WorldWideScience

Sample records for macular optical coherence

  1. Optic Coherence Tomography of Idiopathic Macular Epiretinal Membranes

    Institute of Scientific and Technical Information of China (English)

    Xing Liu; Yunlan Ling; Jingjing Huang; Xiaoping Zheng

    2002-01-01

    bjectives: To study the characteristics of optical coherence tomography (OCT)inopathic macular epiretinal membranes (IMEM) and the relationship between thethickness offovea and the vision of affected eyes.Methods:A total of 67 cases (73 eyes) with clinical diagnosis of IMEM using direct,indirect ophthalmoscope, three mirror contact lens, fundus color photography or fundusfluorescein angiography (FFA)were examined with OCTResults: Epiretinal membranes (ERMs) with macular edema were found in 32 eyes,proliferative ERMs in 20 eyes, ERMs with macular pseudoholes in 14 eyes and ERMswith laminar macular holes in 7 eyes. Based on OCT, the ERMs were clearly andpartially seperated from the retinal (27 eyes, 38.36% ), the retinal thickness of thefovea was the thickest in the proliferative ERMs and the thinnest in the ERMs withlaminar macular holes. The statistical analysis showed there was a negative correlationbetween the thickness of fovea and visual acuity ( r = - 0. 454, P = 0. 000).Conclusion:There were four types of images of OCT in IMEM: ERMs with macularedema, proliferative ERMs, ERMs with macular pseudohole and ERMs with laminarmacular hole; and the thicker the fovea under the OCT, the poorer the vision acuity in the affected eyes with ERMs.

  2. The predictive value of optical coherence tomography after grid laser photocoagulation for diffuse diabetic macular oedema

    DEFF Research Database (Denmark)

    Soliman, W.; Sander, B.; Soliman, K.A.E.N.

    2008-01-01

    Purpose: To assess the predictive value of optical coherence tomography (OCT) mapping of retinal thickness and intraretinal morphological changes after macular grid for diffuse diabetic macular oedema (DMO). Methods: We carried out a prospective, non-controlled, case series study, in which 28 con...

  3. Macular thickness measurements using Copernicus Spectral Domain Optical Coherence Tomography.

    Science.gov (United States)

    Gella, Laxmi; Raman, Rajiv; Sharma, Tarun

    2015-01-01

    To provide normal macular thickness measurements using Spectral Domain Optical Coherence Tomography (SDOCT, Copernicus, Optopol Technologies, Zawierci, Poland). Fifty-eight eyes of 58 healthy subjects were included in this prospective study. All subjects had comprehensive ophthalmic examination including best-corrected visual acuity (BCVA). All the subjects underwent Copernicus SDOCT. Central foveal thickness (CFT) and photoreceptor layer (PRL) thickness were measured and expressed as mean and standard deviation. Mean retinal thickness for each of the 9 regions defined in the Early Treatment Diabetic Retinopathy Study was reported. The data were compared with published literature in Indians using Stratus and Spectralis OCTs to assess variation in instrument measurements. The mean CFT in the study sample was 173.8 ± 18.16 microns (131-215 microns) and the mean PRL thickness was 65.48 ± 4.23 microns (56-74 microns). No significant difference (p = 0.148) was found between CFT measured automated (179.28 ± 22 microns) and manually (173.83 ± 18.1 microns). CFT was significantly lower in women (167.62 ± 16.36 microns) compared to men (180.03 ± 18 microns) (p = 0.008). Mean retinal thickness reported in this study was significantly different from published literature using Stratus OCT and Spectralis OCT. We report the normal mean retinal thickness in central 1 mm area to be between 138 and 242 microns in Indian population using Copernicus SDOCT. We suggest that different OCT instruments cannot be used interchangeably for the measurement of macular thickness as they vary in segmentation algorithms.

  4. Microperimetry and optical coherence tomography in a case of traumatic macular hole and associated macular detachment with spontaneous resolution

    Directory of Open Access Journals (Sweden)

    Lalit Aalok

    2012-01-01

    Full Text Available The association of macular detachment with posttraumatic macular hole is a known but rare occurrence. Spontaneously occurring resolution of the detachment and closure of the macular hole has been reported only once in the literature. We describe a similar rare event in a young male, the documentation of which was done serially by microperimetry (MP and optical coherence tomography (OCT. A 17-year-old male presented with a decrease in vision following a closed globe injury to the left eye. A coexisting macular hole and macular detachment were detected in the affected eye. Serial follow-up with OCT and MP documented complete resolution of the macular hole and the macular detachment within 1 week of presentation. The case highlights that spontaneous resolution of traumatic macular hole and related macular detachment may occur and a waiting period is advisable before undertaking any corrective surgical procedure. The pathophysiologic mechanisms of causation and the resolution of posttraumatic macular hole-related retinal detachment are discussed.

  5. Intraoperative Changes in Idiopathic Macular Holes by Spectral-Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Atsushi Hayashi

    2011-05-01

    Full Text Available Purpose: To examine anatomical changes in idiopathic macular holes during surgery using handheld spectral-domain optical coherence tomography (SD-OCT. Methods: Five eyes of 5 patients who underwent surgery for the repair of idiopathic macular holes were examined. The surgery included standard 25-gauge, 3-port pars plana vitrectomy, removal of the internal limiting membrane (ILM, fluid-air exchange, and 20% sulfur hexafluoride tamponade. Intraoperative SD-OCT images of the macular holes were obtained after ILM removal and under fluid-air exchange using a handheld SD-OCT. From SD-OCT images, the macular hole base diameter (MHBD was measured and compared. Results: All macular holes were successfully closed after the primary surgery. The mean MHBD under fluid-air exchange was significantly smaller than the mean MHBD after ILM removal and the preoperative mean MHBD. In 1 eye with a stage 3 macular hole, SD-OCT images revealed that the inner edges of the macular hole touched each other under fluid-air exchange. Conclusion: Fluid-air exchange significantly reduced MHBD during surgery to repair macular holes. Fluid-air exchange may be an important step for macular hole closure as it reduces the base diameter of the macular hole.

  6. Correlation between the optical coherence tomography and electroretinogram in retinal vein occlusion macular edema

    Directory of Open Access Journals (Sweden)

    Ya Xu

    2014-11-01

    Full Text Available AIM: To evaluate the correlation between retinal thickness and photopic flash electroretinogram(ERGparameters(Cone a-wave, Cone b-wave, and 30Hz flickerin patients with central retinal vein occlusion(CRVOand macular edema. METHODS: A total of 25 patients(25 CRVO eyes and 25 unaffected fellow eyeswith CRVO underwent the examination of optical coherence tomography(OCTand photopic falsh ERG. The amplitude and implicit time of the ERG parameters were extracted from the ERG traces. Retinal thicknesses were measured by OCT in nine macular subfields. Then the correlations between ERG parameters and macular morphological parameters were analyzed. RESULTS: The Cone b-wave and 30Hz flicker implicit time were correlated with macular retinal thickness in seven out of nine subfields, excluding the temporal subfields. CONCLUSION: The retinal thickness of the macular edema may be associated with inner retinal function in CRVO patients.

  7. EVALUATION OF MACULAR ISCHEMIA IN EYES WITH CENTRAL RETINAL VEIN OCCLUSION: An Optical Coherence Tomography Angiography Study.

    Science.gov (United States)

    Ghashut, Rima; Muraoka, Yuki; Ooto, Sotaro; Iida, Yuto; Miwa, Yuko; Suzuma, Kiyoshi; Murakami, Tomoaki; Kadomoto, Shin; Tsujikawa, Akitaka; Yoshimura, Nagahisa

    2017-06-30

    To quantitatively assess macular perfusion status using optical coherence tomography angiography in eyes with aflibercept-treated central retinal vein occlusion and resolved macular edema and to investigate the impact of macular morphology and perfusion status on visual function. This prospective consecutive case series included 23 patients with central retinal vein occlusion. All patients received intravitreal aflibercept injections before analysis. Visual acuity, macular sensitivity, and the macular nonperfusion area (NPA) were evaluated in eyes without macular edema. The macular NPA was evaluated by optical coherence tomography angiography using 3 mm × 3 mm images of the macula. Foveal ellipsoid zone disruption was also analyzed. The superficial macular NPA measured 4.15 mm ± 0.71 mm (95% confidence interval 3.85-4.46), and the deep macular NPA measured 4.23 mm ± 0.97 mm (95% confidence interval 3.82-4.56). The logarithm of the minimum angle of resolution visual acuity was significantly associated with foveal ellipsoid zone disruption (P = 0.001), the superficial macular NPA (P = 0.015), and the deep macular NPA (P = 0.018). Macular sensitivity correlated negatively with logarithm of the minimum angle of resolution visual acuity (P = 0.007), the superficial macular NPA (P = 0.029), and the deep macular NPA (P = 0.040), but not with the foveal ellipsoid zone disruption (P = 0.435). Optical coherence tomography angiography is a novel technique that enables segmented evaluation of the macular perfusion status in eyes with central retinal vein occlusion and provides visual prognostic information. Enlargement of the macular NPA in the superficial and deep layers was significantly correlated with impaired visual acuity and with decreased macular sensitivity in patients with aflibercept-treated central retinal vein occlusion and resolved macular edema.

  8. Quantitative analysis of the Stratus optical coherence tomography fast macular thickness map reports

    Directory of Open Access Journals (Sweden)

    Domalpally Amitha

    2010-01-01

    Full Text Available The cross sectional optical coherence tomography images have an important role in evaluating retinal diseases. The reports generated by the Stratus fast macular thickness scan protocol are useful for both clinical and research purposes. The centerpoint thickness is an important outcome measure for many therapeutic trials related to macular disease. The data is susceptible to artifacts such as decentration and boundary line errors and could be potentially erroneous. An understanding of how the data is generated is essential before utilizing the data. This article describes the interpretation of the fast macular thickness map report, assessment of the quality of an optical coherence tomography image and identification of the artifacts that could influence the numeric data.

  9. Spectral domain optical coherence tomography documented rapid resolution of pseudophakic cystoid macular edema with topical difluprednate

    Directory of Open Access Journals (Sweden)

    Chalam KV

    2012-01-01

    Full Text Available KV Chalam, Vijay Khetpal, Chirag J PatelDepartment of Ophthalmology, University of Florida Jacksonville, FL, USAIntroduction: Pseudophakic cystoid macular edema is a common cause of poor vision after cataract surgery, and topical corticosteroids and nonsteroidal anti-inflammatory drugs are used for its treatment. We investigated the effectiveness of difluprednate (Durezol®, recently approved by the US Food and Drug Administration in the treatment of cystoid macular edema, assisted with spectral domain optical coherence tomography (SD-OCT.Case report: A 63-year-old African-American woman presented 6 weeks after uneventful cataract surgery in her left eye with decreased vision and associated distortion of the central visual field. Fluorescein angiogram and SD-OCT confirmed pseudophakic cystoid macular edema. Difluprednate was topically administered twice daily and monitored with serial imaging. Resolution was noted after 1 month of topical therapy, with improvement in visual acuity and resolution of distortion.Conclusion: Difluprednate is an effective treatment for patients with severe pseudophakic cystoid macular edema. SD-OCT allows the physician to monitor resolution of the macular edema easily.Keywords: cystoid macular edema, difluprednate, spectral domain optical coherence tomography, pseudophakic

  10. Machine learning based detection of age-related macular degeneration (AMD) and diabetic macular edema (DME) from optical coherence tomography (OCT) images

    OpenAIRE

    Wang, Yu; Zhang, Yaonan; Yao, Zhaomin; Zhao, Ruixue; Zhou, Fengfeng

    2016-01-01

    Non-lethal macular diseases greatly impact patients’ life quality, and will cause vision loss at the late stages. Visual inspection of the optical coherence tomography (OCT) images by the experienced clinicians is the main diagnosis technique. We proposed a computer-aided diagnosis (CAD) model to discriminate age-related macular degeneration (AMD), diabetic macular edema (DME) and healthy macula. The linear configuration pattern (LCP) based features of the OCT images were screened by the Corr...

  11. Macular hole: 10 and 20-MHz ultrasound and spectral-domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Juliana Mantovani Bottós

    2012-12-01

    Full Text Available PURPOSE: Optical coherence tomography (OCT is valuable for macula evaluation. However, as this technique relies on light energy it cannot be performed in the presence of opaque media. In such cases, the ultrasound (US may predict some macular features. The aim of this study was to characterize images obtained by ultrasound with 10 and 20-MHz transducers comparing to OCT, as well as to analyze the relationship between the vitreous and retina in eyes with macular hole (MH. METHODS: 29 eyes of 22 patients with biomicroscopic evidence of MH at different stages were included. All patients were evaluated using ultrasonography with 10 and 20-MHz transducers and OCT. RESULTS: OCT identified signs of MH in 25 of 29 eyes. The remaining 4 cases not identified by US were pseudoholes caused by epiretinal membranes. In MH stages I (2 eyes and II (1 eye, both transducers were not useful to analyze the macular thickening, but suggestive findings as macular irregularity, operculum or partial posterior vitreous detachment (PVD were highlighted. In stages III (14 eyes and IV (5 eyes, both transducers identified the double hump irregularity and thickening. US could measure the macular thickness and other suggestive findings for MH: operculum, vitreomacular traction and partial or complete PVD. In cases of pseudoholes, US identified irregularities macular contour and a discrete depression. CONCLUSION: 10-MHz US was useful for an overall assessment of the vitreous body as well as its relationship to the retina. The 20-MHz transducer allowed valuable information on the vitreomacular interface and macular contour. OCT provides superior quality for fine morphological study of macular area, except in cases of opaque media. In these cases, and even if OCT is not available, the combined US study is able to provide a valid evaluation of the macular area improving therapeutic approach.

  12. Macular surgery using intraoperative spectral domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Mohammad Riazi-Esfahani

    2015-01-01

    Conclusion: Intraoperative SD-OCT is a useful imaging technique which provides vitreoretinal surgeons with rapid awareness of changes in macular anatomy during surgery and may therefore result in better anatomical and visual outcomes.

  13. Macular laser photocoagulation guided by spectral-domain optical coherence tomography versus fluorescein angiography for diabetic macular edema

    Directory of Open Access Journals (Sweden)

    Gallego-Pinazo R

    2011-05-01

    Full Text Available Roberto Gallego-Pinazo1,2, Ana Marina Suelves-Cogollos1, Rosa Dolz-Marco1, J Fernando Arevalo3, Salvador García-Delpech1, J Luis Mullor4, Manuel Díaz-Llopis1,2,51Department of Ophthalmology, Hospital Universitario La Fe, Valencia, Spain; 2Centro de Investigación Biomédica en Red de Enfermedades Raras, Valencia, Spain; 3Retina and Vitreous Service, Clinical Ophthalmology Center, Caracas, Venezuela; 4Unit of Experimental Ophthalmology, Hospital Universitario La Fe, Valencia, Spain; 5University of Valencia, Faculty of Medicine, Valencia, SpainBackground: The aim of this study was to compare the efficacy of spectral-domain optical coherence tomography (SD-OCT and fluorescein angiography (FA in the guidance of macular laser photocoagulation for diabetic macular edema.Methods: This was a prospective interventional clinical comparative pilot study. Forty eyes from 24 consecutive patients with diabetic macular edema were allocated to receive laser photocoagulation guided by SD-OCT or FA. Best-corrected visual acuity (BCVA, central macular thickness, and retinal volume were assessed at baseline and two months after treatment.Results: Subjects treated using FA-guided laser improved BCVA from the logarithm of the minimum angle of resolution (logMAR 0.52 ± 0.2 to 0.37 ± 0.2 (P < 0.001, and decreased mean central macular thickness from 397.25 ± 139.1 to 333.50 ± 105.7 µm (P < 0.001 and retinal volume from 12.61 ± 1.6 to 10.94 ± 1.4 mm3 (P < 0.001. Subjects treated using SD-OCT guided laser had improved BCVA from 0.48 ± 0.2 to 0.33 ± 0.2 logMAR (P < 0.001, and decreased mean central macular thickness from 425.90 ± 149.6 to 353.4 ± 140 µm (P < 0.001 and retinal volume from 12.38 ± 2.1 to 11.53 ± 1.1 mm3 (P < 0.001. No significant differences between the groups were found in two-month BCVA (P = 0.505, two-month central macular thickness (P = 0.660, or two-month retinal volume (P = 0.582.Conclusion: The short-term results of this pilot study

  14. Evaluation of Macular Thickness by Optical Coherence Tomography After Phacoemulsification Surgery

    Directory of Open Access Journals (Sweden)

    Mehmet Tetikoğlu

    2014-03-01

    Full Text Available Objectives: To evaluate the incidence of cystoid macular edema (CME, its risk factors, and macular changes by optical coherence tomography (OCT after phacoemulsification. Materials and Methods: This study included 99 eyes of 65 patients who underwent phacoemulsification surgery in Okmeydanı Training and Research Hospital, Department of Ophthalmology. Foveal thickness, macular volume, and mean macular thickness were measured by OCT preoperatively and at 1st day, 1st week, 1st, and 3rd months postoperatively. Results: In this study, the incidence of postoperative CME was 3%. The mean central foveal thickness was preoperatively 250.4 (±18.5 μm, and postoperatively was 252.08 (±23.2 μm at 1st day, 261.4 (±27.8 μm at 1st week, 270.6 (±44.4 μm at 1st month, and 265.4 (±41.6 μm at 3rd month. The statistically significant increase in foveal thickness was defined between preoperative and 1st week, 1st month, 3rd month as well as between 1st week, 1st month, and 3rd month (p<0.01. Increase in macular thickness was demonstrated in 44 eyes (44.4% which was most frequently located in the parafoveal region. Intraoperative complications like iris trauma, posterior capsule tear, and vitreous loss were increased risk of CME (p=0.001. Conclusion: Subclinical macular thickness increment begins at 1st week and reaches maximum point at 1st month. Incidence of CME increased in patients who had a complicated cataract surgery, so they should be followed closely by OCT. (Turk J Ophthalmol 2014; 44: 88-91

  15. Assessment of Macular Parameter Changes in Patients with Keratoconus Using Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Srujana Sahebjada

    2015-01-01

    Full Text Available Keratoconus is typically diagnosed through changes at the anterior ocular surface. However, we wished to assess if macular parameter changes might also occur in these patients. We assessed posterior changes through the use of optical coherence tomography and compared to a nonkeratoconus patient group. All subjects underwent clinical examination including macular thickness measurements. The generalized estimation equation model was used to estimate the means and compare the differences in various measurements between keratoconus and nonkeratoconus patients. A total of 129 keratoconus eyes of 67 cases and 174 nonkeratoconus eyes of 87 controls were analysed. Keratoconus individuals presented with a significantly greater mean retinal thickness in the central fovea, inner, and outer macula compared to the nonkeratoconus group (p<0.05. In addition, individuals presenting with the early signs of keratoconus had significantly greater inner and outer macular volume compared to the nonkeratoconus group (p<0.05. This study indicates the retina appears to thicken at the fovea and macula and had increased macular volume in keratoconus individuals compared to nonkeratoconus individuals. Thus we posit that structural retinal changes exist in keratoconus eyes that are additional to those typically seen in the anterior segment.

  16. Machine learning based detection of age-related macular degeneration (AMD) and diabetic macular edema (DME) from optical coherence tomography (OCT) images.

    Science.gov (United States)

    Wang, Yu; Zhang, Yaonan; Yao, Zhaomin; Zhao, Ruixue; Zhou, Fengfeng

    2016-12-01

    Non-lethal macular diseases greatly impact patients' life quality, and will cause vision loss at the late stages. Visual inspection of the optical coherence tomography (OCT) images by the experienced clinicians is the main diagnosis technique. We proposed a computer-aided diagnosis (CAD) model to discriminate age-related macular degeneration (AMD), diabetic macular edema (DME) and healthy macula. The linear configuration pattern (LCP) based features of the OCT images were screened by the Correlation-based Feature Subset (CFS) selection algorithm. And the best model based on the sequential minimal optimization (SMO) algorithm achieved 99.3% in the overall accuracy for the three classes of samples.

  17. Classification of wet aged related macular degeneration using optical coherence tomographic images

    Science.gov (United States)

    Haq, Anam; Mir, Fouwad Jamil; Yasin, Ubaid Ullah; Khan, Shoab A.

    2013-12-01

    Wet Age related macular degeneration (AMD) is a type of age related macular degeneration. In order to detect Wet AMD we look for Pigment Epithelium detachment (PED) and fluid filled region caused by choroidal neovascularization (CNV). This form of AMD can cause vision loss if not treated in time. In this article we have proposed an automated system for detection of Wet AMD in Optical coherence tomographic (OCT) images. The proposed system extracts PED and CNV from OCT images using segmentation and morphological operations and then detailed feature set are extracted. These features are then passed on to the classifier for classification. Finally performance measures like accuracy, sensitivity and specificity are calculated and the classifier delivering the maximum performance is selected as a comparison measure. Our system gives higher performance using SVM as compared to other methods.

  18. Optical coherence tomography of macular atrophy associated with microcephaly and presumed intrauterine Zika virus infection

    Directory of Open Access Journals (Sweden)

    Adriana Gondim de Moura Campos

    Full Text Available ABSTRACT This case report describes the retinal optical coherence tomography (OCT findings in a microcephalic infant with macular atrophy presumably caused by intrauterine Zika virus infection. OCT demonstrated atrophy of the outer retinal layers and choriocapillaris, including the outer nuclear layer and ellipsoid zone, associated with retinal pigment epithelium hyper-reflectivity and increased OCT penetration into deeper layers of the choroid and sclera. A major concern associated with this infection is the apparent increased incidence of microcephaly in fetuses born to mothers infected with the Zika virus. It is becoming increasingly difficult to ignore the upsurge in congenital microcephaly observed in Brazil. Recently, ocular findings in infants with microcephaly associated with intrauterine Zika virus infection have been described. This is the first report of OCT imaging of macular atrophy in a child with presumed Zika virus infection-associated microcephaly.

  19. Macular epiretinal brachytherapy in treated age-related macular degeneration (MERITAGE): month 12 optical coherence tomography and fluorescein angiography.

    Science.gov (United States)

    Petrarca, Robert; Dugel, Pravin U; Nau, Jeffrey; Slakter, Jason S; Jaffe, Glenn J; Jackson, Timothy L

    2013-02-01

    To report the optical coherence tomography (OCT) and fundus fluorescein angiography (FFA) results of the Macular Epiretinal Brachytherapy in Treated Age-Related Macular Degeneration study. Prospective, multicenter, interventional, noncontrolled clinical trial. Fifty-three eyes of 53 participants with chronic, active neovascular age-related macular degeneration (AMD) requiring frequent anti-vascular endothelial growth factor retreatment. Participants underwent pars plana vitrectomy with a single 24-gray dose of epimacular brachytherapy (EMB), delivered with an intraocular, handheld, cannula containing a strontium 90/yttrium 90 source positioned over the active lesion. Participants were retreated with ranibizumab administered monthly as needed, using predefined retreatment criteria. Patients underwent FFA at baseline, month 1, and month 12. Patients underwent optical coherence tomography (OCT) at baseline and then monthly for 12 months. The FFA and OCT images were evaluated by independent, central reading facilities. Change in OCT centerpoint thickness and angiographic lesion size 12 months after EMB. Mean centerpoint thickness increased by 50 μm, from 186 to 236 μm (P = 0.292), but 70% of participants had an increase of less than the mean, with a median increase of only 1.8 μm. The FFA total lesion size increased slightly by 0.79 mm(2), from 14.69 to 15.48 mm(2) (P = 0.710). Total choroidal neovascularization (CNV) area increased by 1.17 mm(2), from 12.94 to 14.12 mm(2) (P = 0.556). The classic CNV area decreased substantially by 3.70 mm(2), from 3.90 to 0.20 mm(2) (P<0.01). Predominantly classic lesions showed the greatest response, with mean Early Treatment Diabetic Retinopathy Study visual acuity improving by 1.5 letters (versus -4.0 for all participants combined); mean centerpoint thickness decreased by 43 μm (P = 0.875). The angiographic and OCT response did not correlate with lesion size at baseline. In chronic, active, neovascular AMD, EMB is associated

  20. Macular Findings Obtained by Spectral Domain Optical Coherence Tomography in Retinopathy of Prematurity

    Directory of Open Access Journals (Sweden)

    Muhammet Kazim Erol

    2014-01-01

    Full Text Available Purpose. To examine the macular findings obtained with spectral domain optical coherence tomography (SD OCT in infants with retinopathy of prematurity (ROP. Materials and Methods. The macular SD OCT images of 190 premature infants were analyzed. Data regarding central foveal thickness (CFT, cystoid macular edema (CME, and cyst grading were compared. The relationships of CFT with gestational age and birth weight were investigated. Results. The results were obtained from 358 eyes of 179 infants (81 females and 98 males of a mean gestational age of 30.9±2.7 weeks and a mean birth weight of 1609±477 g. ROP was diagnosed in 126 eyes and CME in 139 eyes. A significantly greater percentage of eyes with ROP were found to have CME (54% compared to eyes without ROP (31%; P=0.001. The incidence of CME was 46.3% for stage 1 ROP, 57.1% for stage 2, and 87.5% for stage 3. There was a weakly inverse correlation between CFT, gestational age, and birth weight (P=0.025, r=-0.227; P=0.002, r=-0.182, resp., Spearman correlation test. Conclusions. High-quality SD OCT images can be obtained from premature infants using the iVue system. Severity and frequency of CME in premature infants increase as stage of ROP increases.

  1. Macular changes of neuromyelitis optica through spectral-domain optical coherence tomography

    Science.gov (United States)

    Cheng, Lu; Wang, Jing; He, Xu; Xu, Xun; Ling, Zhen-Fen

    2016-01-01

    AIM To evaluate the thickness of the retinal layers in the macula using spectral-domain optical coherence tomography (SD-OCT) in patients with neuromyelitis optica (NMO). METHODS Spectralis SD-OCT, utilizing automated macular layer segmentation, was performed in 26 NMO patients and 26 healthy controls. Visual function including visual field tests and pattern visual evoked potential were recorded in study subjects. RESULTS Forty-one eyes from 26 NMO patients and 52 eyes from 26 age- and sex-matched healthy controls were included. Besides total macular volume, peri-paipillary retinal nerve fiber layer (RNFL) thickness, the thickness of macular RNFL, ganglion cell layer (GCL) and inner plexiform layer (IPL) were also significantly reduced in NMO patients compared to those inhealthy controls (P<0.000). No differences were found in the thickness of macular inner nuclear layer (INL), outer plexiform layer (OPL), and outer nuclear layer (ONL) between the two groups. Reversely, the outer retinal layer (ORL) was shown to be thicker in NMO than controls (P<0.05). Compared with the peri-papillary RNFL thickness, the GCL thickness was demonstrated to correlate with visual function better. CONCLUSION The study provides in vivo evidence of retinal neural loss in NMO patients and demonstrates a better structure-function correlation between retinal ganglion cell and visual function than peri-papillary RNFL does. In addition, no evidence of primary neural damage is found. Besides, the photoreceptor cells and retinal pigments epithelial (RPE) cells presumably proliferated in compensation in NMO after retinal neural loss. PMID:27990369

  2. Repeatability of swept-source optical coherence tomography retinal and choroidal thickness measurements in neovascular age-related macular degeneration

    DEFF Research Database (Denmark)

    Hanumunthadu, Daren; Ilginis, Tomas; Restori, Marie

    2017-01-01

    BACKGROUND: The aim was to determine the intrasession repeatability of swept-source optical coherence tomography (SS-OCT)-derived retinal and choroidal thickness measurements in eyes with neovascular age-related macular degeneration (nAMD). METHODS: A prospective study consisting of patients with...

  3. Correlation between intraretinal changes in diabetic macular oedema seen in fluorescein angiography and optical coherence tomography

    DEFF Research Database (Denmark)

    Soliman, W.; Sander, B.; Hasler, P.W.;

    2008-01-01

    Purpose: To study the relationship between intraretinal optical coherence tomography (OCT) and fluorescein angiography (FA) findings in eyes with diabetic macular oedema (DMO). Methods: We carried out a retrospective observational case series. Thirty eyes with previously untreated DMO underwent FA...... correlated with changes in FA: (a) focal angiographic leakage did not correspond to any obvious intraretinal abnormality in OCT in four eyes; (b) localized thickening of the outer nuclear layer in OCT corresponded to focal leaking microaneurysm (focal oedema) in FA in 11 eyes; (c) diffuse thickening...... oedema in five eyes, and (f) serous detachment of the fovea in OCT did not correspond to any distinct finding in FA in four eyes. Conclusions: Intraretinal abnormalities found in OCT correlate systemically with changes in FA. Very early DMO morphological changes may be seen better with FA than with OCT...

  4. A STUDY TO COMPARE FUNDUS FLUORESCEIN ANGIOGRAPHY AND OPTICAL COHERENCE TOMOGRAPHY IN AGE RELATED MACULAR DEGENERATION

    Directory of Open Access Journals (Sweden)

    Rani Sujatha

    2016-02-01

    Full Text Available PURPOSE To compare the diagnostic accuracy of optical coherence tomography with Fundus Fluorescein Angiography in diagnosing Age related macular degeneration. METHODS A total 25 patients newly diagnosed as Age related macular degeneration were included in the study. The study was done during the time period between August 2013 to November 2015 this is a prospective randomized hospital based study. RESULTS Maximum no of patients affected belonged to the age group of 50-70 years and 60% were females. The most common symptom was defective vision accounting for 92%. Hypertension and hyperlipidemia were the most common risk factors. 12% of the cases had unilateral disease and 88% had bilateral disease. 6% of eyes were normal in both FFA and OCT. 62% of the eyes by FFA and 61% of the eyes by OCT had dry ARMD and 32 % of the eye by FFA and 33 % by OCT had wet ARMD. CONCLUSION Fundus Fluorescein Angiography is the gold standard tool for screening ARMD and OCT is more specific in detecting early subretinal neovascular membrane and also to assess the activity of the neovascular membranes. Hence OCT is superior to FFA in diagnosing early wet ARMD and thus helps in early management of patients with ARMD.

  5. Automated Fovea Detection in Spectral Domain Optical Coherence Tomography Scans of Exudative Macular Disease

    Directory of Open Access Journals (Sweden)

    Jing Wu

    2016-01-01

    Full Text Available In macular spectral domain optical coherence tomography (SD-OCT volumes, detection of the foveal center is required for accurate and reproducible follow-up studies, structure function correlation, and measurement grid positioning. However, disease can cause severe obscuring or deformation of the fovea, thus presenting a major challenge in automated detection. We propose a fully automated fovea detection algorithm to extract the fovea position in SD-OCT volumes of eyes with exudative maculopathy. The fovea is classified into 3 main appearances to both specify the detection algorithm used and reduce computational complexity. Based on foveal type classification, the fovea position is computed based on retinal nerve fiber layer thickness. Mean absolute distance between system and clinical expert annotated fovea positions from a dataset comprised of 240 SD-OCT volumes was 162.3 µm in cystoid macular edema and 262 µm in nAMD. The presented method has cross-vendor functionality, while demonstrating accurate and reliable performance close to typical expert interobserver agreement. The automatically detected fovea positions may be used as landmarks for intra- and cross-patient registration and to create a joint reference frame for extraction of spatiotemporal features in “big data.” Furthermore, reliable analyses of retinal thickness, as well as retinal structure function correlation, may be facilitated.

  6. Diabetic Macular Ischemia Diagnosis: Comparison between Optical Coherence Tomography Angiography and Fluorescein Angiography

    Science.gov (United States)

    Lima, Talita Toledo; Louzada, Ricardo Noguera; Rassi, Alessandra Thome; Isaac, David Leonardo Cruvinel; Avila, Marcos

    2016-01-01

    Purpose. To compare fluorescein angiography (FA) and optical coherence tomography angiography (OCTA) images of foveal avascular zone (FAZ) in patients with diabetic retinopathy (DR) with and without diabetic macular ischemia (DMI). Methods. The Wilcoxon signed-rank test was used to compare area measurements and p values of <0.05 were considered statistically significant. FA and OCTA images were independently graded by 2 observers that reached agreement regarding quantitative DMI according established protocols. The ischemic area was divided into “large” macular ischemia (superior to 0.32 mm2) and “small” (inferior to 0.32 mm2) groups. Quantitative analyses of the FAZ were performed using custom software. Results. Thirty-four eyes from 34 diabetic patients were enrolled. Subjects with DMI presented a mean area on FA and OCTA of 0.68 ± 0.53 mm2 and 0.58 ± 0.35 mm2, respectively (p = 0.1374). Patients without DMI presented a mean area on FA and OCTA of 0.19 ± 0.67 mm2 and 0.20 ± 0.79 mm2, respectively (p = 0.9594). The ICC for the FAZ measurements between the 2 observers on FA and OCTA was 0.96 and 0.92, respectively. Conclusion. OCTA represents a novel technique for the diagnosis of DMI and it may become an alternative to FA for this purpose. PMID:27891250

  7. Effect of ocular magnification on macular measurements made using spectral domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Mohana Kuppuswamy Parthasarathy

    2015-01-01

    Full Text Available Aim: The aim of the present study was to study the effect of ocular magnification on macular measurements made using spectral domain optical coherence tomography (OCT. Materials and Methods: One hundred and fifty-one subjects were included from the normative study of foveal morphology carried out at our hospital. Subjects underwent comprehensive eye examination and macular scanning using Cirrus high-definition OCT and axial length (AXL measurement. Macular cube 512 × 128 scan protocol was used for scanning the macula. Automated measurements of the fovea namely foveal diameter, foveal slope (lateral measurements and foveal depth (axial measurement were taken. A correction factor for ocular magnification was done using the formula t = p × q × s, where "t0" is the corrected measurement, "p" is the magnification of OCT, "q0" is the ocular magnification, and "s" is the measurement on OCT without correction. The difference between corrected and uncorrected measurements was evaluated for statistical significance. Results: Mean AXL was 22.95 ± 0.78 mm. Refractive error ranged from −3D to +4D. Mean difference between measured and corrected foveal diameter, slope and depth was 166.05 ± 95.37 ΅m (P < 0.001, 0.81° ± 0.53° (P < 0.001 and 0.05 ± 0.49 ΅m (P = 0.178 respectively. AXL lesser than the OCT calibrated value of 24.46 mm showed an increased foveal diameter (r = 0.961, P < 0.001 and a reduced foveal slope (r = −0.863, P < 0.001 than the corrected value. Conclusion: Lateral measurements made on OCT varied with AXL s other than the OCT calibrated value of 24.46 mm. Therefore, to estimate the actual dimensions of a retinal lesion using OCT, especially lateral dimensions, we recommend correction for the ocular magnification factor.

  8. OPTICAL COHERENCE TOMOGRAPHY–BASED CORRELATION BETWEEN CHOROIDAL THICKNESS AND DRUSEN LOAD IN DRY AGE-RELATED MACULAR DEGENERATION

    Science.gov (United States)

    KO, ASHLEY; CAO, SIJIA; PAKZAD-VAEZI, KAIVON; BRASHER, PENELOPE M.; MERKUR, ANDREW B.; ALBIANI, DAVID A.; KIRKER, ANDREW W.; CUI, JING; MATSUBARA, JOANNE; FOROOGHIAN, FARZIN

    2014-01-01

    Purpose Spectral domain optical coherence tomography can be used to measure both choroidal thickness and drusen load. The authors conducted an exploratory study using spectral domain optical coherence tomography to determine if a correlation between choroidal thickness and drusen load exists in patients with dry age-related macular degeneration. Methods Forty-four patients with dry age-related macular degeneration were recruited. The drusen area and volume were determined using the automated software algorithm of the spectral domain optical coherence tomography device, and choroidal thickness was measured using enhanced depth imaging. Correlations were determined using multivariable and univariable analyses. Results The authors found an inverse correlation between choroidal thickness and drusen load (r = −0.35, P = 0.04). Drusen load was also correlated with visual acuity (r = 0.32, P = 0.04). A correlation between choroidal thickness and visual acuity was suggested (r = −0.22, P = 0.21). Conclusion Spectral domain optical coherence tomography can be used to assess the correlation between drusen load and choroidal thickness, both of which show a relationship with visual acuity. The measurement of these outcomes may serve as important outcome parameters in routine clinical care and in clinical trials for patients with dry age-related macular degeneration. PMID:23474546

  9. Diabetic Macular Ischemia Diagnosis: Comparison between Optical Coherence Tomography Angiography and Fluorescein Angiography

    Directory of Open Access Journals (Sweden)

    Jose Mauricio Botto de Barros Garcia

    2016-01-01

    Full Text Available Purpose. To compare fluorescein angiography (FA and optical coherence tomography angiography (OCTA images of foveal avascular zone (FAZ in patients with diabetic retinopathy (DR with and without diabetic macular ischemia (DMI. Methods. The Wilcoxon signed-rank test was used to compare area measurements and p values of <0.05 were considered statistically significant. FA and OCTA images were independently graded by 2 observers that reached agreement regarding quantitative DMI according established protocols. The ischemic area was divided into “large” macular ischemia (superior to 0.32 mm2 and “small” (inferior to 0.32 mm2 groups. Quantitative analyses of the FAZ were performed using custom software. Results. Thirty-four eyes from 34 diabetic patients were enrolled. Subjects with DMI presented a mean area on FA and OCTA of 0.68 ± 0.53 mm2 and 0.58 ± 0.35 mm2, respectively (p=0.1374. Patients without DMI presented a mean area on FA and OCTA of 0.19 ± 0.67 mm2 and 0.20 ± 0.79 mm2, respectively (p=0.9594. The ICC for the FAZ measurements between the 2 observers on FA and OCTA was 0.96 and 0.92, respectively. Conclusion. OCTA represents a novel technique for the diagnosis of DMI and it may become an alternative to FA for this purpose.

  10. Macular edema in central retinal vein occlusion: correlation between optical coherence tomography, angiography and visual acuity.

    Science.gov (United States)

    Martinet, Virginie; Guigui, Benjamin; Glacet-Bernard, Agnès; Zourdani, Alain; Coscas, Gabriel; Soubrane, Gisèle; Souied, Eric H

    2012-08-01

    To analyze the characteristics and the course of macular edema secondary to central retinal vein occlusion (CRVO) using optical coherence tomography (OCT) and to determine correlations between clinical, tomographic and angiographic data, in particular including retinal ischemia. In this retrospective study, 53 consecutive patients with CRVO were included. At each follow-up visit, patients underwent complete ophthalmological examination, including best-corrected visual acuity (BCVA) and OCT. Fluorescein angiography was performed at baseline and on demand during follow-up. 243 OCTs were analyzed. Mean age was 61 years and mean follow-up 13 months. The first structural change, observed very early after the onset of the occlusion, was a diffuse increase at the level of the outer nuclear layer without change at the level of the inner retina. This early change seemed characteristic of retinal vein occlusion. Cystoid spaces were subsequently observed in all retinal layers and were combined with serous retinal detachment in 51 %. During the first 6 months, central retinal thickness was higher in ischemic CRVO (mean, 691 μm) than in non-ischemic CRVO (mean, 440 μm, p central retinal thickness without subretinal fluid) of 700 μm or greater, peripheral ischemia was present in 69 % of eyes, final BCVA was 20/200 or less in 75 % and never reached 20/40 during follow-up. The integrity of the junction of the photoreceptors' inner and outer segments was correlated with a better prognosis (p < 0.05). Foveal thickness was inversely correlated to BCVA at each visit and could have a prognostic value. OCT examination in CRVO revealed useful data for the diagnosis of CRVO and its prognosis. The largest macular edemas seemed to be the hallmark of ischemic CRVO.

  11. Repeatability of swept-source optical coherence tomography retinal and choroidal thickness measurements in neovascular age-related macular degeneration.

    Science.gov (United States)

    Hanumunthadu, Daren; Ilginis, Tomas; Restori, Marie; Sagoo, Mandeep S; Tufail, Adnan; Balaggan, Kamaljit S; Patel, Praveen J

    2017-05-01

    The aim was to determine the intrasession repeatability of swept-source optical coherence tomography (SS-OCT)-derived retinal and choroidal thickness measurements in eyes with neovascular age-related macular degeneration (nAMD). A prospective study consisting of patients with active nAMD enrolled in the Distance of Choroid Study at Moorfields Eye Hospital, London. Patients underwent three 12×9 mm macular raster scans using the deep range imaging (DRI) OCT-1 SS-OCT (Topcon) device in a single imaging session. Retinal and choroidal thicknesses were calculated for the ETDRS macular subfields. Repeatability was calculated according to methods described by Bland and Altman. 39 eyes of 39 patients with nAMD were included with a mean (±SD) age of 73.9 (±7.2) years. The mean (±SD) retinal thickness of the central macular subfield was 225.7 μm (±12.4 μm). The repeatability this subfield, expressed as a percentage of the mean central macular subfield thickness, was 23.2%. The percentage repeatability of the other macular subfields ranged from 13.2% to 28.7%. The intrasession coefficient of repeatability of choroidal thickness of the central macular subfield was 57.2 μm with a mean choroidal thickness (±SD) of 181 μm (±15.8 μm). This study suggests that a change >23.2% of retinal thickness and 57.2 μm choroidal thickness in the central macular subfield is required to distinguish true clinical change from measurement variability when using the DRI OCT-1 device to manage patients with nAMD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  12. Value of optical coherence tomography in the detection of macular pathology before the removal of silicone oil

    Directory of Open Access Journals (Sweden)

    Rashad MA

    2016-01-01

    Full Text Available Mohammad Ahmad Rashad, Ahmed Abdel Aliem Mohamed, Asmaa Ismail Ahmed Department of Ophthalmology, Faculty of Medicine, Ain Shams University, Cairo, Egypt Purpose: To assess the pathological macular changes with optical coherence tomography (OCT before the removal of silicone oil (SiO in eyes that had undergone pars plana vitrectomy for complicated forms of retinal detachment (RD.Patients and methods: Subjects included 48 patients (51 eyes with complicated RD including proliferative vitreoretinopathy, proliferative diabetic retinopathy, recurrent RD, penetrating trauma, uveitis, giant retinal tears, and macular holes. All the eyes had undergone SiO injection. Furthermore, all eyes had been planned for the removal of SiO 6–12 months after the primary surgery. Finally, all eyes had a fundus examination and OCT examination before the silicone oil removal.Results: OCT findings indicated epiretinal membrane in 41% of the eyes, macular edema in 17%, macular detachment in 13.5%, macular thinning in 13.5%, macular holes in 10%, and subretinal membranes in 2%. Preoperative OCT was normal in only 12% of the eyes, while a clinical fundus examination was normal in 43% (P<0.001. Eyes with normal OCT had significantly better mean logMAR (0.35 than eyes with pathological changes detected through OCT (1.28; P<0.001. Surgical modifications were made during the removal of SiO in 74.5% of the eyes.Conclusion: OCT detected significantly more pathological changes than a clinical fundus examination. This had an impact on both surgical step modification during the removal of SiO and predictability of visual outcome after the removal of SiO. Keywords: optical coherence tomography, silicone oil, pars plana vitrectomy, proliferative vitreoretinopathy, proliferative diabetic retinopathy

  13. Using optical coherence tomography to evaluate macular changes after surgical management for rhegmatogenous retinal detachment

    Directory of Open Access Journals (Sweden)

    Kai-Chun Cheng

    2016-05-01

    Full Text Available Incomplete visual recovery, color vision defects, or persistent metamorphopsia may persist even after successful surgery for rhegmatogenous retinal detachment (RRD, especially in cases of RD with macula off, suggesting microstructural macular damage that standard fundus biomicroscopy could not detect. We compared spectral-domain optical coherence tomography imaging with preoperative and postoperative visual acuity to evaluate the relationship between morphological changes in the outer retina and visual outcome after successful repair of RRD with macula on or off. We enrolled 43 patients (43 eyes with successful repair of RRD and a minimum 6-month follow up after surgery in this retrospective research. Patients accepted spectral-domain optical coherence tomography postoperatively and visual acuity examination preoperatively and postoperatively. The mean age of the patients was 48.74 ± 12.68 years (range: 16–77 years. The mean visual acuity (logarithm of minimal angle of resolution before surgery was 0.87 ± 0.70. Disrupted ellipsoid zone was noted in one of 11 eyes in the macula-on group (9.1% and 19 of 32 eyes in the macula-off group (59.4%. Disrupted external limiting membrane (ELM was noted in no eye in the macula-on group (0% and 11 of 32 eyes in the macula-off group (34.4%. The macula-off group was associated with better postoperative visual gains than the macula-on group (p = 0.013. Patients with integrity of the ellipsoid zone and ELM were associated with significant visual improvement than patients with disruption of the ellipsoid zone or ELM.

  14. Kernel regression based segmentation of optical coherence tomography images with diabetic macular edema.

    Science.gov (United States)

    Chiu, Stephanie J; Allingham, Michael J; Mettu, Priyatham S; Cousins, Scott W; Izatt, Joseph A; Farsiu, Sina

    2015-04-01

    We present a fully automatic algorithm to identify fluid-filled regions and seven retinal layers on spectral domain optical coherence tomography images of eyes with diabetic macular edema (DME). To achieve this, we developed a kernel regression (KR)-based classification method to estimate fluid and retinal layer positions. We then used these classification estimates as a guide to more accurately segment the retinal layer boundaries using our previously described graph theory and dynamic programming (GTDP) framework. We validated our algorithm on 110 B-scans from ten patients with severe DME pathology, showing an overall mean Dice coefficient of 0.78 when comparing our KR + GTDP algorithm to an expert grader. This is comparable to the inter-observer Dice coefficient of 0.79. The entire data set is available online, including our automatic and manual segmentation results. To the best of our knowledge, this is the first validated, fully-automated, seven-layer and fluid segmentation method which has been applied to real-world images containing severe DME.

  15. Macular thickness measured by stratus optical coherence tomography in patients with diabetes type 2 and mild nonproliferative retinopathy without clinical evidence of macular edema.

    Science.gov (United States)

    Pires, Isabel; Santos, Ana Rita; Nunes, Sandrina; Lobo, Conceição

    2013-01-01

    To evaluate macular thickness in eyes with mild nonproliferative diabetic retinopathy (NPDR), patients with diabetes type 2, NPDR level 20 or 35, and without evidence of clinical macular edema underwent best-corrected visual acuity assessment, color fundus photography and Stratus optical coherence tomography. Mean center point thickness (CPT) and mean central subfield (CSF) thickness were compared with those of a healthy control population. 410 eyes/patients aged 61.2 ± 8.3 years, and with glycosylated hemoglobin of 7.9 ± 1.5% were included. Mean CPT and CSF were 186.6 ± 28.4 and 215.2 ± 25 µm, respectively, significantly increased compared to healthy subjects (p < 0.001). CSF thickness was abnormally increased in 17.6% of the patients, with values within the normal range in 79.5%, and abnormally decreased in 2.9%. CPT and CSF thickness were significantly thicker in men. No systemic factors showed a significant association. A significant increase in the macular thickness was found in eyes/patients with mild NPDR without clinical macular edema; however, only 17.6% of the eyes/patients had abnormally increased values and less than 3% abnormally decreased values.

  16. Optical coherence tomography (OCT) for detection of macular oedema in patients with diabetic retinopathy

    Science.gov (United States)

    Virgili, Gianni; Menchini, Francesca; Casazza, Giovanni; Hogg, Ruth; Das, Radha R; Wang, Xue; Michelessi, Manuele

    2015-01-01

    Background Diabetic macular oedema (DMO) is a thickening of the central retina, or the macula, and is associated with long-term visual loss in people with diabetic retinopathy (DR). Clinically significant macular oedema (CSMO) is the most severe form of DMO. Almost 30 years ago, the Early Treatment Diabetic Retinopathy Study (ETDRS) found that CSMO, diagnosed by means of stereoscopic fundus photography, leads to moderate visual loss in one of four people within three years. It also showed that grid or focal laser photocoagulation to the macula halves this risk. Recently, intravitreal injection of antiangiogenic drugs has also been used to try to improve vision in people with macular oedema due to DR. Optical coherence tomography (OCT) is based on optical reflectivity and is able to image retinal thickness and structure producing cross-sectional and three-dimensional images of the central retina. It is widely used because it provides objective and quantitative assessment of macular oedema, unlike the subjectivity of fundus biomicroscopic assessment which is routinely used by ophthalmologists instead of photography. Optical coherence tomography is also used for quantitative follow-up of the effects of treatment of CSMO. Objectives To determine the diagnostic accuracy of OCT for detecting DMO and CSMO, defined according to ETDRS in 1985, in patients referred to ophthalmologists after DR is detected. In the update of this review we also aimed to assess whether OCT might be considered the new reference standard for detecting DMO. Search methods We searched the Cochrane Database of Systematic Reviews (CDSR), the Database of Abstracts of Reviews of Effects (DARE), the Health Technology Assessment Database (HTA) and the NHS Economic Evaluation Database (NHSEED) (The Cochrane Library 2013, Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2013), EMBASE (January 1950 to June 2013), Web

  17. Teleophthalmology with optical coherence tomography imaging in community optometry. Evaluation of a quality improvement for macular patients

    Directory of Open Access Journals (Sweden)

    Kelly SP

    2011-12-01

    Full Text Available Simon P Kelly1, Ian Wallwork2, David Haider1, Kashif Qureshi11Ophthalmology Department, Royal Bolton Hospital National Health Service Foundation Trust, Bolton, 2Wallwork Opticians, Salford, UKPurpose: To describe a quality improvement for referral of National Health Service patients with macular disorders from a community optometry setting in an urban area.Methods: Service evaluation of teleophthalmology consultation based on spectral domain optical coherence tomography images acquired by the community optometrist and transmitted to hospital eye services.Results: Fifty patients with suspected macular conditions were managed via telemedicine consultation over 1 year. Responses were provided by hospital eye service-based ophthalmologists to the community optometrist or patient within the next day in 48 cases (96% and in 34 (68% patients on the same day. In the consensus opinion of the optometrist and ophthalmologist, 33 (66% patients required further “face-to-face” medical examination and were triaged on clinical urgency. Seventeen cases (34% were managed in the community and are a potential cost improvement. Specialty trainees were supervised in telemedicine consultations.Conclusion: Innovation and quality improvement were demonstrated in both optometry to ophthalmology referrals and in primary optometric care by use of telemedicine with spectral domain optical coherence tomography images. E-referral of spectral domain optical coherence tomography images assists triage of macular patients and swifter care of urgent cases. Teleophthalmology is also, in the authors’ opinion, a tool to improve interdisciplinary professional working with community optometrists. Implications for progress are discussed.Keywords: telemedicine, teleophthalmology, innovation, community referral, optical coherence tomography, service evaluation

  18. Normal macular thickness measurements using optical coherence tomography in healthy eyes of adult Chinese persons: the Handan Eye Study.

