka; Kwon, Andrew T.; Laros, Jeroen F. J.; Lee, Weonju; Lennartsson, Andreas; Li, Kang; Lilje, Berit; Lipovich, Leonard; Mackay-sim, Alan; Manabe, Ri-ichiroh; Mar, Jessica C.; Marchand, Benoit; Mathelier, Anthony; Mejhert, Niklas; Meynert, Alison; Mizuno, Yosuke; Morais, David A. de Lima; Morikawa, Hiromasa; Morimoto, Mitsuru; Moro, Kazuyo; Motakis, Efthymios; Motohashi, Hozumi; Mummery, Christine L.; Murata, Mitsuyoshi; Nagao-Sato, Sayaka; Nakachi, Yutaka; Nakahara, Fumio; Nakamura, Toshiyuki; Nakamura, Yukio; Nakazato, Kenichi; van Nimwegen, Erik; Ninomiya, Noriko; Nishiyori, Hiromi; Noma, Shohei; Nozaki, Tadasuke; Ogishima, Soichi; Ohkura, Naganari; Ohno, Hiroshi; Ohshima, Mitsuhiro; Okada-Hatakeyama, Mariko; Okazaki, Yasushi; Orlando, Valerio; Ovchinnikov, Dmitry A.; Pain, Arnab; Passier, Robert; Patrikakis, Margaret; Persson, Helena; Piazza, Silvano; Prendergast, James G. D.; Rackham, Owen J. L.; Ramilowski, Jordan A.; Rashid, Mamoon; Ravasi, Timothy; Rizzu, Patrizia; Roncador, Marco; Roy, Sugata; Rye, Morten B.; Saijyo, Eri; Sajantila, Antti; Saka, Akiko; Sakaguchi, Shimon; Sakai, Mizuho; Sato, Hiroki; Satoh, Hironori; Savvi, Suzana; Saxena, Alka; Schneider, Claudio; Schultes, Erik A.; Schulze-Tanzil, Gundula G.; Schwegmann, Anita; Sengstag, Thierry; Sheng, Guojun; Shimoji, Hisashi; Shimoni, Yishai; Shin, Jay W.; Simon, Christophe; Sugiyama, Daisuke; Sugiyama, Takaaki; Suzuki, Masanori; Swoboda, Rolf K.; 't Hoen, Peter A. C.; Tagami, Michihira; Takahashi, Naoko; Takai, Jun; Tanaka, Hiroshi; Tatsukawa, Hideki; Tatum, Zuotian; Thompson, Mark; Toyoda, Hiroo; Toyoda, Tetsuro; Valen, Eivind; van de Wetering, Marc; van den Berg, Linda M.; Verardo, Roberto; Vijayan, Dipti; Vorontsov, Ilya E.; Wasserman, Wyeth W.; Watanabe, Shoko; Wells, Christine A.; Winteringham, Louise N.; Wolvetang, Ernst; Wood, Emily J.; Yamaguchi, Yoko; Yamamoto, Masayuki; Yoneda, Misako; Yonekura, Yohei; Yoshida, Shigehiro; Zabierowski, Suzan E.; Zhang, Peter G.; Zhao, Xiaobei; Zucchelli, Silvia; Summers, Kim M.; Suzuki, Harukazu; Daub, Carsten O.; Kawai, Jun; Heutink, Peter; Hide, Winston; Freeman, Tom C.; Lenhard, Boris; Bajic, Vladimir B.; Taylor, Martin S.; Makeev, Vsevolod J.; Sandelin, Albin; Hume, David A.; Carninci, Piero


    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

  13. Síndrome erosivo corneal recurrente enmascarado como queratitis epitelial herpética

    Directory of Open Access Journals (Sweden)

    Manuel A. de Alba-Castilla


    Conclusiones: Los rasgos distintivos del SECR son: inicio abrupto por la noche o madrugada al despertar, antecedente de trauma corneal o distrofia corneal anterior y ausencia de leucomas corneales. La semejanza sintomatológica y el desconocimiento del SECR incrementan la posibilidad de confundir el diagnóstico.

  14. Active Pedicle Epithelial Flap Transposition Combined with Amniotic Membrane Transplantation for Treatment of Nonhealing Corneal Ulcers


    Zhang, Ting; Wang, Yuexin; Jia, Yanni; Liu, Dongle; Li, Suxia; Shi, Weiyun; Gao, Hua


    Introduction. The objective was to evaluate the efficacy of active pedicle epithelial flap transposition combined with amniotic membrane transplantation (AMT) in treating nonhealing corneal ulcers. Material and Methods. Eleven patients (11 eyes) with nonhealing corneal ulcer who underwent the combined surgery were included. Postoperatively, ulcer healing time was detected by corneal fluorescein staining. Visual acuity, intraocular pressure, surgical complications, and recurrence were recorded...

  15. Generation of Femtosecond Laser-Cut Decellularized Corneal Lenticule Using Hypotonic Trypsin-EDTA Solution for Corneal Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Man-Il Huh


    Full Text Available Purpose. To establish an optimized and standardized protocol for the development of optimal scaffold for bioengineering corneal substitutes, we used femtosecond laser to process human corneal tissue into stromal lenticules and studied to find the most efficient decellularization method among various reagents with different tonicities. Methods. The decellularization efficacy of several agents (0.1%, 0.25%, and 0.5% of Triton X-100, SDS, and trypsin-EDTA (TE, resp. with different tonicities was evaluated. Of all protocols, the decellularization methods, which efficiently removed nuclear materials examined as detected by immunofluorescent staining, were quantitatively tested for sample DNA and glycosaminoglycan (GAG contents, recellularization efficacy, and biocompatibilities. Results. 0.5% SDS in hypertonic and isotonic buffer, 0.25% TE in hypotonic buffer, and 0.5% TE in all tonicities completely decellularized the corneal lenticules. Of the protocols, decellularization with hypotonic 0.25 and 0.5% TE showed the lowest DNA contents, while the GAG content was the highest. Furthermore, the recellularization efficacy of the hypotonic TE method was better than that of the SDS-based method. Hypotonic TE-treated decellularized corneal lenticules (DCLs were sufficiently transparent and biocompatible. Conclusion. We generated an ideal protocol for DCLs using a novel method. Furthermore, it is possible to create a scaffold using a bioengineered corneal substitute.