    Science.gov (United States)

    Duan, Xin Rong; Liang, Yuan Bo; Friedman, David S; Sun, Lan Ping; Wong, Tien Yin; Tao, Qiu Shan; Bao, Lingzhi; Wang, Ning Li; Wang, Jie Jin

    2010-08-01

    To describe macular thickness measured by optical coherence tomography (OCT) in healthy eyes of adult Chinese persons. Population-based cross-sectional study. Chinese adults aged 30+ years who were residents of Handan, North China. The Handan Eye Study is a population-based study of eye disease in Chinese persons. Eligible residents underwent a comprehensive ophthalmic examination including OCT (Stratus OCT, Carl Zeiss Meditec Inc., Jena, Germany). Fast macular thickness scans were performed over maculae within 6 mm in diameter, divided into 3 regions (central, inner, and outer, with a diameter of 1, 3, and 6 mm, respectively) and 9 quadrants (1 in the central region and 4 each in the inner and outer regions). Retinal thickness (means and standard deviations) was calculated by OCT mapping software, presented for foveal minimum, central macula (within 1 mm diameter), and inner and outer regions divided by 8 quadrants. Macular thickness measured by OCT. Of the 6830 participants (90.4% response rate) examined, 2230 eyes of healthy subjects with high-quality OCT scans were selected (32.7% of participants; mean age, 46.4+/-9.9 years, 58.4% were women). The mean foveal minimum, central, inner, and outer macular thicknesses were 150.3 (18.1) microm, 176.4 (17.5) microm, 255.3 (14.9) microm, and 237.7 (12.4) microm, respectively (overall differences, Pregion, the nasal quadrant was thinner than the superior and inferior quadrants, and in the outer region, the nasal quadrant was the thickest (Pmeasurements using OCT in a large population-based sample of adult Chinese persons aged 30 to 85 years were generally thinner in the foveal and central macular areas than measurements reported in other populations. Age and axial length were positively correlated with macular thickness. Copyright 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  19. Optical Coherence Tomography Measurement of Macular and Nerve Fiber Layer Thickness in Normal and Glaucomatous Human Eyes

    Science.gov (United States)

    Guedes, Viviane; Schuman, Joel S.; Hertzmark, Ellen; Wollstein, Gadi; Correnti, Anthony; Mancini, Ronald; Lederer, David; Voskanian, Serineh; Velazquez, Leonardo; Pakter, Helena M.; Pedut-Kloizman, Tamar; Fujimoto, James G.; Mattox, Cynthia

    2007-01-01

    Purpose To evaluate the hypothesis that macular thickness correlates with the diagnosis of glaucoma. Design Cross-sectional study. Participants We studied 367 subjects (534 eyes), including 166 eyes of 109 normal subjects, 83 eyes of 58 glaucoma suspects, 196 eyes of 132 early glaucoma patients, and 89 eyes of 68 advanced glaucoma patients. Methods We used optical coherence tomography (OCT) to measure macular and nerve fiber layer (NFL) thickness and to analyze their correlation with each other and with glaucoma status. We used both the commercial and prototype OCT units and evaluated correspondence between measurements performed on the same eyes on the same days. Main Outcome Measure Macular and NFL thickness as measured by OCT. Results All NFL parameters both in prototype and commercial OCT units were statistically significantly different comparing normal subjects and either early or advanced glaucoma (P < 0.001). Inner ring, outer ring, and mean macular thickness both in prototype and commercial OCT devices were found to be significantly different between normal subjects and advanced glaucomatous eyes (P < 0.001). The outer ring was the only macular parameter that could significantly differentiate between normal and early glaucoma with either the prototype or commercial OCT unit (P = 0.003, P = 0.008, respectively). The area under the receiver operator characteristic (AROC) curves comparing mean NFL thickness between normal and advanced glaucomatous eyes was 1.00 for both the prototype and commercial OCT devices for eyes scanned on both machines on the same day. The AROC comparing mean macular thickness in normal and advanced glaucomatous eyes scanned on both machines on the same day was 0.88 for the prototype OCT device and 0.80 for the commercial OCT. Conclusions Both macular and NFL thickness as measured by OCT showed statistically significant correlations with glaucoma, although NFL thickness showed a stronger association than macular thickness. There was

  20. Optical coherence tomographic evaluation of foveal hard exudates in patients with diabetic maculopathy accompanying macular detachment.

    Science.gov (United States)

    Ota, Masafumi; Nishijima, Kazuaki; Sakamoto, Atsushi; Murakami, Tomoaki; Takayama, Kohei; Horii, Takahiro; Yoshimura, Nagahisa

    2010-10-01

    To study morphologic changes of serous retinal detachment (SRD) and hyperreflective dots, which have been reported to be precursors of hard exudates, detectable in SRD using optical coherence tomography (OCT) to assess whether or not the OCT findings are correlated with the subfoveal deposition of hard exudates in patients with diabetic macular edema (DME) accompanied by SRD. Retrospective chart review. Twenty-eight eyes of 19 patients with DME accompanied by SRD. We imaged SRD and the hyperreflective dots in SRD using spectral domain OCT (SD-OCT). The number and distribution of the hyperreflective dots in SRD were evaluated before the initial treatment at our hospital for DME accompanied by SRD. Based on a difference in the SD-OCT findings, the study eyes were divided into 2 groups: eyes with a few dots and those with many dots. We studied the clinical course of these 2 groups to assess whether or not the findings of SRD and hyperreflective dots on the SD-OCT images were correlated with deposition of hard exudates in the subfoveal space during follow-up. Correlation of the SD-OCT findings of SRD and hyperreflective dots with deposition of hard exudates in the subfovea of patients with DME accompanied by SRD. Subfoveal deposition of hard exudates was seen in 11 of the 28 eyes at the final examination. Before initial treatment at our hospital, 14 eyes had a few hyperreflective dots SRD and 14 eyes had many hyperreflective dots. Whereas no deposition of hard exudates in the subfoveal space was seen in the former eyes, it was seen in 11 of the latter 14 eyes (P exudates during follow-up. Copyright © 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  1. Real-Time Automatic Segmentation of Optical Coherence Tomography Volume Data of the Macular Region.

    Directory of Open Access Journals (Sweden)

    Jing Tian

    Full Text Available Optical coherence tomography (OCT is a high speed, high resolution and non-invasive imaging modality that enables the capturing of the 3D structure of the retina. The fast and automatic analysis of 3D volume OCT data is crucial taking into account the increased amount of patient-specific 3D imaging data. In this work, we have developed an automatic algorithm, OCTRIMA 3D (OCT Retinal IMage Analysis 3D, that could segment OCT volume data in the macular region fast and accurately. The proposed method is implemented using the shortest-path based graph search, which detects the retinal boundaries by searching the shortest-path between two end nodes using Dijkstra's algorithm. Additional techniques, such as inter-frame flattening, inter-frame search region refinement, masking and biasing were introduced to exploit the spatial dependency between adjacent frames for the reduction of the processing time. Our segmentation algorithm was evaluated by comparing with the manual labelings and three state of the art graph-based segmentation methods. The processing time for the whole OCT volume of 496×644×51 voxels (captured by Spectralis SD-OCT was 26.15 seconds which is at least a 2-8-fold increase in speed compared to other, similar reference algorithms used in the comparisons. The average unsigned error was about 1 pixel (∼ 4 microns, which was also lower compared to the reference algorithms. We believe that OCTRIMA 3D is a leap forward towards achieving reliable, real-time analysis of 3D OCT retinal data.

  2. Automatic detection and recognition of multiple macular lesions in retinal optical coherence tomography images with multi-instance multilabel learning

    Science.gov (United States)

    Fang, Leyuan; Yang, Liumao; Li, Shutao; Rabbani, Hossein; Liu, Zhimin; Peng, Qinghua; Chen, Xiangdong

    2017-06-01

    Detection and recognition of macular lesions in optical coherence tomography (OCT) are very important for retinal diseases diagnosis and treatment. As one kind of retinal disease (e.g., diabetic retinopathy) may contain multiple lesions (e.g., edema, exudates, and microaneurysms) and eye patients may suffer from multiple retinal diseases, multiple lesions often coexist within one retinal image. Therefore, one single-lesion-based detector may not support the diagnosis of clinical eye diseases. To address this issue, we propose a multi-instance multilabel-based lesions recognition (MIML-LR) method for the simultaneous detection and recognition of multiple lesions. The proposed MIML-LR method consists of the following steps: (1) segment the regions of interest (ROIs) for different lesions, (2) compute descriptive instances (features) for each lesion region, (3) construct multilabel detectors, and (4) recognize each ROI with the detectors. The proposed MIML-LR method was tested on 823 clinically labeled OCT images with normal macular and macular with three common lesions: epiretinal membrane, edema, and drusen. For each input OCT image, our MIML-LR method can automatically identify the number of lesions and assign the class labels, achieving the average accuracy of 88.72% for the cases with multiple lesions, which better assists macular disease diagnosis and treatment.

  3. Effect of Hemodialysis on Retinal Thickness in Patients with Diabetic Retinopathy, with and without Macular Edema, Using Optical Coherence Tomography.

    Science.gov (United States)

    Azem, Nur; Spierer, Oriel; Shaked, Meital; Neudorfer, Meira

    2014-01-01

    Background. Effects of hemodialysis (HD) treatment on retinal thickness and macular edema are unclear. Objective. To evaluate changes in retinal thickness using optical coherence tomography (OCT) in end stage renal disease (ESRD) patients with diabetic retinopathy (DR), with and without diabetic macular edema (DME), undergoing HD. Methods. Nonrandomized prospective study. Forty eyes of DR patients with ESRD treated with HD were divided into two groups: patients with macular edema and patients without macular edema. Both eyes were analyzed. Patients underwent an ophthalmic examination including OCT measurements of retinal thickness, blood albumin and hemoglobin A1C levels, blood pressure, and body weight, 30 minutes before and after HD. Results. We found no significant effects of HD on retinal thickness among patients both with and without DME. The former showed a trend towards reduction in retinal thickness in foveal area following HD, while the latter showed an increase. There was no correlation between retinal thickness and mean blood pressure, weight, kinetic model value-Kt/V, glycemic hemoglobin, or albumin levels before and after HD. Conclusions. HD has no significant effect on retinal thickness among patients with or without DME. Further studies on larger cohorts and repeated OCT examinations are needed to confirm the preliminary findings in this study.

  4. Effect of Hemodialysis on Retinal Thickness in Patients with Diabetic Retinopathy, with and without Macular Edema, Using Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Nur Azem

    2014-01-01

    Full Text Available Background. Effects of hemodialysis (HD treatment on retinal thickness and macular edema are unclear. Objective. To evaluate changes in retinal thickness using optical coherence tomography (OCT in end stage renal disease (ESRD patients with diabetic retinopathy (DR, with and without diabetic macular edema (DME, undergoing HD. Methods. Nonrandomized prospective study. Forty eyes of DR patients with ESRD treated with HD were divided into two groups: patients with macular edema and patients without macular edema. Both eyes were analyzed. Patients underwent an ophthalmic examination including OCT measurements of retinal thickness, blood albumin and hemoglobin A1C levels, blood pressure, and body weight, 30 minutes before and after HD. Results. We found no significant effects of HD on retinal thickness among patients both with and without DME. The former showed a trend towards reduction in retinal thickness in foveal area following HD, while the latter showed an increase. There was no correlation between retinal thickness and mean blood pressure, weight, kinetic model value—Kt/V, glycemic hemoglobin, or albumin levels before and after HD. Conclusions. HD has no significant effect on retinal thickness among patients with or without DME. Further studies on larger cohorts and repeated OCT examinations are needed to confirm the preliminary findings in this study.

  5. Optical coherence tomography for age-related macular degeneration and diabetic macular edema: an evidence-based analysis.

    Science.gov (United States)

    2009-01-01

    The purpose of this evidence-based review was to examine the effectiveness and cost-effectiveness of spectral-domain (SD) optical coherence tomography (OCT) in the diagnosis and monitoring of patients with retinal disease, specifically age-related macular degeneration (AMD) and diabetic macular edema (DME). Specifically, the research question addressed was: What is the sensitivity and specificity of spectral domain OCT relative to the gold standard? TARGET POPULATION AND CONDITION The incidence of blindness has been increasing worldwide. In Canada, vision loss in those 65 years of age and older is primarily due to AMD, while loss of vision in those 18 years of age and older is mainly due to DME. Both of these conditions are diseases of the retina, which is located at the back of the eye. At the center of the retina is the macula, a 5 mm region that is responsible for what we see in front of us, our ability to detect colour, and fine detail. Damage to the macula gives rise to vision loss, but early detection of asymptomatic disease may lead to the prevention or slowing of the vision loss process. There are two main types of AMD, 'dry' and 'wet'. Dry AMD is the more prevalent of the two, accounting for approximately 85% of cases and characterized by small deposits of extracellular material called "drusen" that build up in Bruch's membrane of the eye. Central vision loss is gradual with blurring and eventual colour fading. Wet AMD is a less prevalent condition (15% of all AMD cases) but it accounts for 90% of severe cases. It's characterized by the appearance of retinal fluid with vision loss due to abnormal blood vessels/leakage within weeks to months of diagnosis. In 2003, the Canadian National Institute for the Blind (CNIB) prevalence estimate for AMD was 1 million Canadians, including approximately 400,000 affected Ontarians. The incidence in 2003 was estimated to be 78,000 new cases in Canada, with approximately one-third of these cases arising in Ontario (n=26

  6. Consistency of ocular coherence tomography fast macular thickness mapping in diabetic diffuse macular edema

    Energy Technology Data Exchange (ETDEWEB)

    Saraiva, Fabio Petersen; Costa, Patricia Grativol; Inomata, Daniela Lumi; Melo, Carlos Sergio Nascimento; Helal Junior, John; Nakashima, Yoshitaka [Universidade de Sao Paulo (USP), SP (Brazil). Hospital das Clinicas. Dept. de Oftalmologia]. E-mail: fabiopetersen@yahoo.com.br

    2007-07-01

    Objectives: To investigate optical coherence tomography consistency on foveal thickness, foveal volume, and macular volume measurements in patients with and without diffuse diabetic macular edema. Introduction: Optical coherence tomography represents an objective technique that provides cross-sectional tomographs of retinal structure in vivo. However, it is expected that poor fixation ability, as seen in diabetic macular edema, could alter its results. Several authors have discussed the reproducibility of optical coherence tomography, but only a few have addressed the topic with respect to diabetic maculopathy. Methods: The study recruited diabetic patients without clinically evident retinopathy (control group) and with diffuse macular edema (case group). Only one eye of each patient was evaluated. Five consecutive fast macular scans were taken using Ocular Coherence Tomography 3; the 6 mm macular map was chosen. The consistency in measurements of foveal thickness, foveal volume, and total macular volume for both groups was evaluated using the Pearson's coefficient of variation. The T-test for independent samples was used in order to compare measurements of both groups. Results: Each group consisted of 20 patients. All measurements had a coefficient of variation less than 10%. The most consistent parameter for both groups was the total macular volume. Discussion: Consistency in measurement is a mainstay of any test. A test is unreliable if its measurements can not be correctly repeated. We found a good index of consistency, even considering patients with an unstable gaze. Conclusions: Optical coherence tomography is a consistent method for diabetic subjects with diffuse macular edema. (author)

  7. OPTICAL COHERENCE TOMOGRAPHY CHARACTERISTICS OF MACULAR EDEMA AND HARD EXUDATES AND THEIR ASSOCIATION WITH LIPID SERUM LEVELS IN TYPE 2 DIABETES.

    Science.gov (United States)

    Davoudi, Samaneh; Papavasileiou, Evangelia; Roohipoor, Ramak; Cho, Heeyoon; Kudrimoti, Shreyas; Hancock, Heather; Hoadley, Suzanne; Andreoli, Christopher; Husain, Deeba; James, Maurice; Penman, Alan; Chen, Ching J; Sobrin, Lucia

    2016-09-01

    To determine whether hyperreflective foci (HF) and macular thickness on spectral domain ocular coherence tomography are associated with lipid levels in patients with Type 2 diabetes. Two hundred and thirty-eight participants from four sites had fundus photographs and spectral domain ocular coherence tomography images graded for hard exudates and HF, respectively. Regression models were used to determine the association between serum lipid levels and 1) presence of HF and hard exudates and 2) central subfield macular thickness, central subfield macular volume, and total macular volume. All patients with hard exudates on fundus photographs had corresponding HF on spectral domain ocular coherence tomography, but 57% of patients with HF on optical coherence tomography did not have hard exudates detected in their fundus photographs. Presence of HF was associated with higher total cholesterol (odds ratio = 1.13, 95% confidence interval = 1.01-1.27, P = 0.03) and higher low-density lipoprotein levels (odds ratio = 1.17, 95% confidence interval = 1.02-1.35, P = 0.02) in models adjusting for other risk factors. The total macular volume was also associated with higher total cholesterol (P = 0.009) and triglyceride (P = 0.02) levels after adjusting for other risk factors. Higher total and low-density lipoprotein cholesterol were associated with presence of HF on spectral domain ocular coherence tomography. Total macular volume was associated with higher total cholesterol and triglyceride levels.

  8. Sensitivity and specificity of time-domain versus spectral-domain optical coherence tomography in diabetic macular edema

    Directory of Open Access Journals (Sweden)

    Nishal Patel

    2013-01-01

    Full Text Available Purpose: The purpose was to evaluate the sensitivity and specificity of measurements of central macular thickness (CMT in diabetic macular edema using stratus time-domain and cirrus spectral-domain optical coherence tomography (OCT; Carl Zeiss Meditec, Dublin, CA. Materials and Methods: A total of 36 eyes from 19 patients with clinically significant diabetic macular edema (DME were included. All participants underwent automated scanning patterns using cirrus HD-OCT and stratus OCT examinations on the same day. The sensitivity/specificity of retinal thickness measurements was calculated from published normative data. Agreement was calculated using Bland--Altman method. The receiver operating characteristic curves (ROC and areas under the ROC were plotted. Results: The mean difference between the cirrus HD-OCT and stratus OCT in the central foveal zone was 49.89 μm. Bland--Altman analysis confirmed that the retinal thickness measurements had poor agreement in patients with DME. The areas under the ROC for retinal thickness measurements were 0.88 using cirrus HD-OCT and 0.94 with stratus. Conclusions: In patients with DME, the cirrus HD-OCT gives a higher reading than stratus OCT with poor agreement between the devices in most regions within the nine subfield zones. The sensitivity and specificity of the stratus OCT was comparable to the cirrus.

  9. Presence of foveal bulge in optical coherence tomographic images in eyes with macular edema associated with branch retinal vein occlusion.

    Science.gov (United States)

    Hasegawa, Taiji; Ueda, Tetsuo; Okamoto, Masahiro; Ogata, Nahoko

    2014-02-01

    To determine whether a significant correlation exists between the presence of a bulge in the photoreceptor inner segment/outer segment (IS/OS) line and the best-corrected visual acuity (BCVA) in eyes with resolved macular edema associated with branch retinal vein occlusion (BRVO). Retrospective, observational case series. We retrospectively reviewed the medical records of patients who had a complete resolution of macular edema and had an intact IS/OS line in the central fovea in the spectral-domain optical coherence tomographic (SDOCT) images. Thirty-one eyes with macular edema associated with BRVO (BRVO group) and 31 unaffected fellow eyes (control group) of 31 patients were evaluated. In normal eyes, the intact IS/OS line determined by SDOCT has a bulge at the central fovea, called the foveal bulge. The eyes in the BRVO group were classified by the presence or absence of foveal bulge, and the characteristics of the 2 groups were compared. A foveal bulge was present in 7 of 31 eyes in the BRVO group. The incidence of a foveal bulge was significantly lower in the BRVO group (22.6%) than in the control group (100%; P < .0001). All 7 eyes with foveal bulge had a decimal BCVA of ≥1.0 at the final visit. The incidence of a foveal bulge was significantly higher in eyes with BCVA of ≥1.0 (77.8%) than in the eyes with BCVA of <1.0 (0%; P < .0001). The foveal bulge is a good marker of the functional properties of the fovea in eyes with resolved macular edema associated with BRVO. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Segmentation error and macular thickness measurements obtained with spectral-domain optical coherence tomography devices in neovascular age-related macular degeneration

    Directory of Open Access Journals (Sweden)

    Moosang Kim

    2013-01-01

    Full Text Available Purpose: To evaluate frequency and severity of segmentation errors of two spectral-domain optical coherence tomography (SD-OCT devices and error effect on central macular thickness (CMT measurements. Materials and Methods: Twenty-seven eyes of 25 patients with neovascular age-related macular degeneration, examined using the Cirrus HD-OCT and Spectralis HRA + OCT, were retrospectively reviewed. Macular cube 512 × 128 and 5-line raster scans were performed with the Cirrus and 512 × 25 volume scans with the Spectralis. Frequency and severity of segmentation errors were compared between scans. Results: Segmentation error frequency was 47.4% (baseline, 40.7% (1 month, 40.7% (2 months, and 48.1% (6 months for the Cirrus, and 59.3%, 62.2%, 57.8%, and 63.7%, respectively, for the Spectralis, differing significantly between devices at all examinations (P < 0.05, except at baseline. Average error score was 1.21 ± 1.65 (baseline, 0.79 ± 1.18 (1 month, 0.74 ± 1.12 (2 months, and 0.96 ± 1.11 (6 months for the Cirrus, and 1.73 ± 1.50, 1.54 ± 1.35, 1.38 ± 1.40, and 1.49 ± 1.30, respectively, for the Spectralis, differing significantly at 1 month and 2 months (P < 0.02. Automated and manual CMT measurements by the Spectralis were larger than those by the Cirrus. Conclusions: The Cirrus HD-OCT had a lower frequency and severity of segmentation error than the Spectralis HRA + OCT. SD-OCT error should be considered when evaluating retinal thickness.

  11. Volcano like pattern in optical coherence tomography in chronic diabetic macular edema.

    Science.gov (United States)

    Pai, Sivakami A; Hussain, Nazimul; Hebri, Sudhira P; Lootah, Afra M; Dekhain, Moza A

    2014-04-01

    In this article we herein report an interesting vitreo-macular interface abnormality associated with chronic diabetic cystoid macular edema. It is an observational case study of three diabetic patients examined in the diabetic clinic. All the patients had proliferative diabetic retinopathy with chronic macular edema. A serial cross sectional OCT examination and tracking of both the longitudinal progression of macular thickening and vitreo-macular interface revealed cystoid macular edema with a characteristic hyperreflective vitreous shadow emerging from the vitreofoveal interface. All the patients had dehiscence of inner retinal layers. This particular morphological feature at the vitreo-foveolar interface, which we name as "volcano sign", has not been described earlier. The probable mechanism of such a finding probably could be due to slow progressive leakage of chronic cytoid fluid into the vitreous with condensation of the overlying vitreous. Vitreo-macular traction followed by posterior vitreous detachment probably would have contributed to such a morphological event.

  12. Diabetic macular oedema quantified with spectral-domain optical coherence tomography

    DEFF Research Database (Denmark)

    Hodzic-Hadzibegovic, Delila; Sander, Birgit A; Lund-Andersen, Henrik

    2015-01-01

    causing artefacts including hard exudates (HE), epiretinal membranes (ERM), optical opacities and serous detachments. Boundary line artefacts were manually corrected and the corrected central subfield thickness (CST) and macular volume were compared with automated values. Data were compared.......7%) and others (1.2%). The number of artefacts due to HE decreased significantly (p = 0.0005), and the number of artefacts due to ERM were unchanged (p = 0.087) during 12 months. In OCT examinations with artefacts caused by HE, manually corrected CST was statistically significant higher than automated value...... at baseline and 3 months. For ERM, manually corrected CST was statistically significant lower than automated value at baseline and 12 months. CONCLUSION: Boundary line artefacts in OCT examinations of ciDME patients using Topcon 3D OCT occur in 51.8%. In situation of boundary line artefacts in centre 1-mm...

  13. Segmentation and quantification of retinal lesions in age-related macular degeneration using polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Baumann, Bernhard; Gotzinger, Erich; Pircher, Michael; Sattmann, Harald; Schuutze, Christopher; Schlanitz, Ferdinand; Ahlers, Christian; Schmidt-Erfurth, Ursula; Hitzenberger, Christoph K

    2010-01-01

    We present polarization-sensitive optical coherence tomography (PS-OCT) for quantitative assessment of retinal pathologies in age-related macular degeneration (AMD). On the basis of the polarization scrambling characteristics of the retinal pigment epithelium, novel segmentation algorithms were developed that allow one to segment pathologic features such as drusen and atrophic zones in dry AMD as well as to determine their dimensions. Results from measurements in the eyes of AMD patients prove the ability of PS-OCT for quantitative imaging based on the retinal features polarizing properties. Repeatability measurements were performed in retinas diagnosed with drusen and geographic atrophy in order to evaluate the performance of the described methods. PS-OCT appears as a promising imaging modality for three-dimensional retinal imaging and ranging with additional contrast based on the structures' tissue-inherent polarization properties.

  14. Segmentation and quantification of retinal lesions in age-related macular degeneration using polarization-sensitive optical coherence tomography

    Science.gov (United States)

    Baumann, Bernhard; Götzinger, Erich; Pircher, Michael; Sattmann, Harald; Schütze, Christopher; Schlanitz, Ferdinand; Ahlers, Christian; Schmidt-Erfurth, Ursula; Hitzenberger, Christoph K.

    2010-11-01

    We present polarization-sensitive optical coherence tomography (PS-OCT) for quantitative assessment of retinal pathologies in age-related macular degeneration (AMD). On the basis of the polarization scrambling characteristics of the retinal pigment epithelium, novel segmentation algorithms were developed that allow one to segment pathologic features such as drusen and atrophic zones in dry AMD as well as to determine their dimensions. Results from measurements in the eyes of AMD patients prove the ability of PS-OCT for quantitative imaging based on the retinal features polarizing properties. Repeatability measurements were performed in retinas diagnosed with drusen and geographic atrophy in order to evaluate the performance of the described methods. PS-OCT appears as a promising imaging modality for three-dimensional retinal imaging and ranging with additional contrast based on the structures' tissue-inherent polarization properties.

  15. Fully automated macular pathology detection in retina optical coherence tomography images using sparse coding and dictionary learning

    Science.gov (United States)

    Sun, Yankui; Li, Shan; Sun, Zhongyang

    2017-01-01

    We propose a framework for automated detection of dry age-related macular degeneration (AMD) and diabetic macular edema (DME) from retina optical coherence tomography (OCT) images, based on sparse coding and dictionary learning. The study aims to improve the classification performance of state-of-the-art methods. First, our method presents a general approach to automatically align and crop retina regions; then it obtains global representations of images by using sparse coding and a spatial pyramid; finally, a multiclass linear support vector machine classifier is employed for classification. We apply two datasets for validating our algorithm: Duke spectral domain OCT (SD-OCT) dataset, consisting of volumetric scans acquired from 45 subjects-15 normal subjects, 15 AMD patients, and 15 DME patients; and clinical SD-OCT dataset, consisting of 678 OCT retina scans acquired from clinics in Beijing-168, 297, and 213 OCT images for AMD, DME, and normal retinas, respectively. For the former dataset, our classifier correctly identifies 100%, 100%, and 93.33% of the volumes with DME, AMD, and normal subjects, respectively, and thus performs much better than the conventional method; for the latter dataset, our classifier leads to a correct classification rate of 99.67%, 99.67%, and 100.00% for DME, AMD, and normal images, respectively.

  16. Effect of retinal photocoagulation on intraretinal lipid exudates in diabetic macular edema documented by optical coherence tomography.

    Science.gov (United States)

    Deák, Gábor Gy; Bolz, Matthias; Kriechbaum, Katharina; Prager, Sonja; Mylonas, Georgios; Scholda, Christoph; Schmidt-Erfurth, Ursula

    2010-04-01

    To study the changes in the distribution and morphologic features of intraretinal microexudates after macular photocoagulation. Prospective cohort study. Thirteen treatment-naïve patients with clinically significant macular edema in type 2 diabetes. Patients were treated with focal macular photocoagulation. Changes in the localization of hyperreflective foci were analyzed by spectral domain (SD) optical coherence tomography (OCT) during follow-up at day 1, week 1, and months 1, 2, 3, and 4 in defined areas. Further, fundus photography and infrared imaging were performed at all visits and findings were correlated to OCT results. Changes in retinal morphologic features detected in OCT. A dynamic change in the distribution pattern of hyperreflective foci was observed over 4 months after the photocoagulation. With the decrease of retinal thickness, the dots either resolved completely or became confluent at the apical border of the outer nuclear layer, and finally formed ophthalmoscopically detectable hard exudates during extended follow-up. In the event of retinal thickening despite laser treatment, the hyperreflective dots maintained their previous distribution throughout all retinal layers. As a fourth response, dissemination of plaques of hard exudates into multiple, separate, hyperreflective foci were detected. Hyperreflective foci in the retina seem to represent precursors or components of hard exudates. Their specific localization depends greatly on the presence of microvascular extravasation and intraretinal fluid accumulation. Retinal photocoagulation has a major impact on retinal edema and subsequently on the distribution of intraretinal lipid deposits. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  17. Morphological and functional changes in spectral domain optical coherence tomography and microperimetry in macular microhole variants: Spectral domain optical coherence tomography and microperimetry correlation

    Directory of Open Access Journals (Sweden)

    Laxmi Gella

    2012-01-01

    Full Text Available Purpose: To evaluate the relationship between the morphology and retinal function of macular microhole (MMH variants. Materials and Methods: We evaluated 12 eyes of 11 patients with defects in the IS/OS junction of photoreceptor layer with SD-OCT. All patients underwent comprehensive ophthalmic examination including spectral domain optical coherence tomography (SD-OCT and microperimetry. Results: The mean logMAR visual acuity in the affected eye was 0.15 ± 0.17 (range 0.00-0.5. Mean horizontal diameter of the MMH was 163 ± 99 μm; the mean retinal sensitivity in the area corresponding to the MMH was 13.79 ± 4.6 dB. Negative correlation was found between the MMH diameter and the retinal sensitivity (r = -0.65, p0 = 0.02. Three morphological patterns of MMH variants were recognized on SD-OCT, which did not differ in retinal sensitivities. Conclusion: We described and classified the MMH variants and made an assessment on the physiological functions using microperimeter.

  18. Macular Effects of Silicone Oil Tamponade: Optical Coherence Tomography Findings During and After Silicone Oil Removal.

    Science.gov (United States)

    Lo, Danielle M; Flaxel, Christina J; Fawzi, Amani A

    2017-01-01

    To investigate retinal morphologic changes during silicone oil tamponade and after its removal using spectral domain OCT (SD-OCT) imaging. Retrospective review of 12 patients who underwent silicone oil tamponade for repair of retinal detachments. Macular OCT scans and volumetric thickness maps were examined qualitatively and quantitatively. Volumetric OCT revealed two distinct patterns during silicone oil: macular thickening (Group A) and macular thinning (Group B). In Group A, mean foveal thickness (507 ± 169 µm vs. 407 ± 163 µm, p = 0.003) and mean macular volume (11.6 ± 2.4 mm(3) vs. 9.9 ± 1.5 mm(3)) were significantly increased during tamponade compared to post-oil removal. Group B had significantly decreased mean foveal thickness (210 ± 38 µm vs. 276 ± 58 µm, p = 0.009) and macular volume (7.3 ± 1.8 mm(3) vs. 8.4 ± 1.8 mm(3)) during tamponade. Importantly, resolution of macular changes occurred without further intervention and was associated with improved visual acuity in both groups. Our series suggests that when faced with unexplained macular edema or macular thinning during tamponade, silicone oil removal alone can achieve resolution of these structural changes.

  19. SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY-BASED MICROSTRUCTURAL ANALYSIS OF RETINAL ARCHITECTURE POST INTERNAL LIMITING MEMBRANE PEELING FOR SURGERY OF IDIOPATHIC MACULAR HOLE REPAIR.

    Science.gov (United States)

    Modi, Aditya; Giridhar, Anantharaman; Gopalakrishnan, Mahesh

    2017-02-01

    Spectral domain optical coherence tomography-based analysis of retinal architecture after internal limiting membrane peeling for macular hole surgery. Prospective, interventional study. Fifty eyes underwent the surgical procedure with minimum internal limiting membrane peel of 3 mm diameter. Automatic segmentation software was used to assess individual layers preoperatively and postoperatively, 1.5 millimeters medial and lateral to fovea at 3 months postoperative visit. Main outcome measures were final central macular thickness and variation in individual retinal layer thickness. Mean central macular thickness postoperatively was 201 microns. Retinal thickening was observed, 1.5 mm medial to fovea (P Internal limiting membrane peel is associated with significant alteration in inner retinal architecture, especially in ganglion cell layer, which can adversely influence functional outcome of the surgery and makes it imperative to avoid peeling internal limiting membrane over a larger surface area.

  20. Interpreting Thickness Changes in the Diabetic Macula: The Problem of Short-Term Variation in Optical Coherence Tomography–Measured Macular Thickening (An American Ophthalmological Society Thesis)

    Science.gov (United States)

    Browning, David J.

    2010-01-01

    Purpose: To estimate the short-term variability of macular thickness in eyes with refractory and regressed diabetic macular edema (DME). Methods: In this retrospective review of consecutive cases from a retina practice, optical coherence tomography (OCT) measurements of macular thickness were extracted from the clinical charts of patients with refractory DME and regressed DME. Variation in macular thickness was defined as maximal central subfield mean thickness (CSMT) minus minimal CSMT during a period of observation in which clinical macular status did not change. Results: There were 36 eyes of 29 patients in the refractory DME group and 93 eyes of 93 patients in the regressed DME group. Median intervals during which macular status was unchanged and OCTs were collected were 7 months for the refractory DME group and 22 months for the regressed DME group. Baseline CSMTs were 321 μm for the refractory DME group and 217 μm for the regressed DME group. The median variation in CSMT was 89 μm for the refractory DME group and 19 μm for the regressed DME group. Results for total macular volume paralleled those for CSMT. Conclusions: In consonance with eyes having treatment-naïve DME, eyes with refractory DME have short-term fluctuation in macular thickness larger than OCT measurement variability. In eyes with regressed DME, short-term fluctuation is less than in eyes with refractory DME, yet can also exceed measurement variability. This information is clinically important in deciding whether subsequent treatment is indicated. PMID:21212849

  1. Analysis of the results of multifocal electroretinogram and optical coherence tomography in diagnosis and monitoring of patients with age-related macular degeneration

    Directory of Open Access Journals (Sweden)

    Ait Ahmed Кh.

    2014-06-01

    Full Text Available Purpose: to study the correlation between the results of the macular area responses by multifocal-electroretinog-raphy (mf-ERG and the retina thickness obtained by the spectralis optical coherence tomography (ОСТ in patients with age-related macular degeneration (AMD. Material and methods. 28 patients (32 eyes where enrolled in the main group. The control group was up to 10 patients without any AMD's pathological sign in retina. All patients were examined by the optical coherence tomography (ОСТ and multifocal electroretinography (mf-ERG. Results. The data showed a high level of negative correlation between the retinal thickness and electrical amplitudes of the fovea. With the group of "dry" AMD the rise of the macular thickness (drusen not over 290 urn showed a moderate reduction of the amplitude on mf-ERG The group with "wet" AMD showed that a higher rise of the retinal thickness (edema, fibrosis of the macular zone negatively influences the bio-electrical activity of this area and this fact was confirmed by a considerable decline of the amplitude on the mf-ERG. Conclusion. The AMD's pathological changes that have been observed by ОСТ are objectively confirmed by mf-ERG. The mf-ERG in supplement of ОСТ can be used as an important element in the complex studies and objectively monitoring of patients with AMD.

  2. High-speed ultrahigh resolution optical coherence tomography before and after ranibizumab for age-related macular degeneration.

    Science.gov (United States)

    Witkin, Andre J; Vuong, Laurel N; Srinivasan, Vivek J; Gorczynska, Iwona; Reichel, Elias; Baumal, Caroline R; Rogers, Adam H; Schuman, Joel S; Fujimoto, James G; Duker, Jay S

    2009-05-01

    To evaluate intraretinal anatomy in patients with exudative age-related macular degeneration (AMD) using high-speed ultrahigh resolution optical coherence tomography (hsUHR-OCT) before and 1 month after intravitreal injection of ranibizumab. Retrospective case series. Twelve eyes of 12 patients. A broad bandwidth superluminescent diode laser light source and spectral/Fourier domain signal detection were used to create a prototype hsUHR-OCT instrument with 3.5 mum axial image resolution and approximately 25,000 lines/second acquisition speed. Twelve eyes of 12 patients with exudative AMD were imaged with hsUHR-OCT before and 1 month after intravitreal ranibizumab injection. High pixel density and raster-scanned 3-dimensional (3D) OCT data sets were generated. Three-dimensional imaging software was used to calculate subretinal/retinal pigment epithelium fluid volume and volume of the fibrovascular lesion. Qualitative and quantitative analysis of hsUHR-OCT images and 3D data sets. All eyes had some degree of normalization of macular contour after intravitreal ranibizumab. The inner/outer photoreceptor segment junction visualized on hsUHR-OCT was discontinuous, overlying the fibrovascular lesion in all 12 of 12 eyes both before and after treatment; 9 of 12 eyes had focal areas of thinning of the outer nuclear layer, which remained after treatment. Volumetric measurements were possible in 8 of 12 eyes with 3D-rendering software. Fibrovascular lesion volume did not change significantly after treatment. hsUHR-OCT is capable of unprecedented imaging speed and resolution, making it a valuable instrument in measuring in vivo intraretinal pathology. All 12 eyes had some normalization of macular contour. Fibrovascular lesion volume did not change significantly 1 month after treatment, suggesting that ranibizumab does not cause much initial regression of preexisting neovascular tissue. Photoreceptor abnormalities remained in all patients after treatment of wet AMD, suggesting

  3. Optical coherence tomography and vessel diameter changes after intravitreal bevacizumab in diabetic macular oedema

    DEFF Research Database (Denmark)

    Soliman, W.; Vinten, M.; Sander, B.

    2008-01-01

    Purpose: To assess the effect of intravitreal bevacizumab on diabetic macular oedema (DMO) and retinal vessel calibres. Methods: We performed a consecutive case series study in which 10 consecutive eyes with diffuse DMO, two of which had not previously been treated, received an intravitreal injec...

  4. Improving the economic value of photographic screening for optical coherence tomography-detectable macular oedema: a prospective, multicentre, UK study.

    Science.gov (United States)

    Olson, J; Sharp, P; Goatman, K; Prescott, G; Scotland, G; Fleming, A; Philip, S; Santiago, C; Borooah, S; Broadbent, D; Chong, V; Dodson, P; Harding, S; Leese, G; Styles, C; Swa, K; Wharton, H

    2013-11-01

    To determine the best photographic surrogate markers for detecting sight-threatening macular oedema (MO) in people with diabetes attending UK national screening programmes. A multicentre, prospective, observational cohort study of 3170 patients with photographic signs of diabetic retinopathy visible within the macular region [exudates within two disc diameters, microaneurysms/dot haemorrhages (M/DHs) and blot haemorrhages (BHs)] who were recruited from seven study centres. All patients were recruited and imaged at one of seven study centres in Aberdeen, Birmingham, Dundee, Dunfermline, Edinburgh, Liverpool and Oxford. Subjects with features of diabetic retinopathy visible within the macular region attending one of seven diabetic retinal screening programmes. Alternative referral criteria for suspected MO based on photographic surrogate markers; an optical coherence tomographic examination in addition to the standard digital retinal photograph. (1) To determine the best method to detect sight-threatening MO in people with diabetes using photographic surrogate markers. (2) Sensitivity and specificity estimates to assess the costs and consequences of using alternative strategies. (3) Modelled long-term costs and quality-adjusted life-years (QALYs). Prevalence of MO was strongly related to the presence of lesions and was roughly five times higher in subjects with exudates or BHs or more than two M/DHs within one disc diameter. Having worse visual acuity was associated with about a fivefold higher prevalence of MO. Current manual screening grading schemes that ignore visual acuity or the presence of M/DHs could be improved by taking these into account. Health service costs increase substantially with more sensitive/less specific strategies. A fully automated strategy, using the automated detection of patterns of photographic surrogate markers, is superior to all current manual grading schemes for detecting MO in people with diabetes. The addition of optical coherence

  5. Dynamics of the Macular Hole-Silicone Oil Tamponade Interface with Patient Positioning as Imaged by Spectral Domain Optical Coherence Tomography

    Science.gov (United States)

    Oster, Stephen F.; Mojana, Francesca; Bartsch, Dirk-Uwe G.; Goldbaum, Michael; Freeman, William R.

    2010-01-01

    Purpose To evaluate with spectral domain optical coherence tomography (SD-OCT) the relationship between the retina and overlying silicone oil tamponade after macular hole surgery, and to evaluate how this relationship changes with patient positioning. Patients and Methods Retrospective consecutive case series of 10 eyes from 9 patients who underwent macular hole surgery with silicone oil tamponade and subsequent SD-OCT scans. Four of the included eyes were also imaged with patients in face-down posture to determine if the silicone-retina apposition changes with prone positioning. Finally, a single patient was additionally scanned in the lateral and supine positions. Results The posterior surface of the silicone oil bubble was well visualized in all 10 eyes. In the majority of eyes (7/10) the oil tamponade bridged across the macular hole creating a pre-foveal fluid space, but in 3 eyes the silicone oil filled the macular hole and was seen in touch with the underlying foveal depression or retinal pigment epithelium. In 75% of eyes (3/4) the silicone oil-retinal approximation did not vary with face-down position. Supine positioning clearly floated the silicone tamponade anteriorly and off of the retinal surface. Conclusions Silicone oil tamponade can either bridge across macular holes, or in a novel finding, can fill the underlying foveal depression or macular hole space. Generally, the oil position is stable between face-forward and prone SD-OCT images, suggesting that either of these patient positions allows waterproofing of the underlying macular hole. Finally, our images confirm that supine positioning should be avoided post-operatively as it leads to loss of oil-retinal tamponade. PMID:20531144

  6. [Normal macular thickness and volume using spectral domain optical coherence tomography in a reference population].

    Science.gov (United States)

    Solé González, L; Abreu González, R; Alonso Plasencia, M; Abreu Reyes, P

    2013-09-01

    To establish normal values of macular thickness and volume obtained by the Cirrus SD-OCT (Carl ZeissMeditec, Dublin, CA, U.S.A.). Secondly, to assess the association between macular thickness and volume, sex and age. A prospective study was conducted on patients who were seen in a hospital Retina Unit, and who only had retinal disease in one eye. All the Macular Cube 512 × 128 scan protocols were performed by the same operator. Only the healthy eye was scanned in each patient. A total of 100 eyes of 100 patients were analysed. The mean central foveal thickness was 261.31 ± 17.67 microns, and was significantly (P<.05) higher in males (267.74 ± 16.98 microns) than in females (255.60 ± 16.40 microns). The mean obtained for the volume of the cube was 10.09 ± 0.37mm 3, and the mean thickness of 280.33 ± 10.34 cube um, with no statistically significant differences between gender being found (P<.05). The mean macular thickness is less at central level, increases in the inner perifoveal ring, and then decreases in the outer perifoveal ring. Furthermore, of all quadrants the greatest thickness was the nasal (328.27 ± 12.96 microns), followed by the upper (326.27 ± 11.89 microns), lower (322.53 ± 12.37mm) sectors, with the temporal sector being the thinnest (313.35 ± 14.20 microns). The mean age of the patients was 60.86 ± 14 years. The mean central foveal thickness and the thickness of the inner perifoveal ring are significantly higher in men than in women. Both the mean volume and thickness of the cube, as well as nasal and inner superior sectors decrease with age, being significantly only in women. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  7. Spectral domain optical coherence tomography changes following intravitreal dexamethasone implant, Ozurdex ® in patients with uveitic cystoid macular edema

    Directory of Open Access Journals (Sweden)

    Pooja Bansal

    2015-01-01

    Full Text Available Purpose: To correlate the structural and functional changes following intravitreal injection of dexamethasone 0.7 mg (Ozurdex ® implant in patients with recalcitrant uveitic cystoid macular edema (CME. Materials and Methods: In a prospective, interventional, nonrandomized study, 30 eyes (27 patients with uveitic CME received Ozurdex ® implant and were followed-up for 24 weeks at periodic intervals to monitor structural alterations seen on spectral domain optical coherence tomography (SD-OCT. The outcome measures included change in central macular thickness (CMT and best-corrected visual acuity (BCVA as well as structural alterations seen on OCT such as change in the height of cystoid spaces (CSs and sub-foveal serous retinal detachment (SSRD. The integrity of external limiting membrane and inner-outer segment junction was assessed at baseline and follow-up visits. Results: Mean age of the patients was 46.09 ± 15.66 years. The mean CMT decreased by 96 μm at 1-day, 231.64 μm at 1-week, 254.21 μm at 4 weeks and 249.14 μm at 12 weeks (P < 0.001 compared with baseline. BCVA improved from a baseline mean of 0.62 LogMAR units to 0.49 on day 1 to 0.31 at 24 weeks (P < 0.001. A decrease in the mean height of CS, that is, 133.28 μm from a baseline of 317.71 μm was noted on the 1 st day (P < 0.001. 4 eyes demonstrated the presence of CS at 4 weeks, 1 eye at 6 weeks and 3 eyes at 12 weeks. At baseline, 16 eyes (53.33% demonstrated the presence of SSRD. Among these, 11 eyes showed resolution of SSRD on day 1. SSRD resolved in all patients at 4 weeks and was maintained up to 24 weeks. Conclusions: Ozurdex ® implant improves the visual outcome of patients with recalcitrant uveitic CME. Reversibility of retinal changes may be possible following treatment with dexamethasone implant. Thus final visual outcome may be independent of pretreatment CMT, the height of CS or SSRD.

  8. Polycystic Ovary Syndrome: Aggressive or Protective Factor for the Retina? Evaluation of Macular Thickness and Retinal Nerve Fiber Layers Using High-Definition Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    José Edvan de Souza-Júnior

    2015-01-01

    Full Text Available Objective. To compare macular thickness (MT and retinal nerve fiber layers (RNFL between women with polycystic ovary syndrome (PCOS and healthy women. Materials and Methods. The study included 45 women with PCOS and 47 ovulatory women undergoing clinical-gynecological and ophthalmic evaluations, including measurement of MT, RNFL, and optic disc parameters using optical coherence tomography. Results. The superior RNFL around the optic nerve was significantly thicker in PCOS than in healthy volunteers (P=0.036. After stratification according to insulin resistance, the temporal inner macula (TIM, the inferior inner macula (IIM, the nasal inner macula (NIM, and the nasal outer macula (NOM were significantly thicker in PCOS group than in control group (P<0.05. Both the presence of obesity associated with insulin resistance (P=0.037 and glucose intolerance (P=0.001 were associated with significant increase in the PC1 mean score, relative to MT. A significant increase in the PC2 mean score occurred when considering the presence of metabolic syndrome (P<0.0001. There was a significant interaction between obesity and inflammation in a decreasing mean PC2 score relative to macular RNFL thickness (P=0.034. Conclusion. Decreased macular RNFL thickness and increased total MT are associated with metabolic abnormalities, while increased RNFL thickness around the optic nerve is associated with hormonal changes inherent in PCOS.

  9. Improvement of visual acuity based on optical coherence tomography patterns following intravitreal bevacizumab treatment in patients with diabetic macular edema

    Directory of Open Access Journals (Sweden)

    Haider R. Cheema

    2014-04-01

    Full Text Available AIM:To report the visual outcome based on various patterns of optical coherence tomography (OCT morphology in diabetic macular edema (DME, following treatment with anti-VEGF intravitreal bevacizumab (IVB injection.METHODS:Sixty-seven consecutive subjects with centre involving DME underwent intravitreal injection of Bevacizumab (1.25 mg/0.05 mL in this retrospective, comparative, non randomized study. The DME was classified into one of four categories:focal, diffuse, focal cystoid and neurosensory detachment based on OCT. Best corrected visual acuity (BCVA, macular appearance, and OCT findings were used to decide whether the subject should have a repeat injection of intravitreal bevacizumab. Outcome measures were a change in mean BCVA (Snellen converted to logMAR and central macular thickness (CMT in each group during the six month follow-up period.RESULTS:The mean BCVA improved to logMAR 0.23 at final follow-up from a baseline of 0.32 logMAR (P=0.040 in the focal group, logMAR 0.80 at final follow-up from a baseline of 0.82 logMAR (P=0.838 in the diffuse group, worsened to logMAR 0.53 at final follow-up from a baseline of 0.43 logMAR (P=0.276 in the focal cystoid group, and improved to logMAR 0.79 at final follow-up from a baseline of 0.93 logMAR (P=0.490 in the neurosensory detachment group. The mean CMT before treatment were 298.8±25.03 μm in the focal group, 310.8±40.6 μm in the diffuse group, 397.15±31.05 μm in the focal cystoid group and 401.03±75.1 μm in the neurosensory detachment group. A mean of 2.05 (range:1-5 injections in the focal group, 1.32 (range:1-2 in the diffuse group, 2.6 (range:1-6 in the focal cystoid group and 2.6 (range:1-6 in the neurosensory detachment group were performed during the six month follow-up period. Following intravitreal bevacizumab treatment, vision improved, remained unchanged or worsened in 11, 7 and 2 subjects in focal group; 11, 9 and 8 in diffuse group; 0, 2 and 4 in focal cystoid group and 5

  10. Distribution of intraretinal exudates in diabetic macular edema during anti-vascular endothelial growth factor therapy observed by spectral domain optical coherence tomography and fundus photography.

    Science.gov (United States)

    Pemp, Berthold; Deák, Gábor; Prager, Sonja; Mitsch, Christoph; Lammer, Jan; Schmidinger, Gerald; Scholda, Christoph; Schmidt-Erfurth, Ursula; Bolz, Matthias

    2014-12-01

    To evaluate changes in the distribution and morphology of intraretinal microexudates and hard exudates (HEs) during intravitreal anti-vascular endothelial growth factor therapy in patients with persistent diabetic macular edema. Twenty-four patients with persistent diabetic macular edema after photocoagulation were investigated in this prospective cohort study. Each eye was assigned to a loading dose of three anti-vascular endothelial growth factor treatments at monthly intervals. Additional single treatments were performed if diabetic macular edema persisted or recurred. Intraretinal exudates were analyzed over 6 months using spectral domain optical coherence tomography (SD-OCT) and fundus photography. Before treatment, microexudates were detected by SD-OCT as hyperreflective foci in 24 eyes, whereas HEs were seen in 22 eyes. During therapy, HE increased significantly in number and size. This was accompanied by accumulation of microexudates in the outer retina. Enlargement of hyperreflective structures in SD-OCT was accompanied by enlargement of HE at corresponding fundus locations. A rapid reduction in diabetic macular edema was seen in all patients, but to varying degrees. Patients with hemoglobin A1c levels exudates at corresponding locations in fundus photography and SD-OCT. Intraretinal aggregates of microexudates detectable as hyperreflective foci by SD-OCT may compose and precede HE before they become clinically visible.

  11. Spectral domain optical coherence tomography for quantitative evaluation of drusen and associated structural changes in non-neovascular age-related macular degeneration.

    Science.gov (United States)

    Yi, K; Mujat, M; Park, B H; Sun, W; Miller, J W; Seddon, J M; Young, L H; de Boer, J F; Chen, T C

    2009-02-01

    To demonstrate how spectral domain optical coherence tomography (SDOCT) can better evaluate drusen and associated anatomical changes in eyes with non-neovascular age-related macular degeneration (AMD) compared with time domain optical coherence tomography (TDOCT). Images were obtained from three eyes of three patients with AMD using an experimental SDOCT system. Both a titanium-sapphire (Ti:sapphire) laser and a superluminescent diode (SLD) were used as a broadband light source to achieve cross-sectional images of the retina. A qualitative and quantitative analysis was performed for structural changes associated with non-neovascular AMD. An automated algorithm was developed to analyse drusen area and volume from SDOCT images. TDOCT was performed using the fast macular scan (StratusOCT, Carl Zeiss Meditec, Dublin, California). SDOCT images can demonstrate structural changes associated with non-neovascular AMD. A new SDOCT algorithm can determine drusen area, drusen volume and proportion of drusen. With new algorithms to determine drusen area and volume and its unprecedented simultaneous ultra-high speed ultra-high resolution imaging, SDOCT can improve the evaluation of structural abnormalities in non-neovascular AMD.

  12. Leber Hereditary Optic Neuropathy Associated with Bilateral Macular Holes

    Science.gov (United States)

    Shimada, Yoshiaki; Horiguchi, Masayuki

    2016-01-01

    ABSTRACT Leber hereditary optic neuropathy (LHON) causes visual loss, predominantly in healthy young men. We recently examined a patient who previously had bilateral macular holes and subsequently developed LHON at 74 years of age. Although his central scotomas were initially attributed to the macular holes, his visual acuity declined following an initial improvement after operative closure of the macular holes; thus, other diagnoses, including LHON, were considered. Furthermore, macular optical coherence tomography (OCT) images remained unchanged in this time. A mitochondrial genetic analysis identified a 11778G→A mutation. From this case, we propose that LHON remains in the differential diagnosis even in older patients, as has previously been reported. PMID:27335507

  13. Correlation Between the Findings of Optical Coherent Retinal Tomography (OCT), Stereo Biomicroscopic Images from Fundus of an Eye and Values from Visual Acuity of Diabetic Macular Edema

    Science.gov (United States)

    Nisic, Faruk; Turkovic, Samir; Mavija, Milka; Jovanovic, Nina; Alimanovic, Emina Halilovic-

    2014-01-01

    Introduction: Diabetic maculopathy is the major cause of reduced visual acuity in patients with non-proliferative diabetic retinopathy and occurs on average in 29% of patients who have diabetes for 20 or more years. Aim: The aim of this study is to re examine the correlation between the findings of optical coherence retinal tomography, stereo bio-microscopic images from fundus of an eye and values from visual acuity of diabetic macular edema. In addition, the aim is to show the importance of various ophthalmic tests for establishing diagnosis in time. Material and methods: The research sample consisted of 90 subjects-patients from Cabinet for photographic documentation, fluorescein angiography and laser photocoagulation in Department of Ophthalmology at the University Clinical Centre in Sarajevo. The study was a one-year long, prospective, clinical study. Results: Research has shown a positive correlation between the various tests that are applied for the diagnosis of diabetic macular edema. Accurate and early diagnosis is of great importance for the treatment in time of this disease by applying laser photocoagulation, intravitreal injections of Anti-VEGF drugs or surgical treatment by Pars Plana Vitrectomy. PMID:25395723

  14. En-face optical coherence tomography in the diagnosis and management of age-related macular degeneration and polypoidal choroidal vasculopathy

    Directory of Open Access Journals (Sweden)

    Tiffany Lau

    2015-01-01

    Full Text Available Optical coherence tomography (OCT is a noninvasive imaging modality providing high-resolution images of the central retina that has completely transformed the field of ophthalmology. While traditional OCT has produced longitudinal cross-sectional images, advancements in data processing have led to the development of en-face OCT, which produces transverse images of retinal and choroidal layers at any specified depth. This offers additional benefit on top of longitudinal cross-sections because it provides an extensive overview of pathological structures in a single image. The aim of this review was to discuss the utility of en-face OCT in the diagnosis and management of age-related macular degeneration (AMD and polypoidal choroidal vasculopathy (PCV. En-face imaging of the inner segment/outer segment junction of retinal photoreceptors has been shown to be a useful indicator of visual acuity and a predictor of the extent of progression of geographic atrophy. En-face OCT has also enabled high-resolution analysis and quantification of pathological structures such as reticular pseudodrusen (RPD and choroidal neovascularization, which have the potential to become useful markers for disease monitoring. En-face Doppler OCT enables subtle changes in the choroidal vasculature to be detected in eyes with RPD and AMD, which has significantly advanced our understanding of their pathogenesis. En-face Doppler OCT has also been shown to be useful for detecting the polypoid lesions and branching vascular networks diagnostic of PCV. It may therefore serve as a noninvasive alternative to fluorescein and indocyanine green angiography for the diagnosis of PCV and other forms of the exudative macular disease.

  15. Differential diagnosis (occlusion and unocclusal kind of complicated and diffuse diabetic macular edema with optical coherence tomography method in patients with diabetes type II

    Directory of Open Access Journals (Sweden)

    O. V. Zborovskaya

    2013-10-01

    Full Text Available Introduction. Diabetic macular edema (DME is a common manifestation of diabetic retinopathy and an important cause of visual impairment in people with diabetes. DME is the most common cause of decreased vision in patients with diabetes. It can accompany any stage of the disease and occurs on average 10% of patients with diabetes. In this case, due to structural changes in the endothelium of retinal vessels violation of the retinal barrier increased permeability of blood vessels wall and fluid accumulation in the intercellular space retinal optical coherence tomography (OCT is a method of diagnostic morphological structure of the retina and allows high precision of the DME diagnose, assess the severity and observe the dynamics. Materials and methods. During the work general ophthalmic examination, OCT, PAH and immunological studies were performed in all patients. Total 64 patients (128 eyes, including 28 women (43.8% and 36 men (56.3%, whose average age was '58 (SD 10, 24 to 78 years with diabetes type II diabetic macular edema of various kinds took part in the study. Diffuse (occlusal and unocclusal kind and complicated (occlusal and unocclusal DME were studied. Diffuse occlusal DME was diagnosed in 33 cases, diffuse unocclusal DME – in 35 cases, complicated occlusal DME - in 28 cases, complicated unocclusal DME - in 32. Statistical analysis was performed in the program MedCalc 9.0. Results and Discussion: In this clinical study there is a clear pattern between the type and the presence of DME. Conclusions: We can talk about the use of the criterion of the presence or absence of RPE detachment to differentiate species (occlusion or unocclusual diffuse and complicated DME in patients with diabetes type II.

  16. Role of Tractional Forces and Internal Limiting Membrane in Macular Hole Formation: Insights from Intraoperative Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Elad Moisseiev

    2016-07-01

    Full Text Available We report the case of a 69-year-old patient who underwent vitrectomy for vitreomacular traction (VMT and developed a postoperative macular hole that was observed 1 week after surgery. The hole did not close by in-office fluid-gas exchange alone, but was achieved after repeat surgery with internal limiting membrane (ILM peeling. Intraoperative OCT (iOCT images from the first surgery revealed an occult macular hole that formed after VMT release. We discuss how iOCT findings provide insight into the role of the ILM in macular hole formation and emphasize the importance of carefully inspecting iOCT images in real time to avoid missing small but important findings.

  17. Optical coherence tomography and multifocal electroretinography of patients with advanced neovascular age-related macular degeneration before, during, and after treatment with ranibizumab

    Directory of Open Access Journals (Sweden)

    Izabela Negrão Frota de Almeida

    2015-04-01

    Full Text Available Purpose: To evaluate retinal morphology and function of patients with advanced neovascular age-related macular degeneration (AMD before, during, and after treatment with ranibizumab. Methods: Twenty-one eyes diagnosed with advanced AMD were studied with optical coherence tomography (OCT and multifocal electroretinography (mfERG. Three intravitreal injections of ranibizumab were administered at 1-month intervals. Evaluations were performed before the first injection (D0 and at 30 (D30, 60 (D60, and 90 days (D90 after the first injection and compared to an age-matched control group (n=21 eyes. Results: The thickness of macular retinal layers increased before treatment due to the presence of intraretinal fluid. A thick retinal pigment epithelium-choriocapillaris complex (RPE-CC suggested the presence of choroidal neovascular membrane. Intraretinal edema decreased after treatment (P<0.01, but persisting RPE-CC thickness resulted in a subretinal scar. Three different annular retinal areas were studied with mfERG (from center to periphery: rings R1, R2, and R3. The amplitude of the first negative component (N1 decreased in R1, R2, and R3 at D30, D60, and D90 when compared with that in controls (P<0.05; the N1 implicit time was delayed in R3 at D30 (P<0.05. The amplitude of the first positive component (P1 was reduced in R1 and R2 at D30, D60, and D90 when compared with that in controls (P<0.01; the P1 implicit time was delayed in R1 at D0 and D60 (P<0.05, in R2 at D0, D30, and D90 (P<0.01, and in R3 at D30 and D60 (P<0.05. Conclusion: Ranibizumab reduces intraretinal edema, even in advanced cases. Central macular activity appeared to increase after the initiation of treatment, improving over time.

  18. Spectral-domain Optical Coherence Tomography Retinal and Choroidal Thickness Metric Repeatability in Age-related Macular Degeneration

    DEFF Research Database (Denmark)

    Hanumunthadu, Daren; Ilginis, Tomas; Restori, Marie

    2016-01-01

    ) macular subfields. Center point thickness and total macular volume were also included in the analysis. Manual subfoveal choroidal thickness measurements were made by a masked observer. RESULTS: A total of 40 eyes of 40 patients were included in this analysis (mean [± standard deviation] age: 74.1 [± 7...... for the center point was 47.5 μm (95% CI 46.2-48.7 μm). Images were also reviewed for the presence of segmentation error in the central macular subfield, and after exclusion of these eyes the revised CR for this subfield was 13.7 μm (95% CI 13.3-14.1 μm). The intrasession CR of subfoveal choroidal thickness...... was 34.7 μm (95% CI 33.7-35.7 μm). CONCLUSIONS: This study suggests that a change of greater than 31 μm in Spectralis SDOCT-derived retinal thickness measurement of the central macular subfield and 35 μm in subfoveal choroidal thickness is necessary to detect true clinical change associated with disease...

  19. Semiautomated segmentation and analysis of retinal layers in three-dimensional spectral-domain optical coherence tomography images of patients with atrophic age-related macular degeneration.

    Science.gov (United States)

    Hu, Zhihong; Shi, Yue; Nandanan, Kiran; Sadda, Srinivas R

    2017-01-01

    Historically, regular drusen and geographic atrophy (GA) have been recognized as the hallmarks of nonneovascular age-related macular degeneration (AMD). Recent imaging developments have revealed another distinct nonneovascular AMD phenotype, reticular pseudodrusen (RPD). We develop an approach to semiautomatically quantify retinal surfaces associated with various AMD lesions (i.e., regular drusen, RPD, and GA) in spectral domain (SD) optical coherence tomography (OCT) images. More specifically, a graph-based algorithm was used to segment multiple retinal layers in SD-OCT volumes. Varying surface feasibility constraints based on the presegmentation were applied on the double-surface graph search to refine the surface segmentation. The thicknesses of these layers and their correlation with retinal functional measurements, including microperimetry (MP) sensitivity and visual acuity (VA), were investigated. The photoreceptor outer segment layer demonstrated significant thinning with a reduction in MP sensitivity and VA score when atrophic AMD lesions were present. Regular drusen and RPD were separately segmented on SD-OCT images to allow their characteristics and distribution to be studied separately. The mean thickness of regular drusen was found to significantly correlate with the VA score. RPD appeared to be distributed evenly throughout the macula and regular drusen appeared to be more concentrated centrally.

  20. Volumetric image classification using homogeneous decomposition and dictionary learning: A study using retinal optical coherence tomography for detecting age-related macular degeneration.

    Science.gov (United States)

    Albarrak, Abdulrahman; Coenen, Frans; Zheng, Yalin

    2017-01-01

    Three-dimensional (3D) (volumetric) diagnostic imaging techniques are indispensable with respect to the diagnosis and management of many medical conditions. However there is a lack of automated diagnosis techniques to facilitate such 3D image analysis (although some support tools do exist). This paper proposes a novel framework for volumetric medical image classification founded on homogeneous decomposition and dictionary learning. In the proposed framework each image (volume) is recursively decomposed until homogeneous regions are arrived at. Each region is represented using a Histogram of Oriented Gradients (HOG) which is transformed into a set of feature vectors. The Gaussian Mixture Model (GMM) is then used to generate a "dictionary" and the Improved Fisher Kernel (IFK) approach is used to encode feature vectors so as to generate a single feature vector for each volume, which can then be fed into a classifier generator. The principal advantage offered by the framework is that it does not require the detection (segmentation) of specific objects within the input data. The nature of the framework is fully described. A wide range of experiments was conducted with which to analyse the operation of the proposed framework and these are also reported fully in the paper. Although the proposed approach is generally applicable to 3D volumetric images, the focus for the work is 3D retinal Optical Coherence Tomography (OCT) images in the context of the diagnosis of Age-related Macular Degeneration (AMD). The results indicate that excellent diagnostic predictions can be produced using the proposed framework.

  1. Macular Choroidal Thickness and Volume Measured by Swept-source Optical Coherence Tomography in Healthy Korean Children.

    Science.gov (United States)

    Lee, Jung Wook; Song, In Seok; Lee, Ju-hyang; Shin, Yong Un; Lim, Han Woong; Lee, Won June; Lee, Byung Ro

    2016-02-01

    To evaluate the thickness and volume of the choroid in healthy Korean children using swept-source optical coherence tomography. We examined 80 eyes of 40 healthy children and teenagers (choroidal thickness map. We also examined 44 eyes of 35 healthy adult volunteers (≥18 years) and compared adult measurements with the findings in children. The mean age of the children and teenagers was 9.47 ± 3.80 (4 to 17) vs. 55.04 ± 12.63 years (36 to 70 years) in the adult group (p choroid were thinner (p = 0.004, p = 0.002, respectively) than the surrounding areas. The mean choroidal volumes of the inner and outer nasal areas were smaller (p = 0.004, p = 0.003, respectively) than those of all the other areas in each circle. Among the nine subfields, all areas in the children, except the outer nasal subfield, were thicker than those in adults (p choroidal thickness (p choroidal thickness and volume in children and teenagers were significantly greater than in adults. The nasal choroid was significantly thinner than the surrounding areas. The pediatric subfoveal choroid is prone to thinning with increasing age, axial length, and refractive error. These differences should be considered when choroidal thickness is evaluated in children with chorioretinal diseases.

  2. Lack of Association between Glaucoma and Macular Choroidal Thickness Measured with Enhanced Depth-Imaging Optical Coherence Tomography

    Science.gov (United States)

    Mwanza, Jean-Claude; Hochberg, Jessica T.; Banitt, Michael R.; Feuer, William J.

    2011-01-01

    Purpose. To compare choroidal thickness measurements among normal eyes, eyes with normal tension glaucoma (NTG), and those with primary open-angle glaucoma (POAG), and to correlate choroidal thickness with demographic and clinical ocular parameters. Methods. Choroidal thickness was measured with enhanced depth-imaging (EDI) optical coherence tomography (OCT) in one eye of 38 normal, 20 NTG, and 56 POAG subjects and compared among groups. The mean age was 69.3 ± 13.6 years (60.1 ± 13.4 years for normal subjects and 73.8 ± 11.3 years for glaucoma subjects; P choroid every 0.5 mm up to 3 mm away from the fovea. Univariate and multivariate linear regression analyses were performed to assess the association between choroidal thickness and demographic and ocular parameters. Results. There were no differences in foveal, temporal, or nasal choroidal thickness between normal, NTG, and POAG subjects (all P > 0.05) after adjusting for age, axial length, and intraocular pressure. Similarly, glaucoma severity groups did not differ from each other in all choroidal thickness measurements (all P > 0.05). Age (β = −1.78; P choroidal thickness in the entire group, followed by axial length (β = −11.8; P = 0.002). Conclusions. Choroidal thickness does not differ among normal, NTG, and POAG subjects, suggesting a lack of relationship between choroidal thickness and glaucoma based on EDI OCT measurements. PMID:21357398

  3. 频域光学相干断层扫描在黄斑部疾病的应用%Application of spectral domain optical coherence tomography in macular diseases

    Institute of Scientific and Technical Information of China (English)

    黄中宁; 黄杜茹; 张良; 尹东明

    2011-01-01

    Objective To evaluate the application of the spectral domain optical coherence tomography in macular diseases.Methods Retrospective analysis the data of spectral domain optical coherence tomography which from 49 patients with macular diseases whom were received treatment from 13th May 2010 to 13th June 2010 at department of ophthalmology in Guangdong General Hospital.Results The 49 patients' OCT examination images showed characteristic morphological changes in different macular diseases.Conclusions Spectral domain optical coherence tomography is a reliable and noninvasive examination method for the diagnosis of macular disease and for the follow up procedure.%目的 观察并评估频域光学相干断层扫描在黄斑部病变的应用价值.方法 回顾分析2010年5月13日至2010年6月13日在广东省人民医院眼科就诊的49例累及眼底黄斑部的患者,用频域光学相干断层扫描的检查结果.结果 49例累及黄斑部的眼底疾病患者频域光学相干扫描图像显示其各自特征性形态学改变.结论 频域光学相干断层扫描对于黄斑部疾病的诊断及随诊是一种可靠的无创性检查方法.

  4. Optical Coherence Tomography Updates on Clinical and Technical Developments. Age-Related Macular Degeneration: Drusen and Geographic Atrophy

    Science.gov (United States)

    Fleckenstein, Monika; Schmitz-Valckenberg, Steffen; Holz, Frank G.

    Age-related macular degeneration (AMD) is a complex disease with both genetic and environmental factors influencing its development. With the advent of high-resolution OCT imaging, the characterization of drusen in AMD has become possible. The in vivo morphologic characteristics imaged with SD-OCT may represent distinct subclasses of drusen variants, may relate closely to ultrastructural drusen elements identified in donor eyes, and may be useful imaging biomarkers for disease severity or risk of progression [Khanifar et al. Ophthalmology 115(11):1883-1890, 2008].

  5. Optical Coherence Tomography

    Science.gov (United States)

    Huang, David

    Optical coherence tomography (OCT) is a new method for noninvasive cross-sectional imaging in biological systems. In OCT, the longitudinal locations of tissue structures are determined by measuring the time-of-flight delays of light backscattered from these structures. The optical delays are measured by low coherence interferometry. Information on lateral position is provided by transverse scanning of the probe beam. The two dimensional map of optical scattering from internal tissue microstructures is then represented in a false-color or grayscale image. OCT is the optical analog of ultrasonic pulse-echo imaging, but with greatly improved spatial resolutions (a few microns). This thesis describes the development of this new high resolution tomographic imaging technology and the demonstration of its use in a variety of tissues under both in vitro and in vivo conditions. In vitro OCT ranging and imaging studies were performed using human ocular and arterial tissues, two clinically relevant examples of transparent and turbid media, respectively. In the anterior eye, precise measurements of cornea and anterior chamber dimensions were made. In the arterial specimens, the differentiation between fatty -calcified and fibromuscular tissues was demonstrated. In vivo OCT imaging in the retina and optic nerve head in human subjects was also performed. The delineation of retinal layers, which has not been possible with other noninvasive imaging techniques, is demonstrated in these OCT images. OCT has high spatial resolution but limited penetration into turbid tissue. It has potential for diagnostic applications where high resolution is needed and optical access is available, such as in the eye, skin, surgically exposed tissues, and surfaces that can be reached by various catheters and endoscopic probes. In particular, the measurement of fine retinal structures promises improvements in the diagnosis and management of glaucoma, macular edema and other vitreo-retinal diseases

  6. Optical coherence tomography in late solar retinopathy

    Directory of Open Access Journals (Sweden)

    Janković Aleksandar

    2011-01-01

    Full Text Available Introduction. Solar retinopathy refers to retinal injury induced by direct or indirect solar viewing. Case report. We presented a patient who had observed partial solar eclipse 51 year before. He had bilaterally decreased vision and scar of the macular region at the time of presentation. The basic diagnostic tool applied in the presented patient, optical coherence tomography, showed hyporeflexivity of the outer retina in the segment of retinal pigment epithelialphotoreceptors complex with atrophy and thinning of the foveolar region. Conclusion. Optical coherence tomography is a powerful, non-invasive diagnostic tool which can ease the diagnosis and estimate the level and nature of the macular region damage.

  7. [A preliminary study on macular retinal and choroidal thickness and blood flow change after posterior scleral reinforcement by optical coherence tomography angiography].

    Science.gov (United States)

    Zhang, X F; Qiao, L Y; Li, X X; Ma, N; Li, M; Guan, Z; Wang, H Z; Wang, N L

    2017-01-11

    Objective: To investigate macular retinal and choroidal thickness and blood flow change using optical coherence tomography angiography after posterior scleral reinforcement (PSR) surgery. Methods: Prospective study. Twenty eyes of 10 patients with high myopia were enrolled in this open-label, single-treatment group and prospective study. Radial lines and Angio retina (3 mm×3 mm) module were performed for 20 eyes using Angio-vue optical coherence tomography (Avanti, Optovue) without pupil dilation, and best corrected visual acuity, spherical equivalent and axial length were compared before and 60 days after surgery. Retinal and choroidal thickness was measured in the fovea, 1 mm superior, 1 mm inferior, 1 mm nasal and 1 mm temporal to the fovea. Flow area, flow density and flow index were recorded using self-provided software in the superficial retina layer, deep retina layer, outer retina layer and choroid capillary layer, respectively. Statistical analysis was performed using SPSS 16.0. Data that followed normal distribution were compared with paired two-sample t-test, while others were compared with Wilcoxon signed rank test. Results: Of the patients participating in this preliminary study, the mean age was (35.5±4.2) years, and 50% were female. No significant difference was found between before and 60 days after PSR surgery in best corrected visual acuity (t=0.99, P=0.33), spherical equivalent (t=-1.89, P=0.07) and axial length (t=0.2, P=0.08). The retinal thickness in the fovea was thinner (Z=-2.58, P=0.01), while there was no significant difference in the 1 mm superior (t=0.44, P=0.67) , 1 mm inferior (t=0.05, P=0.96) , 1 mm nasal (Z=0.87, P=0.64) and 1 mm temporal (Z=-0.78, P=0.99) to the fovea. No significant difference was found in choroidal thickness (t=-0.12, P=0.87; t=-0.25, P=0.81. t=0.53, P=0.61; t=-0.91, P=0.38. t=1.2, P=0.25) before and after surgery. The postoperative flow density in the superficial and deep retinal layers (48.18±4.56% and 31.47

  8. Measurement of peripapillary retinal nerve fiber layer thickness and macular thickness in anisometropia using spectral domain optical coherence tomography: a prospective study

    Science.gov (United States)

    Singh, Neha; Rohatgi, Jolly; Gupta, Ved Prakash; Kumar, Vinod

    2017-01-01

    Purpose To study whether there is a difference in central macular thickness (CMT) and peripapillary retinal nerve fiber layer (RNFL) thickness between the two eyes of individuals having anisometropia >1 diopter (D) using spectral domain optical coherence tomography (OCT). Material and methods One hundred and one subjects, 31 with myopic anisometropia, 28 with astigmatic anisometropia, and 42 with hypermetropic anisometropia, were enrolled in the study. After informed consent, detailed ophthalmological examination was performed for every patient including cycloplegic refraction, best corrected visual acuity, slit lamp, and fundus examination. After routine ophthalmic examination peripapillary RNFL and CMT were measured using spectral domain OCT and the values of the two eyes were compared in the three types of anisometropia. Axial length was measured using an A Scan ultrasound biometer (Appa Scan-2000). Results The average age of subjects was 21.7±9.3 years. The mean anisometropia was 3.11±1.7 D in myopia; 2±0.99 D in astigmatism; and 3.68±1.85 D in hypermetropia. There was a statistically significant difference in axial length of the worse and better eye in both myopic and hypermetropic anisometropia (P=0.00). There was no significant difference between CMT of better and worse eyes in anisomyopia (P=0.79), anisohypermetropia (P=0.09), or anisoastigmatism (P=0.16). In anisohypermetropia only inferior quadrant RNFL was found to be significantly thicker (P=0.011) in eyes with greater refractive error. Conclusion There does not appear to be a significant difference in CMT and peripapillary RNFL thickness in anisomyopia and anisoastigmatism. However, in anisohypermetropia inferior quadrant RNFL was found to be significantly thicker. PMID:28260856

  9. Age-Related Vitamin D Deficiency Is Associated with Reduced Macular Ganglion Cell Complex: A Cross-Sectional High-Definition Optical Coherence Tomography Study.

    Directory of Open Access Journals (Sweden)

    Mathieu Uro

    Full Text Available Vitamin D deficiency is associated with smaller volume of optic chiasm in older adults, indicating a possible loss of the visual axons and their cellular bodies. Our objective was to determine whether vitamin D deficiency in older adults is associated with reduced thickness of the ganglion cell complex (GCC and of the retinal nerve fibre layer (RNFL, as measured with high-definition optical coherence tomography (HD-OCT.Eighty-five French older community-dwellers without open-angle glaucoma and patent age-related macular degeneration (mean, 71.1±4.7 years; 45.9% female from the GAIT study were separated into 2 groups according to serum 25OHD level (i.e., deficient≤25 nmol/L or sufficient>25 nmol/L. Measurements of GCC and RNFL thickness were performed using HD-OCT. Age, gender, body mass index, number of comorbidities, dementia, functional autonomy, intracranial volume, visual acuity, serum calcium concentration and season of testing were considered as potential confounders.Mean serum 25OHD concentration was 58.4±26.8 nmol/L. Mean logMAR visual acuity was 0.03±0.06. Mean visual field mean deviation was -1.25±2.29 dB. Patients with vitamin D deficiency (n=11 had a reduced mean GCC thickness compared to those without vitamin D deficiency (72.1±7.4 μm versus 77.5±7.5 μm, P=0.028. There was no difference of the mean RNFL thickness in these two groups (P=0.133. After adjustment for potential confounders, vitamin D deficiency was associated with reduced GCC thickness (ß=-5.12, P=0.048 but not RNFL thickness (ß=-9.98, P=0.061. Specifically, vitamin D deficiency correlated with the superior medial GCC area (P=0.017 and superior temporal GCC area (P=0.010.Vitamin D deficiency in older patients is associated with reduced mean GCC thickness, which can represent an early stage of optic nerve damage, prior to RNFL loss.

  10. Coherent amplified optical coherence tomography

    Science.gov (United States)

    Zhang, Jun; Rao, Bin; Chen, Zhongping

    2007-07-01

    A technique to improve the signal-to-noise ratio (SNR) of a high speed 1300 nm swept source optical coherence tomography (SSOCT) system was demonstrated. A semiconductor optical amplifier (SOA) was employed in the sample arm to coherently amplify the weak light back-scattered from sample tissue without increasing laser power illuminated on the sample. The image quality improvement was visualized and quantified by imaging the anterior segment of a rabbit eye at imaging speed of 20,000 A-lines per second. The theory analysis of SNR gain is given followed by the discussion on the technologies that can further improve the SNR gain.

  11. Optical Coherence and Quantum Optics

    CERN Document Server

    Mandel, Leonard

    1995-01-01

    This book presents a systematic account of optical coherence theory within the framework of classical optics, as applied to such topics as radiation from sources of different states of coherence, foundations of radiometry, effects of source coherence on the spectra of radiated fields, coherence theory of laser modes, and scattering of partially coherent light by random media. The book starts with a full mathematical introduction to the subject area and each chapter concludes with a set of exercises. The authors are renowned scientists and have made substantial contributions to many of the topi

  12. Vitrectomy for bilateral macular schisis without apparent optic disc anomalies

    Science.gov (United States)

    Andonegui, José; Maya, José Ramón; Echeverría, Marta; Alcaine, Araceli

    2016-01-01

    A 78-year-old man complained of bilateral visual acuity loss. Optical coherence tomography examination showed bilateral macular schisis with fluid accumulation in the external retinal layers without vitreous traction. Fundus examination and fluorescein angiography were normal in both eyes. Both eyes were treated by phacoemulsification, intraocular lens implantation, and vitrectomy without laser, gas exchange, or retinal fenestration. Slow and progressive fluid resorption and improvement in VA were observed in both eyes. Macular schisis similar to the one associated with optic disc anomalies is a possibility in patients without apparent disc anomalies. Vitrectomy without laser, gas, or retinal fenestration may be a good therapeutic option even in patients with a PVD preoperatively. PMID:27703873

  13. Localized bi-nasal macular edema in optic chiasmal syndrome

    Directory of Open Access Journals (Sweden)

    Alejandro J Lavaque

    2013-01-01

    Full Text Available A 28-year-old healthy male complaining of vision loss in his right eye was discovered to have localized bi-nasal macular edema in the presence of a pituitary adenoma. The presence of a junctional scotoma composed by a central scotoma in the right eye associated with superior temporal quadrantanopia in the fellow eye was seen. The pattern detected in the visual field suggested the presence of an expansive mass at the level of the optic chiasm. Optical coherence tomography findings also revealed subtle macular thickness beyond normal in the superior and nasal quadrants of both maculae. This report illustrates the importance of suspecting a pituitary adenoma in the light of uncharacteristic retinal alterations.

  14. Consistency of ocular coherence tomography fast macular thickness mapping in diabetic diffuse macular edema Consistência da tomografia de coerência óptica no edema macular difuso diabético

    Directory of Open Access Journals (Sweden)

    Fábio Petersen Saraiva

    2007-01-01

    Full Text Available OBJECTIVES: To investigate optical coherence tomography consistency on foveal thickness, foveal volume, and macular volume measurements in patients with and without diffuse diabetic macular edema. INTRODUCTION: Optical coherence tomography represents an objective technique that provides cross-sectional tomographs of retinal structure in vivo. However, it is expected that poor fixation ability, as seen in diabetic macular edema, could alter its results. Several authors have discussed the reproducibility of optical coherence tomography, but only a few have addressed the topic with respect to diabetic maculopathy. METHODS: The study recruited diabetic patients without clinically evident retinopathy (control group and with diffuse macular edema (case group. Only one eye of each patient was evaluated. Five consecutive fast macular scans were taken using Ocular Coherence Tomography 3; the 6 mm macular map was chosen. The consistency in measurements of foveal thickness, foveal volume, and total macular volume for both groups was evaluated using the Pearson's coefficient of variation. The T-test for independent samples was used in order to compare measurements of both groups. RESULTS: Each group consisted of 20 patients. All measurements had a coefficient of variation less than 10%. The most consistent parameter for both groups was the total macular volume. DISCUSSION: Consistency in measurement is a mainstay of any test. A test is unreliable if its measurements can not be correctly repeated. We found a good index of consistency, even considering patients with an unstable gaze. CONCLUSIONS: Optical coherence tomography is a consistent method for diabetic subjects with diffuse macular edema.OBJETIVOS: Investigar a consistência das medidas de espessura foveal, volume foveal e volume macular total feitas pela tomografia de coerência óptica em pacientes com e sem edema macular difuso diabético. INTRODUÇÃO: A tomografia de coerência óptica é uma t

  15. Cierre espontáneo de agujero macular idiopático:: seguimiento por tomografía de coherencia óptica y microperimetría MP1 Spontaneous closure of the idiopathic macular hole.: Follow-up of this case by optical coherence tomography and microperimetry MP1

    Directory of Open Access Journals (Sweden)

    Julio César Molina Martín

    2010-12-01

    Full Text Available Se presenta un caso de cierre espontáneo de agujero macular idiopático seguido por tomografía de coherencia óptica y microperimetría MP1 antes y después del cierre. El cierre espontáneo de un estadio 4 no ocurre con frecuencia, sin embargo, puede aparecer fundamentalmente en pacientes con diámetro superior del agujero menor a 150 micras. La tomografía de coherencia óptica y la microperimetría constituyen herramientas útiles en el diagnóstico, pronóstico y seguimiento de esta entidad.The case of spontaneous closure of a stage 4 idiopathic macular hole at followed up by Optical Coherence Tomography and microperimetry MP1 before and after the closure was presented. The spontaneous closure of a stage 4 macular hole is rare but it can occur in patients with hole upper diameters less than 150 µm. The OCT and the microperimetry MP1 are very useful tools in the diagnosis, prognosis and follow-up of this maculopathy.

  16. Optical Coherency Matrix Tomography

    Science.gov (United States)

    2015-10-19

    optics has been studied theoretically11, but has not been demonstrated experimentally heretofore. Even in the simplest case of two binary DoFs6 (e.g...coherency matrix G spanning these DoFs. This optical coherency matrix has not been measured in its entirety to date—even in the simplest case of two...dense coding, etc. CREOL, The College of Optics & Photonics, University of Central Florida, Orlando , Florida 32816, USA. Correspondence and requests

  17. The Choroid and Optical Coherence Tomography

    OpenAIRE

    Taha Sezer; Muhammet Altınışık; İbrahim Arif Koytak

    2016-01-01

    The choroid is the most vascular tissue in the eye and it plays an important role in the pathophysiology of various common chorioretinal diseases such as central serous retinopathy, age-related macular degeneration and degenerative myopia. Quantitative assessment of the choroid has been quite challenging with traditional imaging modalities such as indocyanine green angiography and ultrasonography due to limited resolution and repeatability. With the advent of optical coherence tomography (OCT...

  18. Imaging characteristics of optical coherence tomography in vitelliform macular dystrophy%卵黄样黄斑营养不良的光学相干断层扫描影像学特征

    Institute of Scientific and Technical Information of China (English)

    李娟娟; 张文佳; 盛智超; 胡竹林

    2011-01-01

    Objcetive To evaluate the imaging characteristics of optical coher ence tomography( OCT)irIvitelliform macular dystrophy at different stages. Methods The imaging characteristics of OCT in 6 patients(8eyes) with vitelliform macular dys trophy were retrospectively analyzed, which were compared with the results of their fundus examination and fundus fluorescein angiography. Results At the stage of vi telliform, the fundus examination disclosed a round elevated yellowish lesion, OCT showed an area of hyper reflectivity locating between the retinal pigment epithelium lay er and the photoreceptor layer. With the progression of disease, the thickness of ner osensory was increased. At the stage of atrophy, the atrophic focus was observed in the macular area, OCT showed the retinal pignent epithelium-choroid complement was thick.the nerve layer was thin,and the high reflective vessel membrane was seen in the combined choroidal neovascuLarization.Conclusion OCT combined with detailed medical recard,fundus examination and tluorescence fundus angiography can be helpful for the analysis of clinical characteristics and pathologic changes.%目的 探讨卵黄样黄斑营养不良各病变阶段光学相干断层扫描(optical coherence tomography,OCT)的影像学特征.方法 回顾性分析6例(8眼)卵黄样黄斑营养不良患者的OCT图像特征,并与眼底特征、眼底荧光血管造影进行对照分析.结果 卵黄样病变期患者眼底检查可见黄斑区卵圆形隆起病灶,OCT可见视网膜色素上皮层和光感受器层之间有一中等密度反射区域,随病变进展,沉积物厚度增高.萎缩期患者黄斑区见萎缩灶,OCT表现为视网膜色素上皮层脉络膜复合体弥漫性增厚,神经感觉层变薄,合并脉络膜新生血管形成时可见高反射的新生血管膜.结论 详细的病史资料、眼底检查、眼底荧光血管造影以及OCT的联合应用,有助于更科学的分析卵黄样黄斑营养不良的临床特征和病理改变.

  19. 病理性近视黄斑区的光学相干断层扫描图像分析%Analysis of the image features in macular of pathologic myopia by Optical Coherence Tomography

    Institute of Scientific and Technical Information of China (English)

    朱丽; 宋艳萍; 丁琴; 陈晓; 陈中山; 江黎; 李丹

    2012-01-01

    Objective To study and analyze the characteristics of Optical Coherence Tomography (OCT) image in macular of pathologic myopia. Methods A total of 122 cases (238 eyes) of pathologic myopia were examined with OCT.The refraction error ranges of all the cases were -6.00D to -32.00 D. Results OCT image was normal in 11 eyes (4.6%),the reflectivity band of RPE and choriod capillaries were uneven and thinning in 211 eyes (88.7%),macular hole was found in 31 eyes (13.0%),of which 12 eyes was associated with retinal detachment; shallow retinal detachment without hole was found in 11 eyes (4.6%); 32 eyes (13.4%) had retinal schisis; 28 eyes (11.8%) with macular choroidal neovascularization (CNV); epiretinal macular membrane 26 eyes (10.9%),of which 19 eyes was associated with chronic macular edema; Fuchs spot 12 eyes (5.0%); macular hemorrhage 8 eyes (3.4%). Conclusions OCT has unique preference for observation of the change of macular in pathologic myopia.However,it has some limitations.%目的 研究分析病理性近视患者黄斑区的光学相干断层扫描(OCT)的图像特征.方法 对122例(238只眼)病理性近视患者行黄斑区OCT检查.患者屈光度数为-6.00~-32.00 D.结果 OCT检查黄斑区正常者11只眼(4.6%),黄斑区神经上皮层、视网膜色素上皮层和脉络膜毛细血管层光带反射不均匀及萎缩变薄者211只眼(88.7%);黄斑裂孔31只眼(13.0%),其中合并视网膜脱离者12只眼;无裂孔视网膜浅脱离11只眼(4.6%);黄斑部视网膜劈裂32只眼(13.4%),黄斑脉络膜新生血管28只眼(11.8%),黄斑前膜26只眼(10.9%),其中合并黄斑囊样水肿19只眼;Fuchs斑12只眼(5.0%),黄斑区色素沉着14只眼(5.9%),黄斑出血8只眼(3.4%).结论 OCT在观察病理性近视黄斑部病变具有独特的优越性,但也有一定的局限性.

  20. Estudo da morfologia macular após a remoção da membrana epirretiniana idiopática utilizando a tomografia de coerência óptica (OCT: um estudo piloto Study on macular morphology after removal of the idiopathic epiretinal membrane using the optical coherence tomography (OCT: a pilot study

    Directory of Open Access Journals (Sweden)

    Janaína Jamile Ferreira Saraceno

    2007-12-01

    ções estruturais antes e depois da cirurgia para remoção de membrana epirretiniana idiopática. Os resultados funcionais da vitrectomia posterior via pars plana são satisfatórios embora outros fatores prognósticos possam estar envolvidos nos resultados visuais finais desta patologia.PURPOSE: To describe the relation between visual results and macular morphology through optical coherence tomography (OCT in patients submitted to removal of the idiopathic epiretinal membranes. METHODS: Ten eyes of ten patients with diagnosis of idiopathic epiretinal membranes underwent standard 20-G pars plana vitrectomy. Posterior hyaloid attachments were identified and dealt with. Idiopathic epiretinal membranes were removed in all cases. Corrected visual acuity, retinography, fluorescein angiography, fundus biomicroscopy and the optical coherence tomography in the pre- and postoperative periods were performed in all patients. In OCT, three characteristics were considered in each image: presence of foveal depression, presence of cystoid macular edema and mean central macular thickness. RESULTS: Pre-operative visual acuity varied from 20/80 to counting fingers. The mean age was 63 years, ranging from 57 to 78 years. Five patients were male and five female. Preoperative visual acuity (VA varied from 20/80 to CD to 1 meter. An improvement in VA of at least two lines was noted in all cases and metamorphopsia in eight eyes (80%. Four patients did not present metamorphopsia according to Amsler grid test, and the remaining presented partial improvement. On optical coherence tomography all eyes maintained increased central thickness, ranging from 232 to 605 µ (mean of 351.9 µ. Three eyes maintained cystoid macular edema. Four eyes presented final VA better or equal to 20/30. In this group the mean central thickness was of 277 µ. Foveal contour was recovered in two of these eyes. Four patients had no residual cystoid macular edema. CONCLUSIONS: Optical coherence tomography is a tool that evaluates

  1. Relationship between central visual acuity and retinal volume of macular fovea accessed by spectral domain optical coherence tomography in Stargardt disease%Stargardt病的频域相干光断层扫描图像分析

    Institute of Scientific and Technical Information of China (English)

    张枝桥; 张承芬; 董方田; 陈有信; 于伟泓; 戴荣平; 郑霖

    2011-01-01

    Objective To assess the relationship between central visual acuity and retinal volume of macular fovea in patients with Stargardt disease by spectral-domain optical coherence tomography ( SD OCT). Methods It was a retrospective case series study. Twenty eyes of 10 patients with Stargardt disease were investigated by three-dimensional spectral-domain optical coherence tomography. SD OCT images were obtained and retrospectively analyzed. The retinal volumes of macular fovea were measured by SD OCT,whose diameters were set as 3 mm and 1 mm separately ( volume 3 and volume 1). The retinal thickness of macular fovea (macular thickness) and the width of IS/OS conjunction loss of macular fovea (IS/OS loss)were also measured by SD OCT. We correlated the logMAR BCVA with IS/OS loss, macular thickness,volume 3 and volume 1 by linear regression analysis. Results LogMAR BCVA was from 0. 3 to 1. 22.IS/OS loss was from 847 μm to 5306 μm. Macular thickness was from 20 μm to 126μm. Volume 3 and volume 1 was from 1. 06 to 1. 76 mm3 and 0. 06 to 0. 13 mm3. LogMAR BCVA correlated with the IS/OS loss (r = 0.695,P<0. 05) , macular thickness (r= - 0. 601 ,P < 0. 05), and volume 3 ( r = -0.725,P<0. 05 ). LogMAR BCVA did not correlate with volume 1 ( r = - 0. 364, P > 0. 05). Conclusions SD OCT could demonstrate the retinal structure of Stargardt disease clearly. The retinal volume of macular fovea accessed by SD OCT correlated with the visual acuity of Stargardt disease.%目的 应用频域相干光断层扫描(OCT)技术评价Stargardt病患者黄斑区视网膜容积与中心视力之间的关系.方法 回顾性病例系列研究.收集10例(20只眼)Stargardt病的临床资料进行回顾性分析.所有患者均使用频域OCT分别测量黄斑中心凹区视网膜厚度、黄斑中心凹区光感受器细胞内外节缺失宽度、黄斑中心凹区直径3 mm和1 mm范围内的视网膜容积.运用线性回归分析法,比较最小分辨角对数(logMAR)视力与黄

  2. Comparison of diagnostic capability of macular ganglion cell complex and retinal nerve fiber layer among primary open angle glaucoma, ocular hypertension, and normal population using Fourier-domain optical coherence tomography and determining their functional correlation in Indian population

    Directory of Open Access Journals (Sweden)

    Nabanita Barua

    2016-01-01

    Full Text Available Context: Analysis of diagnostic ability of macular ganglionic cell complex and retinal nerve fiber layer (RNFL in glaucoma. Aim: To correlate functional and structural parameters and comparing predictive value of each of the structural parameters using Fourier-domain (FD optical coherence tomography (OCT among primary open angle glaucoma (POAG and ocular hypertension (OHT versus normal population. Setting and Design: Single centric, cross-sectional study done in 234 eyes. Materials and Methods: Patients were enrolled in three groups: POAG, ocular hypertensive and normal (40 patients in each group. After comprehensive ophthalmological examination, patients underwent standard automated perimetry and FD-OCT scan in optic nerve head and ganglion cell mode. The relationship was assessed by correlating ganglion cell complex (GCC parameters with mean deviation. Results were compared with RNFL parameters. Statistical Analysis: Data were analyzed with SPSS, analysis of variance, t-test, Pearson′s coefficient, and receiver operating curve. Results: All parameters showed strong correlation with visual field (P 0.5 when compared with other parameters. None of the parameters showed significant diagnostic capability to detect OHT from normal population. In diagnosing early glaucoma from OHT and normal population, only inferior GCC had statistically significant AUC value (0.715. Conclusion: In this study, GCC and RNFL parameters showed equal predictive capability in perimetric versus normal group. In early stage, inferior GCC was the best parameter. In OHT population, single day cross-sectional imaging was not valuable.

  3. Reliability and reproducibility of spectral and time domain optical coherence tomography images before and after correction for patients with age-related macular degeneration [v2; ref status: indexed, http://f1000r.es/50m

    Directory of Open Access Journals (Sweden)

    Mohammad A. Sadiq

    2015-03-01

    Full Text Available Purpose: To evaluate the reproducibility and reliability of optical coherence tomography scans obtained using the time domain (TD-OCT StratusTM OCT, and the Spectral Domain (SD-OCT SpectralisTM and CirrusTM OCT devices before and after manual correction in eyes with either Neovascular (NV-AMD or Non-Neovascular (NNV-AMD age-related macular degeneration. Design: Prospective observational study. Methods: Setting: University-based retina practice. Patients: Thirty-six patients (50 eyes with NV-AMD or NNV-AMD. Procedure: OCT scans were taken simultaneously using one TD-OCT and two SD-OCT devices. Main Outcome Measures: Macular thickness measurements were assessed before and after correction of the algorithm by constructing Bland-Altman plots for agreement and calculating intraclass correlation coefficients (ICCs and coefficients of repeatability (COR to evaluate intraclass repeatability. Results: Spectralis had the highest number of images needing manual correction.  All machines had high ICCs, with Spectralis having the highest.  Also, Bland-Altman plots indicated that there was low agreement between Cirrus™ and Stratus™, Spectralis™ and Stratus™, while there was good agreement between the Cirrus™ and Spectralis™.  The CORs were lowest for SpectralisTM and similar and higher for CirrusTM and StratusTM.  Agreement, CORs, and ICCs generally improved after manual correction, but only minimally.  Conclusion: Agreement is low between devices, except between both SD-OCT machines.  Manual correction tends to improve results.