  16. Corneal Biomechanical Properties after FS-LASIK with Residual Bed Thickness Less Than 50% of the Original Corneal Thickness

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    Haixia Zhang


    Full Text Available Background. The changes in corneal biomechanical properties after LASIK remain an unknown but important topic for surgical design and prognostic evaluation. This study aims to observe the postoperative corneal biomechanical properties one month after LASIK with amount of corneal cutting (ACC greater than 50% of the central corneal thickness (CCT. Methods. FS-LASIK was performed in 10 left rabbit eyes with ACC being 60% (L60 and 65% (L65 of the CCT, while the right eyes (R were the control. After 4 weeks, rabbits were executed and corneal strip samples were prepared for uniaxial tensile tests. Results. At the same strain, the stresses of L65 and L60 were larger than those of R. The elastic moduli of L60 and L65 were larger than those of R when the stress was 0.02 MPa, while they began to be less than those of R when stress exceeds the low-stress region. After 10 s relaxation, the stress of specimens L65, L60, and R increased in turn. Conclusion. The elastic moduli of the cornea after FS-LASIK with ACC greater than 50% of the CCT do not become less under normal rabbit IOP. The limit stress grows with the rise of ACC when relaxation becomes stable.

  17. Measurement of Angle Kappa Using Ultrasound Biomicroscopy and Corneal Topography. (United States)

    Yeo, Joon Hyung; Moon, Nam Ju; Lee, Jeong Kyu


    To introduce a new convenient and accurate method to measure the angle kappa using ultrasound biomicroscopy (UBM) and corneal topography. Data from 42 eyes (13 males and 29 females) were analyzed in this study. The angle kappa was measured using Orbscan II and calculated with UBM and corneal topography. The angle kappa of the dominant eye was compared with measurements by Orbscan II. The mean patient age was 36.4 ± 13.8 years. The average angle kappa measured by Orbscan II was 3.98° ± 1.12°, while the average angle kappa calculated with UBM and corneal topography was 3.19° ± 1.15°. The difference in angle kappa measured by the two methods was statistically significant (p topography to calculate the angle kappa. This method is convenient to use and allows for measurement of the angle kappa without an expensive device. © 2017 The Korean Ophthalmological Society

  18. Tectonic corneal graft for conjunctival rhinosporidiosis with scleral melt

    Directory of Open Access Journals (Sweden)

    Pushpa Jacob


    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.

  19. Photo-activated riboflavin therapy of refractory corneal ulcers. (United States)

    Panda, Anita; Krishna, Sasikala N; Kumar, Sandeep


    To evaluate the therapeutic effect of photo-activated riboflavin (PAR) for treating refractory corneal ulcers. Seven eyes with infectious keratitis, presented with a gradually deteriorating, vision-threatening, corneal ulcer, despite intense antimicrobial therapy, were treated with PAR. The surgical procedure was deepithelialization of the affected corneas followed by UV-A riboflavin (B2) cross-linking. Local antimicrobial therapy was continued after the procedure. In all cases, the progression of corneal melting was halted after PAR treatment. Emergency keratoplasty was not necessary in any of the 7 eyes presented. More importantly, all the ulcers were healed without significant vascularization. PAR is a promising option for treating patients with therapy-refractory infectious keratitis to avoid emergency keratoplasty and should be considered as a potential adjuvant therapeutic tool in such eyes.

  20. Corneal wound healing is compromised by immunoproteasome deficiency.

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    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.

  1. Optimal blind quantum computation. (United States)

    Mantri, Atul; Pérez-Delgado, Carlos A; Fitzsimons, Joseph F


    Blind quantum computation allows a client with limited quantum capabilities to interact with a remote quantum computer to perform an arbitrary quantum computation, while keeping the description of that computation hidden from the remote quantum computer. While a number of protocols have been proposed in recent years, little is currently understood about the resources necessary to accomplish the task. Here, we present general techniques for upper and lower bounding the quantum communication necessary to perform blind quantum computation, and use these techniques to establish concrete bounds for common choices of the client's quantum capabilities. Our results show that the universal blind quantum computation protocol of Broadbent, Fitzsimons, and Kashefi, comes within a factor of 8/3 of optimal when the client is restricted to preparing single qubits. However, we describe a generalization of this protocol which requires exponentially less quantum communication when the client has a more sophisticated device.

  2. A Smart Infrared Microcontroller-Based Blind Guidance System

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    Amjed S. Al-Fahoum


    Full Text Available Blindness is a state of lacking the visual perception due to physiological or neurological factors. The partial blindness represents the lack of integration in the growth of the optic nerve or visual centre of the eye, and total blindness is the full absence of the visual light perception. In this work, a simple, cheap, friendly user, smart blind guidance system is designed and implemented to improve the mobility of both blind and visually impaired people in a specific area. The proposed work includes a wearable equipment consists of head hat and mini hand stick to help the blind person to navigate alone safely and to avoid any obstacles that may be encountered, whether fixed or mobile, to prevent any possible accident. The main component of this system is the infrared sensor which is used to scan a predetermined area around blind by emitting-reflecting waves. The reflected signals received from the barrier objects are used as inputs to PIC microcontroller. The microcontroller is then used to determine the direction and distance of the objects around the blind. It also controls the peripheral components that alert the user about obstacle's shape, material, and direction. The implemented system is cheap, fast, and easy to use and an innovative affordable solution to blind and visually impaired people in third world countries.

  3. Traumatic Wound Dehiscence following Corneal Transplantation

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    Mohammad-Reza Jafarinasab


    Full Text Available Purpose: To investigate the incidence, mechanisms, characteristics, and visual outcomes of traumatic wound dehiscence following keratoplasty. Methods: Medical records of 32 consecutive patients with traumatic globe rupture following keratoplasty who had been treated at our center from 2001 to 2009 were retrospectively reviewed. Results: The study population consisted of 32 eyes of 32 patients including 25 men and 7 women with history of corneal transplantation who had sustained eye trauma leading to globe rupture. Mean patient age was 38.1 (range, 8 to 87 years and median interval between keratoplasty and the traumatic event was 9 months (range, 30 days to 20 years. Associated anterior segment findings included iris prolapse in 71.9%, lens extrusion in 34.4%, and hyphema in 40.6% of eyes. Posterior segment complications included vitreous prolapse (56%, vitreous hemorrhage (28% and retinal detachment (18%. Eyes which had undergone deep anterior lamellar keratoplasty (DALK; 5 cases, 15.6% tended to have less severe presentation and better final visual acuity. There was no correlation between the time interval from keratoplasty to the traumatic event, and final visual outcomes. Conclusion: The host-graft interface demonstrates decreased stability long after surgery and the visual prognosis of traumatic wound dehiscence is poor in many cases. An intact Descemet′s membrane in DALK may mitigate the severity of ocular injuries, but even in these cases, the visual outcome of globe rupture is not good and prevention of ocular trauma should be emphasized to all patients undergoing any kind of keratoplasty.

  4. The theory and art of corneal cross-linking

    Directory of Open Access Journals (Sweden)

    Rebecca McQuaid


    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.

  5. Corneal complications and visual impairment in vernal keratoconjunctivitis patients

    International Nuclear Information System (INIS)

    Arif, A.S.; Aaqil, B.; Siddiqui, A.; Nazneen, Z.; Farooq, U.


    Vernal kerato-conjunctivitis (VKC) is an infrequent but serious form of allergic conjunctivitis common in warm and humid areas where air is rich in allergens. It affects both eyes asymmetrically. Although VKC is a self-limiting disease but visions affecting corneal complications influence the quality of life in school children. The aim of this study was to list the corneal complications due to this condition and to find out the extent of visual impairment among VKC patients. Methods: This cross-sectional study was conducted in the department of Ophthalmology, Benazir Bhutto Shaheed Hospital on 290 eyes of diagnosed cases of VKC. The diagnosis of VKC was made on the basis of history and examination. Visual acuity was recorded using Snellen's notation and visual impairment was classified according to World Health Organization classification for visual disabilities. Results: The mean age of presentation was 10.83+-6.13 years. There were 207 (71.4%) males and 83 (28.6%) females. Corneal scarring was observed in 59 (20.3%) eyes. Keratoconus was found to be in 17 (5.9%) eyes. Shield ulcer was detected in 09 (3.1%) eyes while 07 (2.4%) eyes had corneal neovascularization. Majority of the patients with visual loss had corneal scarring and the complication that led to severe visual loss in most of the eyes was Keratoconus. Conclusion: Vernal kerato-conjunctivitis in the presence of corneal complications is a sight threatening disease and can lead to severe visual impairment. (author)

  6. Community practice patterns for bacterial corneal ulcer evaluation and treatment. (United States)

    Park, Jennifer; Lee, Kim M; Zhou, Helen; Rabin, Moriah; Jwo, Kevin; Burton, William B; Gritz, David C


    To examine current practice patterns in the management of bacterial keratitis among U.S. ophthalmologists and differences in the management and opinions between cornea specialists and non-cornea specialists. A questionnaire was distributed to randomly selected ophthalmologists in July 2011 using an online survey system. It inquired about the number of patients with corneal ulcers seen monthly, frequency of Gram staining and culturing corneal ulcers, maintenance of diagnostic supplies, opinions on when culturing is necessary for corneal ulcers, treatment preferences for different severities of bacterial corneal ulcers, and opinions regarding relative efficacy of fourth-generation fluoroquinolones and fortified broad-spectrum antibiotics. One thousand seven hundred one surveys were distributed, and 486 (28.6%) surveys were returned. A minority of corneal ulcers was Gram stained (23.7%±34.1%, mean±SD) or cultured (35.1%±38.0%), but cornea specialists were more likely to perform both. The most popular antibiotic for the treatment of less severe ulcers was moxifloxacin (55.4%), and the most popular treatment of more severe ulcers was fortified broad-spectrum antibiotics (62.7%). Cornea specialists were significantly more likely than non-cornea specialists to prescribe fortified antibiotics for more severe corneal ulcers (78.1% vs. 53.7%, Pcorneal ulcers (79.6% of cornea specialists vs. 60.9% of non-cornea specialists, P<0.001). Cornea specialists and non-cornea specialists manage bacterial keratitis differently, with cornea specialists more likely to perform diagnostic testing and prescribe fortified broad-spectrum antibiotics for severe bacterial keratitis. Additional prospective studies demonstrating visual outcomes after differential treatment of bacterial keratitis are needed.


    Directory of Open Access Journals (Sweden)

    E. A. Kasparova


    Full Text Available Aim. To improve the treatment of early infectious corneal ulcers by combining microdiathermocoagulation (MDC, external autocytokinotherapy, and antiviral and/or antibacterial therapy. patients and methods. The study enrolled 2 groups of outpatients (a total of 112 patients, 112 eyes who either showed no improvement or deteriorated under 7-day to 1.5-month therapeutic treatment. Group I included 70 patients (70 eyes with superficial corneal ulcers due to herpes virus infection under antiviral therapy (instillations and periocular injections of Poludan (PolyA:PoliU as well as Zovirax 3% ophthalmic ointment, group II — 42 patients (42 eyes with early-stage purulent corneal ulcers under instillations of modern antibiotics (current-generation fluoroquinolones. results and discussion. The combination of MDC and external autocytokinotherapy is the most effective treatment for torpid herpetic ulcerative keratitis that allows a reliable reduction in the recovery period: from 24.1±2.2 days (therapeutic treatment only down to 9.2±1.3 days (both methods plus antiviral therapy. Moreover, MDC is the treatment of choice in outpatients with purulent corneal ulcer in its early stage. The healing period in this case can be also reliably reduced (р<0.05 from 18.6±1.9 days (MDC plus antibacterial therapy. Hence, MDC is a highly effective urgent method of treatment available to ambulatory care patients with herpetic keratitis and early-stage purulent corneal ulcers. External autocytokinotherapy shows a pronounced anti-inflammatory and regenerative effect. When applied together, MDC and external autocytokinotherapy act synergistically and provide twice as short treatment periods. MDC as well as its combination with external autocytokinotherapy, if started early, allow to avoid keratoplasty in most patients with herpetic keratitis and early-stage purulent corneal ulcers.

  8. Karyotype changes in cultured human corneal endothelial cells


    Miyai, Takashi; Maruyama, Yoko; Osakabe, Yasuhiro; Nejima, Ryohei; Miyata, Kazunori; Amano, Shiro


    Purpose To examine karyotype changes in cultured human corneal endothelial cells (HCECs). Methods HCECs with Descemet’s membrane were removed from 20 donors of various ages (range, 2–77 years; average, 43.7±26.4 years) and cultured on dishes coated with extracellular matrix produced by bovine corneal endothelial cells (BCECs). Karyotype changes were examined by G-band karyotyping of HCECs at the third passage from 12 donors and the fifth passage from 16 donors. The number of chromosomes was a...