  4. Dental Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Kun-Feng Lin

    2013-07-01

    Full Text Available This review paper describes the applications of dental optical coherence tomography (OCT in oral tissue images, caries, periodontal disease and oral cancer. The background of OCT, including basic theory, system setup, light sources, spatial resolution and system limitations, is provided. The comparisons between OCT and other clinical oral diagnostic methods are also discussed.

  5. Optical Coherence Tomography

    DEFF Research Database (Denmark)

    Andersen, Peter E.

    2015-01-01

    Optical coherence tomography (OCT) is a noninvasive imaging technique that provides real-time two- and three-dimensional images of scattering samples with micrometer resolution. Mapping the local reflectivity, OCT visualizes the morphology of the sample, in real time or at video rate. In addition...

  6. Retinal thickness measurement and evaluation of natural history of the diabetic macular edema through optical coherence tomography Medida da espessura retiniana e avaliação da história natural do edema macular diabético pela tomografia de coerência óptica

    Directory of Open Access Journals (Sweden)

    Rosana Zacarias Hannouche

    2009-08-01

    Full Text Available PURPOSE: 1 Diagnose, through optical coherence tomography (OCT exam, the occurrence of diabetic macular edema in patients with diabetic retinopathy and visual acuity of 20/40 or better, by measuring the foveal center point thickness, during one year. 2 Evaluate the edema natural history, during this period, associating the center point thickness with hemoglobin A1c and changes in visual acuity. 3 Correlate the obtained results with the control group. METHODS: A prospective study was done, of a sample of 30 patients with diabetic macular edema and visual acuity of 20/40 or better. Measurements of the best corrected visual acuity, hemoglobin A1c level, biomicroscopy with 78-diopter lens, fluorescein angiogram and optical coherence tomography were made. The retinal thickness was selected as the main variable. Besides descriptive statistics, additional tests were applied to analyze the results and determine the correlation between these variables, such as t-Student, Chi-Square, Tukey and ANOVA. The relation of optical coherence tomography with visual acuity and hemoglobin A1c was studied through linear regression. RESULTS: It was found that there is no significant difference between patients and normal individuals, for the variables age and gender. The values of center point thickness found for men were greater than those for women, showing the influence of gender on that thickness. As many as 83.33% of the diabetic patients with clinically significant macular edema presented moderate non-proliferative diabetic retinopathy (NPDR, 10% presented mild NPDR and 6.66% severe non-proliferative diabetic retinopathy. Patients under combined treatment of insulin and oral hypoglycemiant presented influence on the results of center point thickness (through OCT and visual acuity. The mean duration of diabetes was 9.63 years. Values of center point thickness were always found greater for patients than those for normal eyes. Levels of hemoglobin A1c did not have

  7. 黄斑部脉络膜新生血管的OCT图像特征及与视力的相关性%Correlation between optical coherence tomography image characteristics of macular choroidal neovascularization and visual acuity

    Institute of Scientific and Technical Information of China (English)

    张敏芳; 孟晓红; 陈军; 冉黎

    2011-01-01

    目的 观察黄斑部脉络膜新生血管(choroidal neovascularization,CNV)的光学相干断层扫描(optical coherence tomography,OCT)图像特征,评估其与最佳矫正视力的相关性. 方法 收集在我院经眼底荧光血管造影(fundus fluorescein angiography,FFA)及吲哚氰绿血管造影(indocyanine green angiography,ICGA)检查确诊为黄斑部典型性CNV高度近视(high myopia,HM)、年龄相关性黄斑变性(age-related macular degeneration,AMD)及中心性渗出性脉络膜视网膜病变(central exudative chorioretinopathy,CEC)患者共34例36眼,经验光检查得到最佳矫正视力(best corrected visual acuity,BCVA);采用OCT仪检查并分析CNV的图像特征,并测量CNV突破RPE/脉络膜毛细血管复合层的基底部宽度、高度、离中心凹的距离及中心处视网膜神经上皮层组织厚度,分别评估其与视力改变的相关性. 结果 CNV的OCT图像特征:RPE/脉络膜毛细血管层下见大小不等局限性增强隆起反射带;合并病灶周围视网膜神经上皮层组织下局限性无反射暗区或组织内反射增厚.AMD所引起的CNV基底部宽度、高度及中心处神经上皮层组织厚度值均最大.经直线相关分析统计显示:AMD和CEC所引起CNV的基底部宽度及中心处视网膜神经上皮层组织厚度均与BCVA具有负相关性(均为P<0.05),而HM所引起的CNV仅中心处视网膜神经上皮层组织厚度与BCVA具有负相关性(P<0.05). 结论 OCT能有效测量CNV的长度及黄斑水肿程度,在有效评估其与BCVA的相关性中具有重要作用.%Objective To investigate the optical coherence tomography (OCT) image characteristics of macular choroidal neovascularization (CNV) and evaluate their correlation with visual acuity. Methods Thirty-six eyes of 34 cases with high myopia, age-related macular degeneration ( AMD) and center exudation chorioretinopathy, which were diagnosed as typical macular CNV using fundus fluorescein angiography and indocyanine

  8. Choroidal Thickness and Choroidal Vessel Density in Nonexudative Age-Related Macular Degeneration Using Swept-Source Optical Coherence Tomography Imaging.

    Science.gov (United States)

    Zheng, Fang; Gregori, Giovanni; Schaal, Karen B; Legarreta, Andrew D; Miller, Andrew R; Roisman, Luiz; Feuer, William J; Rosenfeld, Philip J

    2016-11-01

    To analyze the relationship between choroidal thickness and the distribution of choroidal blood vessels in eyes with nonexudative AMD. Eyes with a diagnosis of nonexudative AMD were imaged using a prototype 100-kHz swept-source (SS) optical coherence tomography (OCT) instrument (Carl Zeiss Meditec, Dublin, CA, USA) with a central wavelength of 1050 nm. We used an OCT cube scan pattern consisting of 512 × 512 A-scans over a 12 × 12 mm retinal area. The eyes were partitioned into two groups based on the presence or absence of reticular pseudodrusen (RPD). All scans were segmented using an automated algorithm. In addition, five eyes from each of the two groups were randomly chosen for manual segmentation. Binary choroidal vessels maps were generated from suitable OCT choroidal slabs, and the relationship between the density of large choroidal vessels and choroidal thickness was analyzed using an Early Treatment Diabetic Retinopathy Study-like target centered on the fovea. Twenty-five eyes were enrolled in each group. The automated algorithm produced accurate choroidal thickness maps with an average difference between the manual and automated segmentations of 13.7 μm. There was a significant and stable correlation between choroidal thickness and choroidal vessel density across the two groups. Both average choroidal thickness and vessel density were significantly lower in eyes with RPD. Our fully automated choroidal segmentation algorithm was able to capture the different patterns of choroidal thickness over a wide area. Choroidal thickness has a clear relationship with the density of large choroid vessels in our sample, irrespective of the presence or absence of RPD.

  9. Repeatability of Perimacular Ganglion Cell Complex Analysis with Spectral-Domain Optical Coherence Tomography

    OpenAIRE

    Ng, Dorothy S. K.; Preeti Gupta; Yih Chung Tham; Chye Fong Peck; Tien Yin Wong; Mohammad Kamran Ikram; Cheung, Carol Y.

    2015-01-01

    Purpose. To assess the repeatability of spectral-domain optical coherence tomography to measure macular and perimacular ganglion cell complex thicknesses and compare retinal ganglion cell parameters between algorithms. Methods. Ninety-two nonglaucomatous eyes from 92 participants underwent macular and perimacular ganglion cell complex thickness measurement using OCT-HS100 Glaucoma 3D algorithm and these measurements were repeated for 34 subjects. All subjects also had macular ganglion cell-in...

  10. Analysis of macular edema characteristics with the spectral domain optical coherence tomography%频域OCT检查对黄斑水肿特点的分析

    Institute of Scientific and Technical Information of China (English)

    李岩; 王兰惠; 韩梅; 解士勇

    2010-01-01

    目的 通过频域OCT对黄斑水肿形态进行观察,了解水肿程度及分布情况,并分析水肿与视力的相关性.方法 选取患黄斑水肿患者25例29只眼,病例包括视网膜中央静脉阻塞所致为8例8只眼,视网膜分支静脉阻塞7例7只眼,葡萄膜炎4例4只眼,糖尿病性视网膜病变6例10只眼.年龄52-83(64.76±8.30)岁.最佳矫正视力(BCVA)0.05~1.0(0.35±0.12).利用最新一代频域RTVueFD-OCT对黄斑区进行扫描.结果 黄斑区15°范围内神经上皮厚度(453.00±103.12)μm,其中各区域神经上皮层厚度为:中心凹(533.10±115.23)μm,旁中心区(488.93±89.71)μm,中心凹边缘区(397.05±83.52)μm.不同区域神经上皮层厚度比较差异有统计学意义(F=2.937,P0.05.患者BCVA与中心凹神经上皮层厚度间存在负相关关系(r=-0.784,P0.05),与中心凹边缘区神经上皮层厚度间无相关关系(r=.275,P>0.05).结论 频域OCT能够精确地对黄斑水肿进行活体组织学成像,具有简便、非侵入性、重复性好等特点.%Objective To find out the degree and distribufion of macular edema and analyze the corelation between macular edema and visual acuity by observing morphology of maeular edema under the spectral domain OCT.Methods Selecting 29 eyes of 25 cases suffered from macular edema.including 8 eyes of 8 cases with central retinal vein occlusion,7 eyes of 7 cases with branch retinal vein occlusion.4 eyes of 4 cases with uveitis,and 10 eyes of 6 cases with diabetic retinopathy.Age was 52~85(average 64.76±8.30),best corrected visual acuity (BCVA) was 0.05~1.0 (average0.35±0.12).Scanning macular with the newest spectral domain RTVue FD-OCT.Results In 15°macular afea,the thickness of neuro-epithelium layers were(453.00±103.12)μ m,thickness of various sectiolls Were:fovea (533.10±115.23)μ m,parafovea (488.93±89.71)μm,perifovea(397.05~83.52)μ m.There was statistically significant difference of neuroep. Ithelium layers thickness in various areas

  11. Anterior Segment Tomography with the Cirrus Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Eduardo B. Rodrigues

    2012-01-01

    Full Text Available Optical coherence tomography (OCT is an optical acquisition method to examine biological tissues. In recent years, OCT has become an important imaging technology used in diagnosing and following macular pathologies. Further development enabled application of optical coherence tomography in evaluation of the integrity of the nerve fiber layer, optic nerve cupping, anterior chamber angle, or corneal topography. In this manuscript we overview the use of OCT in the clinical practice to enable corneal, iris, ciliary body, and angle evaluation and diagnostics.

  12. Interocular agreement in melanin and macular pigment optical density.

    NARCIS (Netherlands)

    Kanis, M.J.; Berendschot, T.T.J.M.; van Norren, D.

    2007-01-01

    Macular pigment (MP) and melanin possibly protect the macular area by absorbing blue light and acting as antioxidants. Because little is known about the interocular correlation of melanin, we determined its optical density (MOD) in both eyes of healthy subjects using fundus reflectometry. The measur

  13. Diffraction coherence in optics

    CERN Document Server

    Françon, M; Green, L L

    2013-01-01

    Diffraction: Coherence in Optics presents a detailed account of the course on Fraunhofer diffraction phenomena, studied at the Faculty of Science in Paris. The publication first elaborates on Huygens' principle and diffraction phenomena for a monochromatic point source and diffraction by an aperture of simple form. Discussions focus on diffraction at infinity and at a finite distance, simplified expressions for the field, calculation of the path difference, diffraction by a rectangular aperture, narrow slit, and circular aperture, and distribution of luminous flux in the airy spot. The book th

  14. Optical coherence tomography changes on age - related macular degeneration patients after photodynamic therapy%光动力学疗法治疗AMD后OCT检查的特征性改变

    Institute of Scientific and Technical Information of China (English)

    李秀梅; 高宗银; 张柳; 朱远军; 匡丽晖

    2014-01-01

    目的:通过前瞻性观察PDT治疗湿性年龄相关性黄斑变性(aged-related macular degeneration,AMD)前后不同随访时间点光学相干断层成像( optical coherence tomography, OCT)的特征性改变,旨在更好地反馈 PDT治疗后黄斑区结构的变化过程。  方法:将在本院接受PDT治疗的26例30眼湿性AMD患者纳入本研究。维速达尔用量根据厂家推荐方法计算。治疗前后均行FFA,ICG,OCT及最佳矫正视力等相关临床检查,术后随访日期为术后2wk;1,2,3mo。傅立叶OCT扫描以标准五线结合六线扫描,覆盖病变的关键部位并保持前后扫描位置的一致性。重点观察黄斑中心凹层间厚度、外层高反射带高度、囊肿(包括视网膜下积液和视网膜内积液)的总面积。分析这些变化与随访时间的依赖关系。统计分析使用SPSS 13.0软件。  结果:至治疗后3mo,PDT治疗后22眼(73%)视力提高两行以上,3眼视力无明显改变,3眼视力下降,2例患者因故失访。视力提高的22眼治疗前平均黄斑厚度为722.5±55.6μm,治疗后2wk,平均黄斑层间厚度为708.3±45.3μm,1mo 为584.4±49.3μm,2mo 为430.7±50.2μm,3 mo为180.6±36.3μm。治疗前和治疗后外层高反射带厚度分别为302.3±50.2,277.5±42.3,202.7±40.1,180-6±35.7,100.8±22.9μm,囊肿的总面积为0.34±0-12,0.25±0.07,0.10±0.05,0.08±0.04,0.05±0.01mm2。  结论:AMD患者在PDT治疗后1 mo黄斑区视网膜下液有显著吸收,视网膜水肿显著吸收,黄斑中心凹层间厚度、外层高反射厚度也有明显变薄倾向。%AIM: To better reveal the changing process of macula area after photodynamic therapy (PDT), the changes of tomographic imaging on macular fovea optical coherence tomography ( OCT ) scan at different follow- up time points after treating age-related macular degeneration ( AMD) by PDT were investigated. METHODS: This cohort study included 30 eyes of 26 patients diagnosed as AMD. The dosage of

  15. Optical Coherence Tomography

    DEFF Research Database (Denmark)

    Mogensen, Mette; Themstrup, Lotte; Banzhaf, Christina

    2014-01-01

    as the optical analogue to ultrasound. The inherent safety of the technology allows for in vivo use of OCT in patients. The main strength of OCT is the depth resolution. In dermatology, most OCT research has turned on non-melanoma skin cancer (NMSC) and non-invasive monitoring of morphological changes......Optical coherence tomography (OCT) has developed rapidly since its first realisation in medicine and is currently an emerging technology in the diagnosis of skin disease. OCT is an interferometric technique that detects reflected and backscattered light from tissue and is often described...... in a number of skin diseases based on pattern recognition, and studies have found good agreement between OCT images and histopathological architecture. OCT has shown high accuracy in distinguishing lesions from normal skin, which is of great importance in identifying tumour borders or residual neoplastic...

  16. Retinal Spectral Domain Optical Coherence Tomography in Early Atrophic Age-Related Macular Degeneration (AMD and a New Metric for Objective Evaluation of the Efficacy of Ocular Nutrition

    Directory of Open Access Journals (Sweden)

    Stuart Richer

    2012-11-01

    Full Text Available Purpose: A challenge in ocular preventive medicine is identification of patients with early pathological retinal damage that might benefit from nutritional intervention. The purpose of this study is to evaluate retinal thinning (RT in early atrophic age-related macular degeneration (AMD against visual function data from the Zeaxanthin and Visual Function (ZVF randomized double masked placebo controlled clinical trial (FDA IND #78973. Methods: Retrospective, observational case series of medical center veterans with minimal visible AMD retinopathy (AREDS Report #18 simplified grading 1.4/4.0 bilateral retinopathy. Foveal and extra-foveal four quadrant SDOCT RT measurements were evaluated in n = 54 clinical and ZVF AMD patients. RT by age was determined and compared to the OptoVue SD OCT normative database. RT by quadrant in a subset of n = 29 ZVF patients was correlated with contrast sensitivity and parafoveal blue cone increment thresholds. Results: Foveal RT in AMD patients and non-AMD patients was preserved with age. Extrafoveal regions, however, showed significant slope differences between AMD patients and non-AMD patients, with the superior and nasal quadrants most vulnerable to retinal thinning (sup quad: −5.5 μm/decade thinning vs. Non-AMD: −1.1 μm/decade, P < 0.02; nasal quad: −5.0 μm/decade thinning vs. Non-AMD: −1.0 μm/decade, P < 0.04. Two measures of extrafoveal visual deterioration were correlated: A significant inverse correlation between % RT and contrast sensitivity (r = −0.33, P = 0.01, 2 Tailed Paired T and an elevated extrafoveal increment blue cone threshold (r = +0.34, P = 0.01, 2 Tailed T. Additional SD OCT RT data for the non-AMD oldest age group (ages 82–91 is needed to fully substantiate the model. Conclusion: A simple new SD OCT clinical metric called “% extra-foveal RT” correlates well with functional visual loss in early AMD patients having minimal visible retinopathy. This metric can be used to

  17. Emprego das medidas anatômicas do buraco macular idiopático obtidas pela tomografia de coerência óptica como fator preditivo nos resultados visuais: um estudo piloto Use of anatomical measures of idiopathic macular hole obtained through optical coherence tomography as a predictive factor in visual results: a pilot study

    Directory of Open Access Journals (Sweden)

    Alan Diego Negretto

    2007-10-01

    Full Text Available OBJETIVO: Avaliar a anatomia do buraco macular idiopático (BMI a partir da tomografia de coerência óptica (OCT e construir índice prognóstico que possa ser correlacionado com os resultados visuais e o fechamento anatômico. MÉTODOS: Estudo prospectivo, no qual 22 olhos com BMI foram avaliados pelo OCT no pré-operatório da cirurgia do BMI. Foi criado o índice prognóstico do buraco macular (IPBM que foi correlacionado com o resultado anatômico e a acuidade visual pós-operatória seis meses após a cirurgia. RESULTADOS: Dezesseis olhos (72,7% obtiveram fechamento anatômico ao final de seis meses de acompanhamento. Na análise do IPBM, houve diferença significativa entre o grupo 1 (BM aberto e o grupo 2 (BM fechado (p=0,0018. O risco de insucesso para o fechamento anatômico é 11 vezes maior quando o diâmetro da base interna for superior a 600 µm ou o IPBM for inferior a 0,6 (p=0,0495. No que diz respeito à AV final, observou-se que o IPBM tem correlação negativa significante na AV (p=0,001. CONCLUSÃO: O IPBM se apresentou como o melhor preditor de fechamento anatômico e acuidade visual pós-operatória entre as variáveis aqui estudadas. Responde por 41% da acuidade visual pós-operatória final, nos levando a crer que outros fatores, como o tempo de história e a degeneração dos fotorreceptores nestes BM mais antigos, possam estar envolvidos nos resultados visuais.PURPOSE: To evaluate the anatomy of idiopathic macular hole (IMH using Optical Coherence Tomography (OCT and to construct a prognostic index that can be correlated with the visual outcomes and the anatomical closing. METHODS: Prospective study, in which 22 eyes with IMH had been evaluated through OCT in the daily postoperative period of IMH surgery. The Prognostic of Macular Hole Index (PMHI was created which was correlated with the anatomical result and the postoperative visual acuity (VA six months after surgery. RESULTS: Sixteen eyes (72.7% got anatomical

  18. Coherent optics in students' laboratories

    Science.gov (United States)

    Senderáková, Dagmar; Mesaros, Vladimir; Drzik, Milan

    2014-12-01

    Lasers provide us with unique kind of light - coherent light. Besides being the keystone of historical interferometric measuring methods, coherent waves, now accessible in a very easy way, become a base of new optical measuring and information processing methods. Moreover, holographic recording seems today to have become a common term, even among common, not especially optically educated people. The presentation deals with our attempt to take our students' interest in the coherence of light and getting them familiar with the phenomenon, indeed.

  19. Adaptive Optics Reveals Photoreceptor Abnormalities in Diabetic Macular Ischemia

    Science.gov (United States)

    Nesper, Peter L.; Scarinci, Fabio

    2017-01-01

    Diabetic macular ischemia (DMI) is a phenotype of diabetic retinopathy (DR) associated with chronic hypoxia of retinal tissue. The goal of this prospective observational study was to report evidence of photoreceptor abnormalities using adaptive optics scanning laser ophthalmoscopy (AOSLO) in eyes with DR in the setting of deep capillary plexus (DCP) non-perfusion. Eleven eyes from 11 patients (6 women, age 31–68), diagnosed with DR without macular edema, underwent optical coherence tomography angiography (OCTA) and AOSLO imaging. One patient without OCTA imaging underwent fluorescein angiography to characterize the enlargement of the foveal avascular zone. The parameters studied included photoreceptor heterogeneity packing index (HPi) on AOSLO, as well as DCP non-perfusion and vessel density on OCTA. Using AOSLO, OCTA and spectral domain (SD)-OCT, we observed that photoreceptor abnormalities on AOSLO and SD-OCT were found in eyes with non-perfusion of the DCP on OCTA. All eight eyes with DCP non-flow on OCTA showed photoreceptor abnormalities on AOSLO. Six of the eight eyes also had outer retinal abnormalities on SD-OCT. Three eyes with DR and robust capillary perfusion of the DCP had normal photoreceptors on SD-OCT and AOSLO. Compared to eyes with DR without DCP non-flow, the eight eyes with DCP non-flow had significantly lower HPi (P = 0.013) and parafoveal DCP vessel density (P = 0.016). We found a significant correlation between cone HPi and parafoveal DCP vessel density (r = 0.681, P = 0.030). Using a novel approach with AOSLO and OCTA, this study shows an association between capillary non-perfusion of the DCP and abnormalities in the photoreceptor layer in eyes with DR. This observation is important in confirming the significant contribution of the DCP to oxygen requirements of photoreceptors in DMI, while highlighting the ability of AOSLO to detect subtle photoreceptor changes not always visible on SD-OCT. PMID:28068435

  20. 光学相干断层扫描在特发性黄斑前膜诊治中的应用价值%Clinical application of optical coherence tomography in idiopathic macular epiretinal membranes

    Institute of Scientific and Technical Information of China (English)

    周正申; 孙静芬

    2012-01-01

    Objective To investigate the application of optical coherence tomography ( OCT) in idiopathic macular epirelinal membranes (IMEM), and explore its correlation with visual acuity. Methods The clinical data of 107 patients (121 eyes) with IMEM were retrospectively analysed. Macular epiretinal membranes were classified according to OCT images, and macular central fovea thickness (CFT), volume (V), average thickness (AT) and fovea thickness (FT) were measured. The correlation of OCT parameters and clinical findings with besl corrected visual acuity of LogMAR was analysed. Results IMEM were visible on OCT as high reflective tissues, which were thin or thick, and were separated from or nestled up against the retinal surface. In most fovea, the depth decreased and the thickness increased. The average best corrected visual acoity of LogMAR of 121 eyes was 0. 67 (0 to 2), CFT was (481. 34 ±68. 13) μm (206 -572 μm), and FT was (311. 57 ± 124. 76) μm (134 -639 μm). Statistic analysis revealed that the average best corrected visual acuity of LogMAR was signifieantly related to CFT (r = 0. 761, P <0. 05), while was not related to age, gender, V, AT, FT, retinal edema, lamellar maeular hole, retinal nerve fiber layer achisis and damage of inner segment/outer segment of photosensory cells. Conclusion OCT has a high sensitivity in clinical diagnosis of IMEM, and can objectively display the morphological change of macular tissues. Increased central fovea thickness caused by IMEM is closely related to the impairment of visual acuity.%目的 观察光学相干断层扫描(OCT)检查在特发性黄斑前膜(IMEM)诊治中的应用价值,分析OCT检查指标与患者视力的相关性.方法 回顾分析107例(121眼)IMEM患者的临床资料.根据OCT图像对黄斑前膜进行分类,测量黄斑中央中心凹厚度(CFT)、体积(V)、平均厚度(AT)以及黄斑中心凹厚度(FT).分析OCT各项指标和临床检查结果与患者LogMAR最佳

  1. Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Pier Alberto Testoni

    2007-01-01

    Full Text Available Optical coherence tomography (OCT is an optical imaging modality that performs high-resolution, cross-sectional, subsurface tomographic imaging of the microstructure of tissues. The physical principle of OCT is similar to that of B-mode ultrasound imaging, except that it uses infrared light waves rather than acoustic waves. The in vivo resolution is 10–25 times better (about 10 µm than with high-frequency ultrasound imaging, but the depth of penetration is limited to 1–3 mm, depending on tissue structure, depth of focus of the probe used, and pressure applied to the tissue surface. In the last decade, OCT technology has evolved from an experimental laboratory tool to a new diagnostic imaging modality with a wide spectrum of clinical applications in medical practice, including the gastrointestinal tract and pancreatico-biliary ductal system. OCT imaging from the gastrointestinal tract can be done in humans by using narrow-diameter, catheter-based probes that can be inserted through the accessory channel of either a conventional front-view endoscope, for investigating the epithelial structure of the gastrointestinal tract, or a side-view endoscope, inside a standard transparent ERCP (endoscopic retrograde cholangiopancreatography catheter, for investigating the pancreatico-biliary ductal system. The esophagus and esophagogastric junction have been the most widely investigated organs so far; more recently, duodenum, colon, and the pancreatico-biliary ductal system have also been extensively investigated. OCT imaging of the gastrointestinal wall structure is characterized by a multiple-layer architecture that permits an accurate evaluation of the mucosa, lamina propria, muscularis mucosae, and part of the submucosa. The technique may therefore be used to identify preneoplastic conditions of the gastrointestinal tract, such as Barrett's epithelium and dysplasia, and evaluate the depth of penetration of early-stage neoplastic lesions. OCT imaging

  2. Optical coherence tomography examination of patients with hyperopic ametropic amblyopia

    Directory of Open Access Journals (Sweden)

    Hong-Chao Xu

    2013-08-01

    Full Text Available AIM: To investigate the changes of retina in amblyopic eye by measuring macular retinal thickness in hyperopicametropic amblyopic patients.METHODS: Optical coherence tomography(OCTwas used to measure the macular retinal thickness value in 17 amblyopic patients(20 eyesand 14 healthy controls(20 eyes. The result was processed as retinal thickness value and thickness map by computer. The data were analyzed by SPSS 13.0 software package. RESULTS: The retinal thickness of central sector or region in amblyopic eyes were thicker than those in normal eyes(PPP>0.05. CONCLUSION: The macular retina thickness of the central region is thicker in hyperopic ametropic amblyopic patient. OCT is a noninvasive, noncontact technique that visualizes the retinal structure in vivo, this technique may be used to find the potential initial neural site of the visual deficit in this condition.

  3. The Choroid and Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Taha Sezer

    2016-01-01

    Full Text Available The choroid is the most vascular tissue in the eye and it plays an important role in the pathophysiology of various common chorioretinal diseases such as central serous retinopathy, age-related macular degeneration and degenerative myopia. Quantitative assessment of the choroid has been quite challenging with traditional imaging modalities such as indocyanine green angiography and ultrasonography due to limited resolution and repeatability. With the advent of optical coherence tomography (OCT technology, detailed visualization of the choroid in vivo is now possible. Measurements of choroidal thickness have also enabled new directions in research to study normal and pathological processes within the choroid. The aim of the present study is to review the current literature on choroidal imaging using OCT

  4. The Choroid and Optical Coherence Tomography

    Science.gov (United States)

    Sezer, Taha; Altınışık, Muhammet; Koytak, İbrahim Arif; Özdemir, Mehmet Hakan

    2016-01-01

    The choroid is the most vascular tissue in the eye and it plays an important role in the pathophysiology of various common chorioretinal diseases such as central serous retinopathy, age-related macular degeneration and degenerative myopia. Quantitative assessment of the choroid has been quite challenging with traditional imaging modalities such as indocyanine green angiography and ultrasonography due to limited resolution and repeatability. With the advent of optical coherence tomography (OCT) technology, detailed visualization of the choroid in vivo is now possible. Measurements of choroidal thickness have also enabled new directions in research to study normal and pathological processes within the choroid. The aim of the present study is to review the current literature on choroidal imaging using OCT. PMID:27800255

  5. Second harmonic optical coherence tomography

    OpenAIRE

    Jiang,Yi; Tomov, Ivan; Wang, Yimin; Chen, Zhongping

    2004-01-01

    Second harmonic optical coherence tomography, which uses coherence gating of second-order nonlinear optical response of biological tissues for imaging, is described and demonstrated. Femtosecond laser pulses were used to excite second harmonic waves from collagen harvested from rat tail tendon and a reference nonlinear crystal. Second harmonic interference fringe signals were detected and used for image construction. Because of the strong dependence of second harmonic generation on molecular ...

  6. Visual loss related to macular subretinal fluid and cystoid macular edema in HIV-related optic neuropathy

    DEFF Research Database (Denmark)

    Gautier, David; Rabier, Valérie; Jallet, Ghislaine;

    2012-01-01

    Optic nerve involvement may occur in various infectious diseases, but is rarely reported after infection by the human immunodeficiency virus (HIV). We report the atypical case of a 38-year-old patient in whom the presenting features of HIV infection were due to a bilateral optic neuropathy associ...... associated with macular subretinal fluid and cystoid macular edema, which responded well to antiretroviral therapy....

  7. Optical coherence tomography findings of quinine poisoning

    Directory of Open Access Journals (Sweden)

    John Christoforidis

    2011-01-01

    Full Text Available John Christoforidis, Robert Ricketts, Theodore Loizos, Susie ChangThe Ohio State University College of Medicine, Columbus, OH, USAPurpose: To report a case of acute quinine poisoning, document acute and chronic macular changes with optical coherence tomography imaging and fluorescein angiography (FA, and to review the literature on ocular toxicity of quinine.Methods: A 32-year-old white female presented to our Emergency Department after ingesting over 7.5 g of quinine. She underwent a complete ophthalmologic examination, fluorescein angiography, Stratus time-domain optical coherence tomography (OCT, and electroretinography at 72 hours and 15 months postingestion. Stratus time-domain and Cirrus spectral-domain OCT, fundus autofluorescence, and FA were obtained at 28 months postingestion.Results: Fluorescein angiography at 72 hours postingestion revealed normal filling times and vasculature. OCT showed marked thickening of the inner retina bilaterally. At 15 and 28 months follow-up, fundus photography and fluorescein angiography demonstrated optic nerve pallor, severely attenuated retinal vessels while OCT showed inner retinal atrophy. Fundus autofluorescence did not reveal any retinal pigmentary abnormalities.Conclusions: Quinine toxicity as seen by OCT reveals increased thickness with inner retinal hyperreflectivity acutely with development of significant retinal atrophy in the long-term. Fundus autofluorescence reveals an intact retinal pigment epithelial layer at 28 months. These findings suggest that quinine poisoning may produce a direct toxic effect on the inner retina in the acute phase resulting in long-term retinal atrophy.Keywords: retinal, optical coherence tomography, quinine toxicity 

  8. Optical Coherence Tomography to Assess Neurodegeneration in Multiple Sclerosis.

    Science.gov (United States)

    Petzold, Axel

    2016-01-01

    Retinal spectral domain optical coherence tomography (OCT) has emerged as a clinical and research tool in multiple sclerosis (MS) and optic neuritis (ON). This chapter summarizes a short OCT protocol as included in international consensus guidelines. The protocol was written for hands-on style such that both clinicians and OCT technicians can make use of it. The protocol is suitable for imaging of the optic nerve head and macular regions as a baseline for follow-up investigations, individual layer segmentation, and diagnostic assessment.

  9. Spectral-domain optical coherence tomography findings of the macula in 500 consecutive patients with uveitis.

    Science.gov (United States)

    Grajewski, R S; Boelke, A C; Adler, W; Meyer, S; Caramoy, A; Kirchhof, B; Cursiefen, C; Heindl, L M

    2016-11-01

    PurposeTo analyze the macular structure in a large series of consecutive patients with different types of uveitis using spectral-domain optical coherence tomography (SD-OCT).Patients and methodsFive hundred eyes of 500 consecutive patients with anterior, intermediate, posterior, and panuveitis underwent standardized macular examination using SD-OCT. Central retinal thickness (CRT), macular volume (MV), and presence of cystoid macular edema (CME), diffuse macular edema (DME), serous retinal detachment (SRD), epiretinal membrane with (ERM+) and without (ERM-) retinal surface wrinkling were determined.ResultsThe anatomic location of inflammation affected significantly CRT and MV (Puveitis (17%); SRD was most frequent in panuveitis (15%) and posterior uveitis (10%); ERM+ was most frequent in panuveitis (45%) and intermediate uveitis (30%); and ERM- was most frequent in intermediate (14%) and posterior uveitis (15%).ConclusionSD-OCT of the macula is recommended for all uveitis patients. CRT, MV, and the incidence of CME were highest in intermediate and panuveitis.

  10. Experimental generation of optical coherence lattices

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yahong; Cai, Yangjian, E-mail: serpo@dal.ca, E-mail: yangjiancai@suda.edu.cn [College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006 (China); Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province and Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006 (China); Ponomarenko, Sergey A., E-mail: serpo@dal.ca, E-mail: yangjiancai@suda.edu.cn [Department of Electrical and Computer Engineering, Dalhousie University, Halifax, Nova Scotia B3J 2X4 (Canada)

    2016-08-08

    We report experimental generation and measurement of recently introduced optical coherence lattices. The presented optical coherence lattice realization technique hinges on a superposition of mutually uncorrelated partially coherent Schell-model beams with tailored coherence properties. We show theoretically that information can be encoded into and, in principle, recovered from the lattice degree of coherence. Our results can find applications to image transmission and optical encryption.

  11. Optical coherence refractometry.

    Science.gov (United States)

    Tomlins, Peter H; Woolliams, Peter; Hart, Christian; Beaumont, Andrew; Tedaldi, Matthew

    2008-10-01

    We introduce a novel approach to refractometry using a low coherence interferometer at multiple angles of incidence. We show that for plane parallel samples it is possible to measure their phase refractive index rather than the group index that is usually measured by interferometric methods. This is a significant development because it enables bulk refractive index measurement of scattering and soft samples, not relying on surface measurements that can be prone to error. Our technique is also noncontact and compatible with in situ refractive index measurements. Here, we demonstrate this new technique on a pure silica test piece and a highly scattering resin slab, comparing the results with standard critical angle refractometry.

  12. Optical coherence in astrophysics

    CERN Document Server

    Moret-Bailly, Jacques

    2013-01-01

    Many physicists and most astrophysicists assume that the photon is a small particle which, in a very low pressure gas can only interact with a single molecule. Thus, the interaction of light with this gas is incoherent. W. E.Lamb Jr, W. P. Schleich, M. O. Scully and C. H. Townes (Reviews of Modern Physics 71, S263, 1999) have criticized this view: In accordance with quantum electrodynamics the photon is a pseudo-particle resulting from the quantization of a deterministic exchange of energy between identical molecules and a normal mode of electromagnetic field. Following Lamb et al., we study models in which some variables have an unusual value for a spectroscopist: extremely low pressure hydrogen, but huge light paths, extremely hot sources. However, the magnitudes of the spectral radiances and column densities can be similar in astrophysics and in a laboratory using lasers. Thus, several coherent effects must be taken into account: superradiance, multiphoton interactions, impulsive stimulated Raman scatterin...

  13. Integrated-optics-based optical coherence tomography

    NARCIS (Netherlands)

    Nguyen, D.V.

    2013-01-01

    Optical coherence tomography (OCT) is a high resolution, imaging technique that has developed over the last 20 years from a complicated laboratory setup into a ready-to-use commercially available device. Instead of using electronic time gating as being used by ultrasound (US) imaging, in OCT, the op

  14. Coherent signal processing in optical coherence tomography

    Science.gov (United States)

    Kulkarni, Manish Dinkarrao

    1999-09-01

    Optical coherence tomography (OCT) is a novel method for non-invasive sub-surface imaging of biological tissue micro-structures. OCT achieves high spatial resolution ( ~ 15 m m in three dimensions) using a fiber-optically integrated system which is suitable for application in minimally invasive diagnostics, including endoscopy. OCT uses an optical heterodyne detection technique based on white light interferometry. Therefore extremely faint reflections ( ~ 10 fW) are routinely detected with high spatial localization. The goal of this thesis is twofold. The first is to present a theoretical model for describing image formation in OCT, and attempt to enhance the current level of understanding of this new modality. The second objective is to present signal processing methods for improving OCT image quality. We present deconvolution algorithms to obtain improved longitudinal resolution in OCT. This technique may be implemented without increasing system complexity as compared to current clinical OCT systems. Since the spectrum of the light backscattered from bio-scatterers is closely associated with ultrastructural variations in tissue, we propose a new technique for measuring spectra as a function of depth. This advance may assist OCT in differentiating various tissue types and detecting abnormalities within a tissue. In addition to depth resolved spectroscopy, Doppler processing of OCT signals can also improve OCT image contrast. We present a new technique, termed color Doppler OCT (CDOCT). It is an innovative extension of OCT for performing spatially localized optical Doppler velocimetry. Micron-resolution imaging of blood flow in sub-surface vessels in living tissue using CDOCT is demonstrated. The fundamental issues regarding the trade- off between the velocity estimation precision and image acquisition rate are presented. We also present novel algorithms for high accuracy velocity estimation. In many blood vessels velocities tend to be on the order of a few cm

  15. Optical Coherence Tomography

    DEFF Research Database (Denmark)

    Fercher, A.F.; Andersen, Peter E.

    2017-01-01

    with a resolution comparable to conventional histology, but in real time, it can be used as a biopsy technique in a wide range of biological systems to detect diseases. These include the tomographic imaging of the internal microstructure of in vivo atherosclerotic plaques, the tomographic real-time diagnostics...... for intraoperative monitoring, and in microsurgical intervention. Optical biopsy based on OCT also provides diagnostic information by differentiating the architectural morphology of urological tissue, gastrointestinal tissue, and respiratory tissue....

  16. 3D光学相干断层扫描在特发性黄斑前膜诊治中的应用%Value of spectral optical coherence tomography on idiopathic macular epiretinal membrane diagnosis and treatment

    Institute of Scientific and Technical Information of China (English)

    黄慧君; 晏世刚; 陈建明

    2012-01-01

    Objective To explore the effect of idiopathic macular epiretinal membranes (IMEM) on vision. Methods Forty-two patients (46 eyes) in our hospital who were diagnosed as IMEM with visual acuity and spectral domain opti -cal coherence tomography ( OCT). Then the relationship between the results above and vision were analyzed . Results In 42 cases of (46 eyes) IMEM performance in the former 3D-OCT images of membrance patients as huangbanon retinal sur -face varying thickness high reflecting light. The overwhelming majority of the degree in macular fovea is more thicker , the eyesight is more poor. 34 eyes (73. 9% ) OCT image to the floor with the retina , s report to adhere to the council of the zon -al strong reflecting the light ,most of the reflecting light separate from the inner layer of the retin . The other 12 eyes (26. 1% ) performance with the retina is more close to the sticking up against stood wide . Conclusion 3D-OCT can be precise measurement the thickness of retinal macular. Objective and comprehensive information provided in retinal thickness , and preliminary evaluation of the relationship between IMEM and eyesight . To provide reference value of the surgery and surgical operation guide.%目的 应用3D光学相干断层扫描(OCT)观察特发性黄斑前膜(IMEM)的形态特征及其对视力的影响.方法 应用3D-OCT观察42例(46只眼)IMEM患者的OCT图像,分析黄斑中心凹形态、中心凹厚度与视力的关系.结果 在42例(46只眼)IMEM患者的3D-OCT图像中表现为黄斑区视网膜表面厚薄不一的高反光带,绝大多数伴不同程度的黄斑中心凹厚度增加,黄斑中心凹越厚,视力越差.34只眼(73.9%)OCT图像表现为与视网膜内层局灶性粘附的条带状强反光,大部分与视网膜内层分离,另12只眼(26.1%)表现为与视网膜内层完全紧密粘连的增强增宽的反光带.结论 3D-OCT可以精确测量黄斑视网膜厚度,客观而全面地提供视网膜各层之间以及厚度变

  17. Coherent optical methods for metallography

    Energy Technology Data Exchange (ETDEWEB)

    Pechersky, M.J.

    1991-01-01

    Numerous methods based on coherent optical techniques have been developed over the past two decades for nondestructive evaluation, vibration analysis and experimental mechanics. These methods have a great deal of potential for the enhancement of metallographic evaluations and for materials characterization in general. One such technique described in this paper is the determination of the material damping factors in metals. Damping loss factors as low as 10-5 were measured on bronze and aluminum specimens using a technique based on laser vibrometry. Differences between cast and wrought bronze were easily distinguishable as well as the difference between the bronze and aluminum. Other coherent optical techniques may be used to evaluate residual stresses and to locate and identify microcracking, subsurface voids and other imperfections. These techniques and others can serve as a bridge between microstructural investigations and the macroscopic behavior of materials.

  18. Coherent optical methods for metallography

    Energy Technology Data Exchange (ETDEWEB)

    Pechersky, M.J.

    1991-12-31

    Numerous methods based on coherent optical techniques have been developed over the past two decades for nondestructive evaluation, vibration analysis and experimental mechanics. These methods have a great deal of potential for the enhancement of metallographic evaluations and for materials characterization in general. One such technique described in this paper is the determination of the material damping factors in metals. Damping loss factors as low as 10-5 were measured on bronze and aluminum specimens using a technique based on laser vibrometry. Differences between cast and wrought bronze were easily distinguishable as well as the difference between the bronze and aluminum. Other coherent optical techniques may be used to evaluate residual stresses and to locate and identify microcracking, subsurface voids and other imperfections. These techniques and others can serve as a bridge between microstructural investigations and the macroscopic behavior of materials.

  19. Wavefront sensing reveals optical coherence.

    Science.gov (United States)

    Stoklasa, B; Motka, L; Rehacek, J; Hradil, Z; Sánchez-Soto, L L

    2014-01-01

    Wavefront sensing is a set of techniques providing efficient means to ascertain the shape of an optical wavefront or its deviation from an ideal reference. Owing to its wide dynamical range and high optical efficiency, the Shack-Hartmann wavefront sensor is nowadays the most widely used of these sensors. Here we show that it actually performs a simultaneous measurement of position and angular spectrum of the incident radiation and, therefore, when combined with tomographic techniques previously developed for quantum information processing, the Shack-Hartmann wavefront sensor can be instrumental in reconstructing the complete coherence properties of the signal. We confirm these predictions with an experimental characterization of partially coherent vortex beams, a case that cannot be treated with the standard tools. This seems to indicate that classical methods employed hitherto do not fully exploit the potential of the registered data.

  20. Coherence Constraints and the Last Hidden Optical Coherence

    CERN Document Server

    Qian, Xiao-Feng; Vamivakas, A Nick; Eberly, Joseph H

    2016-01-01

    We have discovered a new domain of optical coherence, and show that it is the third and last member of a previously unreported fundamental triad of coherences. These are unified by our derivation of a parallel triad of coherence constraints that take the form of complementarity relations. We have been able to enter this new coherence domain experimentally and we describe the novel tomographic approach devised for that purpose.

  1. Autologous platelet concentrate in surgery for macular detachment associated with congenital optic disc pit

    Directory of Open Access Journals (Sweden)

    Nadal J

    2015-10-01

    Full Text Available Jeroni Nadal,1,2 Marta S Figueroa,3 Elisa Carreras,2,4 Patricia Pujol,2,4 Maria Isabel Canut,2,4,5 Rafael Ignacio Barraquer2,6 1Vitreoretinal Surgery Department at Centro de Oftalmología Barraquer, 2Universitat autónoma de Barcelona, Barcelona, 3Vissum Madrid, Madrid, 4Instituto Barraquer, 5Glaucoma Department at Centro de Oftalmología Barraquer, 6Cornea and Cataract Surgery Department at Centro de Oftalmología Barraquer, Barcelona, Spain Purpose: To evaluate the anatomical and functional results obtained with pars plana vitrectomy (PPV plus autologous platelet concentrate (APC as a treatment for macular detachment associated with optic disc pit (ODP.Methods: We performed a prospective interventional study of 19 eyes of 19 consecutive patients with posterior macular detachment due to ODP. All patients underwent PPV, posterior hyaloid peeling, fluid–air exchange, injection of 0.05 mL of APC over the ODP and 15% perfluoropropane (C3F8 endotamponade. Postoperative measures included face-up positioning for 2 hours and then avoidance of the face-up position during the ensuing 10 days. All patients underwent complete ophthalmologic examination and optical coherence tomography preoperatively at 1 month, 3 months, 6 months, 9 months, and 12 months postoperatively and then annually. Outcome measures were best corrected visual acuity (BCVA by logMAR, improvement of quality of vision, macular attachment, and resolution of intraretinal schisis-like separation.Results: Preoperatively, the median BCVA was 0.70 (range: 0.30–1.70 and all patients showed improved visual acuity after surgery; BCVA was 0.22 (range: 0.07–0.52 at 12 months follow-up. All patients showed complete reabsorption of intraretinal fluid (median time: 3.5 months [range: 2–8 months] and macular attachment at the end of follow-up (median: 60 months [range: 12–144 months], with stable or improved visual acuity. No reoperations were needed and no major adverse events were

  2. Optical coherence tomography angiography in retinal diseases

    Directory of Open Access Journals (Sweden)

    K V Chalam

    2016-01-01

    Full Text Available Optical coherence tomography angiography (OCTA is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. Split-spectrum amplitude-decorrelation angiography (SSADA algorithm (a vital component of OCTA software helps to decrease the signal to noise ratio of flow detection thus enhancing visualization of retinal vasculature using motion contrast. Published studies describe potential efficacy for OCTA in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age related macular degeneration (AMD, retinal vascular occlusions and sickle cell disease. OCTA provides a detailed view of the retinal vasculature, which allows accurate delineation of microvascular abnormalities in diabetic eyes and vascular occlusions. It helps quantify vascular compromise depending upon the severity of diabetic retinopathy. OCTA can also elucidate the presence of choroidal neovascularization (CNV in wet AMD. In this paper, we review the knowledge, available in English language publications regarding OCTA, and compare it with the conventional angiographic standard, fluorescein angiography (FA. Finally, we summarize its potential applications to retinal vascular diseases. Its current limitations include a relatively small field of view, inability to show leakage, and tendency for image artifacts. Further larger studies will define OCTA's utility in clinical settings and establish if the technology may offer a non-invasive option of visualizing the retinal vasculature, enabling us to decrease morbidity through early detection and intervention in retinal diseases.

  3. Optical Coherence Tomography Angiography in Retinal Diseases.

    Science.gov (United States)

    Chalam, K V; Sambhav, Kumar

    2016-01-01

    Optical coherence tomography angiography (OCTA) is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. Split-spectrum amplitude-decorrelation angiography (SSADA) algorithm (a vital component of OCTA software) helps to decrease the signal to noise ratio of flow detection thus enhancing visualization of retinal vasculature using motion contrast. Published studies describe potential efficacy for OCTA in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age related macular degeneration (AMD), retinal vascular occlusions and sickle cell disease. OCTA provides a detailed view of the retinal vasculature, which allows accurate delineation of microvascular abnormalities in diabetic eyes and vascular occlusions. It helps quantify vascular compromise depending upon the severity of diabetic retinopathy. OCTA can also elucidate the presence of choroidal neovascularization (CNV) in wet AMD. In this paper, we review the knowledge, available in English language publications regarding OCTA, and compare it with the conventional angiographic standard, fluorescein angiography (FA). Finally, we summarize its potential applications to retinal vascular diseases. Its current limitations include a relatively small field of view, inability to show leakage, and tendency for image artifacts. Further larger studies will define OCTA's utility in clinical settings and establish if the technology may offer a non-invasive option of visualizing the retinal vasculature, enabling us to decrease morbidity through early detection and intervention in retinal diseases.

  4. Macular edema in uveitis with emphasis on ocular sarcoidosis

    NARCIS (Netherlands)

    Norel, J. van

    2015-01-01

    This thesis investigates the accumulation of fluid in the yellow spot (macular edema) in ocular inflammation (uveitis). Macular edema may result in definitive loss of vision.Two methods of imaging of macular edema are fluorescein angiography (FA) and optical coherence tomography (OCT). The first met

  5. Macular edema in uveitis with emphasis on ocular sarcoidosis

    NARCIS (Netherlands)

    Norel, J. van

    2015-01-01

    This thesis investigates the accumulation of fluid in the yellow spot (macular edema) in ocular inflammation (uveitis). Macular edema may result in definitive loss of vision.Two methods of imaging of macular edema are fluorescein angiography (FA) and optical coherence tomography (OCT). The first met

  6. Dynamic Optical Coherence Tomography Capillaroscopy

    DEFF Research Database (Denmark)

    Ring, Hans Christian; Themstrup, Lotte; Banzhaf, Christina Alette

    2016-01-01

    status, or morphology of the deeper dermal vessels. Dynamic optical coherence tomography (D-OCT) is a recently developed OCT technique that enables detection of high-speed changes in back-scattered light caused by moving cells in vessels. The high resolution of OCT enables the detection of the papillary...... loops. OBJECTIVE To explore the potential for OCT capillaroscopy of the nailfolds using D-OCT. DESIGN, SETTING, AND PARTICIPANTS In this case series study of 4 participants, the nailfolds in 2 patients with systemic sclerosis, 1 patient with dermatomyositis, and a healthy volunteer were scanned using D...