  9. Effect of 0.4% benoxinate hydrochloride on corneal sensitivity, measured using the non-contact corneal aesthesiometer (NCCA). (United States)

    Murphy, P J; Blades, K J; Patel, S


    The Non-Contact Corneal Aesthesiometer (NCCA) was used to monitor the effect of topical anesthesia on corneal sensitivity loss and recovery. In a single masked randomized study, one drop of nonpreserved 0.4% benoxinate hydrochloride was instilled in either the right, left, or both eyes of 20 subjects on separate days, and measurements were made of the central corneal sensitivity in the right eye over a 60-min period. As controls, 10 subjects were retested, without any anesthetic instillation, over the same time period. No significant differences were found between these two benoxinate treatments, nor between the contralateral treatment and controls. Results indicate that there is no contralateral effect of benoxinate anesthesia, and that full recovery does not occur until 60 min after instillation. No effect on the depth and duration of anesthesia was found for iris color.

  10. Prevalence and Causes of Visual Impairment and Blindness in Shanxi Province, China. (United States)

    Li, Tong; Du, Liping; Du, Lingzhen


    To estimate the prevalence and causes of visual impairment and blindness in Shanxi Province, China. Data were obtained from the Second National Sampling Survey of Disability conducted in 2006. Blindness and visual impairment were defined as best corrected visual acuity Visual acuity (VA) was measured using a Standard Logarithmic Visual Acuity E chart (Snellen) for subjects aged 7 years and older. Participants younger than 7 years were examined using special experiments or the Childhood Graphical Visual Chart. The prevalence of visual impairment and blindness in Shanxi was estimated to be 0.6% (466/75,016) among persons up to 80 years old. The prevalence in rural areas (0.7%; 351/48,137) was significantly higher than that in urban areas (0.4%; 115/26,879) and was higher in females (0.8%; 298/36,933) than in males (0.4%; 168/38,083). The most common cause of visual impairment and blindness was cataract (44.9%), followed by retinopathy and choroidopathy (12.5%), hereditary and developmental disorders (10.3%), corneal disease (5.2%), and refractive error (4.9%). Prevalences of visual impairment and blindness in women and in rural areas were higher than in men and urban areas, and increased with age. Cataract was the most prevalent cause of visual impairment and blindness. Based on the findings from this study, we suggest that provision of support and welfare services should be organized.

  11. Nationwide reduction in the number of corneal transplantations for keratoconus following the implementation of cross-linking

    NARCIS (Netherlands)

    Godefrooij, Daniel A; Gans, Renze; Imhof, Saskia M; Wisse, Robert P L


    PURPOSE: Keratoconus is characterized by corneal ectasia and irregular astigmatism, which can lead to diminished vision and corneal scarring. Approximately 10-20% of patients with keratoconus eventually require a corneal transplant. Corneal cross-linking (CXL) is a relatively new treatment that may

  12. Deep Learning as a Tool for Automatic Segmentation of Corneal Endothelium Images

    Directory of Open Access Journals (Sweden)

    Karolina Nurzynska


    Full Text Available The automatic analysis of the state of the corneal endothelium is of much interest in ophthalmology. Up till now, several manual and semi-automatic methods have been introduced, but the need of fully-automatic segmentation of cells in the endothelium is still in search. This work addresses the problem of automatic delineation of cells in the corneal endothelium images and suggests to use the convolutional neural network (CNN to classify between cell center, cell body, and cell border in order to achieve precise segmentation. Additionally, a method to automatically select and split merged cells is given. In order to skeletonize the result, the best-fit method is used. The achieved outcomes are compared to manual annotations in order to define the mutual overlapping. The Dice index, Jaccard coefficient, modified Hausdorff distance, and several other metrics for mosaic overlapping are used. As a final check-up, the visual inspection is shown. The performed experiments revealed the best architecture for CNN. The correctness and precision of the segmentation were evaluated on Endothelial Cell “Alizarine” dataset. According to the Dice index and Jaccard coefficient, the automatically achieved cell delineation overlaps the original one with 93% precision. While modified Hausdorff distance shows 0.14 pixel distance, proving very high accuracy. These findings are confirmed by other metrics and also supported by presented visual inspection of achieved segmentations. To conclude, the methodology to achieve fully-automatic delineation of cell boundaries in the corneal endothelium images was presented. The segmentation obtained as a result of pixel classification with CNN proved very high precision.

  13. Acute corneal edema without epithelium compromise. A case report and literature review

    Directory of Open Access Journals (Sweden)

    José Augusto Urrego-Díaz


    Full Text Available Acute corneal edema is caused by various factors, with different levels of severity, and various forms of presentation. This paper reports the case of a male patient presenting with acute corneal edema without epithelium compromise, whose clinical picture, ophthalmological examination and additional tests did not reveal its etiology. Also, a review of available literature was conducted looking for all known causes of acute corneal edema, which are classified according to the etiology of the corneal edema into injury or inflammation of the corneal epithelium or stroma, endothelial dysfunction or increase in intraocular pressure.

  14. Corneal Collagen Cross-linking for the Treatment of Progressive Corneal Ectasia: 6-Year Prospective Outcome in a French Population. (United States)

    Poli, Muriel; Lefevre, Amélie; Auxenfans, Céline; Burillon, Carole


    To evaluate 6-year results of standardized epithelium-off corneal collagen cross-linking (CXL) for treatment of progressive corneal ectasia. Prospective, consecutive, interventional case series. Thirty-six eyes of 25 consecutive patients with documented progressive primary or iatrogenic corneal ectasia underwent CXL following the Siena protocol. The main outcome measures included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, biomicroscopy and fundus appearance, topography-derived steep and flat keratometry (Kmax, Kmin), central corneal thickness (CCT), intraocular pressure with Goldmann applanation tonometer (GAT-IOP), and endothelial cell density (ECD), recorded at baseline and months 1, 3, 6, 12, 24, 36, and 72. Bilateral macular optical coherence tomography was performed at the endpoint visit. The mean follow-up was 66 ± 6 months (range, 60-78 months). At 6 years, CXL stabilized primary and iatrogenic corneal ectasia in 89% of the patients. In bilateral CXL, the progression of the first eye was highly predictive of the fellow eye's outcome. At the endpoint follow-up, the mean outcome variations were: UDVA: -0.08 ± 0.36 logMAR (P = .2); CDVA: -0.14 ± 0.28 logMAR (P = .004); Kmax: +0.11 ± 1.70 diopters (D) (P = .7); Kmin: -0.25 ± 1.25 D (P = .2); CCT: -16.38 ± 37 μm (P = .01); GAT-IOP: +1.0 ± 2.3 mm Hg (P = .01); ECD: +31 ± 400 cells/mm(2) (P = .6); no cases of macular toxicity or severe adverse events were reported. At 6 years, CXL maintains long-term results in halting the progression of corneal ectasia, with significant improvement in CDVA and long-term stability of keratometry. Further clinical studies with longer follow-up and larger series would be necessary to definitely confirm these results. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. RUDO: A Home Ambient Intelligence System for Blind People. (United States)