  7. Motion contrast using optical coherence tomography

    Science.gov (United States)

    Fingler, Jeffrey Paul

    Diagnosis of ophthalmic diseases like age-related macular degeneration is very important for treatment of the disease as well as the development of future treatments. Optical coherence tomography (OCT) is an optical interference technique which can measure the three-dimensional structural information of the reflecting layers within a sample. In retinal imaging, OCT is used as the primary diagnostic tool for structural abnormalities such as retinal holes and detachments. The contrast within the images of this technique is based upon reflectivity changes from different regions of the retina. This thesis demonstrates the developments of methods used to produce additional contrast to the structural OCT images based on the tiny fluctuations of motion experienced by the mobile scatterers within a sample. Motion contrast was observed for motions smaller than 50 nm in images of a variety of samples. Initial contrast method demonstrations used Brownian motion differences to separate regions of a mobile Intralipid solution from a static agarose gel, chosen in concentration to minimize reflectivity contrast. Zebrafish embryos in the range of 3-4 days post fertilization were imaged using several motion contrast methods to determine the capabilities of identifying regions of vascular flow. Vasculature identification was demonstrated in zebrafish for blood vessels of all orientations as small as 10 microns in diameter. Mouse retinal imaging utilized the same motion contrast methods to determine the contrast capabilities for motions associated with vasculature within the retina. Improved contrast imaging techniques demonstrated comparable images to fluorescein angiography, the gold standard of retinal vascular imaging. Future studies can improve the demonstrated contrast analysis techniques and apply them towards human retinal motion contrast imaging for ophthalmic diagnostic purposes.

  8. Optical Coherence Tomography: Advanced Modeling

    DEFF Research Database (Denmark)

    Andersen, Peter E.; Thrane, Lars; Yura, Harold T.;

    2013-01-01

    Analytical and numerical models for describing and understanding the light propagation in samples imaged by optical coherence tomography (OCT) systems are presented. An analytical model for calculating the OCT signal based on the extended Huygens-Fresnel principle valid both for the single......- and multiple-scattering regimes is derived. An advanced Monte Carlo model for calculating the OCT signal is also derived, and the validity of this model is shown through a mathematical proof based on the extended Huygens-Fresnel principle. From the analytical model, an algorithm for enhancing OCT images...... is developed, the so-called true-reflection algorithm in which the OCT signal may be corrected for the attenuation caused by scattering. The algorithm is verified experimentally and by using the Monte Carlo model as a numerical tissue phantom. Applications of extraction of optical properties from tissue...

  9. Stellate figure in the macula: visualization in the Henle fiber layer on optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Makino S

    2014-01-01

    Full Text Available Shinji Makino, Meri Watanabe, Hironobu TampoDepartment of Ophthalmology, Jichi Medical University, Shimotsuke, Tochigi, JapanAbstract: A 21-year-old woman complaining of a sudden visual disturbance in her left eye was referred to our hospital. The best-corrected visual acuity (BCVA in the left eye was 0.3. Fundus examination revealed tortuous retinal veins, soft exudates, and retinal edema. Optical coherence tomography showed that the macular thickness was increased to 685 µm. We diagnosed the condition as a central retinal vein occlusion. Systemic administration of an antiplatelet agent was initiated. The BCVA improved to 0.6, the retinal edema dramatically resolved, and the macular thickness was reduced to 318 µm 1 week later. Furthermore, the reduced retinal edema had transformed to many spokes in a wheel of exudates, a so-called “stellate figure”s, in the macula. On optical coherence tomography, hyper-reflective substances were detected in the Henle fiber layer. One month later, the BCVA improved to 1.0. Changes in microstructural findings and visual acuity were analogous during the recovery of macular edema in our patient.Keywords: stellate figure in the macula, Henle fiber layer, central retinal vein occlusion, macular edema, optical coherence tomography

  10. Ocular coherence tomographic examination of postoperative foveal architecture after scleral buckling vs vitrectomy for macular off retinal detachment.

    LENUS (Irish Health Repository)

    Gibran, S K

    2012-02-03

    AIMS: This pilot study uses Optical Coherence Tomography (OCT) imaging to compare the difference in foveal architecture after successful retinal detachment (RD) surgery by scleral buckling or pars plana vitrectomy (PPV). METHODS: Prospective recruitment of patients with macular off RDs. Detachment surgery was undertaken by scleral buckling, external drainage, and air injection (group 1) or by PPV (group 2). Postoperatively patients had clinical examinations and OCT at 1, 3, 6, and 12 months. If abnormalities persisted, a further OCT was obtained at 18 months. RESULTS: Retinal reattachment, including clinical macular reattachment, was achieved in all cases within 24 h postoperatively. In group 1 (n=22), postoperative OCT showed persistent foveal detachment in 63% of cases (n=14) at 1 and 3 months. At 6 and 12 months, 36% (n=8) and 9% (n=2) had a persistent foveal detachment, respectively, and at 18 months, foveal detachment eventually. In group 2 (n=21), postoperative OCT showed an attached fovea in all cases; however, foveal thickening suggesting intraretinal oedema was present in all cases. The oedematous appearance of retina on OCT settled in 1-3 months. No foveal abnormality was seen at 6 and 12 months postoperatively. CONCLUSIONS: A high proportion of patients with successful retinal reattachment surgery by scleral buckling had foveal detachments postoperatively. No cases who had PPV had foveal detachments; however, transient retinal oedema was evident in all cases. The aetiology of these changes is unknown and warrants further investigation, as there is the potential of a long-term effect on vision.

  11. Retinal Optical Coherence Tomography Imaging

    Science.gov (United States)

    Drexler, Wolfgang; Fujimoto, James G.

    The eye is essentially transparent, transmitting light with only minimal optical attenuation and scattering providing easy optical access to the anterior segment as well as the retina. For this reason, ophthalmic and especially retinal imaging has been not only the first but also most successful clinical application for optical coherence tomography (OCT). This chapter focuses on the development of OCT technology for retinal imaging. OCT has significantly improved the potential for early diagnosis, understanding of retinal disease pathogenesis, as well as monitoring disease progression and response to therapy. Development of ultrabroad bandwidth light sources and high-speed detection techniques has enabled significant improvements in ophthalmic OCT imaging performance, demonstrating the potential of three-dimensional, ultrahigh-resolution OCT (UHR OCT) to perform noninvasive optical biopsy of the living human retina, i.e., the in vivo visualization of microstructural, intraretinal morphology in situ approaching the resolution of conventional histopathology. Significant improvements in axial resolution and speed not only enable three-dimensional rendering of retinal volumes but also high-definition, two-dimensional tomograms, topographic thickness maps of all major intraretinal layers, as well as volumetric quantification of pathologic intraretinal changes. These advances in OCT technology have also been successfully applied in several animal models of retinal pathologies. The development of light sources emitting at alternative wavelengths, e.g., around #1,060 nm, not only enabled three-dimensional OCT imaging with enhanced choroidal visualization but also improved OCT performance in cataract patients due to reduced scattering losses in this wavelength region. Adaptive optics using deformable mirror technology, with unique high stroke to correct higher-order ocular aberrations, with specially designed optics to compensate chromatic aberration of the human eye, in

  12. Optical Microangiography Based on Optical Coherence Tomography

    Science.gov (United States)

    Reif, Roberto; Wang, Ruikang K.

    Proper homeostasis regulation of in vivo biological systems requires microvascular blood perfusion, which is the process of delivering blood into the tissue's capillary beds. Abnormal tissue vascularization has been associated with various diseases such as cancer, diabetes, neurological disorders, wounds, and inflammation. Understanding the changes in the vascular network or microangiography will have an important role in determining the causes and developing potential treatments for these diseases. Optical coherence tomography (OCT) is a noninvasive method for imaging three-dimensional biological tissues with high resolution (~10 µm) and without requiring the use of contrast agents. In this chapter we review several techniques for using OCT to determine blood flow velocities and the vessel morphology (optical microangiography). Different techniques will be discussed with a brief explanation of their limitations. Also, methods for quantifying these images are presented, as well as the depiction of several applications.

  13. Self-Optical Coherence Tomography and Angiography

    Directory of Open Access Journals (Sweden)

    Ahmad M. Mansour

    2017-02-01

    Full Text Available Purpose: To present a new concept of self-optical coherence tomography (OCT and self-OCT angiography. Methods: The operator sits in the patient seat and manipulates the instrument body via the joystick with the dominant hand, while the dominant index is ready to press the capture button and while focusing on the fixation target. One senior ophthalmologist judged various OCT machines for ease of self-scan during a major ophthalmic convention. Separately, self-scans were also captured using a single OCT machine by one senior ophthalmologist and 5 junior optometrists and the scans were analyzed for both centration and image quality value (IQV, and compared to regular scans done by an operator. Results: Ten available OCT machines were tested for their ability to allow self-OCT. Machines that had one or more features of auto-alignment, auto-focus, and auto-shoot were ideal for self-OCT or self-OCT angiography. Self-scans done by the ophthalmologist (total 27 scans of right eye, mean IQV = 32.6, and 24 left eyes, mean IQV = 37.3, done over 9 months and 5 optometrists (total 24 scans, mean 34.8 done in one session were comparable to scans (total 11, mean IQV = 38.1 done by an operator for image quality. Decentration was very common in self-scans of the macula (37% right eye and 46% left eye versus 0% for scans of the right eye done by an operator. Conclusions: Self-OCT scans of the macular region can be done with good image quality but are often decentered. Advantages include privacy, potential use by ophthalmic health professionals, airspace station officers, and possible future home self-imaging of macula.

  14. Imaging granulomatous lesions with optical coherence tomography

    DEFF Research Database (Denmark)

    Banzhaf, Christina; Jemec, Gregor B E

    2012-01-01

    To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT) images and compare this to previous studies of nonmelanoma skin tumors.......To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT) images and compare this to previous studies of nonmelanoma skin tumors....

  15. Cystoid Macular Edema in Bietti's Crystalline Retinopathy

    Directory of Open Access Journals (Sweden)

    Ali Osman Saatci

    2014-01-01

    Full Text Available A 27-year-old man with progressive bilateral visual decline was diagnosed to have Bietti's crystalline dystrophy (BCD. Fluorescein angiography revealed bilateral petaloid type late hyperfluorescence implicating concurrent cystoid macular edema (CME. Optical coherence tomography exhibited cystoid foveal lacunas OU. During the follow-up of six years, intraretinal crystals reduced in amount but CME persisted angiographically and tomographically. CME is among the rare macular features of BCD including subfoveal sensorial detachment, subretinal neovascular membrane, and macular hole.

  16. Optical coherence tomography in dermatology

    Science.gov (United States)

    Sattler, Elke; Kästle, Raphaela; Welzel, Julia

    2013-06-01

    Optical coherence tomography (OCT) is a noninvasive diagnostic method that offers a view into the superficial layers of the skin in vivo in real-time. An infrared broadband light source allows the investigation of skin architecture and changes up to a depth of 1 to 2 mm with a resolution between 15 and 3 μm, depending on the system used. Thus OCT enables evaluation of skin lesions, especially nonmelanoma skin cancers and inflammatory diseases, quantification of skin changes, visualization of parasitic infestations, and examination of other indications such as the investigation of nails. OCT provides a quick and useful diagnostic imaging technique for a number of clinical questions and is a valuable addition or complement to other noninvasive imaging tools such as dermoscopy, high-frequency ultrasound, and confocal laser scan microscopy.

  17. Edema quístico macular diagnosticado por tomografía de coherencia óptica en pacientes operados de catarata Cystoid macular edema diagnosed with optical coherente tomography in patients operated on from cataract

    Directory of Open Access Journals (Sweden)

    Omar Díaz Arencibia

    2009-12-01

    Full Text Available OBJETIVOS: Describir la frecuencia de edema quístico macular diagnosticado por tomografía de coherencia óptica en pacientes operados de catarata senil en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer", de diciembre 2006 a febrero 2007. MÉTODOS: Se realizó un estudio descriptivo, prospectivo en 108 ojos de 94 pacientes operados, a los que se les realizó un examen con el Stratus OCT 3000 de Zeiss Meditec AG. RESULTADOS: El 20,3 % de los pacientes presentó edema quístico macular. El 59,1 % de pacientes con edema quístico macular no manifestaron sintomatología alguna. Existió mayor probabilidad de desarrollar edema quístico macular cuando ocurrieron complicaciones durante la cirugía. Se observó por biomicroscopia del polo posterior, quistes intrarretiniales perifoveolares en el 81,8 % de los operados, y una relación inversamente proporcional entre el grosor macular y la agudeza visual alcanzada. CONCLUSIONES: Un número apreciable de pacientes con edema quístico macular fueron diagnosticados por tomografía de coherencia óptica. Se presentó de manera asintomática en la mayoría de los pacientes. Existe mayor probabilidad de desarrollar edema quístico macular cuando ocurren complicaciones durante la cirugía, en especial la ruptura de la cápsula posterior con vitreorragia. Los cambios morfológicos que se presentan en estos pacientes determinan que exista una relación inversamente proporcional entre el grosor macular y la agudeza visual alcanzada.OBJECTIVES: To describe the frequency of cystoid macular edema diagnosed with optical coherence tomography in patients operated on from senile cataract at "Ramón Pando Ferrer" Cuban Institute of Ophthalmology in the period from December 2006 to February 2007. METHODS: A prospective and descriptive study of 106 eyes from 94 surgical patients was conducted; they were examined with Zeiss Meditec AG Stratus OCT 3000. RESULTS: Of the total number of patients, 20,3 % presented

  18. Repeatability of Perimacular Ganglion Cell Complex Analysis with Spectral-Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Dorothy S. K. Ng

    2015-01-01

    Full Text Available Purpose. To assess the repeatability of spectral-domain optical coherence tomography to measure macular and perimacular ganglion cell complex thicknesses and compare retinal ganglion cell parameters between algorithms. Methods. Ninety-two nonglaucomatous eyes from 92 participants underwent macular and perimacular ganglion cell complex thickness measurement using OCT-HS100 Glaucoma 3D algorithm and these measurements were repeated for 34 subjects. All subjects also had macular ganglion cell-inner plexiform layer thickness measured by Cirrus HD-OCT Ganglion Cell Analysis algorithm. Intraclass correlation coefficient and Pearson’s correlation analyses were performed. Results. Subfields of both macular and perimacular ganglion cell complex thicknesses had high intraclass correlation coefficient values between 0.979 (95% confidence interval [CI]: 0.958–0.989 and 0.981 (95% CI: 0.963, 0.991 and between 0.70 (95% CI: 0.481–0.838 and 0.987 (95% CI: 0.956–0.989, respectively. The overall average ganglion cell complex and macular average ganglion cell-inner plexiform layer thicknesses were strongly correlated (r=0.83, P<0.001.  Conclusions. The assessment of macular and perimacular retinal ganglion cell parameters by OCT-HS100 Glaucoma 3D algorithm is highly repeatable, and strongly correlates to retinal ganglion cell parameters assessed by Ganglion Cell Analysis algorithm. A comprehensive evaluation of retinal ganglion cells may be possible with OCT-HS100.

  19. Second-harmonic optical coherence tomography

    Science.gov (United States)

    Jiang, Yi; Tomov, Ivan; Wang, Yimin; Chen, Zhongping

    2004-05-01

    Second-harmonic optical coherence tomography, which uses coherence gating of second-order nonlinear optical responses of biological tissues for imaging, is described and demonstrated. Femtosecond laser pulses were used to excite second-harmonic waves from collagen harvested from rat tail tendon and a reference nonlinear crystal. Second-harmonic interference fringe signals were detected and used for image construction. Because of the strong dependence of second-harmonic generation on molecular and tissue structures, this technique imparts contrast and resolution enhancement to conventional optical coherence tomography.

  20. Macular Microcysts in Mitochondrial Optic Neuropathies: Prevalence and Retinal Layer Thickness Measurements.

    Directory of Open Access Journals (Sweden)

    Michele Carbonelli

    Full Text Available To investigate the thickness of the retinal layers and to assess the prevalence of macular microcysts (MM in the inner nuclear layer (INL of patients with mitochondrial optic neuropathies (MON.All patients with molecularly confirmed MON, i.e. Leber's Hereditary Optic Neuropathy (LHON and Dominant Optic Atrophy (DOA, referred between 2010 and 2012 were enrolled. Eight patients with MM were compared with two control groups: MON patients without MM matched by age, peripapillary retinal nerve fiber layer (RNFL thickness, and visual acuity, as well as age-matched controls. Retinal segmentation was performed using specific Optical coherence tomography (OCT software (Carl Zeiss Meditec. Macular segmentation thickness values of the three groups were compared by one-way analysis of variance with Bonferroni post hoc corrections.MM were identified in 5/90 (5.6% patients with LHON and 3/58 (5.2% with DOA. The INL was thicker in patients with MON compared to controls regardless of the presence of MM [133.1±7μm vs 122.3±9μm in MM patients (p<0.01 and 128.5±8μm vs. 122.3±9μm in no-MM patients (p<0.05], however the outer nuclear layer (ONL was thicker in patients with MM (101.4±1mμ compared to patients without MM [77.5±8mμ (p<0.001] and controls [78.4±7mμ (p<0.001]. ONL thickness did not significantly differ between patients without MM and controls.The prevalence of MM in MON is low (5-6%, but associated with ONL thickening. We speculate that in MON patients with MM, vitreo-retinal traction contributes to the thickening of ONL as well as to the production of cystic spaces.

  1. Macular Microcysts in Mitochondrial Optic Neuropathies: Prevalence and Retinal Layer Thickness Measurements

    Science.gov (United States)

    Carbonelli, Michele; La Morgia, Chiara; Savini, Giacomo; Cascavilla, Maria Lucia; Borrelli, Enrico; Chicani, Filipe; do V. F. Ramos, Carolina; Salomao, Solange R.; Parisi, Vincenzo; Sebag, Jerry; Bandello, Francesco; Sadun, Alfredo A.; Carelli, Valerio; Barboni, Piero

    2015-01-01

    Purpose To investigate the thickness of the retinal layers and to assess the prevalence of macular microcysts (MM) in the inner nuclear layer (INL) of patients with mitochondrial optic neuropathies (MON). Methods All patients with molecularly confirmed MON, i.e. Leber’s Hereditary Optic Neuropathy (LHON) and Dominant Optic Atrophy (DOA), referred between 2010 and 2012 were enrolled. Eight patients with MM were compared with two control groups: MON patients without MM matched by age, peripapillary retinal nerve fiber layer (RNFL) thickness, and visual acuity, as well as age-matched controls. Retinal segmentation was performed using specific Optical coherence tomography (OCT) software (Carl Zeiss Meditec). Macular segmentation thickness values of the three groups were compared by one-way analysis of variance with Bonferroni post hoc corrections. Results MM were identified in 5/90 (5.6%) patients with LHON and 3/58 (5.2%) with DOA. The INL was thicker in patients with MON compared to controls regardless of the presence of MM [133.1±7μm vs 122.3±9μm in MM patients (p<0.01) and 128.5±8μm vs. 122.3±9μm in no-MM patients (p<0.05)], however the outer nuclear layer (ONL) was thicker in patients with MM (101.4±1mμ) compared to patients without MM [77.5±8mμ (p<0.001)] and controls [78.4±7mμ (p<0.001)]. ONL thickness did not significantly differ between patients without MM and controls. Conclusion The prevalence of MM in MON is low (5-6%), but associated with ONL thickening. We speculate that in MON patients with MM, vitreo-retinal traction contributes to the thickening of ONL as well as to the production of cystic spaces. PMID:26047507

  2. Dental optical coherence domain reflectometry explorer

    Energy Technology Data Exchange (ETDEWEB)

    Everett, Matthew J. (Livermore, CA); Colston, Jr., Billy W. (Livermore, CA); Sathyam, Ujwal S. (Livermore, CA); Da Silva, Luiz B. (Pleasanton, CA)

    2001-01-01

    A hand-held, fiber optic based dental device with optical coherence domain reflectometry (OCDR) sensing capabilities provides a profile of optical scattering as a function of depth in the tissue at the point where the tip of the dental explorer touches the tissue. This system provides information on the internal structure of the dental tissue, which is then used to detect caries and periodontal disease. A series of profiles of optical scattering or tissue microstructure are generated by moving the explorer across the tooth or other tissue. The profiles are combined to form a cross-sectional, or optical coherence tomography (OCT), image.

  3. Adaptive optics optical coherence tomography in glaucoma.

    Science.gov (United States)

    Dong, Zachary M; Wollstein, Gadi; Wang, Bo; Schuman, Joel S

    2017-03-01

    Since the introduction of commercial optical coherence tomography (OCT) systems, the ophthalmic imaging modality has rapidly expanded and it has since changed the paradigm of visualization of the retina and revolutionized the management and diagnosis of neuro-retinal diseases, including glaucoma. OCT remains a dynamic and evolving imaging modality, growing from time-domain OCT to the improved spectral-domain OCT, adapting novel image analysis and processing methods, and onto the newer swept-source OCT and the implementation of adaptive optics (AO) into OCT. The incorporation of AO into ophthalmic imaging modalities has enhanced OCT by improving image resolution and quality, particularly in the posterior segment of the eye. Although OCT previously captured in-vivo cross-sectional images with unparalleled high resolution in the axial direction, monochromatic aberrations of the eye limit transverse or lateral resolution to about 15-20 μm and reduce overall image quality. In pairing AO technology with OCT, it is now possible to obtain diffraction-limited resolution images of the optic nerve head and retina in three-dimensions, increasing resolution down to a theoretical 3 μm(3). It is now possible to visualize discrete structures within the posterior eye, such as photoreceptors, retinal nerve fiber layer bundles, the lamina cribrosa, and other structures relevant to glaucoma. Despite its limitations and barriers to widespread commercialization, the expanding role of AO in OCT is propelling this technology into clinical trials and onto becoming an invaluable modality in the clinician's arsenal. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Optical Coherence Tomography (OCT) in ophthalmology: introduction.

    Science.gov (United States)

    Fujimoto, James G; Drexler, Wolfgang; Schuman, Joel S; Hitzenberger, Christoph K

    2009-03-02

    The Optical Society (OSA) is pleased to present this special issue of Optics Express on "Optical Coherence Tomography (OCT) in Ophthalmology" as part of the new Interactive Science Publishing (ISP) project. The project is being performed in collaboration with the National Library of Medicine and represents a new paradigm for the publication of digital image and large dataset information.

  5. Coherence and incoherence in an optical comb.

    Science.gov (United States)

    Viktorov, Evgeny A; Habruseva, Tatiana; Hegarty, Stephen P; Huyet, Guillaume; Kelleher, Bryan

    2014-06-06

    We demonstrate a coexistence of coherent and incoherent modes in the optical comb generated by a passively mode-locked quantum dot laser. This is experimentally achieved by means of optical linewidth, radio frequency spectrum, and optical spectrum measurements and confirmed numerically by a delay-differential equation model showing excellent agreement with the experiment. We interpret the state as a chimera state.

  6. Spectral Domain optical coherence tomography findings in patients with retinitis pigmentosa.

    Science.gov (United States)

    Chebil, Ahmed; Touati, Salma; Maamouri, Rym; Kort, Fedra; El Matri, Leila

    2016-04-01

    Background Maculopathy is a common complication of retinitis pigmentosa (RP), and compromise the visual acuity of RP patients even in the less advanced stages. Aim To report the morphological macular findings detected by spectral domain optical coherence tomography (SD-OCT) and to determine their prevalence in patients with retinitis pigmentosa (RP). Methods  SD-OCT scans from 100 patients (196 eyes) affected by RP were reviewed. Results We noted a normal macula appearance in 48.5%, macular edema in 14.5% and macular atrophy in 37%. Mean central macular thickness was 167.79 microns and we did not note any statistically significant correlation between visual acuity and foveal thickness. Visual acuity was statistically better in eyes with a larger number of hyper-reflective layers (p<0.001) and in eyes with photoreceptor inner/outer (IS/OS) segment junction distinct (p<0.001). We have identified three types of tomographic macular edema: a cystoids macular edema in 6.8%, a tractional edema in 8.2% and mixed edema in 1%. We identified two tomographic types of macular atrophy: a central- foveal atrophy in 34 eyes (11.6%) and diffuse atrophy in 38 eyes (12.9%). Epiretinal membrane was present in 24 eyes (8.2%). Conclusions The OCT contributes to the analysis of epidemiological and morphological of different macular involvement in RP. OCT has a prognostic value, which essentially depends on the morphology of the IS/OS line and number of hyper-reflective layers.

  7. Optical Coherent Receiver Enables THz Wireless Bridge

    DEFF Research Database (Denmark)

    Yu, Xianbin; Liu, Kexin; Zhang, Hangkai

    2016-01-01

    We experimentally demonstrated a 45 Gbit/s 400 GHz photonic wireless communication system enabled by an optical coherent receiver, which has a high potential in fast recovery of high data rate connections, for example, in disaster....

  8. Function and morphology in macular retinoschisis associated with optic disc pit in a child before and after its spontaneous resolution.

    Science.gov (United States)

    Polunina, Anna A; Todorova, Margarita G; Palmowski-Wolfe, Anja M

    2012-04-01

    Optic disc pit (ODP) is a rare congenital defect within the optic nerve head. Macula elevation associated with ODP develops in 75-93% of the adult patients. Macular involvement in children with optic disc pit is rare, and only a few cases have been published to date. In the present case, we have observed morphology and function of the central retina in a child with ODP-associated macular detachment and following its spontaneous resolution. An 8-year-old white boy diagnosed with a macular detachment in an eye with an ODP. Optical coherent tomography (OCT) and multifocal electroretinography (mfERG), as well as visual acuity and visual field, were performed in the follow-up of the unilateral schisis-like retinal detachment. A large retinoschisis associated with ODP in a child showed a tendency to spontaneously resolve at 3 months, which was confirmed on OCT. At this time, an mfERG revealed markedly reduced responses. Despite morphologic reattachment at follow-up and improvement in visual acuity, increased mfERG responses were still not the same as in the fellow healthy eye. In contrast to the OCT which is very helpful to assess the extent of the neurosensory detachment, the mfERG offers an additional tool for follow-up of retinal function in this disorder. The good visual outcome in our patient shows that in the presence of residual retinal function on mfERG and in the absence of further lesions on OCT, follow-up is a valid option in children with an ODP-associated macular detachment.

  9. [Optical coherence tomography in solar eclipse retinopathy].

    Science.gov (United States)

    Calvo-González, C; Reche-Frutos, J; Santos-Bueso, E; Díaz-Valle, D; Benítez-del-Castillo, J M; García-Sánchez, J

    2006-05-01

    We describe the case of a patient suffering from acute visual loss soon after watching a solar eclipse. Optical coherence tomography was the main diagnostic tool used. Solar retinopathy is now an unusual cause of visual loss, although there are still some cases diagnosed, especially after viewing solar eclipses. Optical coherence tomography is suitable for detecting permanent retinal injuries related to solar exposure, with the outer retinal layers being typically affected.

  10. Coherent optical pumping of semiconductor lasers

    Energy Technology Data Exchange (ETDEWEB)

    Pfister, M.; Dupertuis, M.A. [Inst. de Micro- et Optoelectronique, Lausanne (Switzerland). Dept. de Physique

    1995-01-01

    The influence of coherent optical pumping in semiconductor lasers is investigated theoretically. In particular the mathematical conditions under which an optically pumped system behaves like an electrically (incoherently) pumped system are derived. The authors show that it is practically impossible to reach the interesting regime where coherent effects are important because of the inherent constraints to absorb photons at the pump frequency and to reach threshold gain at the lasing frequency. The effects of changing the temperature and of reduced dimensionality are discussed.

  11. Coherent broadband light source for parallel optical coherence tomography

    NARCIS (Netherlands)

    Rivier, S.; Laversenne, L.; Bourquin, S.; Salathé, R.P.; Pollnau, M.; Grivas, C.; Shepherd, D.P.; Eason, R.W.; Flury, M.; Philipoussis, I.; Herzig, H.P.

    2004-01-01

    A Ti:sapphire planar waveguide is rib structured by Ar ion milling to provide parallel channel waveguides. By coupling high-power pump light through a microlens array into the waveguides, a novel broadband luminescent parallel emitter is demonstrated as a light source for parallel optical coherence

  12. Peripapillary subretinal neovascularization and serous macular detachment. Association with congenital optic nerve pits.

    Science.gov (United States)

    Borodic, G E; Gragoudas, E S; Edward, W O; Brockhurst, R J

    1984-02-01

    Congenital anomalous disc changes were associated with acquired macular detachment and peripapillary choroidal neovascularization in two cases. The anomalous disc changes resembled optic nerve pits. In one case, the peripapillary choroidal neovascularization was treated with argon laser photocoagulation, with subsequent reattachment of the macula and considerable improvement in the visual acuity. Although the pathogenesis of macular detachment occurring with optic nerve pits is usually not disclosed by fluorescein angiography, leakage from choroidal neovascularization can occur with this congenital defect and may contribute to the formation of a neurosensory macular detachment. If found, choroidal neovascularization may represent a remedial cause for visual loss in a condition with an otherwise poor prognosis.

  13. Optical coherence tomography-guided classification of epiretinal membranes.

    Science.gov (United States)

    Konidaris, Vasileios; Androudi, Sofia; Alexandridis, Alexandros; Dastiridou, Anna; Brazitikos, Periklis

    2015-08-01

    To study and classify epiretinal membranes (ERMs) based on spectral domain optical coherence tomography (SD-OCT) findings. One hundred and twelve patients with ERMs were examined clinically and underwent OCT examination. The anatomical structure of the macula and vitreoretinal interface was studied. ERMs were classified in two categories: A, with posterior vitreous detachment (PVD) (91 cases), and B, with the absence of PVD (21 cases). Category A was divided into two subcategories: A1, without contraction of the ERM (37 cases), and A2, with the presence of membrane contraction (54 cases). A2 was further subdivided into A2.1, with retinal folding (15 cases), A2.2, with edema (23 cases), A2.3, with cystoid macular edema (9 cases), and A2.4, with lamellar macular hole (7 cases). Category B was divided in two subcategories: B1, without vitreomacular traction (VMT) (4 cases), and B2, with the presence of VMT (17 cases). Category B2 was subdivided into B2.1, with edema (9 cases), B2.2, presenting retinal detachment (5 cases), and B2.3, with schisis (3 cases). OCT classification of ERMs provides useful information on the anatomical structure of the retina, and the accurate estimation of vitreoretinal interface.

  14. Overlapped optics induced perfect coherent effects

    Science.gov (United States)

    Li, Jian Jie; Zang, Xiao Fei; Mao, Jun Fa; Tang, Min; Zhu, Yi Ming; Zhuang, Song Lin

    2013-12-01

    For traditional coherent effects, two separated identical point sources can be interfered with each other only when the optical path difference is integer number of wavelengths, leading to alternate dark and bright fringes for different optical path difference. For hundreds of years, such a perfect coherent condition seems insurmountable. However, in this paper, based on transformation optics, two separated in-phase identical point sources can induce perfect interference with each other without satisfying the traditional coherent condition. This shifting illusion media is realized by inductor-capacitor transmission line network. Theoretical analysis, numerical simulations and experimental results are performed to confirm such a kind of perfect coherent effect and it is found that the total radiation power of multiple elements system can be greatly enhanced. Our investigation may be applicable to National Ignition Facility (NIF), Inertial Confined Fusion (ICF) of China, LED lighting technology, terahertz communication, and so on.

  15. Coherent analysis of quantum optical sideband modes

    CERN Document Server

    Huntington, E H; Robilliard, C; Ralph, T C

    2005-01-01

    We demonstrate a device that allows for the coherent analysis of a pair of optical frequency sidebands in an arbitrary basis. We show that our device is quantum noise limited and hence applications for this scheme may be found in discrete and continuous variable optical quantum information experiments.

  16. Coherence-Multiplexed Optical RF Feeder Networks

    NARCIS (Netherlands)

    Meijerink, Arjan; Taniman, Robert O.; Etten, van Wim

    2007-01-01

    An optical RF feeding system for wireless access is proposed, in which the radio access points are distinguished by means of coherence multiplexing (CM). CM is a rather unknown and potentially inexpensive optical code division multiple access technique, which is particularly suitable for relatively

  17. Repeatability of Perimacular Ganglion Cell Complex Analysis with Spectral-Domain Optical Coherence Tomography.

    Science.gov (United States)

    Ng, Dorothy S K; Gupta, Preeti; Tham, Yih Chung; Peck, Chye Fong; Wong, Tien Yin; Ikram, Mohammad Kamran; Cheung, Carol Y

    2015-01-01

    Purpose. To assess the repeatability of spectral-domain optical coherence tomography to measure macular and perimacular ganglion cell complex thicknesses and compare retinal ganglion cell parameters between algorithms. Methods. Ninety-two nonglaucomatous eyes from 92 participants underwent macular and perimacular ganglion cell complex thickness measurement using OCT-HS100 Glaucoma 3D algorithm and these measurements were repeated for 34 subjects. All subjects also had macular ganglion cell-inner plexiform layer thickness measured by Cirrus HD-OCT Ganglion Cell Analysis algorithm. Intraclass correlation coefficient and Pearson's correlation analyses were performed. Results. Subfields of both macular and perimacular ganglion cell complex thicknesses had high intraclass correlation coefficient values between 0.979 (95% confidence interval [CI]: 0.958-0.989) and 0.981 (95% CI: 0.963, 0.991) and between 0.70 (95% CI: 0.481-0.838) and 0.987 (95% CI: 0.956-0.989), respectively. The overall average ganglion cell complex and macular average ganglion cell-inner plexiform layer thicknesses were strongly correlated (r = 0.83,  P HS100 Glaucoma 3D algorithm is highly repeatable, and strongly correlates to retinal ganglion cell parameters assessed by Ganglion Cell Analysis algorithm. A comprehensive evaluation of retinal ganglion cells may be possible with OCT-HS100.

  18. Diabetic Macular Edema

    Science.gov (United States)

    Lobo, Conceição; Pires, Isabel; Cunha-Vaz, José

    The optical coherence tomography (OCT), a noninvasive and noncontact diagnostic method, was introduced in 1995 for imaging macular diseases. In diabetic macular edema (DME), OCT scans show hyporeflectivity, due to intraretinal and/or subretinal fluid accumulation, related to inner and/or outer blood-retinal barrier breakdown. OCT tomograms may also reveal the presence of hard exudates, as hyperreflective spots with a shadow, in the outer retinal layers, among others. In conclusion, OCT is a particularly valuable diagnostic tool in DME, helpful both in the diagnosis and follow-up procedure.

  19. An evaluation of a novel instrument for measuring macular pigment optical density: the MPS 9000.

    Science.gov (United States)

    Loughman, James; Scanlon, Grainne; Nolan, John M; O'Dwyer, Veronica; Beatty, Stephen

    2012-03-01

    Of the antioxidants found in the human retina, only the macular carotenoid quantities can be estimated noninvasively (albeit in a collective fashion), thus facilitating study of their role in that tissue. The aim of this study was to evaluate concordance between macular pigment optical density (MPOD) values recorded on a commercially available instrument, the MPS 9000, with those of an already validated heterochromatic flicker photometry instrument. Also, we assessed and compared test-retest variability for each instrument. Macular pigment optical density at 0.5 retinal eccentricity was measured using two different heterochromatic flicker photometers, the MPS 9000 and the Macular Densitometer(TM), in 39 healthy subjects. Test-retest variability was evaluated separately for each instrument by taking three readings over a 1-week period in 25 subjects. There was a moderate positive correlation for MPOD at 0.5° of retinal eccentricity between the MPS 9000 and the Macular Densitometer described by the linear equation y = 0.763x + 0.172 (r = 0.68, p MPS 9000 (t = -4.103, p MPS 9000 and from 0.11 to 0.12 [mean (±SD): 0.12 (0.01)] for the Macular Densitometer. The results demonstrate that the MPS 9000 consistently yields MPOD readings, which are lower than that found with the Macular Densitometer, and exhibits substantial test-retest variability. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.

  20. Optical biopsy of epithelial cancers by optical coherence tomography

    NARCIS (Netherlands)

    Wessels, R.; Wessels, R.; de Bruin, D.M.; Faber, D.J.; van Leeuwen, Ton; van Beurden, M.F.B.; Ruers, Theo J.M.

    2014-01-01

    Optical coherence tomography (OCT) is an optical technique that measures the backscattering of near-infrared light by tissue. OCT yields in 2D and 3D images at micrometer-scale resolution, thus providing optical biopsies, approaching the resolution of histopathological imaging. The technique has

  1. Optical coherent control in semiconductors

    DEFF Research Database (Denmark)

    Østergaard, John Erland; Vadim, Lyssenko; Hvam, Jørn Märcher

    2001-01-01

    of quantum control including the recent applications to semiconductors and nanostructures. We study the influence of inhomogeneous broadening in semiconductors on CC results. Photoluminescence (PL) and the coherent emission in four-wave mixing (FWM) is recorded after resonant excitation with phase...

  2. Spectral domain optical coherence tomography morphology in optic disc pit associated maculopathy

    Directory of Open Access Journals (Sweden)

    Janusz Michalewski

    2014-01-01

    Full Text Available Purpose: Our purpose was to study the clinical manifestation and course of optic pit maculopathy using Spectral Domain Optical Coherence Tomography (SD- OCT images. Materials and Methods: We used SD-OCT to examine 20 eyes of 19 patients with a macular detachment in combination with an optic. Results: We observed five different fovea appearances in regard to fluid localization. In five eyes, we recorded changes in the fluid distribution with SD-OCT. In 17/20 eyes, we noted a communication between the perineural and subretinal and/or intraretinal space at the margin of the optic disc. Conclusion: 3-dimensional SD-OCT (3D-SDOCT scans revealed a three-fold connection, between subretinal and intraretinal space, perineural space, and the vitreous cavity. Therefore, we suppose that intraretinal or subretinal fluid in optic pit maculopathy may have both a vitreous and cerebrospinal origin. A membrane, covering the optic nerve was noted in 14 cases. Even if it seems intact in some B-scans, it is not complete in others several micrometers apart. Additionally, we observed fluid accumulation below the margin of the optic disc and hyperreflective porous tissue in the optic disc excavation. Those findings do not influence the course of maculopathy.

  3. Audio frequency in vivo optical coherence elastography

    Energy Technology Data Exchange (ETDEWEB)

    Adie, Steven G; Kennedy, Brendan F; Armstrong, Julian J; Alexandrov, Sergey A; Sampson, David D [Optical-Biomedical Engineering Laboratory (OBEL), School of Electrical, Electronic and Computer Engineering, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009 (Australia)], E-mail: dsampson@ee.uwa.edu.au

    2009-05-21

    We present a new approach to optical coherence elastography (OCE), which probes the local elastic properties of tissue by using optical coherence tomography to measure the effect of an applied stimulus in the audio frequency range. We describe the approach, based on analysis of the Bessel frequency spectrum of the interferometric signal detected from scatterers undergoing periodic motion in response to an applied stimulus. We present quantitative results of sub-micron excitation at 820 Hz in a layered phantom and the first such measurements in human skin in vivo.

  4. Optics for coherent X-ray applications

    OpenAIRE

    2014-01-01

    Developments of X-ray optics for full utilization of diffraction-limited storage rings (DLSRs) are presented. The expected performance of DLSRs is introduced using the design parameters of SPring-8 II. To develop optical elements applicable to manipulation of coherent X-rays, advanced technologies on precise processing and metrology were invented. With propagation-based coherent X-rays at the 1 km beamline of SPring-8, a beryllium window fabricated with the physical-vapour-deposition method w...

  5. Demonstrational Optics Part 2: Coherent and Statistical Optics

    CERN Document Server

    Marchenko, Oleg; Windholz, Laurentius

    2007-01-01

    Demonstrational Optics presents a new didactical approach to the study of optics. Emphasizing the importance of elaborate new experimental demonstrations, pictorial illustrations, computer simulations and models of optical phenomena in order to ensure a deeper understanding of wave and geometric optics. It includes problems focused on the pragmatic needs of students, secondary school teachers, university professors and optical engineers. Part 2, Coherent and Statistical Optics, contains chapters on interference, diffraction, Fourier optics, light quanta, thermal radiation (Shot noise and Gaussian light), Correlation of light fields and Correlation of light intensities. A substantial part of this volume is devoted to thermal radiation and its properties, especially with partial coherence. A detailed treatment of the photo-effect with respect to statistical properties leads to the basics of statistical optics. To illustrate the phenomena covered by this volume, a large number of demonstration experiments are de...

  6. Ultra-high resolution optical coherence tomography analysis of bull's eye maculopathy in chloroquine users

    Directory of Open Access Journals (Sweden)

    Celso Morita

    2014-06-01

    Full Text Available Purpose: Register and compare anatomical changes, structural and quantitative found in optical coherence tomography Stratus and Topcon 3D in chronic users of chloroquine. Methods: Five patients were diagnosed with toxic "bull's eye" maculopathy was submitted to macular optical coherence tomography examination (Stratus and Topcon 3D. Results: Both tools demonstrated an increase reflectivity of choriocapillaris unit just foveal retinal pigment epithelium atrophy. However, Topcon 3D provided to all patients better description of the line corresponding to the transition between inner and outer segments of photoreceptors. Using the possibility of assembling threedimensional images and subtraction selective retinal layers, we found a lesion with a target that reflects the greater thickness of retinal pigment epithelium in central and parafoveal region that is matched to preserve macular photoreceptors. Conclusion: it was observed better resolution and faster image capture by Topcon 3D than Stratus OCT, that provided more detailed analysis of the line corresponding to transition between outer and inner segment of photoreceptors in macular region. With Topcon 3D, it was possible to evaluate soundly the thickness of retinal pigment epithelium in central and parafoveal region that caused an increase reflectivity of choriocapillaris creating a image with a target unpublished before.

  7. 抗血管内皮生发因子治疗后湿性AMD患者的OCT特征与视力相关性分析%Correlation between macular structure and visual outcome following anti-VEGF therapy in wet AMD: a spectral domain optical coherence tomography study

    Institute of Scientific and Technical Information of China (English)

    胡旭颋; 丁小燕; 李加青; 雷蕾; 马伟; 袁玲; 梁小玲; 唐仕波

    2010-01-01

    Objective To evaluate the macular structure following anti-VEGF therapy in wet AMD patients and to study the correlation of structural findings with visual acuity outcomes, using spectral domain optical coherence tomography (SD-OCT). Methods Thirty-two cases (32 eyes) with wet AMD after anti-VEGF therapy were included in the study.Ophthalmic examination included best-corrected visual acuity (BCVA), dilated fundus examination and OCT imaging 5-6 months after anti-VEGF therapy.Macular thickness and volume were calculated for morphologic parameters of interest including fovea thickness (FT), central subfield thickness (CST), cube volume (CV), cube average thickness (CAT), subretinal fluid (SRF), intraretinal fluid (IRF), CNV membrane thickness (CNVMT) before and after manually identification of fovea.The correlation between BCVA and OCT parameters were investigated.Results Increased CST was correlated with decreased visual acuity (r =0.447, P=0.019), both pre- and post- manually correction.The association was stronger after manually correction if compared with that before correction.No statistically significant association was detected between BCVA and FT, CA and CAT pre- and post-correction.Decreased visual acuity was also correlated with the presence of the IRF and thicker CNV membrane in the macular region.Con- clusions The manually-corrected CST is strongly correlated with BCVA after anti-VEGF therapy in wet AMD patients. Because of the poor visual function and central fixation in these patients due to the complex macular lesions, manually correction of fovea in OCT analysis is definitely necessary in AMD patients.%目的 评价湿性年龄相关性黄斑变性(AMD)患者抗血管内皮生长因子(VEGF)治疗后术眼OCT参数与视力之间的相关性.方法 32例32只眼湿性AMD患者接受抗VEGF治疗后5-6月,记录患者最佳矫正视力,同一天进行频域OCT扫描,对黄斑中心凹厚度(FT),黄斑中心区厚度(CST),黄斑区容积(CV),黄斑区

  8. Optical coherence tomography: Technique and applications

    DEFF Research Database (Denmark)

    Thomsen, Jakob Borup; Sander, Birgit; Mogensen, Mette;

    2009-01-01

    Optical coherence tomography (OCT) is a noninvasive optical imaging modality providing real-time video rate images in two and three dimensions of biological tissues with micrometer resolution. OCT fills the gap between ultrasound and confocal microscopy, since it has a higher resolution than ultr...... of retinal diseases. The potential of OCT in many other applications is currently being explored, such as in developmental biology, skin cancer diagnostics, vulnerable plaque detection in cardiology, esophageal diagnostics and a number of other applications within oncology....

  9. Evaluation of a cheap ultrasonic stage for light source coherence function measurement, optical coherence tomography, optical coherence microscopy, and dynamic focusing

    NARCIS (Netherlands)

    Krstajic, Nikola; Matcher, Stephen J.; Childs, David; Hogg, Richard; Smallwood, Rod; Steenbergen, Wiendelt; Andersen, Peter E.; Bouma, Brett E.

    2009-01-01

    We evaluate the performance of a cheap ultrasonic stage in setups related to optical coherence tomography. The stage was used in several configurations: 1) optical delay line in optical coherence tomography (OCT) setup; 2) as a delay line measuring coherence function of a low coherence source (e.g.

  10. Optical coherence tomography in conjunction with bronchoscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Ascedio Jose; Takimura, Celso Kiyochi; Lemos Neto, Pedro Alves; Figueiredo, Viviane Rossi, E-mail: ascedio@gmail.com [Servico de Endoscopia Respiratoria, Hospital das Clinicas, Universidade de Sao Paulo (FM/USP), SP (Brazil)

    2012-07-01

    To evaluate the feasibility of and the potential for using optical coherence tomography in conjunction with conventional bronchoscopy in the evaluation of the airways. Methods: This was a pilot study based on an ex vivo experimental model involving three animals: one adult New Zealand rabbit and two Landrace pigs. An optical coherence tomography imaging catheter was inserted through the working channel of a flexible bronchoscope in order to reach the distal trachea of the animals. Images of the walls of the trachea were systematically taken along its entire length, from the distal to the proximal portion. Results: The imaging catheter was easily adapted to the working channel of the bronchoscope. High-resolution images of cross sections of the trachea were taken in real time, precisely delineating microstructures, such as the epithelium, submucosa, and cartilage, as well as the adventitia of the anterior and lateral tracheal walls. The corresponding layers of the epithelium, mucosa, and cartilage were clearly differentiated. The mucosa, submucosa, and trachealis muscle were clearly identified in the posterior wall. Conclusions: It is feasible to use an optical coherence tomography imaging catheter in combination with a flexible bronchoscope. Optical coherence tomography produces high resolution images that reveal the microanatomy of the trachea, including structures that are typically seen only on images produced by conventional histology. (author)

  11. Optical Coherence Tomography for Material Characterization

    NARCIS (Netherlands)

    Liu, P.

    2014-01-01

    Optical coherence tomography (OCT) is a non-invasive, contactless and high resolution imaging method, which allows the reconstruction of two or three dimensional depth-resolved images in turbid media. In the past 20 years, OCT has been extensively developed in the field of biomedical diagnostics, wh

  12. Gabor fusion master slave optical coherence tomography

    DEFF Research Database (Denmark)

    Cernat, Ramona; Bradu, Adrian; Israelsen, Niels Møller

    2017-01-01

    This paper describes the application of the Gabor filtering protocol to a Master/Slave (MS) swept source optical coherence tomography (SS)-OCT system at 1300 nm. The MS-OCT system delivers information from selected depths, a property that allows operation similar to that of a time domain OCT syst...

  13. Functional optical coherence tomography of pigmented lesions

    NARCIS (Netherlands)

    Wessels, R.; Bruin, de D.M.; Relyveld, G.N.; Faber, D.J.; Vincent, A.D.; Sanders, J.; Leeuwen, van T.G.; Ruers, T.J.M.

    2015-01-01

    Background Cutaneous melanomas are diagnosed worldwide in 231 130 patients per year. The sensitivity and specificity of melanoma diagnosis expresses the need for an additional diagnostic method. Optical coherence tomography (OCT) has shown that it allows morphological (qualitative) description of im

  14. Optical coherence tomography as a diagnostic tool

    CSIR Research Space (South Africa)

    Singh, A

    2011-07-01

    Full Text Available Optical Coherence Tomography (OCT) has been used in biomedical applications as a method to non-invasively detect changes occurring in tissue such as the detection of skin cancer. The effect of skin tone on detection of skin cancer has however...

  15. Dynamic Optical Coherence Tomography in Dermatology

    DEFF Research Database (Denmark)

    Ulrich, Martina; Themstrup, Lotte; De Carvalho, Nathalie

    2016-01-01

    Optical coherence tomography (OCT) represents a non-invasive imaging technology, which may be applied to the diagnosis of non-melanoma skin cancer and which has recently been shown to improve the diagnostic accuracy of basal cell carcinoma. Technical developments of OCT continue to expand the app...