    Hudec, Milan; Smutny, Zdenek


    The article introduces an ambient intelligence system for blind people which besides providing assistance in home environment also helps with various situations and roles in which blind people may find themselves involved. RUDO, the designed system, comprises several modules that mainly support or ensure recognition of approaching people, alerting to other household members' movement in the flat, work on a computer, supervision of (sighted) children, cooperation of a sighted and a blind person (e.g., when studying), control of heating and zonal regulation by a blind person. It has a unified user interface that gives the blind person access to individual functions. The interface for blind people offers assistance with work on a computer, including writing in Braille on a regular keyboard and specialized work in informatics and electronics (e.g., programming). RUDO can complement the standard aids used by blind people at home, it increases their independence and creates conditions that allow them to become fully involved. RUDO also supports blind people sharing a home with sighted people, which contributes to their feeling of security and greater inclusion in society. RUDO has been implemented in a household for two years, which allows an evaluation of its use in practice.

  16. Corneal collagen crosslinking for keratoconus and corneal ectasia: One-year results. (United States)

    Hersh, Peter S; Greenstein, Steven A; Fry, Kristen L


    To evaluate 1-year outcomes of corneal collagen crosslinking (CXL) for treatment of keratoconus and corneal ectasia. Cornea and refractive surgery subspecialty practice. Prospective randomized controlled clinical trial. Collagen crosslinking was performed in eyes with keratoconus or ectasia. The treatment group received standard CXL and the sham control group received riboflavin alone. Principal outcomes included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, astigmatism, and topography-derived outcomes of maximum and average keratometry (K) value. The UDVA improved significantly from 0.84 logMAR ± 0.34 (SD) (20/137) to 0.77 ± 0.37 logMAR (20/117) (P = .04) and the CDVA, from 0.35 ± 0.24 logMAR (20/45) to 0.23 ± 0.21 logMAR (20/34) (Pectasia subgroup, respectively. The maximum K value decreased by 2.0 D or more in 22 patients (31.0%) and increased by 2.0 D or more in 3 patients (4.2%). Collagen crosslinking was effective in improving UDVA, CDVA, the maximum K value, and the average K value. Keratoconus patients had more improvement in topographic measurements than patients with ectasia. Both CDVA and maximum K value worsened between baseline and 1 month, followed by improvement between 1, 3, and 6 months and stabilization thereafter. No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  17. One-year follow-up of corneal confocal microscopy after corneal cross-linking in patients with post laser in situ keratosmileusis ectasia and keratoconus. (United States)

    Kymionis, George D; Diakonis, Vasilios F; Kalyvianaki, Maria; Portaliou, Dimitra; Siganos, Charalampos; Kozobolis, Vasilios P; Pallikaris, Aristophanis I


    To investigate corneal tissue alterations after corneal collagen cross-linking in patients with post laser in situ keratosmileusis (LASIK) keratectasia and keratoconus. Prospective comparative case series. Five patients (5 eyes) with iatrogenic keratectasia after LASIK and 5 patients (5 eyes) with progressive keratoconus were included. All eyes underwent corneal cross-linking and were assessed by corneal in vivo confocal microscopy. Three normal/healthy and 3 post-LASIK without ectasia corneas were also examined as controls. All corneas revealed normal epithelial thickness before and after surgery. Images of both keratoconic and post-LASIK corneal ectasia eyes revealed similar morphologic alterations. The subepithelial nerve plexus was absent immediately after treatment; regeneration of nerves was evident after the third postoperative month. Keratocytes were absent from the anterior 300 mum of the stroma in the first 3 months while the posterior stromal density of keratocytes was increased. Corneal collagen fibers in the anterior stroma were distributed unevenly in a net-like formation. Full-thickness keratocyte repopulation in the anterior and mid-corneal stroma was detected 6 months after treatment. The corneal endothelium did not undergo any significant changes, since the cell density and hexagonality was not found altered during the follow-up period. Keratocyte nuclei apoptosis in the anterior and intermediate corneal stroma along with collagen alterations were observed during the first 3 postcorneal cross-linking months. Gradual keratocyte repopulation was demonstrated over the following months. Corneal alterations after corneal cross-linking were similar in both keratoconic and post-LASIK corneal ectasia eyes.

  18. Homer: The Blind Bard (United States)

    Doorley, Rachelle; King, Judith


    This article describes notable cultural, historical, and artistic elements emanating from sculptures originating in ancient Greece. The "blind bard" and its connection to the legendary Greek poet, Homer; Homer's impact on literary history; trends among Roman sculptures; and Roman replication of Greek art are described. Questions to…

  19. Corneal biomechanical properties after femtosecond laser assisted LASIK with the corneal visualization Scheimpflug technology and ocular response analyzer

    Directory of Open Access Journals (Sweden)

    Jing Li


    Full Text Available AIM: To investigate the changes of corneal biomechanical properties before and after femtosecond laser assisted LASIK(FS-LASIKusing Corneal Visualisation Scheimpflug Technology(Corvis STand Ocular Response Analyzer(ORA, and the correlation with other myopic parameters. METHODS:Sixty three patients(63 eyeswho had myopic femtosecond laser assisted LASIK(FS-LASIKwere enrolled in the study. The right eye of each patient was analyzed in this study. The corneal biomechanical parameters pre-operative and 1mo post-operative was measured with the Corvis ST(Oculus, Wetzlar, Germanyand ORA(Reichert, Buffalo, New York, USA. Comparison of the biomechanical property values before and after surgery was peformed using Paired t-test or Mann-Whitney U. Pearson or Spearman correlations were used to evaluate the relationship between parameters.RESULTS: The postoperative 1st A-time, Vin, 2nd A length, Vout, HC time and Radius demonstrate significant decreases comparing with preoperative values(P=0.00, P=0.00, P=0.00, P=0.00, P=0.00, P=0.00 respectively. The postoperative 2nd A-time, DA and PD significantly increases(P=0.00, P=0.00, P=0.00, however, the 1st A length had no significant difference after surgery. The CH and CRF were significantly lower after FS-LASIK(P=0.00, P=0.00. A statistically significant correlation coefficient was found between preoperative central corneal thickness(CCTwith postoperative-preoperative changes of 1st A-time, 2nd A-time, DA and Radius respectively(P=0.01, P=0.04, P=0.03, P=0.01. CONCLUSION:There were significantly changes of corneal biomechanical properties after FS-LASIK surgery. The changes of corneal biomechanical properties after FS-LASIK can be reflected by some parameters of Corvis ST and ORA. The mainly influence of corneal biomechanical alteration was possibly correlation with corneal thickness.

  20. No such thing as a "blind culture". (United States)

    Weisleder, Pedro


    Cochlear implant technology has altered the landscape for the Deaf and for those who provide services to the profoundly hearing impaired. As indicated by Teagle in one of the companion articles, cochlear implants afford the profoundly hearing impaired child the ability to circumvent the effects of deafness. Cochlear implants, as indicated by Lee in the other companion article, are regarded differently by members of the Deaf Community where some see the technology as a threat to Deaf Culture. Members of a different community, which comprises the visually impaired, cite lack of a common language as the main argument against the existence of a "Blind Culture." As indicated by Pierce "We [the blind] often enjoy each other's company, and we certainly spend time together working on the problems that face what we often call the 'blind community,' but I would argue that this community is different from an actual culture."

  1. Severe microbial keratitis and associated perforation after corneal crosslinking for keratoconus. (United States)

    Rana, M; Lau, A; Aralikatti, A; Shah, S


    To report two cases of microbial keratitis with subsequent corneal perforation immediately following corneal collagen crosslinking (CXL). Retrospective case note review. First case was a 19 year old female presented with staphylococcal corneal abscess 3 days post CXL procedure. Corneal perforation occurred during hospital admission and was successfully treated with corneal gluing. Microbial keratitis eventually resolved, with both topical and systemic antibiotics therapy, resulting in a vascularized corneal scar. Second case was an 18 year old male whom developed Methicillin Resistant Staphylococcus aureus (MRSA) corneal abscess 5 days after CXL procedure for progressive keratoconus. Corneal perforation occurred 48 h after presentation and patient underwent uneventful corneal gluing. Although infective keratitis was successfully treated with topical therapy, patient had visual outcome of count fingers due to scarring. CXL has been widely used in the treatment of corneal ectatic conditions and complications, such as infective keratitis, are uncommon post procedure. We present two cases of severe microbial keratitis with subsequent corneal perforation within 7 days of CXL. The exact mechanism for the accelerated keratolysis process is unclear. Nonetheless, patients should be well-informed of such potentially devastating complication. Copyright © 2014. Published by Elsevier Ltd.

  2. Postural control in blind subjects. (United States)

    Soares, Antonio Vinicius; Oliveira, Cláudia Silva Remor de; Knabben, Rodrigo José; Domenech, Susana Cristina; Borges Junior, Noe Gomes


    To analyze postural control in acquired and congenitally blind adults. A total of 40 visually impaired adults participated in the research, divided into 2 groups, 20 with acquired blindness and 20 with congenital blindness - 21 males and 19 females, mean age 35.8 ± 10.8. The Brazilian version of Berg Balance Scale and the motor domain of functional independence measure were utilized. On Berg Balance Scale the mean for acquired blindness was 54.0 ± 2.4 and 54.4 ± 2.5 for congenitally blind subjects; on functional independence measure the mean for acquired blind group was 87.1 ± 4.8 and 87.3 ± 2.3 for congenitally blind group. Based upon the scale used the results suggest the ability to control posture can be developed by compensatory mechanisms and it is not affected by visual loss in congenitally and acquired blindness.





    A review is made on the research and studies concerning physical and motor development of blind children. An emphasis is also put on development of hand movements as part of the whole motor development process of the blind.

  4. Postural control in blind subjects

    Directory of Open Access Journals (Sweden)

    Antonio Vinicius Soares


    Full Text Available Objective: To analyze postural control in acquired and congenitally blind adults. Methods: A total of 40 visually impaired adults participated in the research, divided into 2 groups, 20 with acquired blindness and 20 with congenital blindness - 21 males and 19 females, mean age 35.8 ± 10.8. The Brazilian version of Berg Balance Scale and the motor domain of functional independence measure were utilized. Results: On Berg Balance Scale the mean for acquired blindness was 54.0 ± 2.4 and 54.4 ± 2.5 for congenitally blind subjects; on functional independence measure the mean for acquired blind group was 87.1 ± 4.8 and 87.3 ± 2.3 for congenitally blind group. Conclusion: Based upon the scale used the results suggest the ability to control posture can be developed by compensatory mechanisms and it is not affected by visual loss in congenitally and acquired blindness.

  5. Imaging of the Corneal Subbasal Whorl-like Nerve Plexus: More Accurate Depiction of the Extent of Corneal Nerve Damage in Patients With Diabetes. (United States)

    Utsunomiya, Tsugiaki; Nagaoka, Taiji; Hanada, Kazuomi; Omae, Tsuneaki; Yokota, Harumasa; Abiko, Atsuko; Haneda, Masakazu; Yoshida, Akitoshi


    To show that noninvasive in vivo corneal confocal microscopy (IVCM) can make more accurate imaging of the corneal subbasal nerve plexus possible. This diagnostic technique monitors the status of diabetic peripheral neuropathy. However, it is difficult to accurately confirm the corneal area captured by IVCM, which can induce measurement errors. Because the whorl-like characteristic pattern of the corneal subbasal nerve plexus is in the inferocentral cornea, we evaluated whether IVCM images of the whorl-like patterns can accurately evaluate the corneal nerve fibers in diabetic neuropathy. Forty-seven patients with diabetes (DM group) and 21 healthy control subjects underwent IVCM examination to compare the characteristics of the corneal subbasal nerve plexus around the central cornea (conventional method) and the whorl-like pattern in the inferocentral cornea (study method). We measured the total corneal nerve fiber and branch length (CNFL). The total CNFL were significantly shorter in the DM group than in the control group and tended to decrease with progression of diabetic retinopathy, nephropathy, neuropathy, and decreased corneal sensation. There was a significant positive correlation between the CNFL values obtained with the conventional method and those obtained with the study method. The coefficient of variation of the CNFL values in the study method was significantly smaller than in the conventional method. Our findings indicated that IVCM measurements of the whorl-like patterns may accurately define the extent of corneal nerve damage in order to monitor diabetic peripheral neuropathy.