  16. Evolving techniques in the treatment of macular detachment caused by optic nerve pits.

    Science.gov (United States)

    Cox, M S; Witherspoon, C D; Morris, R E; Flynn, H W

    1988-07-01

    Fourteen patients with macular detachments caused by optic nerve pits were treated for progressive visual loss, cystoid macular changes, or atrophy of the macular retinal pigment epithelium. Photocoagulation of the temporal disc border alone was unsuccessful in two cases but promptly reattached the macula of two patients immobilized after laser surgery. Vitrectomy and gas tamponade improved vision and flattened the macula of three patients over various periods. The detachment recurred in one patient. Prompt and sustained macular reattachment with improved vision was noted after photocoagulation, vitrectomy, and gas tamponade in eight patients, although four required second operations. The prompt reattachment and visual recovery noted in these eight patients surpasses the reported 25% rate of spontaneous resolution.

  17. Detection of retinal changes in Parkinson's disease with spectral-domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Grant D Aaker

    2010-12-01

    Full Text Available Grant D Aaker1, Jane S Myung1, Joshua R Ehrlich1, Mujtaba Mohammed2, Claire Henchcliffe2, Szilárd Kiss11Department of Ophthalmology, 2Department of Neurology, Cornell Medical College, New York, USAPurpose: This pilot study investigated whether high-resolution spectral-domain optical coherence tomography (SD-OCT could detect differences in inner retinal layer (IRL, peripapillary retinal nerve fiber layer (RNFL, and macular thickness between patients with Parkinson's disease (PD and controls.Methods: Both eyes of patients with PD and age-matched controls were imaged with the Heidelberg Spectralis® HRA + OCT. RNFL, IRL, and macular thickness were measured for each eye using Heidelberg software. These measurements were compared with validated, published normal values for macular and RNFL thickness, and compared with matched controls for IRL thickness.Results: Eighteen eyes from nine subjects with PD and 19 eyes of 16 control subjects were evaluated using SD-OCT. The average age of PD patients was 64 years with a range of 52–75 years. The average age of controls was 67 years with a range of 50–81 years. No significant reduction in IRL thickness was detected between PD patients and age-matched controls at 13 points along a 6 mm horizontal section through the fovea. No significant difference in RNFL thickness was detected between PD patients and published normal values. Overall average RNFL thickness was 97 µm for PD patients, which exactly matched the normative database value. However, significant differences in macular thickness were detected in three of nine subfields between PD subjects and published normal values. In PD subjects, the outer superior subfield was 2.8% thinner (P = 0.026, while the outer nasal and inner inferior subfields were 2.8% (P = 0.016 and 2.7% (P = 0.001 thicker compared to published normal values.Conclusion: In this pilot study, significant differences in macular thickness were detected in three of nine subfields by

  18. Vascular flow density in pathological myopia: an optical coherence tomography angiography study.

    Science.gov (United States)

    Mo, Jing; Duan, Anli; Chan, Szyyann; Wang, Xuefei; Wei, Wenbin

    2017-02-03

    To investigate vascular flow density in pathological myopia with optical coherence tomography (OCT) angiography. A prospective comparative study was conducted from December 2015 to March 2016. Participants were recruited in Beijing Tongren Hospital. A total of 131 eyes were enrolled, which were divided into three groups: 45 eyes with emmetropia (EM; mean spherical equivalent (MSE) 0.50D to -0.50D), 41 eyes with high myopia (HM; MSE ≤-6.00D, without pathological changes), and 45 eyes with pathological myopia (PM; MSE ≤-6.00D and axial length (AL) ≥26.5 mm, and with pathological changes). Macular, choriocapillaris and radial peripapillary capillary (RPC) flow densities were measured and compared between groups, and their relationships with AL and best corrected visual acuity (BCVA) were analysed. Significant differences were found in macular, choriocapillaris and RPC flow densities among the three groups (pdensities of the PM group were significantly decreased (pdensity was found between the PM and HM groups (p=0.731). Compared with the EM group, retinal flow density in the macular and arcuate fibre region was not decreased in the HM group. In addition, there was a negative correlation between AL and superficial macular flow density (β=-0.542, pdensity (β=-0.282, p=0.002) and RPC flow density (β=-0.522, pdensity (β=0.194, p=0.021), deep macular flow density (β=0.373, pdensity (β=0.291, p=0.001). Macular and RPC flow densities decreased in pathological myopia compared with high myopia and emmetropia. No significant decrease of retinal flow density in the macular and arcuate fibre region was found in high myopic eyes compared with emmetropic eyes. Moreover, macular and RPC flow densities were negatively related to AL, and macular flow density was positively related to BCVA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  19. Occult Macular Dystrophy

    Directory of Open Access Journals (Sweden)

    Işıl Sayman Muslubaş

    2016-04-01

    Full Text Available Occult macular dystrophy is an inherited macular dystrophy characterized by a progressive decline of bilateral visual acuity with normal fundus appearance, fluorescein angiogram and full-field electroretinogram. This case report presents a 20-year-old female patient with bilateral progressive decline of visual acuity for six years. Her visual acuity was 3-4/10 in both eyes. Anterior segment and fundus examination, fluorescein angiogram and full-field electroretinogram were normal. She could read all Ishihara pseudoisochromatic plates. Fundus autofluorescence imaging was normal. There was a mild central hyporeflectance on fundus infrared reflectance imaging in both eyes. Reduced foveal thickness and alterations of the photoreceptor inner and outer segment junction were observed by optical coherence tomography in both eyes. Central scotoma was also found by microperimetry and reduced central response was revealed by multifocal electroretinogram in both eyes. These findings are consistent with the clinical characteristics of occult macular dystrophy

  20. Homodyne en face optical coherence tomography

    OpenAIRE

    Yaqoob, Zahid; Fingler, Jeff; Heng, Xin; Yang, Changhuei

    2006-01-01

    We demonstrate, for what we believe to be the first time, the use of a 3×3 fiber-optic coupler to realize a homodyne optical coherence tomography (OCT) system for en face imaging of highly scattering tissues and turbid media. The homodyne OCT setup exploits the inherent phase shifts between different output ports of a 3×3 fiber-optic coupler to extract amplitude information of a sample. Our homodyne en face OCT system features a measured resolution of 14 μm axially and 9.4 μm laterally with a...

  1. Coherent optical pulse sequencer for quantum applications.

    Science.gov (United States)

    Hosseini, Mahdi; Sparkes, Ben M; Hétet, Gabriel; Longdell, Jevon J; Lam, Ping Koy; Buchler, Ben C

    2009-09-10

    The bandwidth and versatility of optical devices have revolutionized information technology systems and communication networks. Precise and arbitrary control of an optical field that preserves optical coherence is an important requisite for many proposed photonic technologies. For quantum information applications, a device that allows storage and on-demand retrieval of arbitrary quantum states of light would form an ideal quantum optical memory. Recently, significant progress has been made in implementing atomic quantum memories using electromagnetically induced transparency, photon echo spectroscopy, off-resonance Raman spectroscopy and other atom-light interaction processes. Single-photon and bright-optical-field storage with quantum states have both been successfully demonstrated. Here we present a coherent optical memory based on photon echoes induced through controlled reversible inhomogeneous broadening. Our scheme allows storage of multiple pulses of light within a chosen frequency bandwidth, and stored pulses can be recalled in arbitrary order with any chosen delay between each recalled pulse. Furthermore, pulses can be time-compressed, time-stretched or split into multiple smaller pulses and recalled in several pieces at chosen times. Although our experimental results are so far limited to classical light pulses, our technique should enable the construction of an optical random-access memory for time-bin quantum information, and have potential applications in quantum information processing.

  2. A comparison of two methods to measure choroidal thickness by enhanced depth imaging optical coherence tomography

    DEFF Research Database (Denmark)

    Lundberg, Lars Kristian; Vestergaard, Anders Højslet; Vergmann, Anna Stage

    coherence tomography (EDI-SD OCT) has made it possible to visualize the choroid, and it is generally accepted that Heidelberg Spectralis OCT provides valid measurements of choroidal thickness (CT), although no fully automated software is commercially available. Two methods for CT-measurement are available...... the CT: 1: Segmentation method; by the use of the thickness profile window we manually edited and moved the inner limiting membrane (ILM) line to the choroid-scleral border (CSB), while we kept the automated defined Bruchs membrane (BM). Hereafter, the software calculated the vertical distance between......Introduction The choroid is believed to be involved in the pathophysiology of several vision threatening diseases such as age-related macular degeneration, central serous chorioretinopathy, inflammatory disorders and myopic macular degeneration. Enhanced depth imaging spectral-domain optical...

  3. 巩膜扣带术后黄斑区光学相干断层扫描与视力预后的分析%Correlative analysis of visual recovery and macular reattachment observing by optical coherence tomography after scleral buckling surgery

    Institute of Scientific and Technical Information of China (English)

    王宗华; 陈思扬; 陈杰

    2012-01-01

    目的 对累及黄斑区的孔源性视网膜脱离行巩膜扣带术手术成功眼后极部进行OCT扫描,并分析其与术后视力的关系.方法 28例28只眼视网膜脱离已累及黄斑区者,经间接检查眼镜下巩膜外加压术联合或不联合环扎术,视网膜均成功复位,分别于术后1周、1、3、6、12个月行最佳矫正视力、眼底照相、光学相干断层扫描(OCT)检查,并进行统计分析.结果 最佳矫正视力提高2行以上者于术后1周、3月、6月、12月分别为53.57%、60.71%、78.57%、85.71%、88.46%,最佳矫正视力(BCVA)术后1周视力较术前明显提高(P=0.001),术后1月与术后1周差异无统计学意义(P=0.124);术后3月与术后1月差异有统计学意义(P=0.033);术后6月与术后3月差异无统计学意义(P=0.206);术后12个月与术后6个月差异无统计学意义(P=0.243),但与术后3个月差异有统计学意义(P=0.011).OCT扫描测量黄斑区神经上皮层厚度+视网膜下液高度于术后1周、1月、3月、6月、12月分别为(507.89±144.37)μm、(389.89±104.47)μm、(298.15±97.35)μm、(264.00±82.26)μm、(230.57±58.71)μm;术后1月与1周(P=0.000)、术后3月与1月(P=0.000)、术后6月与3月(P=0.001)差异均有统计学意义,而术后6月和12月则无明显变化(P=0.088).视网膜神经上皮下积液,随着时间的延长,积液不断吸收,至术后12月时达92.31%视网膜神经上皮下积液完全吸收.结论 OCT能清晰地显示视网膜脱离术后黄斑区微观形态结构的变化,黄斑区解剖复位需要较长时间,可以较好地解释术后视力的恢复过程.%Objective To observe the macular histomorphological changes and visual acuity(VA)of the macula-Off rhegmatogenous retinal detachment(RRD)with optical coherence tomography(OCT)after scleral buckling.Methods Twenty-eight eyes of 28 patients with macula-off RD underwent best-corrected visual acuity(BCVA)measurement and optical coherence tomography

  4. Cystoid Macular Edema in Bietti's Crystalline Retinopathy

    OpenAIRE

    Ali Osman Saatci; Hasan Can Doruk; Aylin Yaman

    2014-01-01

    A 27-year-old man with progressive bilateral visual decline was diagnosed to have Bietti's crystalline dystrophy (BCD). Fluorescein angiography revealed bilateral petaloid type late hyperfluorescence implicating concurrent cystoid macular edema (CME). Optical coherence tomography exhibited cystoid foveal lacunas OU. During the follow-up of six years, intraretinal crystals reduced in amount but CME persisted angiographically and tomographically. CME is among the rare macular features of BCD in...

  5. Lasers and holography an introduction to coherent optics

    CERN Document Server

    KOCK, Winston

    1972-01-01

    Science Study Series No. 39: Lasers and Holography: An Introduction to Coherent Optics focuses on the processes, methodologies, and techniques involved in optics, including wave diffraction and patterns, zone plates, holograms, and diffraction. The publication first ponders on holograms as wave patterns, coherence, and lasers. Topics include reflectors and resonators, natural line width, semiconductor lasers, reflectors and spatial coherence, energy conservation with reflectors, frequency coherence and stability, coherent waves from small sources, photographic grating, and properties o

  6. Optics for coherent X-ray applications

    Energy Technology Data Exchange (ETDEWEB)

    Yabashi, Makina, E-mail: yabashi@spring8.or.jp [RIKEN SPring-8 Center, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); Tono, Kensuke [Japan Synchrotron Radiation Research Institute (JASRI), Kouto 1-1-1, Sayo, Hyogo 679-5198 (Japan); Mimura, Hidekazu [The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656 (Japan); Matsuyama, Satoshi; Yamauchi, Kazuto [Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Tanaka, Takashi; Tanaka, Hitoshi; Tamasaku, Kenji [RIKEN SPring-8 Center, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); Ohashi, Haruhiko; Goto, Shunji [Japan Synchrotron Radiation Research Institute (JASRI), Kouto 1-1-1, Sayo, Hyogo 679-5198 (Japan); Ishikawa, Tetsuya [RIKEN SPring-8 Center, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan)

    2014-08-27

    Developments of optics for coherent X-ray applications and their role in diffraction-limited storage rings are described. Developments of X-ray optics for full utilization of diffraction-limited storage rings (DLSRs) are presented. The expected performance of DLSRs is introduced using the design parameters of SPring-8 II. To develop optical elements applicable to manipulation of coherent X-rays, advanced technologies on precise processing and metrology were invented. With propagation-based coherent X-rays at the 1 km beamline of SPring-8, a beryllium window fabricated with the physical-vapour-deposition method was found to have ideal speckle-free properties. The elastic emission machining method was utilized for developing reflective mirrors without distortion of the wavefronts. The method was further applied to production of diffraction-limited focusing mirrors generating the smallest spot size in the sub-10 nm regime. To enable production of ultra-intense nanobeams at DLSRs, a low-vibration cooling system for a high-heat-load monochromator and advanced diagnostic systems to characterize X-ray beam properties precisely were developed. Finally, new experimental schemes for combinative nano-analysis and spectroscopy realised with novel X-ray optics are discussed.

  7. Optical coherence tomography findings in Huntington's disease: a potential biomarker of disease progression.

    Science.gov (United States)

    Kersten, Hannah M; Danesh-Meyer, Helen V; Kilfoyle, Dean H; Roxburgh, Richard H

    2015-11-01

    Previous reports of ocular abnormalities in Huntington's disease (HD) have detailed eye movement disorders. The objective of this case-control study was to investigate optic nerve and macular morphology in HD using optical coherence tomography (OCT). A total of 26 HD patients and 29 controls underwent a thorough ophthalmic examination including spectral domain OCT scans of the macula and peripapillary retinal nerve fibre layer (RNFL). Genetic testing results, disease duration, HD disease burden scores and Unified HD Rating Scale motor scores were acquired for HD patients. Temporal RNFL thickness was significantly reduced in the HD group (62.3 vs. 69.8 μm, p = 0.005), and there was a significant negative correlation between temporal RNFL thickness and disease duration (R (2) = -0.51, p = 0.04). Average peripapillary RNFL thickness was not significantly different between the HD and control groups. There was a significant negative correlation between macular volume and disease duration (R (2) = -0.71, p = 0.002), and motor scores (R (2) = -0.56, p = 0.01). Colour vision was significantly poorer in the HD group. Temporal RNFL is preferentially thinned in HD patients, possibly implicating mitochondrial dysfunction as the temporal RNFL is reduced in the patients with some mitochondrial disorders, including Leber's hereditary optic neuropathy. The correlation between the decrease in macular volume and temporal RNFL, and increasing disease severity suggests that OCT may be a useful biomarker for disease progression in HD. Larger, longitudinal studies are required.

  8. Neuromyelitis optica and multiple sclerosis: Seeing differences through optical coherence tomography.

    Science.gov (United States)

    Bennett, J L; de Seze, J; Lana-Peixoto, M; Palace, J; Waldman, A; Schippling, S; Tenembaum, S; Banwell, B; Greenberg, B; Levy, M; Fujihara, K; Chan, K H; Kim, H J; Asgari, N; Sato, D K; Saiz, A; Wuerfel, J; Zimmermann, H; Green, A; Villoslada, P; Paul, F

    2015-05-01

    Neuromyelitis optica (NMO) is an inflammatory autoimmune disease of the central nervous system that preferentially targets the optic nerves and spinal cord. The clinical presentation may suggest multiple sclerosis (MS), but a highly specific serum autoantibody against the astrocytic water channel aquaporin-4 present in up to 80% of NMO patients enables distinction from MS. Optic neuritis may occur in either condition resulting in neuro-anatomical retinal changes. Optical coherence tomography (OCT) has become a useful tool for analyzing retinal damage both in MS and NMO. Numerous studies showed that optic neuritis in NMO typically results in more severe retinal nerve fiber layer (RNFL) and ganglion cell layer thinning and more frequent development of microcystic macular edema than in MS. Furthermore, while patients' RNFL thinning also occurs in the absence of optic neuritis in MS, subclinical damage seems to be rare in NMO. Thus, OCT might be useful in differentiating NMO from MS and serve as an outcome parameter in clinical studies.

  9. Optical coherence tomographic findings in optic nerve hypoplasia

    Directory of Open Access Journals (Sweden)

    Daruchi Moon

    2013-01-01

    Full Text Available We investigated a case of unilateral optic nerve hypoplasia using spectral domain optical coherence tomography (SDOCT. Optical coherence tomography was done on both eyes using 5-line Raster scan for the fovea to analyze the retinal nerve fiber layer thickness, inner retinal layer thickness, outer retinal layer thickness, and optic disc cube scan for the disc. Retinal nerve fiber layer thickness, inner retinal layer thickness, and outer retinal layer thickness were manually measured at 21-points of each five lines, and results were compared between both eyes. Retinal nerve fiber layer thickness and inner retinal layer thickness of optic nerve hypoplasia were significantly thinner than the opposite eye, but there was no significant difference in the thickness of the outer retinal layer between both eyes.

  10. Analysis of macular and nerve fiber layer thickness in multiple sclerosis patients according to severity level and optic neuritis episodes.

    Science.gov (United States)

    Soler García, A; Padilla Parrado, F; Figueroa-Ortiz, L C; González Gómez, A; García-Ben, A; García-Ben, E; García-Campos, J M

    2016-01-01

    Quantitative assessment of macular and nerve fibre layer thickness in multiple sclerosis patients with regard to expanded disability status scale (EDSS) and presence or absence of previous optic neuritis episodes. We recruited 62 patients with multiple sclerosis (53 relapsing-remitting and 9 secondary progressive) and 12 disease-free controls. All patients underwent an ophthalmological examination, including quantitative analysis of the nerve fibre layer and macular thickness using optical coherence tomography. Patients were classified according to EDSS as A (lower than 1.5), B (between 1.5 and 3.5), and C (above 3.5). Mean nerve fibre layer thickness in control, A, B, and C groups was 103.35±12.62, 99.04±14.35, 93.59±15.41, and 87.36±18.75μm respectively, with statistically significant differences (P<.05). In patients with no history of optic neuritis, history of episodes in the last 3 to 6 months, or history longer than 6 months, mean nerve fibre layer thickness was 99.25±13.71, 93.92±13.30 and 80.07±15.91μm respectively; differences were significant (P<.05). Mean macular thickness in control, A, B, and C groups was 220.01±12.07, 217.78±20.02, 217.68±20.77, and 219.04±24.26μm respectively. Differences were not statistically significant. The mean retinal nerve fibre layer thickness in multiple sclerosis patients is related to the EDSS level. Patients with previous optic neuritis episodes have a thinner retinal nerve fibre layer than patients with no history of these episodes. Mean macular thickness is not correlated to EDSS level. Copyright © 2014 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  11. Ultrahigh Resolution Optical Coherence Tomography

    Science.gov (United States)

    Drexler, Wolfgang; Chen, Yu; Aguirre, Aaron D.; Považay, Boris; Unterhuber, Angelika; Fujimoto, James G.

    Since its invention in the late 1980s [1-4] and early 1990s [5-7], the original idea of OCT was to enable noninvasive optical biopsy, i.e., the in situ imaging of tissue microstructure with a resolution approaching that of histology, but without the need for tissue excision and post-processing. An important advance toward this goal was the introduction of ultrahigh-resolution OCT (UHR OCT). By improving axial OCT resolution by one order of magnitude from the 10 to 15 μm to the sub-μm region [8-11], UHR OCT enables superior visualization of tissue microstructure, including all major intraretinal layers in ophthalmic applications as well as cellular resolution OCT imaging in nontransparent tissue. This chapter reviews state-of-the-art technology that enables ultrahigh-resolution OCT covering the entire wavelength region from 500 to 1,600 nm and discusses fundamental limitations of OCT image resolution.

  12. Two-point optical coherency matrix tomography.

    Science.gov (United States)

    Abouraddy, Ayman F; Kagalwala, Kumel H; Saleh, Bahaa E A

    2014-04-15

    The two-point coherence of an electromagnetic field is represented completely by a 4×4 coherency matrix G that encodes the joint polarization-spatial-field correlations. Here, we describe a systematic sequence of cascaded spatial and polarization projective measurements that are sufficient to tomographically reconstruct G--a task that, to the best of our knowledge, has not yet been realized. Our approach benefits from the correspondence between this reconstruction problem in classical optics and that of quantum state tomography for two-photon states in quantum optics. Identifying G uniquely determines all the measurable correlation characteristics of the field and, thus, lifts ambiguities that arise from reliance on traditional scalar descriptors, especially when the field's degrees of freedom are correlated or classically entangled.

  13. Optical Coherence Tomography Velocimetry with Complex Fluids

    Science.gov (United States)

    Malm, A.; Waigh, T. A.; Jaradat, S.; Tomlin, R.

    2015-04-01

    We present recent results obtained with an Optical Coherence Tomography Velocimetry technique. An optical interferometer measures the velocity of a sheared fluid at specific depths of the sample using the coherence length of the light source. The technique allows the dynamics of 3 pico liter volumes to be probed inside opaque complex fluids. In a study of opaque starch suspensions, classical bulk rheology experiments show non-linear shear thickening, whereas observations of the velocity profiles as a function of distance across the gap show Newtonian behavior. The ability of the technique to measure velocity fluctuations is also discussed for the case of polyacrylamide samples which were observed to display shear banding behavior. A relationship between the viscoelasticity of the sample and the size of the apparent fluctuations is observed.

  14. Optical coherence tomography predictive factors for idiopathic macular hole surgery outcome%相干光断层扫描量化参数与特发性黄斑裂孔患者术后视力预后的相关性分析

    Institute of Scientific and Technical Information of China (English)

    戴元敏; 沈洁; 李九可; 金晓红; 李毓敏

    2013-01-01

    Objective To evaluate the use of preoperative optical coherence tomography (OCT) image and some related indexes as predictive factors for the visual outcomes of the idiopathic macular hole (IMH) after pars plana vitrectomy and the internal limiting membrane(ILM) peeling surgery.Methods This was a case-series study.Twenty-five eyes of 23 IMH patients undergoing a successful vitrectomy and ILM peeling surgery and following up more than 6 months were included in this retrospective study.Of the 23 patients,6 were male and 17 were female.The median patient age was 67-year old (range 63 to 71 years).The median duration of IMH was 6 months (range 3.5 to 12.0 months).In the patients,the macular hole was found in 9 eyes at stage]Ⅱ,11 eyes at stage Ⅲ,and 5 eyes at stage Ⅳ.Best corrected visual acuity(BCVA) were examined before and after the surgery.The minimum diameter(a),the height (b) and the base diameter(c) of macular holes were measured by OCT.According to the indexes,macular hole index (MHI,b/c),tractional hole index (THI,b/a),diameter hole index (DHI,a/c) were calculated,respectively.Spearman rank correlation analysis was performed to understand the correlations between postoperative BCVA and the related indexes.Cut-off values were obtained for MHI and THI,respectively,from receiver operating characteristic(ROC) curve analysis.Results The median preoperative BCVA was 0.100(range 0.050 to 0.180).The median MHI,THI and DHI was 0.476(range 0.416 to 0.684),1.048(range 0.761 to 1.346) and 0.536 (range 0.431 to 0.645),respectively.The median 3-month postoperative BCVA was 0.150 (range 0.120 to 0.275),markedly improved after surgery(Mann-Whitney U test:P =0.002).The median latest postoperative BCVA was 0.250 (range 0.135 to 0.350),also markedly improved(Mann-Whitney U test,P =0.002).M HI,THI and preoperative BCVA correlated significantly with postoperative BCVA by Spearman rank correlation analysis (rMuI =0.481,P =0.015 ; rTHI =0.516,P =0.008 ; rpreoperative BCVA =0

  15. Retinal Imaging of Infants on Spectral Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Anand Vinekar

    2015-01-01

    Full Text Available Spectral domain coherence tomography (SD OCT has become an important tool in the management of pediatric retinal diseases. It is a noncontact imaging device that provides detailed assessment of the microanatomy and pathology of the infant retina with a short acquisition time allowing office examination without the requirement of anesthesia. Our understanding of the development and maturation of the infant fovea has been enhanced by SD OCT allowing an in vivo assessment that correlates with histopathology. This has helped us understand the critical correlation of foveal development with visual potential in the first year of life and beyond. In this review, we summarize the recent literature on the clinical applications of SD OCT in studying the pathoanatomy of the infant macula, its ability to detect subclinical features, and its correlation with disease and vision. Retinopathy of prematurity and macular edema have been discussed in detail. The review also summarizes the current status of SD OCT in other infant retinal conditions, imaging the optic nerve, the choroid, and the retinal nerve fibre in infants and children, and suggests future areas of research.

  16. Macular sensitivity and fixation patterns in patients with autosomal dominant optic atrophy

    DEFF Research Database (Denmark)

    Rönnbäck, Cecilia; Larsen, Michael

    2014-01-01

    INTRODUCTION: The objective of this study was to test macular sensitivity, fixation stability and fixation location using microperimetry in patients with autosomal dominant optic atrophy (ADOA) and mutation-free relatives. MATERIAL AND METHODS: This was a cross-sectional study of 43 patients...

  17. Retinal degeneration in progressive supranuclear palsy measured by optical coherence tomography and scanning laser polarimetry.

    Science.gov (United States)

    Stemplewitz, Birthe; Kromer, Robert; Vettorazzi, Eik; Hidding, Ute; Frings, Andreas; Buhmann, Carsten

    2017-07-13

    This cross-sectional study compared the retinal morphology between patients with progressive supranuclear palsy (PSP) and healthy controls. (The retinal nerve fiber layer (RNFL) around the optic disc and the retina in the macular area of 22 PSP patients and 151 controls were investigated by spectral domain optical coherence tomography (SD-OCT). Additionally, the RNFL and the nerve fiber index (NFI) were measured by scanning laser polarimetry (SLP). Results of RNFL measurements with SD-OCT and SLP were compared to assess diagnostic discriminatory power. Applying OCT, PSP patients showed a smaller RNFL thickness in the inferior nasal and inferior temporal areas. The macular volume and the thickness of the majority of macular sectors were reduced compared to controls. SLP data showed a thinner RNFL thickness and an increase in the NFI in PSP patients. Sensitivity and specificity to discriminate PSP patients from controls were higher applying SLP than SD-OCT. Retinal changes did not correlate with disease duration or severity in any OCT or SLP measurement. PSP seems to be associated with reduced thickness and volume of the macula and reduction of the RNFL, independent of disease duration or severity. Retinal imaging with SD-OCT and SLP might become an additional tool in PSP diagnosis.

  18. Dental diagnostics using optical coherence techniques

    Energy Technology Data Exchange (ETDEWEB)

    Nathel, H. [Lawrence Livermore National Lab., CA (United States); Colston, B. [Univ. of California, San Francisco, CA (United States); Armitage, G. [Univ. of California, Davis, CA (United States)] [and others

    1994-11-15

    Optical radiation can be used for diagnostic purposes in oral medicine. However, due to the turbid, amorphous, and inhomogeneous nature of dental tissue conventional techniques used to transilluminate materials are not well suited to dental tissues. Optical coherence techniques either in the time- of frequency-domain offer the capabilities of discriminating scattered from unscattered light, thus allowing for imaging through turbid tissue. Currently, using optical time-domain reflectometry we are able to discriminate specular from diffuse reflections occurring at tissue boundaries. We have determined the specular reflectivity of enamel and dentin to be approximately 6.6 x 10{sup -5} and 1.3 x 10{sup -6}, respectively. Implications to periodontal imaging will be discussed.

  19. Correlation of optic neuritis and retinal nerve fibre thickness using optical coherence tomography in a cohort of multiple sclerosis patients

    Directory of Open Access Journals (Sweden)

    Izanne Roos

    2016-03-01

    Full Text Available Background: Optical coherence tomography (OCT is a fast, non-invasive imaging technology that produces 3D, high-resolution images of the retina. Direct visualisation of the retina allows a unique opportunity to study the effects of multiple sclerosis (MS-associated neurodegeneration on retinal ganglion cells as well as effects of retrobulbar demyelination on axonal and retinal architecture through measurement of retinal nerve fibre layer (RNFL thickness and total macular volume (TMV. These findings are clinically important as axonal loss is irreversible and correlates with disability.Aim: To determine the role and usefulness of OCT in a local cohort of MS patients.Setting: Neurology Clinic, Inkosi Albert Luthuli Central Hospital, KwaZulu-Natal, South Africa.Methods: Nineteen patients with MS currently being treated with interferon β-1b underwent OCT examination of both eyes. RNFL thickness and macular volume were measured and correlated with clinical disease characteristics, history of optic neuritis and level of disability.Results: Mean RNFL thickness was 77.3 μm with no significant difference in mean RNFL in eyes with a history of optic neuritis (ON and those without (p = 0.4. Eyes with a history of ON did, however, have significantly thinner RNFL compared with the contralateral eye (p = 0.04. Despite a strong correlation between TMV and RNFL (p = 0.001, a subset of patients with normal RNFL had TMV that was less than 1% of what was expected. There was no correlation between RNFL and disability scores.Conclusion: OCT enables a direct axonal ‘optical biopsy’, for monitoring disease progression and treatment response in MS. RNFL thinning occurs independently of a history of optic neuritis and may represent a chronic optic neuropathy in patients with MS.Keywords: Multiple sclerosis; optical coherence tomography

  20. Cubic meter volume optical coherence tomography

    Science.gov (United States)

    WANG, ZHAO; POTSAID, BENJAMIN; CHEN, LONG; DOERR, CHRIS; LEE, HSIANG-CHIEH; NIELSON, TORBEN; JAYARAMAN, VIJAYSEKHAR; CABLE, ALEX E.; SWANSON, ERIC; FUJIMOTO, JAMES G.

    2017-01-01

    Optical coherence tomography (OCT) is a powerful three-dimensional (3D) imaging modality with micrometer-scale axial resolution and up to multi-GigaVoxel/s imaging speed. However, the imaging range of high-speed OCT has been limited. Here, we report 3D OCT over cubic meter volumes using a long coherence length, 1310 nm vertical-cavity surface-emitting laser and silicon photonic integrated circuit dual-quadrature receiver technology combined with enhanced signal processing. We achieved 15 µm depth resolution for tomographic imaging at a 100 kHz axial scan rate over a 1.5 m range. We show 3D macroscopic imaging examples of a human mannequin, bicycle, machine shop gauge blocks, and a human skull/brain model. High-bandwidth, meter-range OCT demonstrates new capabilities that promise to enable a wide range of biomedical, scientific, industrial, and research applications. PMID:28239628

  1. Concept of coherence of learning physical optics

    Science.gov (United States)

    Colombo, Elisa M.; Jaen, Mirta; de Cudmani, Leonor C.

    1995-10-01

    The aim of the actual paper is to enhance achievements of the text 'Optica Fisica Basica: estructurada alrededor del concepto de coherencia luminosa' (in English 'Basic Physical Optics centered in the concept of coherence'). We consider that this book is a very worth tool when one has to learn or to teach some fundamental concepts of physical optics. It is well known that the topics of physical optics present not easy understanding for students. Even more they also present some difficulties for the teachers when they have to introduce them to the class. First, we think that different phenomena like diffraction and polarization could be well understood if the starting point is a deep comprehension of the concept of interference of light and, associated with this, the fundamental and nothing intuitive concept of coherence of the light. In the reference text the authors propose the use of expression 'stable interference pattern of no uniform intensity' instead of 'pattern of interference' and 'average pattern of uniform untested' instead of 'lack of interference' to make reference that light always interfere but just under restrictive conditions it can be got temporal and spatial stability of the pattern. Another idea we want to stand out is that the ability to observe a 'stable interference pattern of no uniform intensity' is associated not only with the coherence of the source but also with the dimensions of the experimental system and with the temporal and spatial characteristics of the detector used - human eye, photographic film, etc. The proposal is well support by quantitative relations. With an alternate model: a train of waves with a finite length of coherence, it is possible to get range of validity of models, to decide when a source could be considered a 'point' or 'monochromatic' or 'remote', an 'infinite' wave or a train of waves, etc. Using this concept it is possible to achieve a better understanding of phenomena like the polarization of light. Here, it

  2. Optics for coherent X-ray applications.

    Science.gov (United States)

    Yabashi, Makina; Tono, Kensuke; Mimura, Hidekazu; Matsuyama, Satoshi; Yamauchi, Kazuto; Tanaka, Takashi; Tanaka, Hitoshi; Tamasaku, Kenji; Ohashi, Haruhiko; Goto, Shunji; Ishikawa, Tetsuya

    2014-09-01

    Developments of X-ray optics for full utilization of diffraction-limited storage rings (DLSRs) are presented. The expected performance of DLSRs is introduced using the design parameters of SPring-8 II. To develop optical elements applicable to manipulation of coherent X-rays, advanced technologies on precise processing and metrology were invented. With propagation-based coherent X-rays at the 1 km beamline of SPring-8, a beryllium window fabricated with the physical-vapour-deposition method was found to have ideal speckle-free properties. The elastic emission machining method was utilized for developing reflective mirrors without distortion of the wavefronts. The method was further applied to production of diffraction-limited focusing mirrors generating the smallest spot size in the sub-10 nm regime. To enable production of ultra-intense nanobeams at DLSRs, a low-vibration cooling system for a high-heat-load monochromator and advanced diagnostic systems to characterize X-ray beam properties precisely were developed. Finally, new experimental schemes for combinative nano-analysis and spectroscopy realised with novel X-ray optics are discussed.

  3. Optical coherence tomography investigations of ceramic lumineers

    Science.gov (United States)

    Fernandes, Luana O.; Graça, Natalia D. R. L.; Melo, Luciana S. A.; Silva, Claudio H. V.; Gomes, Anderson S. L.

    2016-02-01

    Lumineers are veneer laminates used as an alternative for aesthetic dental solutions of the highest quality, but the only current means of its performance assessment is visual inspection. The objective of this study was to use the Optical Coherence Tomography (OCT) technique working in spectral domain to analyze in vivo in a single patient, 14 lumineers 180 days after cementation. It was possible to observe images in various kinds of changes in the cementing line and the laminate. It was concluded that the OCT is an effective and promising method to clinical evaluation of the cementing line in lumineers.

  4. Optical Coherence Tomography Angiography in Fovea Plana.

    Science.gov (United States)

    Dolz-Marco, Rosa; Phasukkijwatana, Nopasak; Sarraf, David; Freund, K Bailey

    2016-07-01

    Fovea plana is characterized by the anatomical absence of the foveal pit in eyes with normal visual function. The authors have analyzed three cases of idiopathic fovea plana with optical coherence tomography angiography (OCTA). As previously reported, the authors found the absence of a foveal avascular zone in all cases with OCTA; however, a preserved fusion of both the superficial and the deep capillary plexuses was found around the foveal center. This novel observation cannot be detected with conventional dye-based angiography, in which the deep capillary plexus is not visualized. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:670-673.].

  5. Integration of spectral domain optical coherence tomography with microperimetry generates unique datasets for the simultaneous identification of visual function and retinal structure in ophthalmological applications

    Science.gov (United States)

    Koulen, Peter; Gallimore, Gary; Vincent, Ryan D.; Sabates, Nelson R.; Sabates, Felix N.

    2011-06-01

    Conventional perimeters are used routinely in various eye disease states to evaluate the central visual field and to quantitatively map sensitivity. However, standard automated perimetry proves difficult for retina and specifically macular disease due to the need for central and steady fixation. Advances in instrumentation have led to microperimetry, which incorporates eye tracking for placement of macular sensitivity values onto an image of the macular fundus thus enabling a precise functional and anatomical mapping of the central visual field. Functional sensitivity of the retina can be compared with the observed structural parameters that are acquired with high-resolution spectral domain optical coherence tomography and by integration of scanning laser ophthalmoscope-driven imaging. Findings of the present study generate a basis for age-matched comparison of sensitivity values in patients with macular pathology. Microperimetry registered with detailed structural data performed before and after intervention treatments provides valuable information about macular function, disease progression and treatment success. This approach also allows for the detection of disease or treatment related changes in retinal sensitivity when visual acuity is not affected and can drive the decision making process in choosing different treatment regimens and guiding visual rehabilitation. This has immediate relevance for applications in central retinal vein occlusion, central serous choroidopathy, age-related macular degeneration, familial macular dystrophy and several other forms of retina related visual disability.

  6. Cone structure imaged with adaptive optics scanning laser ophthalmoscopy in eyes with nonneovascular age-related macular degeneration

    National Research Council Canada - National Science Library

    Zayit-Soudry, Shiri; Duncan, Jacque L; Syed, Reema; Menghini, Moreno; Roorda, Austin J

    2013-01-01

    To evaluate cone spacing using adaptive optics scanning laser ophthalmoscopy (AOSLO) in eyes with nonneovascular AMD, and to correlate progression of AOSLO-derived cone measures with standard measures of macular structure...

  7. Digital processing optical transmission and coherent receiving techniques

    CERN Document Server

    Binh, Le Nguyen

    2013-01-01

    With coherent mixing in the optical domain and processing in the digital domain, advanced receiving techniques employing ultra-high speed sampling rates have progressed tremendously over the last few years. These advances have brought coherent reception systems for lightwave-carried information to the next stage, resulting in ultra-high capacity global internetworking. Digital Processing: Optical Transmission and Coherent Receiving Techniques describes modern coherent receiving techniques for optical transmission and aspects of modern digital optical communications in the most basic lines. The

  8. Multifocal electroretinogram in normal emmetropic subjects: Correlation with optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Rajvardhan Azad

    2012-01-01

    Full Text Available Aim of the Study: To establish the normative database for multifocal electroretinogram (mfERG parameters in a normal emmetropic population. To correlate the data so obtained with the central macular thickness obtained using the optical coherence tomography (OCT scan. Materials and Methods: mfERG data were obtained from 222 eyes of 111 emmetropic subjects. The amplitude (nv/deg 2 and implicit times (ms of the first-order kernel mfERG responses (N1, P1, and N2 waves were obtained and grouped into five rings (Ring 1: Central 2°, Ring 2: 2-5°, Ring 3: 5-10°, Ring 4: 10-15°, Ring 5: >15°. The central macular thickness (CMT was obtained using the macular thickness scan protocol of the OCT. Results: The mfERG data obtained were used to create a normative database. The amplitudes of the mfERG waves were maximum in the fovea and progressively decreased with increasing eccentricity (P = 0.0001. The latencies of the P1 and N2 waves were longest in the central ring and progressively shortened with eccentricity (P = 0.0001. No statistically significant correlations were observed between central ring 1 parameters and the CMT. Conclusion: This study establishes normative database for mfERG parameters in an emmetropic population. No statistically significant correlation was noted between CMT and mfERG parameters.

  9. Snapshot Spectral Domain Optical Coherence Tomography

    Science.gov (United States)

    Valdez, Ashley

    Optical coherence tomography systems are used to image the retina in 3D to allow ophthalmologists diagnose ocular disease. These systems yield large data sets that are often labor-intensive to analyze and require significant expertise in order to draw conclusions, especially when used over time to monitor disease progression. Spectral Domain Optical Coherence Tomography (SD-OCT) instantly acquires depth profiles at a single location with a broadband source. These systems require mechanical scanning to generate two- or three-dimensional images. Instead of mechanically scanning, a beamlet array was used to permit multiple depth measurements on the retina with a single snapshot using a 3x 3 beamlet array. This multi-channel system was designed, assembled, and tested using a 1 x 2 beamlet lens array instead of a 3 x 3 beamlet array as a proof of concept prototype. The source was a superluminescent diode centered at 840nm with a 45nm bandwidth. Theoretical axial resolution was 6.92um and depth of focus was 3.45mm. Glass samples of varying thickness ranging from 0.18mm to 1.14mm were measured with the system to validate that correct depth profiles can be acquired for each channel. The results demonstrated the prototype system performed as expected, and is ready to be modified for in vivo applicability.

  10. Bilateral macular holes in X-linked retinoschisis: Now the spectrum is wider

    Directory of Open Access Journals (Sweden)

    Manoj Gautam

    2011-01-01

    Full Text Available Bilateral occurrence of macular hole in X-linked retinoschisis is an extremely rare event. Spectral domain optical coherence tomography (OCT findings revealed that formation of a macular hole is secondary to the retinoschisis process alone. Bilateral macular holes should be added to the spectrum of X-linked retinoschisis variations and the retinoschisis process alone should be accounted for their formation.

  11. Fiber optic based optical coherence tomography (OCT) for dental applications

    Energy Technology Data Exchange (ETDEWEB)

    Everett, M. J., LLNL

    1998-06-02

    We have developed a hand-held fiber optic based optical coherence tomography (OCT) system for scanning of the oral cavity We have produced, using this scanning device, in viva cross-sectional images of hard and soft dental tissues in human volunteers Clinically relevant anatomical structures, including the gingival margin, periodontal sulcus, and dento-enamel junction, were visible in all the images The dento-enamel junction and the alveolar bone were identifiable in approximately two thirds of the images These images represent, to our knowledge, the first in viva OCT images of human dental tissue.

  12. Adaptive optics optical coherence tomography for retina imaging

    Institute of Scientific and Technical Information of China (English)

    Guohua Shi; Yun Dai; Ling Wang; Zhihua Ding; Xuejun Rao; Yudong Zhang

    2008-01-01

    When optical coherence tomography (OCT) is used for human retina imaging, its transverse resolution is limited by the aberrations of human eyes. To overcome this disadvantage, a high resolution imaging system for living human retina, which consists of a time domain OCT system and a 37-elements adaptive optics (AO) system, has been developed. The AO closed loop rate is 20 frames per second, and the OCT has a 6.7-μm axial resolution. In this paper, this system is introduced and the high resolution imaging results for retina are presented.

  13. Ex vivo imaging of human thyroid pathology using integrated optical coherence tomography and optical coherence microscopy

    Science.gov (United States)

    Zhou, Chao; Wang, Yihong; Aguirre, Aaron D.; Tsai, Tsung-Han; Cohen, David W.; Connolly, James L.; Fujimoto, James G.

    2010-01-01

    We evaluate the feasibility of optical coherence tomography (OCT) and optical coherence microscopy (OCM) for imaging of benign and malignant thyroid lesions ex vivo using intrinsic optical contrast. 34 thyroid gland specimens are imaged from 17 patients, covering a spectrum of pathology ranging from normal thyroid to benign disease/neoplasms (multinodular colloid goiter, Hashimoto's thyroiditis, and follicular adenoma) and malignant thyroid tumors (papillary carcinoma and medullary carcinoma). Imaging is performed using an integrated OCT and OCM system, with sections. Characteristic features that suggest malignant lesions, such as complex papillary architecture, microfollicules, psammomatous calcifications, or replacement of normal follicular architecture with sheets/nests of tumor cells, can be identified from OCT and OCM images and are clearly differentiable from normal or benign thyroid tissues. With further development of needle-based imaging probes, OCT and OCM could be promising techniques to use for the screening of thyroid nodules and to improve the diagnostic specificity of fine needle aspiration evaluation.

  14. Nonarteritic anterior ischemic optic neuropathy following pars plana vitrectomy for macular hole treatment: case report

    Directory of Open Access Journals (Sweden)

    Leonardo Provetti Cunha

    Full Text Available ABSTRACT Herein, we report a case of nonarteritic anterior ischemic optic neuropathy (NAION following uneventful pars plana vitrectomy for macular hole treatment. A 56-year-old previously healthy woman presented with a full-thickness macular hole in right eye (OD and small cup-to-disc ratios in both eyes. Five days after surgery, she noticed sudden painless loss of vision in OD and was found to have an afferent pupillary defect and intraocular pressure of 29 mmHg. Fundus examination showed right optic disc edema and the resolution of a macular hole with an inferior altitudinal visual field defect. Erythrocyte sedimentation rate, C-reactive protein levels, and general physical examination findings were normal. She was treated with hypotensive eyedrops and oral prednisone, resulting in mild visual improvement and a pale optic disc. A combination of face-down position and increased intraocular pressure due to a small optic disc cup were considered as potential mechanisms underlying NAION in the present case. Vitreoretinal surgeons should be aware of NAION as a potentially serious complication and be able to recognize associated risk factors and clinical findings.

  15. Optical Coherence Tomography in a Needle Format

    Science.gov (United States)

    Lorenser, Dirk; McLaughlin, Robert A.; Sampson, David D.

    In this chapter, we review the technology and applications of needle probes for optical coherence tomography (OCT). Needle probes are miniaturized fiber-optic probes that can be mounted inside hypodermic needles, allowing them to be inserted deep into the body during OCT imaging. This overcomes the very limited imaging depth of OCT of only 2-3 mm in biological tissue, enabling access to deep-tissue locations that are beyond the reach of free-space optical scan heads or catheters. This chapter provides an in-depth review of the current state-of-the art in needle probe technology, including optical design and fabrication, scan mechanisms (including three-dimensional scanning), and integration into OCT systems. It also provides an overview of emerging applications of this fascinating new imaging tool in areas such as cancer diagnosis, pulmonary imaging, imaging of the eye and imaging of the brain. Finally, two case studies are presented, illustrating needle-based OCT imaging in breast cancer and lungs.

  16. Optical coherence tomography technology and applications

    CERN Document Server

    Fujimoto, James

    2015-01-01

    Optical coherence tomography (OCT) is the optical analog of ultrasound imaging and is a powerful imaging technique that enables non-invasive, in vivo, high resolution, cross-sectional imaging in biological tissue.  Between 30 to 40 Million OCT imaging procedures are performed per year in ophthalmology.  The overall market is estimated at more than 0.5 Billion USD.  A new generation OCT technology was developed, dramatically increasing resolution and speed, achieving in vivo optical biopsy, i.e. the visualization of tissue architectural morphology in situ and in real time.  Functional extensions of OCT technology enable non-invasive, depth resolved functional assessment and imaging of tissue.  The book introduces OCT technology and applications not only from an optical and technological viewpoint, but also from the biomedical and clinical perspective. This second edition is widely extended and covers significantly more topics then the first edition of this book. The chapters are written leading intern...

  17. Comparison of Snellen acuity, VER acuity, and Arden grating scores in macular and optic nerve diseases.

    Science.gov (United States)

    Skalka, H W

    1980-01-01

    Patients with various macular and optic nerve abnormalities underwent Snellen acuity, transient VER acuity, and Arden grating testing. Snellen acuity was the coarsest of the 3 evaluations, generally falling after Arden scores and VER acuity had already undergone significant degradation. The Arden gratings appeared to be the most sensitive of the 3 tests, equalling VER performance in optic nerve diseases and surpassing it in macular diseases. Variations in results between the different tests are generally understandable if one considers the functions tested by each and the anatomical derangements caused by the diseases in question. The Arden grating test appears to be an excellent and sensitive screening test for central visual disturbances. Images PMID:7356929

  18. Evaluation of a cheap ultrasonic stage for light source coherence function measurement, optical coherence tomography and dynamic focusing

    NARCIS (Netherlands)

    Krstajic, Nikola; Matcher, Stephen J.; Childs, David; Steenbergen, Wiendelt; Hogg, Richard; Smallwood, Rod

    2009-01-01

    We evaluate the performance of a cheap ultrasonic stage in setups related to optical coherence tomography. The stage was used in several configurations: (1) optical delay line in an optical coherence tomography (OCT) setup; (2) as a delay line measuring coherence function of a low coherence source (

  19. In vivo cellular visualization of the human retina using optical coherence tomography and adaptive optics

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, S S; Jones, S M; Chen, D C; Zawadzki, R J; Choi, S S; Laut, S P; Werner, J S

    2006-01-05

    Optical coherence tomography (OCT) sees the human retina sharply with adaptive optics. In vivo cellular visualization of the human retina at micrometer-scale resolution is possible by enhancing Fourier-domain optical-coherence tomography with adaptive optics, which compensate for the eye's optical aberrations.