  6. Automated boundary segmentation and wound analysis for longitudinal corneal OCT images (United States)

    Wang, Fei; Shi, Fei; Zhu, Weifang; Pan, Lingjiao; Chen, Haoyu; Huang, Haifan; Zheng, Kangkeng; Chen, Xinjian


    Optical coherence tomography (OCT) has been widely applied in the examination and diagnosis of corneal diseases, but the information directly achieved from the OCT images by manual inspection is limited. We propose an automatic processing method to assist ophthalmologists in locating the boundaries in corneal OCT images and analyzing the recovery of corneal wounds after treatment from longitudinal OCT images. It includes the following steps: preprocessing, epithelium and endothelium boundary segmentation and correction, wound detection, corneal boundary fitting and wound analysis. The method was tested on a data set with longitudinal corneal OCT images from 20 subjects. Each subject has five images acquired after corneal operation over a period of time. The segmentation and classification accuracy of the proposed algorithm is high and can be used for analyzing wound recovery after corneal surgery.

  7. [Expression and function of receptors for advanced glycation end products in bovine corneal endothelial cells]. (United States)

    Kaji, Yuichi


    Corneal endothelial cell loss is a change that occurs with age, but its mechanism is still unclear. We postulated that interaction between advanced glycation end product(AGE) and its receptors is implicated in the corneal endothelial cell loss with age. We investigated the expression of AGE receptors: receptors for AGE(RAGE) and galectin-3 in bovine corneal endothelial cells by reverse transcription-polymerase chain reaction(RT-PCR) and immunohistochemistry. In addition, we investigated the effect of AGE on the cultured corneal endothelial cells. Expression of RAGE and galectin-3 was detected in bovine corneal endothelial cells. Galectin-3 was important in the internalization of AGE. In contrast, RAGE was important in the generation of reactive oxygen species and induction of apoptosis. Based on these data, the interaction of AGE in aqueous humor and AGE receptors expressed on the corneal endothelial cells was speculated to have a role in the corneal endothelial cell loss with age.

  8. Interaction of ultraviolet light with the cornea: clinical implications for corneal crosslinking. (United States)

    Lombardo, Marco; Pucci, Giuseppe; Barberi, Riccardo; Lombardo, Giuseppe


    Understanding ultraviolet (UV) interaction with the human corneal tissue is of interest among corneal specialists given the widespread application of corneal crosslinking. This article reviews the current knowledge of light interaction with the cornea in the UV wavelength range. It also uses a novel experimental study to illustrate the role of 2 important corneal properties that have not yet been clarified: the epithelial contribution to overall UVA corneal absorbance and the regional anisotropy of UVA light transmittance. Finally, it presents the most recent insights into how different methods of UVA light irradiation and corneal soaking with riboflavin influence the outcome of corneal crosslinking. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  9. Causes of blindness in rural Myanmar (Burma: Mount Popa Taung-Kalat Blindness Prevention Project

    Directory of Open Access Journals (Sweden)

    Arie Y Nemet


    Full Text Available Arie Y Nemet1, Pinhas Nemet2, Geoff Cohn3, Gina Sutton, Gerald Sutton4, Richard Rawson41Department of Ophthalmology, Sydney Hospital and Sydney Eye Hospital, Sydney, Australia; 2Sackler School of Medicine, Tel-Aviv University, Israel; 3Departments of Ophthalmology, University of New South Wales, Sydney, Australia; 4Department of Ophthalmology, University of Sydney, AustraliaPurpose: This study is a review of the major causes of visual impairment (VI and severe visual impairment/blindness (SVI/BL in Mount Popa Taung-Kalat, a rural region in Myanmar (Burma.Methods: A review of our clinical records of consecutive patients attending clinics was conducted. Participants of all ages (n = 650 of the population of Mount Popa Taung-Kalat and villages in its vicinity underwent ophthalmic interview and a detailed dilated ocular evaluation by trained Australian ophthalmologists and ophthalmic nurses. This evaluation included anterior segment examination with a slit lamp, intraocular pressure recording, and direct or indirect ophthalmoscopy. VI and SVI/BL were defined by the World Health Organization (WHO criteria. Results: Six hundred fifty subjects were screened, with a mean age of 49.0 ± 20.6 years (range, 1–99. One hundred five patients (16.2% were children (ages 1–18. Five hundred thirty-one eyes of the total 1,300 eyes (39.5% had VI/SVI/BL, and 40 eyes of the children (38.1% (average age 15.3 ± 13.3 had VI/SVI/BL. The leading causes of VI/SVI/BL were cataract with 288 cases (54.2%, glaucoma with 84 cases (15.8%, and corneal pathology with 78 cases (14.7%. Of all the VI/SVI/BL cases, 8.4% were preventable, 81.9% were treatable, and total of 90.5% were avoidable.Conclusions: In the current study, cataracts were the major cause of blindness and visual impairment, and most of the ophthalmic pathology causing blindness is avoidable. These results highlight the lack of basic ophthalmologist eye care and optician resources in rural regions in Myanmar

  10. The Impact of Pterygium Excision on Corneal Astigmatism

    International Nuclear Information System (INIS)

    Khan, F. A.; Niazi, S. P. K.; Khan, D. A.


    Objective: To compare the corneal astigmatism before and after the excision of pterygium and also to determine the correlation of pterygium size with the postoperative corneal astigmatism. Study Design: Cross-sectional interventional study. Place and Duration of Study: Eye Department, Combined Military Hospital, Abbottabad, from May 2011 to March 2012. Methodology: Thirty patients underwent pterygium excision. Pre-operatively Snellen visual acuity, manifest refraction and slit lamp examination was done. The size of the pterygium was recorded in mm by projecting a horizontal slit lamp beam from the limbus to the apex. All the pterygium were equal to or greater than 2.5 mm. Keratometry was performed with an automated keratometer. Keratometric data was recorded pre-operatively and at 28 days postoperatively. Wilcoxon signed rank test was used for comparing the pre-operative and the postoperative corneal astigmatism. Spearman's rank order was calculated to observe correlation of pterygium size with the postoperative astigmatism. Results: The median (mean rank) pre-operative astigmatism of 2.25 (15.50) reduced to a median (mean rank) postoperative astigmatism of 1.30 (14.96). This decrease in the postoperative astigmatism was statistically significant (p < 0.001). There was a statistically non-significant correlation between the postoperative astigmatism and the pterygium size (rs = -0.29, p = 0.12). Conclusion: Pterygium excision caused significant reduction in corneal astigmatism. (author)

  11. Axial Length/Corneal Radius of Curvature Ratio and Refractive ...

    African Journals Online (AJOL)


    Dec 5, 2017 ... variously described as determined by the ocular biometric variables. There have been many studies on the relationship between refractive error and ocular axial length (AL), anterior chamber depth, corneal radius of curvature (CR), keratometric readings as well as other ocular biometric variables such as ...