  20. Macular Retinal Ganglion Cell Complex Thickness and Its Relationship to the Optic Nerve Head Topography in Glaucomatous Eyes with Hemifield Defects

    Directory of Open Access Journals (Sweden)

    Seiji T. Takagi

    2011-01-01

    Full Text Available Purpose. To evaluate the relationship between the macular ganglion cell complex (mGCC thickness, which is the sum of the retinal nerve fiber, ganglion cell, and inner plexiform layers, measured with a spectral-domain optical coherence tomograph and the optic nerve head topography measured with a confocal scanning laser ophthalmoscope in glaucomatous eyes with visual field defects localized predominantly to either hemifield. Materials and Methods. The correlation between the mGCC thickness in hemispheres corresponding to hemifields with and without defects (damaged and intact hemispheres, respectively and the optic nerve head topography corresponding to the respective hemispheres was evaluated in 18 glaucomatous eyes. Results. The mGCC thickness was significantly correlated with the rim volume, mean retinal nerve fiber layer thickness, and cross-sectional area of the retinal nerve fiber layer in both the intact and the damaged hemispheres (P<.05. Discussion. For detecting very early glaucomatous damage of the optic nerve, changes in the thicknesses of the inner retina in the macular area and peripapillary RNFL as well as rim volume changes in the optic nerve head are target parameters that should be carefully monitored.

  1. High-Resolution En Face Images of Microcystic Macular Edema in Patients with Autosomal Dominant Optic Atrophy

    Directory of Open Access Journals (Sweden)

    Kiyoko Gocho

    2013-01-01

    Full Text Available The purpose of this study was to investigate the characteristics of microcystic macular edema (MME determined from the en face images obtained by an adaptive optics (AO fundus camera in patients with autosomal dominant optic atrophy (ADOA and to try to determine the mechanisms underlying the degeneration of the inner retinal cells and RNFL by using the advantage of AO. Six patients from 4 families with ADOA underwent detailed ophthalmic examinations including spectral domain optical coherence tomography (SD-OCT. Mutational screening of all coding and flanking intron sequences of the OPA1 gene was performed by DNA sequencing. SD-OCT showed a severe reduction in the retinal nerve fiber layer (RNFL thickness in all patients. A new splicing defect and two new frameshift mutations with premature termination of the Opa1 protein were identified in three families. A reported nonsense mutation was identified in one family. SD-OCT of one patient showed MME in the inner nuclear layer (INL of the retina. AO images showed microcysts in the en face images of the INL. Our data indicate that AO is a useful method to identify MME in neurodegenerative diseases and may also help determine the mechanisms underlying the degeneration of the inner retinal cells and RNFL.

  2. Spectral-domain optical coherence tomography staging and autofluorescence imaging in achromatopsia.

    Science.gov (United States)

    Greenberg, Jonathan P; Sherman, Jerome; Zweifel, Sandrine A; Chen, Royce W S; Duncker, Tobias; Kohl, Susanne; Baumann, Britta; Wissinger, Bernd; Yannuzzi, Lawrence A; Tsang, Stephen H

    2014-04-01

    IMPORTANCE Evidence is mounting that achromatopsia is a progressive retinal degeneration, and treatments for this condition are on the horizon. OBJECTIVES To categorize achromatopsia into clinically identifiable stages using spectral-domain optical coherence tomography and to describe fundus autofluorescence imaging in this condition. DESIGN, SETTING, AND PARTICIPANTS A prospective observational study was performed between 2010 and 2012 at the Edward S. Harkness Eye Institute, New York-Presbyterian Hospital. Participants included 17 patients (aged 10-62 years) with full-field electroretinography-confirmed achromatopsia. MAIN OUTCOMES AND MEASURES Spectral-domain optical coherence tomography features and staging system, fundus autofluorescence and near-infrared reflectance features and their correlation to optical coherence tomography, and genetic mutations served as the outcomes and measures. RESULTS Achromatopsia was categorized into 5 stages on spectral-domain optical coherence tomography: stage 1 (2 patients [12%]), intact outer retina; stage 2 (2 patients [12%]), inner segment ellipsoid line disruption; stage 3 (5 patients [29%]), presence of an optically empty space; stage 4 (5 patients [29%]), optically empty space with partial retinal pigment epithelium disruption; and stage 5 (3 patients [18%]), complete retinal pigment epithelium disruption and/or loss of the outer nuclear layer. Stage 1 patients showed isolated hyperreflectivity of the external limiting membrane in the fovea, and the external limiting membrane was hyperreflective above each optically empty space. On near infrared reflectance imaging, the fovea was normal, hyporeflective, or showed both hyporeflective and hyperreflective features. All patients demonstrated autofluorescence abnormalities in the fovea and/or parafovea: 9 participants (53%) had reduced or absent autofluorescence surrounded by increased autofluorescence, 4 individuals (24%) showed only reduced or absent autofluorescence, 3

  3. Angle-resolved optical coherence tomography

    Science.gov (United States)

    Desjardins, Adrien Emmanuel

    Optical coherence tomography (OCT) has emerged as a powerful tool for probing the microstructure of biological tissue non-invasively at high-speed. OCT measures depth-resolved reflectance of infrared light, generating cross-sectional images non-invasively with micron-scale resolution. As with other imaging modalities that employ coherent detection, OCT images are confounded by speckle noise. Speckle imposes a grainy texture on images that reduces the signal-to-noise ratio to near unity values. As a result, it conceals subtle differences in scattering properties known to be crucial for differentiating normal from diseased tissue states. In this thesis, we developed a novel OCT modality called "Angle-Resolved OCT" in which depth scans (A-lines) are obtained simultaneously from a broad range of backscattering angles. We demonstrated that high levels of speckle reduction can be achieved by averaging the magnitudes of A-lines corresponding to the same transverse locations. With both experimental and analytic approaches, we demonstrated that this averaging method does not lead to a substantial loss in spatial resolution. We developed two different imaging systems for performing Angle-Resolved OCT. With the first system, angular data was acquired simultaneously; with the second, it was acquired sequentially. The first system had superior speckle-reduction capabilities but image quality degraded significantly with small sample movements. The second system allowed for in vivo imaging, as demonstrated with Resolved OCT systems, the speckle-reduced images showed hitherto unprecedented delineation of tissue microstructure.

  4. Quantitative contrast-enhanced optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Winetraub, Yonatan; SoRelle, Elliott D. [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Biophysics Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Liba, Orly [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Electrical Engineering, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Zerda, Adam de la [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Biophysics Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Electrical Engineering, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States)

    2016-01-11

    We have developed a model to accurately quantify the signals produced by exogenous scattering agents used for contrast-enhanced Optical Coherence Tomography (OCT). This model predicts distinct concentration-dependent signal trends that arise from the underlying physics of OCT detection. Accordingly, we show that real scattering particles can be described as simplified ideal scatterers with modified scattering intensity and concentration. The relation between OCT signal and particle concentration is approximately linear at concentrations lower than 0.8 particle per imaging voxel. However, at higher concentrations, interference effects cause signal to increase with a square root dependence on the number of particles within a voxel. Finally, high particle concentrations cause enough light attenuation to saturate the detected signal. Predictions were validated by comparison with measured OCT signals from gold nanorods (GNRs) prepared in water at concentrations ranging over five orders of magnitude (50 fM to 5 nM). In addition, we validated that our model accurately predicts the signal responses of GNRs in highly heterogeneous scattering environments including whole blood and living animals. By enabling particle quantification, this work provides a valuable tool for current and future contrast-enhanced in vivo OCT studies. More generally, the model described herein may inform the interpretation of detected signals in modalities that rely on coherence-based detection or are susceptible to interference effects.

  5. Optical coherence tomography for diagnosing periodontal disease

    Science.gov (United States)

    Colston, Bill W., Jr.; Everett, Matthew J.; Da Silva, Luiz B.; Otis, Linda L.; Nathel, Howard

    1997-05-01

    We have, in this preliminary study, investigated the use of optical coherence tomography for diagnosis of periodontal disease. We took in vitro OCT images of the dental and periodontal tissues from a young pig and compared them to histological sections. These images distinguish tooth and soft tissue relationships that are important in diagnosing and assessing periodontal disease. We have imaged the attachment of gingiva to the tooth surface and located the cemento-enamel junction. This junction is an important reference point for defining attachment level in the diagnosis of periodontal disease. the boundary between enamel and dentin is also visible for most of the length of the anatomical crown, allowing quantitation of enamel thickness and character.

  6. Advanced modelling of optical coherence tomography systems

    DEFF Research Database (Denmark)

    Andersen, Peter E.; Thrane, L.; Yura, H.T.;

    2004-01-01

    Analytical and numerical models for describing and understanding the light propagation in samples imaged by optical coherence tomography (OCT) systems are presented. An analytical model for calculating the OCT signal based on the extended Huygens–Fresnel principle valid both for the single...... and multiple scattering regimes is reviewed. An advanced Monte Carlo model for calculating the OCT signal is also reviewed, and the validity of this model is shown through a mathematical proof based on the extended Huygens–Fresnel principle. Moreover, for the first time the model is verified experimentally....... From the analytical model, an algorithm for enhancing OCT images is developed; the so-called true-reflection algorithm in which the OCT signal may be corrected for the attenuation caused by scattering. For the first time, the algorithm is demonstrated by using the Monte Carlo model as a numerical...

  7. Image Distortion of Optical Coherence Tomography

    Institute of Scientific and Technical Information of China (English)

    安源; 姚建铨

    2004-01-01

    A kind of image distortion in Optical Coherence Tomography (OCT) resulted from average refractive index changes between structures of bio-tissue is discussed for the first time.Analysis is given on following situations:1) Exact refraction index changes between microstructures;2)The gradient of average refractive index change between different tissue layers is parallel to the probe beam;3) The gradient of average refractive index change is vertical to the probe beam.The results show that the image distortion of situation 1) is usually negligible;in situation 2) there is a spread or shrink effect without relative location error; however,in situation 3) there is a significant image error inducing relative location displacement between different structures.Preliminary design to eliminate the distortion is presented,the method of which mainly based on the image classification and pixel array re-arrangement.

  8. Simulation of cellular changes on Optical Coherence Tomography of human retina.

    Science.gov (United States)

    Santos, Miriam; Araujo, Aderito; Barbeiro, Silvia; Caramelo, Francisco; Correia, Antonio; Marques, Maria Isabel; Pinto, Luis; Serranho, Pedro; Bernardes, Rui; Morgado, Miguel

    2015-08-01

    We present a methodology to assess cell level alterations on the human retina responsible for functional changes observable in the Optical Coherence Tomography data in healthy ageing and in disease conditions, in the absence of structural alterations. The methodology is based in a 3D multilayer Monte Carlo computational model of the human retina. The optical properties of each layer are obtained by solving the Maxwell's equations for 3D domains representative of small regions of those layers, using a Discontinuous Galerkin Finite Element Method (DG-FEM). Here we present the DG-FEM Maxwell 3D model and its validation against Mie's theory for spherical scatterers. We also present an application of our methodology to the assessment of cell level alterations responsible for the OCT data in Diabetic Macular Edema. It was possible to identify which alterations are responsible for the changes observed in the OCT scans of the diseased groups.

  9. Reproducibility of Perfusion Parameters of Optic Disc and Macula in Rhesus Monkeys by Optical Coherence Tomography Angiography

    Institute of Scientific and Technical Information of China (English)

    Jing Li; Yi-Quan Yang; Di-Ya Yang; Xiang-Xiang Liu; Yun-Xiao Sun; Shi-Fei Wei; Ning-Li Wang

    2016-01-01

    Background:Optical coherence tomography (OCT) angiography is a novel technique by which we can detect the local perfusion of fundus directly.The aim of this study was to evaluate the reproducibility of optic disc and macular flow perfusion parameters in rhesus monkeys using OCT angiography.Methods:Eighteen healthy monkeys (18 eyes) were subjected to optic disc and macula flow index measurements via a high-speed and high-resolution spectral-domain OCT XR Avanti with a split-spectrum amplitude de-correlation angiography algorithm.Right eye was imaged 3 times during the first examination and once during each of the two following examinations.The intra-visit and inter-visit intraclass correlation coefficients (ICCs) were both determined.Results:The average flow indices of the four optic disc area layers were 0.171 ± 0.009 (optic nerve head),0.015 ± 0.004 (vitreous),0.052 ± 0.009 (radial peripapillary capillary),and 0.167 ± 0.011 (choroid).Average flow indices of the four macula area layers were 0.044 ± 0.011 (superficial retina),0.036 ± 0.011 (deep retina),0.016 ± 0.009 (outer retina),and 0.155 ± 0.013 (choroid).Intra-visit (ICC value:0.821-0.954) and inter-visit (ICC value:0.844-0.899) repeatability were both high.Conclusions:The study is about the reproducibility of optic disc and macular perfusion parameters as measured by OCT angiography in healthy rhesus monkeys.Flow index measurement reproducibility is high for both the optic disc and macula of normal monkey eyes.OCT angiography might be a useful technique to assess changes when examining monkeys with experimental ocular diseases.

  10. Optical Coherence Tomography in Tissue Engineering

    Science.gov (United States)

    Zhao, Youbo; Yang, Ying; Wang, Ruikang K.; Boppart, Stephen A.

    Tissue engineering holds the promise for a therapeutic solution in regenerative medicine. The primary goal of tissue engineering is the development of physiologically functional and biocompatible tissues/organs being implanted for the repair and replacement of damaged or diseased ones. Given the complexity in the developing processes of engineered tissues, which involves multi-dimensional interactions among cells of different types, three-dimensionally constructed scaffolds, and actively intervening bioreactors, a capable real-time imaging tool is critically required for expanding our knowledge about the developing process of desired tissues or organs. It has been recognized that optical coherence tomography (OCT), an emerging noninvasive imaging technique that provides high spatial resolution (up to the cellular level) and three-dimensional imaging capability, is a promising investigative tool for tissue engineering. This chapter discusses the existing and potential applications of OCT in tissue engineering. Example OCT investigations of the three major components of tissue engineering, i.e., cells, scaffolds, and bioreactors are overviewed. Imaging examples of OCT and its enabling functions and variants, e.g., Doppler OCT, polarization-sensitive OCT, optical coherence microscopy are emphasized. Remaining challenges in the application of OCT to tissue engineering are discussed, and the prospective solutions including the combination of OCT with other high-contrast and high-resolution modalities such as two-photon fluorescence microscopy are suggested as well. It is expected that OCT, along with its functional variants, will make important contributions toward revealing the complex cellular dynamics in engineered tissues as well as help us culture demanding tissue/organ implants that will advance regenerative medicine.

  11. Detection of retinal changes in Parkinson’s disease with spectral-domain optical coherence tomography

    Science.gov (United States)

    Aaker, Grant D; Myung, Jane S; Ehrlich, Joshua R; Mohammed, Mujtaba; Henchcliffe, Claire; Kiss, Szilárd

    2010-01-01

    Purpose This pilot study investigated whether high-resolution spectral-domain optical coherence tomography (SD-OCT) could detect differences in inner retinal layer (IRL), peripapillary retinal nerve fiber layer (RNFL), and macular thickness between patients with Parkinson’s disease (PD) and controls. Methods Both eyes of patients with PD and age-matched controls were imaged with the Heidelberg Spectralis® HRA + OCT. RNFL, IRL, and macular thickness were measured for each eye using Heidelberg software. These measurements were compared with validated, published normal values for macular and RNFL thickness, and compared with matched controls for IRL thickness. Results Eighteen eyes from nine subjects with PD and 19 eyes of 16 control subjects were evaluated using SD-OCT. The average age of PD patients was 64 years with a range of 52–75 years. The average age of controls was 67 years with a range of 50–81 years. No significant reduction in IRL thickness was detected between PD patients and age-matched controls at 13 points along a 6 mm horizontal section through the fovea. No significant difference in RNFL thickness was detected between PD patients and published normal values. Overall average RNFL thickness was 97 μm for PD patients, which exactly matched the normative database value. However, significant differences in macular thickness were detected in three of nine subfields between PD subjects and published normal values. In PD subjects, the outer superior subfield was 2.8% thinner (P = 0.026), while the outer nasal and inner inferior subfields were 2.8% (P = 0.016) and 2.7% (P = 0.001) thicker compared to published normal values. Conclusion In this pilot study, significant differences in macular thickness were detected in three of nine subfields by SD-OCT. However, SD-OCT did not detect significant reductions in peripapillary RNFL and IRL thickness between PD patients and controls. This suggests that macular thickness measurements by SD-OCT may potentially

  12. Microperimetry Findings of a Patient with Macular Edema Secondary to Retinitis Pigmentosa

    Directory of Open Access Journals (Sweden)

    Cem Ozgonul

    2013-08-01

    Full Text Available Sixty-nine year old male patient with a diagnosis of retinitis pigmentosa admitted to our clinic. In ophthalmologic examination fundoscopy was compatible with retinitis pigmentosa. For evaluation of macular edema, optical coherence tomography and microperimetry were performed to examine the structure and function of the macula. Chronic macular edema findings were obtained with optical coherence tomography. By microperimetry, mean retinal sensitivity in the central 20 degrees of both eyes was measured 8-10 decibels. The aim of this study is, to emphasize the importance of microperimetry for the evaluation of retinal function in a patient with macular edema secondary to retinitis pigmentosa.

  13. Surgical treatment of macular detachment secondary to congenital pit of the optic disc: case report Tratamento cirúrgico do descolamento macular secundário à fosseta congênita do disco óptico: relato de caso

    Directory of Open Access Journals (Sweden)

    Otacílio de Oliveira Maia Júnior

    2008-12-01

    Full Text Available The authors describe a patient with macular detachment in the right eye, secondary to congenital pit of the optic disc, submitted to vitrectomy, drainage of the subretinal fluid, perfluorocarbon, endolaser and perfluoropropane gas (C3F8. A sample of the vitreous humor was taken for comparative analysis with the subretinal fluid. Results of retinography, optical coherence tomography, and illustrations of the surgical procedure are presented. Optical coherence tomography revealed the detachment resolved 6 months after surgery. Visual acuity improved from 20/400 to 20/30. This surgical technique can lead to successful reattachment of the macula and improvement of central vision. Additionally, a qualitative and comparative analysis showed a similar biochemical composition of the subretinal fluid and the vitreous. Despite technical limitations, this analysis can confirm the pathophysiology of the disease, suggesting that the subretinal fluid may originate from the vitreous cavity in macular detachment secondary to congenital pit of the optic disc.Os autores descrevem um paciente portador de descolamento macular secundário à fosseta congênita do nervo óptico no olho direito, submetido à vitrectomia, drenagem do fluido sub-retiniano, perfluorcarbono, endolaser e gás perfluoropropano (C3F8. Foi retirada amostra do humor vítreo para análise comparativa com o fluido sub-retiniano. São apresentadas retinografia, tomografia de coerência óptica e ilustrações do procedimento cirúrgico. Após 6 meses da cirurgia, houve resolução do descolamento evidenciada por meio da tomografia de coerência óptica. A acuidade visual melhorou de 20/400 para 20/30. A técnica cirúrgica utilizada pode ter melhorado os resultados obtidos. Adicionalmente, a análise bioquímica qualitativa e comparativa do fluido sub-retiniano e do vítreo mostrou composição semelhante. Apesar das limitações técnicas, esta análise pode corroborar na fisiopatogênese da

  14. Optical coherence tomography for endodontic imaging

    Science.gov (United States)

    van Soest, G.; Shemesh, H.; Wu, M.-K.; van der Sluis, L. W. M.; Wesselink, P. R.

    2008-02-01

    In root canal therapy, complications frequently arise as a result of root fracture or imperfect cleaning of fins and invaginations. To date, there is no imaging method for nondestructive in vivo evaluation of the condition of the root canal, during or after treatment. There is a clinical need for a technique to detect defects before they give rise to complications. In this study we evaluate the ability of optical coherence tomography (OCT) to image root canal walls, and its capacity to identify complicating factors in root canal treatment. While the potential of OCT to identify caries has been explored before, endodontic imaging has not been reported. We imaged extracted lower front teeth after endodontic preparation and correlated these images to histological sections. A 3D OCT pullback scan was made with an endoscopic rotating optical fiber probe inside the root canal. All oval canals, uncleaned fins, risk zones, and one perforation that were detected by histology were also imaged by OCT. As an example of an area where OCT has clinical potential, we present a study of vertical root fracture identification with OCT.

  15. Optical coherence tomography used for internal biometrics

    Science.gov (United States)

    Chang, Shoude; Sherif, Sherif; Mao, Youxin; Flueraru, Costel

    2007-06-01

    Traditional biometric technologies used for security and person identification essentially deal with fingerprints, hand geometry and face images. However, because all these technologies use external features of human body, they can be easily fooled and tampered with by distorting, modifying or counterfeiting these features. Nowadays, internal biometrics which detects the internal ID features of an object is becoming increasingly important. Being capable of exploring under-skin structure, optical coherence tomography (OCT) system can be used as a powerful tool for internal biometrics. We have applied fiber-optic and full-field OCT systems to detect the multiple-layer 2D images and 3D profile of the fingerprints, which eventually result in a higher discrimination than the traditional 2D recognition methods. More importantly, the OCT based fingerprint recognition has the ability to easily distinguish artificial fingerprint dummies by analyzing the extracted layered surfaces. Experiments show that our OCT systems successfully detected the dummy, which was made of plasticene and was used to bypass the commercially available fingerprint scanning system with a false accept rate (FAR) of 100%.

  16. Digital coherent transceiver for optical communications: from design to implementation

    OpenAIRE

    Anzuola Valencia, Esdras

    2012-01-01

    Establishing the basis of optical coherent transmission and detection which exploit digital signal processing (DSP) to optimize the performance of optical communication systems. [ANGLÈS] In this project we analyze the theoretical models of optical coherent communication systems as well as the front-end arquitectures used to implement them. Key concepts as balanced photo detection and quantum limit are explained and studied. Complex modulation schemes maximize spectral efficiency and power ...

  17. Optical generation and control of quantum coherence in semiconductor nanostructures

    CERN Document Server

    Slavcheva, Gabriela

    2010-01-01

    The unprecedented control of coherence that can be exercised in quantum optics of atoms and molecules has stimulated increasing efforts in extending it to solid-state systems. One motivation to exploit the coherent phenomena comes from the emergence of the quantum information paradigm, however many more potential device applications ranging from novel lasers to spintronics are all bound up with issues in coherence. The book focuses on recent advances in the optical control of coherence in excitonic and polaritonic systems as model systems for the complex semiconductor dynamics towards the goal

  18. Optical coherent control in semiconductors: Fringe contrast and inhomogeneous broadening

    DEFF Research Database (Denmark)

    Østergaard, John Erland; Vadim, Lyssenko; Hvam, Jørn Märcher

    2001-01-01

    Optical coherent control experiments in semiconductors reveal how inhomogeneous broadening must be taken into account in contrast to previous coherent control experiments in atomic and molecular systems. With spectral resolution elf the coherent control signal, the optical phases involved...... is observed in the four-wave mixing spectra as a function of phase-delay representing coherent control in the spectral domain. The spectral phase change of this modulation provides a spectroscopic tool to analyze contributions of inhomogeneous broadening to electronic resonances in semiconductor structures....

  19. Reading Center Characterization of Central Retinal Vein Occlusion Using Optical Coherence Tomography During the COPERNICUS Trial.

    Science.gov (United States)

    Decroos, Francis Char; Stinnett, Sandra S; Heydary, Cynthia S; Burns, Russell E; Jaffe, Glenn J

    2013-11-01

    To determine the impact of segmentation error correction and precision of standardized grading of time domain optical coherence tomography (OCT) scans obtained during an interventional study for macular edema secondary to central retinal vein occlusion (CRVO). A reading center team of two readers and a senior reader evaluated 1199 OCT scans. Manual segmentation error correction (SEC) was performed. The frequency of SEC, resulting change in central retinal thickness after SEC, and reproducibility of SEC were quantified. Optical coherence tomography characteristics associated with the need for SECs were determined. Reading center teams graded all scans, and the reproducibility of this evaluation for scan quality at the fovea and cystoid macular edema was determined on 97 scans. Segmentation errors were observed in 360 (30.0%) scans, of which 312 were interpretable. On these 312 scans, the mean machine-generated central subfield thickness (CST) was 507.4 ± 208.5 μm compared to 583.0 ± 266.2 μm after SEC. Segmentation error correction resulted in a mean absolute CST correction of 81.3 ± 162.0 μm from baseline uncorrected CST. Segmentation error correction was highly reproducible (intraclass correlation coefficient [ICC] = 0.99-1.00). Epiretinal membrane (odds ratio [OR] = 2.3, P < 0.0001), subretinal fluid (OR = 2.1, P = 0.0005), and increasing CST (OR = 1.6 per 100-μm increase, P < 0.001) were associated with need for SEC. Reading center teams reproducibly graded scan quality at the fovea (87% agreement, kappa = 0.64, 95% confidence interval [CI] 0.45-0.82) and cystoid macular edema (92% agreement, kappa = 0.84, 95% CI 0.74-0.94). Optical coherence tomography images obtained during an interventional CRVO treatment trial can be reproducibly graded. Segmentation errors can cause clinically meaningful deviation in central retinal thickness measurements; however, these errors can be corrected reproducibly in a reading center setting. Segmentation errors are common

  20. Ultrathin lensed fiber-optic probe for optical coherence tomography.

    Science.gov (United States)

    Qiu, Y; Wang, Y; Belfield, K D; Liu, X

    2016-06-01

    We investigated and validated a novel method to develop ultrathin lensed fiber-optic (LFO) probes for optical coherence tomography (OCT) imaging. We made the LFO probe by attaching a segment of no core fiber (NCF) to the distal end of a single mode fiber (SMF) and generating a curved surface at the tip of the NCF using the electric arc of a fusion splicer. The novel fabrication approach enabled us to control the length of the NCF and the radius of the fiber lens independently. By strategically choosing these two parameters, the LFO probe could achieve a broad range of working distance and depth of focus for different OCT applications. A probe with 125μm diameter and lateral resolution up to 10μm was demonstrated. The low-cost, disposable and robust LFO probe is expected to have great potential for interstitial OCT imaging.

  1. Transsynaptic retinal degeneration in optic neuropathies: optical coherence tomography study.

    Science.gov (United States)

    Sriram, Prema; Graham, Stuart L; Wang, Chenyu; Yiannikas, Con; Garrick, Raymond; Klistorner, Alexander

    2012-03-09

    Recently demonstrated neuronal loss in the inner nuclear layer of the retina in multiple sclerosis (MS) and glaucoma raises the question of a primary (possibly immune-mediated) or secondary (transsynaptic) mechanism of retinal damage in these diseases. In the present study we used optical coherence tomography to investigate retrograde retinal transsynaptic degeneration in patients with long-standing and severe loss of ganglion cells due to optic neuropathy. Fifteen eyes of glaucoma patients with visual field defect limited to upper hemifield and 15 eyes of MS patients with previous episode of optic neuritis (ON) and extensive loss of ganglion cells were imaged using spectral-domain optical coherence tomography and compared with two groups of age-matched controls. Combined retinal ganglion cell layer/inner plexiform layer (GCL/IPL) thickness and inner nuclear layer (INL) thickness were analyzed. In the glaucoma group there was a significant (P = 0.0005) reduction of GCL/IPL thickness in the lower (affected) retina compared with normal controls; however INL thickness was not statistically reduced (P = 0.49). In the MS group reduction of GCL/IPL thickness in both hemifields of ON eyes was also significant (P = 0.0001 and P < 0.0001 for inferior and superior retina respectively). However, similar to the glaucomatous eyes, there was no significant reduction of INL thickness in both hemifields (P = 0.25 and P = 0.45). This study demonstrates no significant loss of INL thickness in parts of the retina with long-standing and severe loss of retinal ganglion cells.

  2. Integrated optical coherence tomography and optical coherence microscopy imaging of human pathology

    Science.gov (United States)

    Lee, Hsiang-Chieh; Zhou, Chao; Wang, Yihong; Aquirre, Aaron D.; Tsai, Tsung-Han; Cohen, David W.; Connolly, James L.; Fujimoto, James G.

    2010-02-01

    Excisional biopsy is the current gold standard for disease diagnosis; however, it requires a relatively long processing time and it may also suffer from unacceptable false negative rates due to sampling errors. Optical coherence tomography (OCT) is a promising imaging technique that provide real-time, high resolution and three-dimensional (3D) images of tissue morphology. Optical coherence microscopy (OCM) is an extension of OCT, combining both the coherence gating and the confocal gating techniques. OCM imaging achieves cellular resolution with deeper imaging depth compared to confocal microscopy. An integrated OCT/OCM imaging system can provide co-registered multiscale imaging of tissue morphology. 3D-OCT provides architectural information with a large field of view and can be used to find regions of interest; while OCM provides high magnification to enable cellular imaging. The integrated OCT/OCM system has an axial resolution of kidney (19), were imaged with OCT and OCM within 2 to 6 hours after excision. The images were compared with H & E histology to identify characteristic features useful for disease diagnosis. The feasibility of visualizing human pathology using integrated OCT/OCM was demonstrated in the pathology laboratory settings.

  3. Optic neuritis is associated with inner nuclear layer thickening and microcystic macular edema independently of multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Falko Kaufhold

    Full Text Available BACKGROUND: Microcystic macular edema (MME and inner nuclear layer thickening (INL were described in multiple sclerosis (MS and neuromyelitis optica (NMO patients using optical coherence tomography (OCT. The cause of these findings is currently unknown and a relation to inflammatory or degenerative processes in the optic nerve is discussed. OBJECTIVE: The aim of our study was to investigate whether INL thickening and MME are related to optic neuritis (ON in various neuro-inflammatory disorders causingON: MS, NMO and chronic inflammatory optic neuropathy. METHODS: We retrospectively analyzed data from 216 MS patients, 39 patients with a clinically isolated syndrome, 20 NMO spectrum disorder patients, 9 patients with chronic inflammatory optic neuropathy and 121 healthy subjects. Intra-retinal layer segmentation was performed for the eyes of patients with unilateral ON. Scanning laser ophthalmoscopy (SLO images were reviewed for characteristic ocular fundus changes. RESULTS: Intra-retinal layer segmentation showed that eyes with a history of ON displayed MME independent INL thickening compared to contralateral eyes without previous ON. MME was detected in 22 eyes from 15 patients (5.3% of all screened patients, including 7 patients with bilateral edema. Of these, 21 had a prior history of ON (95%. The SLO images of all 22 MME-affected eyes showed crescent-shaped texture changes which were visible in the perifoveal region. A second grader who was blinded to the results of the OCT classified all SLO images for the presence of these characteristic fundus changes. All MME eyes were correctly classified (sensitivity = 100% with high specificity (95.2%. CONCLUSION: This study shows that both MME and INL thickening occur in various neuro-inflammatory disorders associated with ON. We also demonstrate that detection and analysis of MME by OCT is not limited to B-scans, but also possible using SLO images.

  4. The use of optical coherence tomography in maxillofacial surgery

    Science.gov (United States)

    Al-Obaidi, Mohammed; Tandon, Rahul; Tiwana, Paul

    2015-02-01

    The ever-evolving medical field continues to trend toward less invasive approaches to the diagnosis and treatment of pathological conditions. Basic sciences research has allowed for improved technologies that are translated to the clinical sciences. Similarly, advancements in imaging modalities continue to improve and their applications become more varied. As such, surgeons and pathologists are able to depend on smaller samples for tissue diagnosis of pathological disease, where once large sections of tissue were needed. Optical coherence tomography (OCT), a high-resolution imaging technique, has been used extensively in different medical fields to improve diagnostic yield. Its use in dental fields, particularly in oral and maxillofacial surgery, remains limited. Our goal is to assess the use of OCT for improving soft tissue analysis and diagnosis, particularly for its applications in the field of oral and maxillofacial surgery. Optical coherence tomography is a modality that uses an optical signal using safe near-infrared light which is reflected off the sub-surface structures. This allows for high-resolution cross-sectional images of the tissue morphology to be obtained. Ophthalmologists have been using OCT to obtain images of the retina to assess for age-related macular degeneration. More recently, OCT has been used by Interventional Cardiology to image coronary arteries, and assess plaque thickness and morphology. This technology is now being investigated in several medical fields as a form of optical biopsy, providing in situ images with high-resolution morphology of tissues. We are particularly interested in its use on epithelial tissues, and therefore performed a literature review on the use of OCT for assessing epithelium. Evaluation of histologically-diagnosed actinic keratosis, for example, was found to correlate well with the imaging discrepancies found on OCT; and the in vivo assessment of atypical keratinocytes was firmly established. Additionally

  5. Evaluating the Use of Optical Coherence Tomography in Optic Neuritis

    Directory of Open Access Journals (Sweden)

    Fiona Costello

    2011-01-01

    Full Text Available Optic neuritis (ON is an inflammatory optic nerve injury, which is strongly associated with multiple sclerosis (MS. Axonal damage in the optic nerve manifests as retinal nerve fiber layer (RNFL deficits, which can be readily quantified with optical coherence tomography (OCT. The RNFL represents the most proximal region of the afferent visual pathway; and, as such, is a unique region of the central nervous system (CNS because it lacks myelin. Changes in retinal integrity can be correlated with reliable and quantifiable visual outcomes to provide a structural-functional paradigm of CNS injury. Because the eye provides a unique “view” into the effects of CNS inflammation, the ON “system model” may provide greater understanding about disease mechanisms, which underpin disability in MS. This review addresses the applications of OCT in study of ON patients, with specific reference to the published reports to date. The future role of OCT is discussed, both in terms of the potential gains and certain challenges associated with this evolving technology.

  6. Optical Biopsy Using Tissue Spectroscopy and Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Norman S Nishioka

    2003-01-01

    Full Text Available ‘Optical biopsy’ or ‘optical diagnostics’ is a technique whereby light energy is used to obtain information about the structure and function of tissues without disrupting them. In fluorescence spectroscopy, light energy (usually provided by a laser is used to excite tissues and the resulting fluorescence provides information about the target tissue. Its major gastrointestinal application has been in the evaluation of colonic polyps, in which it can reliably distinguish malignant from benign lesions. Optical coherence tomography (OCT has been used in the investigation of Barrett’s epithelium (and dysplasia, although a variety of other applications are feasible. For example, OCT could assist in the identification and staging of mucosal and submucosal neoplasms, the grading of inflammation in the stomach and intestine, the diagnosis of biliary tumours and the assessment of villous architecture. OCT differs from endoscopic ultrasound, a complementary modality, in that it has a much higher resolution but lesser depth of penetration. The images correlate with the histopathological appearance of tissues, and the addition of Doppler methods may enable it to evaluate the vascularity of tumours and the amount of blood flow in varices. Refinements in these new optical techniques will likely make them valuable in clinical practice, although their specific roles have yet to be determined.

  7. Experimental demonstration of coherent feedback control on optical field squeezing

    CERN Document Server

    Iida, Sanae; Yonezawa, Hidehiro; Yamamoto, Naoki; Furusawa, Akira

    2011-01-01

    Coherent feedback is a non-measurement based, hence a back-action free, method of control for quantum systems. A typical application of this control scheme is squeezing enhancement, a purely non-classical effect in quantum optics. In this paper we report its first experimental demonstration that well agrees with the theory taking into account time delays and losses in the coherent feedback loop. The results clarify both the benefit and the limitation of coherent feedback control in a practical situation.

  8. Nonlinear optics with coherent free electron lasers

    Science.gov (United States)

    Bencivenga, F.; Capotondi, F.; Mincigrucci, R.; Cucini, R.; Manfredda, M.; Pedersoli, E.; Principi, E.; Simoncig, A.; Masciovecchio, C.

    2016-12-01

    We interpreted the recent construction of free electron laser (FELs) facilities worldwide as an unprecedented opportunity to bring concepts and methods from the scientific community working with optical lasers into the domain of x-ray science. This motivated our efforts towards the realization of FEL-based wave-mixing applications. In this article we present new extreme ultraviolet transient grating (X-TG) data from vitreous SiO2, collected using two crossed FEL pulses (photon frequency 38 eV) to generate the X-TG and a phase matched optical probing pulse (photon frequency 3.1 eV). This experiment extends our previous investigation, which was carried out on a nominally identical sample using a different FEL photon frequency (45 eV) to excite the X-TG. The present data are featured by a peak intensity of the X-TG signal substantially larger than that previously reported and by slower modulations of the X-TG signal at positive delays. These differences could be ascribed to the different FEL photon energy used in the two experiments or to differences in the sample properties. A systematic X-TG study on the same sample as a function of the FEL wavelength is needed to draw a consistent conclusion. We also discuss how the advances in the performance of the FELs, in terms of generation of fully coherent photon pulses and multi-color FEL emission, may push the development of original experimental strategies to study matter at the femtosecond-nanometer time-length scales, with the unique option of element and chemical state specificity. This would allow the development of advanced experimental tools based on wave-mixing processes, which may have a tremendous impact in the study of a large array of phenomena, ranging from nano-dynamics in complex materials to charge and energy transfer processes.

  9. Complete denture analyzed by optical coherence tomography

    Science.gov (United States)

    Negrutiu, Meda L.; Sinescu, Cosmin; Todea, Carmen; Podoleanu, Adrian G.

    2008-02-01

    The complete dentures are currently made using different technologies. In order to avoid deficiencies of the prostheses made using the classical technique, several alternative systems and procedures were imagined, directly related to the material used and also to the manufacturing technology. Thus, at the present time, there are several injecting systems and technologies on the market, that use chemoplastic materials, which are heat cured (90-100°C), in dry or wet environment, or cold cured (below 60°C). There are also technologies that plasticize a hard cured material by thermoplastic processing (without any chemical changes) and then inject it into a mold. The purpose of this study was to analyze the existence of possible defects in several dental prostheses using a non invasive method, before their insertion in the mouth. Different dental prostheses, fabricated from various materials were investigated using en-face optical coherence tomography. In order to discover the defects, the scanning was made in three planes, obtaining images at different depths, from 0,01 μm to 2 mm. In several of the investigated prostheses we found defects which may cause their fracture. These defects are totally included in the prostheses material and can not be vizualised with other imagistic methods. In conclusion, en-face OCT is an important investigative tool for the dental practice.

  10. International Conference on Coherence and Quantum Optics

    CERN Document Server

    RECENT DEVELOPMENTS IN QUANTUM OPTICS

    1993-01-01

    This volume is composed of papers (invited and contributed) presented at the International Conference on Coherence and Quantum Optics held at the University of Hyderabad January 5-January 10, 1991. It has been organized by Professor Girish Agarwal and his colleagues at the School of Physics, University of Hyderabad, Hyder­ abad, India under partial support from the Department of Science and Technology, Government of India, International Center for Theoretical Physics, Trieste, Italy and the National Science Foundation, USA. Without the untiring efforts of Prof. Girish Agarwal and the members of his quantum office group, the Conference and the present volume would not have been possible. Some extraordinary circumstances resulted in a delay of the publication of the present volume. Our sincere apologies to all the authors. We deeply regret the inconvenience caused due to the delay. A debt of gratitude is due to Ms. Kim Bella for the excellent typing job of the different versions and the final version of the ma...

  11. Anatomic Optical Coherence Tomography of Upper Airways

    Science.gov (United States)

    Chin Loy, Anthony; Jing, Joseph; Zhang, Jun; Wang, Yong; Elghobashi, Said; Chen, Zhongping; Wong, Brian J. F.

    The upper airway is a complex and intricate system responsible for respiration, phonation, and deglutition. Obstruction of the upper airways afflicts an estimated 12-18 million Americans. Pharyngeal size and shape are important factors in the pathogenesis of airway obstructions. In addition, nocturnal loss in pharyngeal muscular tone combined with high pharyngeal resistance can lead to collapse of the airway and periodic partial or complete upper airway obstruction. Anatomical optical coherence tomography (OCT) has the potential to provide high-speed three-dimensional tomographic images of the airway lumen without the use of ionizing radiation. In this chapter we describe the methods behind endoscopic OCT imaging and processing to generate full three dimensional anatomical models of the human airway which can be used in conjunction with numerical simulation methods to assess areas of airway obstruction. Combining this structural information with flow dynamic simulations, we can better estimate the site and causes of airway obstruction and better select and design surgery for patients with obstructive sleep apnea.

  12. Ultrahigh-resolution endoscopic optical coherence tomography

    Science.gov (United States)

    Chen, Yu; Herz, Paul R.; Hsiung, Pei-Lin; Aguirre, Aaron D.; Mashimo, Hiroshi; Desai, Saleem; Pedrosa, Macos; Koski, Amanda; Schmitt, Joseph M.; Fujimoto, James G.

    2005-01-01

    Early detection of gastrointestinal cancer is essential for the patient treatment and medical care. Endoscopically guided biopsy is currently the gold standard for the diagnosis of early esophageal cancer, but can suffer from high false negative rates due to sampling errors. Optical coherence tomography (OCT) is an emerging medical imaging technology which can generate high resolution, cross-sectional images of tissue in situ and in real time, without the removal of tissue specimen. Although endoscopic OCT has been used successfully to identify certain pathologies in the gastrointestinal tract, the resolution of current endoscopic OCT systems has been limited to 10 - 15 m for clinical procedures. In this study, in vivo imaging of the gastrointestinal tract is demonstrated at a three-fold higher resolution (gastro-esophageal junction and colon on animal model display tissue microstructures and architectural details at high resolution, and the features observed in the OCT images are well-matched with histology. The clinical feasibility study is conducted through delivering OCT imaging catheter using standard endoscope. OCT images of normal esophagus, Barrett's esophagus, and esophageal cancers are demonstrated with distinct features. The ability of high resolution endoscopic OCT to image tissue morphology at an unprecedented resolution in vivo would facilitate the development of OCT as a potential imaging modality for early detection of neoplastic changes.

  13. Anterior Eye Imaging with Optical Coherence Tomography

    Science.gov (United States)

    Huang, David; Li, Yan; Tang, Maolong

    The development of corneal and anterior segment optical coherence tomography (OCT) technology has advanced rapidly in recently years. The scan geometry and imaging wavelength are both important choices to make in designing anterior segment OCT systems. Rectangular scan geometry offers the least image distortion and is now used in most anterior OCT systems. The wavelength of OCT light source affects resolution and penetration. An optimal choice of the OCT imaging wavelength (840, 1,050, or 1,310 nm) depends on the application of interest. Newer generation Fourier-domain OCT technology can provide scan speed 100-1000 times faster than the time-domain technology. Various commercial anterior OCT systems are available on the market. A wide spectrum of diagnostic and surgical applications using anterior segment OCT had been investigated, including mapping of corneal and epithelial thicknesses, keratoconus screening, measuring corneal refractive power, corneal surgery planning and evaluation in LASIK, intracorneal ring implantation, assessment of angle closure glaucoma, anterior chamber biometry and intraocular lens implants, intraocular lens power calculation, and eye bank donor cornea screening.

  14. Photodynamic therapy monitoring with optical coherence angiography

    Science.gov (United States)

    Sirotkina, M. A.; Matveev, L. A.; Shirmanova, M. V.; Zaitsev, V. Y.; Buyanova, N. L.; Elagin, V. V.; Gelikonov, G. V.; Kuznetsov, S. S.; Kiseleva, E. B.; Moiseev, A. A.; Gamayunov, S. V.; Zagaynova, E. V.; Feldchtein, F. I.; Vitkin, A.; Gladkova, N. D.

    2017-01-01

    Photodynamic therapy (PDT) is a promising modern approach for cancer therapy with low normal tissue toxicity. This study was focused on a vascular-targeting Chlorine E6 mediated PDT. A new angiographic imaging approach known as M-mode-like optical coherence angiography (MML-OCA) was able to sensitively detect PDT-induced microvascular alterations in the mouse ear tumour model CT26. Histological analysis showed that the main mechanisms of vascular PDT was thrombosis of blood vessels and hemorrhage, which agrees with angiographic imaging by MML-OCA. Relationship between MML-OCA-detected early microvascular damage post PDT (within 24 hours) and tumour regression/regrowth was confirmed by histology. The advantages of MML-OCA such as direct image acquisition, fast processing, robust and affordable system opto-electronics, and label-free high contrast 3D visualization of the microvasculature suggest attractive possibilities of this method in practical clinical monitoring of cancer therapies with microvascular involvement. PMID:28148963

  15. Polarization sensitive optical coherence tomography detection method

    Energy Technology Data Exchange (ETDEWEB)

    Everett, M J; Sathyam, U S; Colston, B W; DaSilva, L B; Fried, D; Ragadio, J N; Featherstone, J D B

    1999-05-12

    This study demonstrates the potential of polarization sensitive optical coherence tomography (PS-OCT) for non-invasive in vivo detection and characterization of early, incipient caries lesions. PS-OCT generates cross-sectional images of biological tissue while measuring the effect of the tissue on the polarization state of incident light. Clear discrimination between regions of normal and demineralized enamel is first shown in PS-OCT images of bovine enamel blocks containing well-characterized artificial lesions. High-resolution, cross-sectional images of extracted human teeth are then generated that clearly discriminate between the normal and carious regions on both the smooth and occlusal surfaces. Regions of the teeth that appeared to be demineralized in the PS-OCT images were verified using histological thin sections examined under polarized light microscopy. The PS-OCT system discriminates between normal and carious regions by measuring the polarization state of the back-scattered 1310 nm light, which is affected by the state of demineralization of the enamel. Demineralization of enamel increases the scattereing coefficient, thus depolarizing the incident light. This study shows that PS-OCT has great potential for the detection, characterization, and monitoring of incipient caries lesions.

  16. Spatial coherence at the output of multimode optical fibers.

    Science.gov (United States)

    Efimov, Anatoly

    2014-06-30

    The modulus of the complex degree of coherence is directly measured at the output of a step-index multimode optical fiber using lateral-sheering, delay-dithering Mach-Zehnder interferometer. Pumping the multimode fiber with monochromatic light always results in spatially-coherent output, whereas for the broadband pumping the modal dispersion of the fiber leads to a partially coherent output. While the coherence radius is a function of the numerical aperture only, the residual coherence outside the main peak is an interesting function of two dimensionless parameters: the number of non-degenerate modes and the ratio of the modal dispersion to the coherence time of the source. We develop a simple model describing this residual coherence and verify its predictions experimentally.

  17. Diagnosis and Follow-Up of Nonexudative Choroidal Neovascularization With Multiple Optical Coherence Tomography Angiography Devices: A Case Report

    Science.gov (United States)

    Lane, Mark; Ferrara, Daniela; Louzada, Ricardo Noguera; Fujimoto, James G.; Seddon, Johanna M.

    2017-01-01

    Nonexudative choroidal neovascularization (CNV) is a new phenomenon that has only recently been described in the literature with the advent of optical coherence tomography angiography (OCTA) imaging. The authors present a 1-year longitudinal follow-up of a nonexudative CNV lesion secondary to age-related macular degeneration. This report describes the appearance of the lesion on two commercially available spectral-domain OCTA devices and one prototype swept-source OCTA device. Management of these cases is still debatable. Watchful waiting with regular follow-up using serial OCTA to monitor disease progression has been valuable in this case. PMID:27548457

  18. Optical coherent and envelope detection for photonic wireless communication links

    DEFF Research Database (Denmark)

    Prince, Kamau; Zibar, Darko; Yu, Xianbin;

    We present two novel optical detection techniques for radio over fiber (RoF) communication links. Firstly, we present recent results obtained with optical digital coherent detection of optical phase-modulated ROF signals supporting error-free transmission over 25 km standard SMF with BPSK and QPSK...

  19. Physical-layer network coding in coherent optical OFDM systems.

    Science.gov (United States)

    Guan, Xun; Chan, Chun-Kit

    2015-04-20

    We present the first experimental demonstration and characterization of the application of optical physical-layer network coding in coherent optical OFDM systems. It combines two optical OFDM frames to share the same link so as to enhance system throughput, while individual OFDM frames can be recovered with digital signal processing at the destined node.

  20. Clinical and tomographic aspects of macular microholes; Aspectos clinicos e tomograficos dos microburacos maculares

    Energy Technology Data Exchange (ETDEWEB)

    Novelli, Fernando Jose de [Hospital de Olhos Sadalla Amin Ghanem, Joinville, SC (Brazil)], e-mail: Fernando.novelli@gmail.com; Maia Junior, Otacilio de Oliveira [Fundacao Monte Tabor, Salvador, BA (Brazil). Hospital Sao Rafael; Nobrega, Mario Junqueira [Universidade da Regiao de Joinville (UNIVILLE), Joinville, SC (Brazil); Garrido Neto, Theodomiro [Universidade do Estado do Amazonas (UEA), Manaus, AM (Brazil); Takahashi, Walter Yukihiko [Universidade de Sao Paulo (USP), SP (Brazil). Hospital das Clinicas. Dept. de Oftalmologia

    2009-07-01

    Purpose: To describe the clinical aspects and evaluate optical coherence tomography of macular microholes. Methods: Seven patients were assessed (8 eyes) with microholes of the macula. All patients underwent complete eye examination, fundus photography, fluorescent angiography and OCT-3 imaging. Results: Ages ranged from 26 to 69 years. Six patients were female (85.7%) and five of them had microhole in the right eye. The presenting symptom was decrease in visual acuity (71.3%) and central scotoma in (14.3%). Five eyes (71.4%) had no defects shown by fluorescent angiography. A defect in the outer retina was demonstrated in all eyes on optical coherence tomography. The lesions were nonprogressive. Conclusion: Macular microholes are small lamellar defects in the outer retina. The condition is nonprogressive, generally unilateral and compatible with good visual acuity. Fundus biomicroscopy associated with an optical coherence tomography are the main elements in the diagnosis and study of this pathology. (author)

  1. Optical coherence tomography and Doppler optical coherence tomography in the gastrointestinal tract

    Institute of Scientific and Technical Information of China (English)

    Eugen Osiac; Adrian S(a)ftoiu; Dan Ionut Gheonea; Ion Mandrila; Radu Angelescu

    2011-01-01

    Optical coherence tomography(OCT)is a noninvasive,high-resolution,high-potential imaging method that has recently been introduced into medical investigations.A growing number of studies have used this technique in the field of gastroenterology in order to assist classical analyses.Lately,3D-imaging and Doppler capabilities have been developed in different configurations,which make this type of investigation more attractive.This paper reviews the principles and characteristics of OCT and Doppler-OCT in connection with analyses of the detection of normal and pathological structures,and with the possibility to investigate angiogenesis in the gastrointestinal tract.