  12. Treatment of Corneal Neovascularization Using Anti-VEGF Bevacizumab

    Directory of Open Access Journals (Sweden)

    Deli Krizova


    Full Text Available Purpose. To evaluate antiangiogenic effect of local use of bevacizumab (anti-VEGF antibody in patients with corneal neovascularization. Methods. Patients were divided into two groups. All patients suffered from some form of corneal neovascularization (NV. Patients in group A received 0.2–0.5 mL of bevacizumab solution subconjunctivally (concentration 25 mg/mL in a single dose. Group A included 28 eyes from 27. Patients in group B applied bevacizumab eye drops twice daily (concentration 2.5 mg/mL for two weeks. Group B included 38 eyes from 35 patients. We evaluated the number of corneal segments affected by NV, CDVA, and the incidence of complications and subjective complaints related to the treatment. The minimum follow-up period was six months. Results. By the 6-month follow-up, in group A the percentage reduction of the affected peripheral segments was 21.6% and of the central segments was 9.6%; in group B the percentage reduction of the central segments was 22.7% and of the central segments was 38.04%. In both groups we noticed a statistically significant reduction in the extent of NV. Conclusion. The use of bevacizumab seems to be an effective and safe method in the treatment of corneal neovascularization, either in the subconjunctival or topical application form.

  13. Scleral lens tolerance after corneal cross-linking for keratoconus

    NARCIS (Netherlands)

    Visser, Esther Simone; Soeters, Nienke; Tahzib, Nayyirih G.


    Purpose. Subjective and objective evaluation of scleral lens tolerance and fitting before and after corneal cross-linking (CXL) for progressive keratoconus. Methods. In this prospective cohort, evaluations were made of 18 unilateral eyes in patients who underwent CXL and had been wearing scleral

  14. Vignetting and Field of View with the KAMRA Corneal Inlay

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    Achim Langenbucher


    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.

  15. Vignetting and Field of View with the KAMRA Corneal Inlay (United States)

    Goebels, Susanne; Szentmáry, Nóra; Seitz, Berthold


    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. PMID:24324954

  16. Genetics Home Reference: lattice corneal dystrophy type II (United States)

    ... network of protein filaments that gives structure to cells (the cytoskeleton). Mutations that cause lattice corneal dystrophy type II change a single protein building block (amino acid) in the gelsolin protein. ... from the cell. These protein fragments clump together and form amyloid ...

  17. Acute hydrops with corneal perforation in post-LASIK ectasia. (United States)

    Gupta, Chirag; Tanaka, Thais Shiota; Elner, Victor M; Soong, H Kaz


    To report a case of corneal hydrops with perforation in a patient with ectasia after undergoing laser in situ keratomileusis (LASIK). An observational study with clinical, optical coherence tomographic, and histopathologic findings. A 41-year-old woman had an acute onset of blurry vision, pain, photophobia, tearing, and foreign body sensation in the right eye 10 years after undergoing unilateral LASIK in Jordan. According to her, the surgeon elected not to operate on the left eye because of a "corneal abnormality." On slit-lamp examination, a tear in Descemet membrane with a stromal cleft extending to the overlying LASIK flap interface was noted. The flap was partially dehisced by a diffuse channel of aqueous humor draining from the cleft and streaming out the temporal flap edge. When leakage failed to stop after 2 weeks of treatment with a bandage contact lens, the patient underwent penetrating keratoplasty. Histopathological examination of the host button showed a fluid-filled cleft connecting the flap interface. Slit-lamp examination and corneal topography of the contralateral left eye were consistent with keratoconus. Corneal hydrops with perforation in the setting of post-LASIK ectasia is extremely rare and may be associated with flap dehiscence requiring penetrating keratoplasty.

  18. Corneal collagen cross-linking: ectasia and beyond. (United States)

    Suri, Kunal; Hammersmith, Kristin M; Nagra, Parveen K


    Corneal collagen cross-linking has recently emerged as a novel approach for management of ectasia. This article reviews the literature published in the past 3 years about the expanding spectrum of cross-linking as a therapeutic modality and its complications. Recent studies have confirmed the beneficial effects of cross-linking in stabilization and to a lesser extent, regression of keratoconus and postrefractive surgery ectasia. Other applications include cross-linking as a combined procedure with intracorneal ring segments, and photorefractive keratectomy for ectasia, corneal edema, and infectious keratitis. Animal studies of chemical cross-linking of sclera as a potential treatment for progressive myopia have also been performed. Various modifications of the technique to increase the safety profile of cross-linking have been reported, including the use of hypoosmolar riboflavin, transepithelial cross-linking, customized epithelial debridement, and higher fluence shorter duration ultraviolet A light exposure. Reported complications include keratitis, corneal haze, endothelial cell loss and failure of treatment. Cross-linking has been shown to be an effective modality for corneal ectasia, the regression being less in patients with postrefractive ectasia than keratoconus. In a few studies, it has been found to be effective in symptomatic improvement of bullous keratopathy, and infectious keratitis but further studies are required. Cross-linking with epithelial debridement is found to be most effective but various modifications are being investigated for an improved, and better safety outcome.

  19. Electrothermal technique for the alteration of corneal curvature

    Energy Technology Data Exchange (ETDEWEB)

    Doss, J.D.; Hutson, R.L.; Albillar, J.I.


    Extreme cases of refractive error, such as those caused by keratoconus, are often not correctable by the addition of external refraction. In such cases, corneal transplant is the usual remedy. Alternatives have recently included modification of the corneal shape by thermal techniques which exploit the dramatic shrinkage of corneal collagen at temperatures of 55 to 63/sup 0/C. The use of conventional thermal techniques has been limited by damage to the epithelium and Bowman's membrane, and by the observation that the change in corneal shape is often temporary. Each of these problems appears to be related to the thermal dose profile that is generated by the conductive heating method; temperature is relatively high in the epithelium, but is below the critical shrinkage temperature in the deeper stromal collagen. A wide variability in treatment results has also been reported; this may be due to unintentional variation in technique, especially in timing the treatment. An alternative heating technique will be discussed that has a more desirable thermal dose distribution. In addition, the technique allows precise electronic control of treatment duration, and other parameters that affect thermal dose to the cornea.

  20. Corneal eccentricity as a tool for the diagnosis of keratoconus

    NARCIS (Netherlands)

    Dao, C. L.; Kok, J. H.; Brinkman, C. J.; van Mil, C. J.


    Ninety-nine eyes with keratoconus of 64 patients were examined using the sagittal radii method to determine the corneal flattening and compared with 100 eyes of 50 healthy controls. To express the degree of this flattening, four numerical eccentricity (E) values for each eye were calculated. The