  2. A Focal Chorioretinal Bartonella Lesion Analyzed by Optical Coherence Tomography Angiography.

    Science.gov (United States)

    Pichi, Francesco; Srivastava, Sunil K; Levinson, Ashleigh; Baynes, Kimberly M; Traut, Caitlyn; Lowder, Careen Y

    2016-06-01

    Neovascularization may be associated with cat-scratch neuroretinitis in the absence of retinal vascular occlusion. Bartonella organisms establish an intimate relationship with the vascular endothelium, causing angioproliferative lesions, which might represent a dedicated pathogenic strategy for expanding the bacterial host cell habitat. In the eye, pathological angiogenesis caused by Bartonella has been described as peripapillary or macular choroidal neovascularization, but the presence of neovascularization within foci of chorioretinitis has never before been reported. The authors present a case of Bartonella chorioretinitis in which optical coherence tomography angiography, by detecting erythrocyte motion, was able to identify neovessels inside the infectious focus. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:585-588.]. Copyright 2016, SLACK Incorporated.

  3. Optical coherence tomography in a patient with chloroquine-induced maculopathy

    Directory of Open Access Journals (Sweden)

    Korah Sanita

    2008-01-01

    Full Text Available We herein report the optical coherence tomography (OCT findings in a case of chloroquine-induced macular toxicity, which to our knowledge, has so far not been reported. A 53-year-old lady on chloroquine for treatment of rheumatoid arthritis developed decrease in vision 36 months after initiation of the treatment. Clinical examination revealed evidence of retinal pigment epithelial (RPE disturbances. Humphrey field analyzer (HFA, fundus fluorescein angiography (FFA and OCT for retinal thickness and volume measurements at the parafoveal region were done. The HFA revealed bilateral superior paracentral scotomas, FFA demonstrated RPE loss and OCT revealed anatomical evidence of loss of ganglion cell layers, causing marked thinning of the macula and parafoveal region. Parafoveal retinal thickness and volume measurements may be early evidence of chloroquine toxicity, and OCT measurements as a part of chloroquine toxicity screening may be useful in early detection of chloroquine maculopathy.

  4. In vivo sectional imaging of the retinal periphery using conventional optical coherence tomography systems

    Directory of Open Access Journals (Sweden)

    Abhishek Kothari

    2012-01-01

    Full Text Available Optical coherence tomography (OCT has transformed macular disease practices. This report describes the use of conventional OCT systems for peripheral retinal imaging. Thirty-six eyes with peripheral retinal pathology underwent imaging with conventional OCT systems. In vivo sectional imaging of lattice degeneration, snail-track degeneration, and paving-stone degeneration was performed. Differences were noted between phenotypes of lattice degeneration. Several findings previously unreported in histopathology studies were encountered. Certain anatomic features were seen that could conceivably explain clinical and intraoperative behavior of peripheral lesions. Peripheral OCT imaging helped elucidate clinically ambiguous situations such as retinal breaks, subclinical retinal detachment, retinoschisis, choroidal nevus, and metastasis. Limitations of such scanning included end-gaze nystagmus and far peripheral lesions. This first of its kind study demonstrates the feasibility of peripheral retinal OCT imaging and expands the spectrum of indications for which OCT scanning may be clinically useful.

  5. Quantitative assessment of the retinal microvasculature using optical coherence tomography angiography

    Science.gov (United States)

    Chu, Zhongdi; Lin, Jason; Gao, Chen; Xin, Chen; Zhang, Qinqin; Chen, Chieh-Li; Roisman, Luis; Gregori, Giovanni; Rosenfeld, Philip J.; Wang, Ruikang K.

    2016-06-01

    Optical coherence tomography angiography (OCTA) is clinically useful for the qualitative assessment of the macular microvasculature. However, there is a need for comprehensive quantitative tools to help objectively analyze the OCT angiograms. Few studies have reported the use of a single quantitative index to describe vessel density in OCT angiograms. In this study, we introduce a five-index quantitative analysis of OCT angiograms in an attempt to detect and assess vascular abnormalities from multiple perspectives. The indices include vessel area density, vessel skeleton density, vessel diameter index, vessel perimeter index, and vessel complexity index. We show the usefulness of the proposed indices with five illustrative cases. Repeatability is tested on both a healthy case and a stable diseased case, giving interclass coefficients smaller than 0.031. The results demonstrate that our proposed quantitative analysis may be useful as a complement to conventional OCTA for the diagnosis of disease and monitoring of treatment.

  6. Optical Coherence Tomography Angiography for Detecting Choroidal Neovascularization Secondary to Choroidal Osteoma.

    Science.gov (United States)

    Szelog, Jason T; Bonini Filho, Marco A; Lally, David R; de Carlo, Talisa E; Duker, Jay S

    2016-01-01

    Choroidal osteoma is an ossifying tumor that is found predominantly in the peripapillary and macular areas. It typically affects otherwise healthy females. Vision loss may occur secondary to the development of choroidal neovascularization (CNV). Fluorescein angiography (FA) remains the gold standard for diagnosing CNV; however, the use of optical coherence tomography angiography (OCTA) as an adjunct to FA is growing. In this report, a 16-year-old female with a large, unilateral peripapillary choroidal osteoma presented with blurred vision. Exam revealed scattered intraretinal hemorrhage, but FA was unable to detect CNV overlying the tumor. OCTA detected abnormal flow in the outer retina corresponding to a type 2 CNV. Following intravitreal anti-vascular endothelial growth factor therapy, the CNV regressed, the hemorrhage resolved, and there was less fluid. OCTA may be helpful in detecting CNV noninvasively in eyes in which FA is equivocal, such as those with choroidal osteoma.

  7. Geometric deformable model driven by CoCRFs: application to optical coherence tomography.

    Science.gov (United States)

    Tsechpenakis, Gabriel; Lujan, Brandon; Martinez, Oscar; Gregori, Giovanni; Rosenfeld, Philip J

    2008-01-01

    We present a geometric deformable model driven by dynamically updated probability fields. The shape is defined with the signed distance function, and the internal (smoothness) energy consists of a C1 continuity constraint, a shape prior, and a term that forces the zero-level of the shape distance function towards a connected form. The image probability fields are estimated by our collaborative Conditional Random Field (CoCRF), which is updated during the evolution in an active learning manner: it infers class posteriors in pixels or regions with feature ambiguities by assessing the joint appearance of neighboring sites and using the classification confidence. We apply our method to Optical Coherence Tomography fundus images for the segmentation of geographic atrophies in dry age-related macular degeneration of the human eye.

  8. Three-Dimensional Optical Coherence Tomography (3D OCT) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Applied Science Innovations, Inc. proposes to develop a new tool of 3D optical coherence tomography (OCT) for cellular level imaging at video frame rates and...

  9. Three-Dimensional Optical Coherence Tomography (3D OCT) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Applied Science Innovations, Inc. proposes a new tool of 3D optical coherence tomography (OCT) for cellular level imaging at video frame rates and dramatically...

  10. Depth profilometry via multiplexed optical high-coherence interferometry

    National Research Council Canada - National Science Library

    Kazemzadeh, Farnoud; Wong, Alexander; Behr, Bradford B; Hajian, Arsen R

    2015-01-01

    ... such as defect detection, corrosion assessment, and dental assessment to name a few. In this study, we investigate the feasibility of depth profilometry using an Multiplexed Optical High-coherence Interferometry MOHI instrument...

  11. Acetazolamide for cystoid macular oedema in Bietti crystalline retinal dystrophy.

    Science.gov (United States)

    Broadhead, Geoffrey K; Chang, Andrew A

    2014-04-01

    Bietti crystalline retinal dystrophy is a rare, inherited disorder whose hallmark is the presence of retinal crystal deposits associated with later chorioretinal degeneration. This condition may rarely be complicated by the development of cystoid macular oedema leading to rapid visual decline. Currently, treatment options for this complication of Bietti dystrophy are limited and the visual prognosis is poor. Here, we present a case of cystoid macular oedema associated with Bietti dystrophy that was successfully diagnosed using multimodal imaging techniques including optical coherence tomography and fluorescein angiography. These modalities confirmed the diagnosis of macular oedema and excluded other possible causes of oedema such as choroidal neovascularisation. In this patient, cystoid macular oedema was resolved with oral acetazolamide therapy, a treatment that has not been previously reported in this context. Acetazolamide treatment resulted in oedema resolution and improvement in visual function, and can be considered a therapeutic option for other patients with Bietti dystrophy who develop cystoid macular oedema.

  12. Fiber-diffraction Interferometer using Coherent Fiber Optic Taper

    CERN Document Server

    Kihm, Hagyong

    2010-01-01

    We present a fiber-diffraction interferometer using a coherent fiber optic taper for optical testing in an uncontrolled environment. We use a coherent fiber optic taper and a single-mode fiber having thermally-expanded core. Part of the measurement wave coming from a test target is condensed through a fiber optic taper and spatially filtered from a single-mode fiber to be reference wave. Vibration of the cavity between the target and the interferometer probe is common to both reference and measurement waves, thus the interference fringe is stabilized in an optical way. Generation of the reference wave is stable even with the target movement. Focus shift of the input measurement wave is desensitized by a coherent fiber optic taper.

  13. Visible light optical coherence tomography measure retinal oxygen metabolic response to systemic oxygenation (Conference Presentation)

    Science.gov (United States)

    Yi, Ji; Liu, Wenzhong; Chen, Siyu; Backman, Vadim; Sheibani, Nader; Sorenson, Christine M.; Fawzi, Amani A.; Linsenmeier, Robert A.; Zhang, Hao F.

    2016-03-01

    The lack of capability to quantify oxygen metabolism noninvasively impedes both fundamental investigation and clinical diagnosis of a wide spectrum of diseases including all the major blinding diseases such as age-related macular degeneration, diabetic retinopathy, and glaucoma. Using visible light optical coherence tomography (vis-OCT), we demonstrated accurate and robust measurement of retinal oxygen metabolic rate (rMRO2) noninvasively in rat eyes. The rMRO2 was calculated by concurrent measurement of blood flow and blood oxygen saturation (sO2). Blood flow was calculated by the principle of Doppler optical coherence tomography, where the phase shift between two closely spaced A-lines measures the axial velocity. The distinct optical absorption spectra of oxy- and deoxy-hemoglobin provided the contrast for sO2 measurement, combined with the spectroscopic analysis of vis-OCT signal within the blood vessels. We continuously monitored the regulatory response of oxygen consumption to a progressive hypoxic challenge. We found that both oxygen delivery, and rMRO2 increased from the highly regulated retinal circulation (RC) under hypoxia, by 0.28+/-0.08 μL/min (pcompensated for the deficient oxygen supply from the poorly regulated choroidal circulation (CC).

  14. Volumetric optical coherence microscopy enabled by aberrated optics (Conference Presentation)

    Science.gov (United States)

    Mulligan, Jeffrey A.; Liu, Siyang; Adie, Steven G.

    2017-02-01

    Optical coherence microscopy (OCM) is an interferometric imaging technique that enables high resolution, non-invasive imaging of 3D cell cultures and biological tissues. Volumetric imaging with OCM suffers a trade-off between high transverse resolution and poor depth-of-field resulting from defocus, optical aberrations, and reduced signal collection away from the focal plane. While defocus and aberrations can be compensated with computational methods such as interferometric synthetic aperture microscopy (ISAM) or computational adaptive optics (CAO), reduced signal collection must be physically addressed through optical hardware. Axial scanning of the focus is one approach, but comes at the cost of longer acquisition times, larger datasets, and greater image reconstruction times. Given the capabilities of CAO to compensate for general phase aberrations, we present an alternative method to address the signal collection problem without axial scanning by using intentionally aberrated optical hardware. We demonstrate the use of an astigmatic spectral domain (SD-)OCM imaging system to enable single-acquisition volumetric OCM in 3D cell culture over an extended depth range, compared to a non-aberrated SD-OCM system. The transverse resolution of the non-aberrated and astigmatic imaging systems after application of CAO were 2 um and 2.2 um, respectively. The depth-range of effective signal collection about the nominal focal plane was increased from 100 um in the non-aberrated system to over 300 um in the astigmatic system, extending the range over which useful data may be acquired in a single OCM dataset. We anticipate that this method will enable high-throughput cellular-resolution imaging of dynamic biological systems over extended volumes.

  15. Adaptive optics optical coherence tomography at 1 MHz.

    Science.gov (United States)

    Kocaoglu, Omer P; Turner, Timothy L; Liu, Zhuolin; Miller, Donald T

    2014-12-01

    Image acquisition speed of optical coherence tomography (OCT) remains a fundamental barrier that limits its scientific and clinical utility. Here we demonstrate a novel multi-camera adaptive optics (AO-)OCT system for ophthalmologic use that operates at 1 million A-lines/s at a wavelength of 790 nm with 5.3 μm axial resolution in retinal tissue. Central to the spectral-domain design is a novel detection channel based on four high-speed spectrometers that receive light sequentially from a 1 × 4 optical switch assembly. Absence of moving parts enables ultra-fast (50ns) and precise switching with low insertion loss (-0.18 dB per channel). This manner of control makes use of all available light in the detection channel and avoids camera dead-time, both critical for imaging at high speeds. Additional benefit in signal-to-noise accrues from the larger numerical aperture afforded by the use of AO and yields retinal images of comparable dynamic range to that of clinical OCT. We validated system performance by a series of experiments that included imaging in both model and human eyes. We demonstrated the performance of our MHz AO-OCT system to capture detailed images of individual retinal nerve fiber bundles and cone photoreceptors. This is the fastest ophthalmic OCT system we know of in the 700 to 915 nm spectral band.

  16. Machine learning concepts in coherent optical communication systems

    DEFF Research Database (Denmark)

    Zibar, Darko; Schäffer, Christian G.

    2014-01-01

    Powerful statistical signal processing methods, used by the machine learning community, are addressed and linked to current problems in coherent optical communication. Bayesian filtering methods are presented and applied for nonlinear dynamic state tracking. © 2014 OSA.......Powerful statistical signal processing methods, used by the machine learning community, are addressed and linked to current problems in coherent optical communication. Bayesian filtering methods are presented and applied for nonlinear dynamic state tracking. © 2014 OSA....

  17. Experimental Demonstration of Spectral Intensity Optical Coherence Tomography

    CERN Document Server

    Ryczkowski, Piotr; Friberg, Ari T; Genty, Goëry

    2015-01-01

    We demonstrate experimentally quantum-inspired, spectral-domain intensity optical coherence tomography. We show that the technique allows for both axial resolution improvement and dispersion cancellation compared to conventional optical coherence tomography. The method does not involve scanning and it works with classical light sources and standard photodetectors. The measurements are in excellent agreement with the theoretical predictions. We also propose an approach that enables the elimination of potential artifacts arising from multiple interfaces.

  18. Machine learning concepts in coherent optical communication systems

    DEFF Research Database (Denmark)

    Zibar, Darko; Schäffer, Christian G.

    2014-01-01

    Powerful statistical signal processing methods, used by the machine learning community, are addressed and linked to current problems in coherent optical communication. Bayesian filtering methods are presented and applied for nonlinear dynamic state tracking. © 2014 OSA.......Powerful statistical signal processing methods, used by the machine learning community, are addressed and linked to current problems in coherent optical communication. Bayesian filtering methods are presented and applied for nonlinear dynamic state tracking. © 2014 OSA....

  19. Bandpass sampling in heterodyne receivers for coherent optical access networks.

    Science.gov (United States)

    Bakopoulos, Paraskevas; Dris, Stefanos; Schrenk, Bernhard; Lazarou, Ioannis; Avramopoulos, Hercules

    2012-12-31

    A novel digital receiver architecture for coherent heterodyne-detected optical signals is presented. It demonstrates the application of bandpass sampling in an optical communications context, to overcome the high sampling rate requirement of conventional receivers (more than twice the signal bandwidth). The concept is targeted for WDM coherent optical access networks, where applying heterodyne detection constitutes a promising approach to reducing optical hardware complexity. The validity of the concept is experimentally assessed in a 76 km WDM-PON scenario, where the developed DSP achieves a 50% ADC rate reduction with penalty-free operation.

  20. Optical Coherence Tomography and Optical Coherence Tomography Angiography in Monitoring Coats’ Disease

    Directory of Open Access Journals (Sweden)

    Wojciech Hautz

    2017-01-01

    Full Text Available Purpose. The aim of this study was to evaluate the usefulness of optical coherence tomography (OCT and optical coherence tomography angiography (OCTA in monitoring pediatric patients with Coats’ disease. Material and Methods. This retrospective study included 9 Caucasian patients receiving treatment for Coats’ disease at the Children’s Memorial Health Institute Ophthalmology Department between December 2014 and May 2016. The course of the disease was monitored with OCTA in combination with OCT and fluorescein angiography (FA. Results. OCT B-scans obtained in all patients correlated with FA findings. Reliable OCTA images were obtained in 8 patients. In one patient, numerous artifacts due to poor visual acuity and retinal detachment confounded the interpretation of findings. Conclusions. OCTA and OCT, in combination with FA, are useful in Coats’ disease diagnostics and treatment monitoring. As noninvasive methods, OCT and OCTA may be performed more often than FA, which enable precise monitoring of the disease and making decisions as to its further treatment.

  1. Imaging Granulomatous Lesions with Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Christina Banzhaf

    2012-01-01

    Full Text Available Aim: To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT images and compare this to previous studies of nonmelanoma skin tumors. Methods: Two patients with granulomas, tophi and granuloma annulare (GA, respectively, were photographed digitally, OCT-scanned and biopsied in the said order. Normal skin was OCT-scanned for comparison, but not biopsied. The OCT images from each lesion were compared with their histologic images as well as with OCT images with similar characteristics obtained from nonmelanoma skin tumors. Results: The OCT images of the tophi showed hyperreflective, rounded cloud-like structures in dermis, their upper part sharply delineated by a hyporeflective fringe. The deeper areas appeared blurred. The crystalline structures were delineated by a hyporeflective fringe. OCT images of GA showed two different structures in dermis: a hyporeflective rounded one, and one that was lobulated and wing-like. Conclusion: Granulomatous tissue surrounding urate deposits appeared as a clear hyporeflective fringe surrounding a light, hyperreflective area. The urate crystals appeared as hyperreflective areas, shielding the deeper part of dermis, meaning OCT could only visualize the upper part of the lesions. The lobulated, wing-like structure in GA may resemble diffuse GA or a dense lymphocytic infiltrate as seen on histology. The rounded structure in GA may represent an actual granuloma or either diffuse GA or a dense lymphocytic infiltrate as described above. This case suggests that OCT images granulomatous tissue as absorbent, hyporeflective areas, and urate crystals appear as reflective areas, obscuring the underlying tissue. In GA a new image shape looking like a wing has been found. The frequency, specificity and sensitivity of this new pattern in OCT imaging will require further studies.

  2. En-face optical coherence tomography revival

    Science.gov (United States)

    Bradu, Adrian; Kapinchev, Konstantin; Barnes, Frederick; Podoleanu, Adrian Gh.

    2016-03-01

    Quite recently, we introduced a novel Optical Coherence Tomography (OCT) method, termed as Master Slave OCT (MS-OCT), especially to deliver en-face images. MS-OCT operates like a time domain OCT, selecting signal from a selected depth only while scanning the laser beam across the sample. Time domain OCT allows real time production of an en-face image, although relatively slowly. As a major advance, the Master Slave method allows collection of signals from any number of depths, as required by the user. MS-OCT is an OCT method that does not require resampling of data and can be used to deliver en-face images from several depths simultaneously. However, as the MS-OCT method requires important computational resources, the number of multiple depth en-face images produced in real-time is limited. Here, we demonstrate that taking advantage of the parallel processing feature of the MS-OCT technology by harnessing the capabilities of graphics processing units (GPU)s, information from 384 depth positions is acquired in one raster with real time display of 40 en-face OCT images. These exhibit comparable resolution and sensitivity to the images produced using the traditional Fourier domain based method. The GPU facilitates versatile real time selection of parameters, such as the depth positions of the 40 images out of a set of 384 depth locations, as well as their axial resolution. Here, we present in parallel with the 40 en-face OCT images of a human tooth, a confocal microscopy lookalike image, together with two B-scan OCT images along rectangular directions.

  3. Carious growth monitoring with optical coherence tomography

    Science.gov (United States)

    Freitas, A. Z.; Zezell, D. M.; Mayer, M. P. A.; Ribeiro, A. C.; Gomes, A. S. L.; Vieira, N. D., Jr.

    2006-02-01

    Optical Coherence Tomography was used to monitor subsurface caries evolution process in vitro. Human tooth was used and bacteria were employed to induce caries lesions. Twenty-five human third molars, were used in this study. The teeth were cut longitudinally at mesio-distal direction; the surfaces were coated with nail varnish except for two squared windows (2x4 mm); at the cement-enamel junction. Artificial lesions were induced by a S. Mutans microbiological culture. The samples (N = 50) were divided into groups according to the demineralization time: 3, 5, 7, 9 and 11 days. The culture medium, was changed each 48 hours. After the demineralization process the samples were rinsed with double-deionized water and stored in a humid environment. The OCT system was implemented with average power of 96 μW in the sample arm, providing a 23 μm of axial resolution. The images were produced with lateral scans step of 10 μm. The detection system was composed by a detector, a demodulator and a computer. With the images generated by OCT it was possible to determine the lesion depth as function of sample exposition time to microbiological culture. We observed that the depth of the lesion in the root dentine increased from 70 μm to 230 μm, depending of exposure time, and follows the bacterial population growth law. This OCT system accurately depicts hard dental tissue and it was able to detect early caries in its structure, providing a powerful contactless high resolution image of lesions.

  4. Internal Defect Measurement of Scattering Media by Optical Coherence Microscopy

    Institute of Scientific and Technical Information of China (English)

    ZHU Yong-kai; ZHAO Hong; WANG Zhao; WANG Jun-li

    2005-01-01

    Optical coherence microscopy is applied to measure scattering media's internal defect, which based on low coherence interferometry and confocal microscopy. Optical coherence microscopy is more effective in the rejection of out of focus and multiple scattered photons originating further away of the focal plane. With the three-dimension scanning, the internal defect is detected by measuring the thickness of different points on the sample. The axial resolution is 6 μm and lateral resolution is 1.2 μm. This method is possessed of the advantages over the other measurement method of scattering media, such as non-destruction and highresolution.

  5. Accommodation-induced variations in retinal thickness measured by spectral domain optical coherence tomography

    Science.gov (United States)

    Fan, Shanhui; Sun, Yong; Dai, Cuixia; Zheng, Haihua; Ren, Qiushi; Jiao, Shuliang; Zhou, Chuanqing

    2014-09-01

    To research retinal stretching or distortion with accommodation, accommodation-induced changes in retinal thickness (RT) in the macular area were investigated in a population of young adults (n=23) by using a dual-channel spectral domain optical coherence tomography (SD-OCT) system manufactured in-house for this study. This dual-channel SD-OCT is capable of imaging the cornea and retina simultaneously with an imaging speed of 24 kHz A-line scan rate, which can provide the anatomical dimensions of the eye, including the RT and axial length. Thus, the modification of the RT with accommodation can be calculated. A significant decrease in the RT (13.50±1.25 μm) was observed during maximum accommodation. In the 4 mm×4 mm macular area centered at the fovea, we did not find a significant quadrant-dependent difference in retinal volume change, which indicates that neither retinal stretching nor distortion was quadrant-dependent during accommodation. We speculate that the changes in RT with maximum accommodation resulted from accommodation-induced ciliary muscle contractions.

  6. Unusual optical coherence tomography and fundus autofluorescence findings of eclipse retinopathy

    Directory of Open Access Journals (Sweden)

    Kun-Hsien Li

    2012-01-01

    Full Text Available A 63-year-old female patient complained of dimness in the central field of vision in the left eye after viewing an annular partial eclipse without adequate eye protection on 22 July 2009. Fundoscopy showed a wrinkled macular surface. Fundus autofluorescence study revealed well-demarcated hyperautofluorescence at the fovea. Optical coherence tomography demonstrated tiny intraretinal cysts. Fluorescein angiography and indocyanine green angiography were unremarkable. Epimacular membrane developed in the following month with deteriorated vision. Vitrectomy, epiretinal membrane and internal limiting membrane peeling were performed. Vision was restored to 20/20 after the operation. Direct sun-gazing may damage the retinal structures resulting in macular inflammation and increased focal metabolism, which explains the hyperautofluorescence. It may also induce epimacular membrane. Fundus autofluorescence might represent a useful technique to detect subtle solar-induced injuries of the retina. The visual prognosis is favorable but prevention remains the mainstay of treatment. Public health education is mandatory in reducing visual morbidity.

  7. The use of optical coherence tomography to aid in diagnosing solar maculopathy.

    Science.gov (United States)

    Suhr, Christopher L; Buffano, Roxanne M; Sellers, Angela

    2011-08-01

    Solar maculopathy is most commonly diagnosed after the direct viewing of solar eclipses. The damage to the retina is located in the outer segments of photoreceptors and in the retinal pigmentary epithelium. It may be acceptable to use optical coherence tomography (OCT) to identify retinal damage caused by the sun. Here we describe a case of a patient who reported with a mild decrease in best-corrected visual acuities. Dilated examination found macular changes that were present in both eyes resembling solar maculopathy. OCT was utilized to aid in the diagnosis of solar maculopathy. With the large number of individuals who spend their time in the sun, a practitioner should consider the possible repercussions of this activity. We are all aware of the damage that the sun can cause to the skin and, as in the case of cataracts, its effects on the eye. In cases in which macular changes are noted we should consider the possibility of solar maculopathy. As is in the case presented here, OCT may be an effective means of assessing the maculopathy. Published by Elsevier Inc.

  8. Optical forces on small particles from partially coherent light

    CERN Document Server

    Auñón, Juan Miguel

    2012-01-01

    We put forward a theory on the optical force exerted upon a dipolar particle by a stationary and ergodic partially coherent light ?eld. We show through a rigorous analysis that the ensemble averaged electromagnetic force is given in terms of a partial gradient of the space variable diagonal elements of the coherence tensor. Further, by following this result we characterize the conservative and non-conservative components of this force. In addition, we establish the propagation law for the optical force in terms of the coherence function of light at a di?raction plane. This permits us to evaluate the e?ect of the degree of coherence on the force components by using the archetypical con?guration of Young's two apertures di?raction pattern, so often employed to characterize coherence of waves.

  9. Applications of Doppler optical coherence tomography

    Science.gov (United States)

    Xu, Zhiqiang

    A major development in biomedical imaging in the last decade has been optical coherence tomography (OCT). This technique enables microscale resolution, depth resolved imaging of the detailed morphology of transparent and nontransparent biological tissue in a noncontact and quasi-noninvasive way. In the first part of this dissertation, we will describe the development and the performance of our home-made OCT systems working with different wavelength regions based on free-space and optical fiber Michelson interferometers. The second part will focus on Doppler OCT (DOCT), an important extension of OCT, which enables the simultaneous evaluation of the structural information and of the fluid flow distribution at a localized position beneath the sample surface. Much effort has been spent during the past few years in our laboratory aimed at providing more accurate velocity measurements with an extended dynamic range. We also applied our technique in different research areas such as microfluidics and hemodynamics. Investigations on the optical properties of the biological tissues (such as absorption and scattering) corresponding to different center wavelengths, have been performed in our laboratory. We used a 10 femtosecond Ti:sapphire laser centered at about 810 nm associated with a free-space Michelson interferometer. The infrared sources were centered at about 1310 and 1560 nm with all-fiber interferometers. Comparative studies using three different sources for several in vitro biological tissues based on a graphical method illustrated how the optical properties affect the quality of the OCT images in terms of the penetration depth and backscattering intensity. We have shown the advantage of working with 810-nm emission wavelength for good backscattering amplitude and contrast, while sources emitting at 1570 nm give good penetration depth. The 1330-nm sources provide a good compromise between the two. Therefore, the choice of the source will ultimately determine the

  10. A morphological study of retinal changes in unilateral amblyopia using optical coherence tomography image segmentation.

    Directory of Open Access Journals (Sweden)

    Andrea Szigeti

    Full Text Available OBJECTIVE: The purpose of this study was to evaluate the possible structural changes of the macula in patients with unilateral amblyopia using optical coherence tomography (OCT image segmentation. PATIENTS AND METHODS: 38 consecutive patients (16 male; mean age 32.4±17.6 years; range 6-67 years with unilateral amblyopia were involved in this study. OCT examinations were performed with a time-domain OCT device, and a custom-built OCT image analysis software (OCTRIMA was used for OCT image segmentation. The axial length (AL was measured by a LenStar LS 900 device. Macular layer thickness, AL and manifest spherical equivalent refraction (MRSE of the amblyopic eye were compared to that of the fellow eye. We studied if the type of amblyopia (strabismus without anisometropia, anisometropia without strabismus, strabismus with anisometropia had any influence on macular layer thickness values. RESULTS: There was significant difference between the amblyopic and fellow eyes in MRSE and AL in all subgroups. Comparing the amblyopic and fellow eyes, we found a statistically significant difference only in the thickness of the outer nuclear layer in the central region using linear mixed model analysis keeping AL and age under control (p = 0.032. There was no significant difference in interocular difference in the thickness of any macular layers between the subgroups with one-way between-groups ANCOVA while statistically controlling for interocular difference in AL and age. CONCLUSIONS: According to our results there are subtle changes in amblyopic eyes affecting the outer nuclear layer of the fovea suggesting the possible involvement of the photoreceptors. However, further studies are warranted to support this hypothesis.

  11. Digital Signal Processing for Optical Coherent Communication Systems

    DEFF Research Database (Denmark)

    Zhang, Xu

    In this thesis, digital signal processing (DSP) algorithms are studied to compensate for physical layer impairments in optical fiber coherent communication systems. The physical layer impairments investigated in this thesis include optical fiber chromatic dispersion, polarization demultiplexing......, light sources frequency and phase offset and phase noise. The studied DSP algorithms are considered as key building blocks in digital coherent receivers for the next generation of optical communication systems such as 112-Gb/s dual polarization (DP) quadrature phase shift keying (QPSK) optical...... spectrum narrowing tolerance 112-Gb/s DP-QPSK optical coherent systems using digital adaptive equalizer. The demonstrated results show that off-line DSP algorithms are able to reduce the bit error rate (BER) penalty induced by signal spectrum narrowing. Third, we also investigate bi...

  12. Macular edema in underserved diabetic patients: Improving detection by enhancing the optical signature and data analysis techniques

    Science.gov (United States)

    Alhamami, Mastour Abdullah

    Diabetic retinopathy and diabetic macular edema are chief causes of vision loss in working adults. Thus, retinal screening of patients with diabetes has become standard practice in some countries to prevent visual impairment and blindness from diabetic retinopathy. One goal is to improve techniques currently used to diagnose diabetic retinopathy. Another goal is to probe pathophysiological changes seen with imaging methods. Analysis was performed on a novel dataset from more than 2000 underserved adult diabetic patients, who were recruited for a screening study for diabetic eye disease. Data were collected from four county clinics at Alameda Health, Alameda County, CA. Over 90% of patients self-identified as a racial/ethnic identity other than non-Hispanic white. We investigated the prevalence and optical properties of macular edema. In the first study, a retrospective cohort study was performed to compare macular thickness in diabetic patients with and without macular edema to determine the presence of damage to the external limiting membrane or and the relation of damage to the ELM to damage to photoreceptors. In the second study, we investigated whether the information in red light better visualizes cysts in diabetic macular edema, as compared to green light. In the third study, we investigated whether the demographic and blood glucose information predict diabetic macular edema. Three logistic regression analyses were compared. In the fourth study, we examined how different outcome measures of retinal thickness vary with demographic and blood glucose measures, using a trichotomous variable for retinal thickness. The findings point strongly to large individual differences in the development of macular edema, which is difficult to diagnose with the most common methods in dark eyes. Further, while blood glucose was found to be important, there are additional differences in the potential for macular edema that are associated with ethnic group and gender.

  13. Classifying murine glomerulonephritis using optical coherence tomography and optical coherence elastography.

    Science.gov (United States)

    Liu, Chih-Hao; Du, Yong; Singh, Manmohan; Wu, Chen; Han, Zhaolong; Li, Jiasong; Chang, Anthony; Mohan, Chandra; Larin, Kirill V

    2016-08-01

    Acute glomerulonephritis caused by antiglomerular basement membrane marked by high mortality. The primary reason for this is delayed diagnosis via blood examination, urine analysis, tissue biopsy, or ultrasound and X-ray computed tomography imaging. Blood, urine, and tissue-based diagnoses can be time consuming, while ultrasound and CT imaging have relatively low spatial resolution, with reduced sensitivity. Optical coherence tomography is a noninvasive and high-resolution imaging technique that provides superior spatial resolution (micrometer scale) as compared to ultrasound and CT. Changes in tissue properties can be detected based on the optical metrics analyzed from the OCT signals, such as optical attenuation and speckle variance. Furthermore, OCT does not rely on ionizing radiation as with CT imaging. In addition to structural changes, the elasticity of the kidney can significantly change due to nephritis. In this work, OCT has been utilized to quantify the difference in tissue properties between healthy and nephritic murine kidneys. Although OCT imaging could identify the diseased tissue, its classification accuracy is clinically inadequate. By combining optical metrics with elasticity, the classification accuracy improves from 76% to 95%. These results show that OCT combined with OCE can be a powerful tool for identifying and classifying nephritis. Therefore, the OCT/OCE method could potentially be used as a minimally invasive tool for longitudinal studies during the progression and therapy of glomerulonephritis as well as complement and, perhaps, substitute highly invasive tissue biopsies. Elastic-wave propagation in mouse healthy and nephritic kidneys.

  14. Neuromyelitis optica and multiple sclerosis: Seeing differences through optical coherence tomography

    Science.gov (United States)

    Bennett, JL; de Seze, J; Lana-Peixoto, M; Palace, J; Waldman, A; Schippling, S; Tenembaum, S; Banwell, B; Greenberg, B; Levy, M; Fujihara, K; Chan, KH; Kim, HJ; Asgari, N; Sato, DK; Saiz, A; Wuerfel, J; Zimmermann, H; Green, A; Villoslada, P

    2015-01-01

    Neuromyelitis optica (NMO) is an inflammatory autoimmune disease of the central nervous system that preferentially targets the optic nerves and spinal cord. The clinical presentation may suggest multiple sclerosis (MS), but a highly specific serum autoantibody against the astrocytic water channel aquaporin-4 present in up to 80% of NMO patients enables distinction from MS. Optic neuritis may occur in either condition resulting in neuro-anatomical retinal changes. Optical coherence tomography (OCT) has become a useful tool for analyzing retinal damage both in MS and NMO. Numerous studies showed that optic neuritis in NMO typically results in more severe retinal nerve fiber layer (RNFL) and ganglion cell layer thinning and more frequent development of microcystic macular edema than in MS. Furthermore, while patients’ RNFL thinning also occurs in the absence of optic neuritis in MS, subclinical damage seems to be rare in NMO. Thus, OCT might be useful in differentiating NMO from MS and serve as an outcome parameter in clinical studies. PMID:25662342

  15. Optical Coherence Tomography Parameters in Morbidly Obese Patients Who Underwent Laparoscopic Sleeve Gastrectomy

    Directory of Open Access Journals (Sweden)

    Berna Dogan

    2016-01-01

    Full Text Available Purpose. To investigate changes in optical coherence tomography parameters in morbidly obese patients who had undergone laparoscopic sleeve gastrectomy (LSG. Methods. A total of 41 eyes of 41 morbidly obese patients (BMI ≥ 40 who had undergone LSG were included in study. The topographic optic disc parameters, central macular thickness (CMT, total macular volume (TMV, and retinal ganglion cell layer (RGCL were measured by spectral-domain optical coherence tomography (SD-OCT. Subfoveal choroidal thickness (SFCT was measured by enhanced deep imaging-optical coherence tomography (EDI-OCT. Results. The mean CMT was 237.4±24.5 μm, 239.3±24.1 μm, and 240.4±24.5 μm preoperatively, 3 months postoperatively, and 6 months postoperatively, respectively (p<0.01. The mean TMV was 9.88±0.52 mm3, 9.96±0.56 mm3, and 9.99±0.56 mm3 preoperatively, 3 months postoperatively, and 6 months postoperatively, respectively (p<0.01. The mean RGCL was 81.2±6.5 μm, 82.7±6.6 μm, and 82.9±6.5 μm preoperatively, 3 months postoperatively, and 6 months postoperatively, respectively (p<0.01. The mean SFCT was 309.8±71.8 μm, 331.0±81.4 μm, and 352.7±81.4 μm preoperatively, 3 months postoperatively, and 6 months postoperatively, respectively (p<0.01. No statistically significant differences were found between the preoperative values and 3- and 6-month postoperative values in rim area (p=0.34, disc area (p=0.64, vertical cup/disc ratio (p=0.39, cup volume (p=0.08, or retinal nerve fiber layer (p=0.90. Conclusions. Morbidly obese patients who undergo LSG experience a statistically significant increase in CMT, TMV, SFCT, and RGCL at 3 months and 6 months after surgery.

  16. High performance fiber-based optical coherent detection

    Science.gov (United States)

    Chen, Youming

    The sensitivity of signal detection is of major interest for optical high speed communication systems and LIght Detection And Ranging (lidar) systems. Sensitive receivers in fiber-optical networks can reduce transmitter power or amplifier amplification requirements and extend link spans. High receiver sensitivity allows links to be established over long distances in deep space satellite communication systems and large atmospheric attenuation to be overcome in terrestrial free space communications. For lidar systems, the sensitivity of signal detection determines how far and how accurately the lidar can detect the remote objects. Optical receivers employ either coherent or direct detection. In addition to amplitude, coherent detection extracts frequency and phase information from received signals, whereas direct detection extracts the received pulse amplitude only. In theory, coherent detection should yield the highest receiver sensitivity. Another possible technique to improve detection sensitivity is to employ a fiber preamplifier. This technique has been successfully demonstrated in direct detection systems but not in the coherent detection systems. Due to the existence of amplified spontaneous emission (ASE) inside the amplifier, the sensitivity of coherent detection varies with the data rate or pulse rate. For this reason, optically preamplified coherent detection is not used in applications as commonly as optically preamplified direct detection. We investigate the performance of coherent detection employing a fiber amplifier and time-domain-filter. The fiber amplifier is used as the optical preamplifier of the coherent detection system. To reduce the noise induced by the preamplifier to a maximum extent, we investigate the noise properties for both a single pass amplifier and a double pass amplifier. The relative intensity noise and linewidth broadening caused by ASE have been experimentally characterized. The results show that the double pass amplifier has

  17. Relationship Between Optic Nerve Appearance and Retinal Nerve Fiber Layer Thickness as Explored with Spectral Domain Optical Coherence Tomography

    Science.gov (United States)

    Aleman, Tomas S.; Huang, Jiayan; Garrity, Sean T.; Carter, Stuart B.; Aleman, Wendy D.; Ying, Gui-shuang; Tamhankar, Madhura A.

    2014-01-01

    Purpose To study the relationship between the appearance of the optic nerve and the retinal nerve fiber layer (RNFL) thickness determined by spectral domain optical coherence tomography (OCT). Methods Records from patients with spectral domain-OCT imaging in a neuro-ophthalmology practice were reviewed. Eyes with glaucoma/glaucoma suspicion, macular/optic nerve edema, pseudophakia, and with refractive errors > 6D were excluded. Optic nerve appearance by slit lamp biomicroscopy was related to the RNFL thickness by spectral domain-OCT and to visual field results. Results Ninety-one patients (176 eyes; mean age: 49 ± 15 years) were included. Eighty-three eyes (47%) showed optic nerve pallor; 89 eyes (50.6%) showed RNFL thinning (sectoral or average peripapillary). Average peripapillary RNFL thickness in eyes with pallor (mean ± SD = 76 ± 17 μm) was thinner compared to eyes without pallor (91 ± 14 μm, P < 0.001). Optic nerve pallor predicted RNFL thinning with a sensitivity of 69% and a specificity of 75%. Optic nerve appearance predicted RNFL thinning (with a sensitivity and specificity of 81%) when RNFL had thinned by ∼ 40%. Most patients with pallor had RNFL thinning with (66%) or without (25%) visual field loss; the remainder had normal RNFL and fields (5%) or with visual field abnormalities (4%). Conclusions Optic nerve pallor as a predictor of RNFL thinning showed fair sensitivity and specificity, although it is optimally sensitive/specific only when substantial RNFL loss has occurred. Translational Relevance Finding an acceptable relationship between the optic nerve appearance by ophthalmoscopy and spectral domain-OCT RNFL measures will help the clinician's interpretation of the information provided by this technology, which is gaining momentum in neuro-ophthalmic research. PMID:25374773

  18. Spectral-domain optical coherence tomography on a silicon chip

    NARCIS (Netherlands)

    Akca, Bakiye Imran

    2012-01-01

    Optical coherence tomography (OCT) is a non-invasive optical technique for high-resolution cross-sectional imaging of specimens, with many applications in clinical medicine and industry (e.g. materials testing, quality assurance, and process control). Current state-of-the-art OCT systems operate in

  19. Phase-coherent all-optical frequency division by three

    NARCIS (Netherlands)

    Lee, Dong-Hoon; Klein, M.E.; Meyn, Jan-Peter; Wallenstein, Richard; Gross, P.; Boller, Klaus J.

    2003-01-01

    The properties of all-optical phase-coherent frequency division by 3, based on a self-phase-locked continuous-wave (cw) optical parametric oscillator (OPO), are investigated theoretically and experimentally. The frequency to be divided is provided by a diode laser master-oscillator power-amplifier

  20. OPTICAL COHERENCE TOMOGRAPHY IN JUVENILE NEURONAL CEROID LIPOFUSCINOSIS

    DEFF Research Database (Denmark)

    Hansen, Michael S.; Hove, Marianne N; Jensen, Hanne;

    2016-01-01

    PURPOSE: To report optical coherence tomography findings obtained in two patients with juvenile neuronal ceroid lipofuscinosis. METHODS: Two case reports. RESULTS: Two 7-year-old girls presented with decreased visual acuity, clumsiness, night blindness, and behavioral problems. Optical coherence...... tomography showed an overall reduction in thickness of the central retina, as well as the outer and the inner retinal layers. The degenerative retinal changes were the same, despite different mutations in the CLN3 gene. CONCLUSION: In these rare cases of juvenile neuronal ceroid lipofuscinosis, optical...

  1. Amplifier Noise Based Optical Steganography with Coherent Detection

    Science.gov (United States)

    Wu, Ben; Chang, Matthew P.; Caldwell, Naomi R.; Caldwell, Myles E.; Prucnal, Paul R.

    2014-12-01

    We summarize the principle and experimental setup of optical steganography based on amplified spontaneous emission (ASE) noise. Using ASE noise as the signal carrier, optical steganography effectively hides a stealth channel in both the time domain and the frequency domain. Coherent detection is used at the receiver of the stealth channel. Because ASE noise has short coherence length and random phase, it only interferes with itself within a very short range. Coherent detection requires the stealth transmitter and stealth receiver to precisely match the optical delay,which generates a large key space for the stealth channel. Several methods to further improve optical steganography, signal to noise ratio, compatibility with the public channel, and applications of the stealth channel are also summarized in this review paper.

  2. Coherent control of optical polarization effects in metamaterials

    Science.gov (United States)

    Mousavi, Seyedmohammad A.; Plum, Eric; Shi, Jinhui; Zheludev, Nikolay I.

    2015-01-01

    Processing of photonic information usually relies on electronics. Aiming to avoid the conversion between photonic and electronic signals, modulation of light with light based on optical nonlinearity has become a major research field and coherent optical effects on the nanoscale are emerging as new means of handling and distributing signals. Here we demonstrate that in slabs of linear material of sub-wavelength thickness optical manifestations of birefringence and optical activity (linear and circular birefringence and dichroism) can be controlled by a wave coherent with the wave probing the polarization effect. We demonstrate this in proof-of-principle experiments for chiral and anisotropic microwave metamaterials, where we show that the large parameter space of polarization characteristics may be accessed at will by coherent control. Such control can be exerted at arbitrarily low intensities, thus arguably allowing for fast handling of electromagnetic signals without facing thermal management and energy challenges. PMID:25755071

  3. One day wonder: Fast resolution of macular edema following intravitreal ranibizumab in retinal venous occlusions

    Directory of Open Access Journals (Sweden)

    Lalit Verma

    2013-01-01

    Full Text Available Macular edema is a significant cause of vision loss in patients with central retinal vein occlusions and branch retinal vein occlusions. Vascular endothelial growth factor (VEGF appears to be a key factor in the pathogenesis of this disease. Anti-VEGF therapy, such as intravitreal ranibizumab provides an effective treatment against vision-threatening macular edema. We report three patients of retinal vein occlusion with macular edema who demonstrated overnight resolution of macular edema following treatment with intravitreal ranibizumab (0.5 mg. 3D optical coherence tomography (Optovue was used as a tool for comparison of the macular thickness before and after treatment. The significant reductions in the central foveal thickness demonstrated in these patients one night after intravitreal injections could have significant influence on modifying current treatment protocols. Early treatment of macular edema related to retinal venous occlusive disease with anti-VEGF injections could result in faster visual rehabilitation in these patients.

  4. Analysis of optical amplifier noise in coherent optical communication systems with optical image rejection receivers

    DEFF Research Database (Denmark)

    Jørgensen, Bo Foged; Mikkelsen, Benny; Mahon, Cathal J.

    1992-01-01

    performance. Two types of optical image rejection receivers are investigated: a novel, all-optical configuration and the conventional, microwave-based configuration. The analysis shows that local oscillator-spontaneous emission beat noise (LO-SP), signal-spontaneous emission beat noise (S-SP), and spontaneous......A detailed theoretical analysis of optical amplifier noise in coherent optical communication systems with heterodyne receivers is presented. The analysis quantifies in particular how optical image rejection receiver configurations reduce the influence of optical amplifier noise on system......-spontaneous beat noise (SP-SP) can all be reduced by 3 dB, thereby doubling the dynamic range of the optical amplifier. A 2.5-dB improvement in dynamic range has been demonstrated experimentally with the all-optical image rejection configuration. The implications of the increased dynamic range thus obtained...

  5. Coherent optical communication using polarization multiple-input-multiple-output.

    Science.gov (United States)

    Han, Yan; Li, Guifang

    2005-09-19

    Polarization-division multiplexed (PDM) optical signals can potentially be demultiplexed by coherent detection and digital signal processing without using optical dynamic polarization control at the receiver. In this paper, we show that optical communications using PDM is analogous to wireless communications using multiple-input-multiple-output (MIMO) antennae and thus algorithms for channel estimation in wireless MIMO can be ready applied to optical polarization MIMO (PMIMO). Combined with frequency offset and phase estimation algorithms, simulations show that PDM quadrature phase-shift keying signals can be coherently detected by the proposed scheme using commercial semiconductor lasers while no optical phase locking and polarization control are required. This analogy further suggests the potential application of space-time coding in wireless communications to optical polarization MIMO systems and relates the problem of polarization-mode dispersion in fiber transmission to the multi-path propagation in wireless communications.

  6. Retinal nerve fiber layer thickness measured by optical coherence tomography in patients with schizophrenia: A short report

    Directory of Open Access Journals (Sweden)

    Francisco J. Ascaso

    2010-12-01

    Full Text Available Background and Objectives: Our study aims to assess retinal nerve fiber layer (RNFL thickness in patients affected by schizophrenia. Methods: Ten schizophrenic patients (mean age 39 +/- 13 years, best corrected visual acuity > 20/20, refractive error between +/-2 diopters, and intraocular pressure <18 mmHg were enrolled. They were compared with 10 age-matched controls. In all subjects, optic nerve head (ONH measurements, peripapillary RNFL thickness, macular thickness and volume were measured by optical coherence tomography (OCT. Results: Schizophrenic patients showed an statistically significant reduction of the overall RNFL thickness (95+/-13 µm, range: 53-110 compared with those values observed in control eyes (103+/-8 µm, range: 88-119 (p = 0.047, Mann-Whitney U test. We also observed reduced peripapillary RNFL thickness in nasal quadrant in schizophrenic patients (75+/-17 µm, range: 41-111 when compared with controls (84+/-10 µm, range: 67-105 (p = 0.048, Mann-Whitney U test. The remaining peripapillary RNFL quadrants, macular thickness and volume did not reveal differences between both groups. No statistically significant differences were observed between the control group and schizophrenia patients with regard to ONH measurements, macular thickness and volume. Conclusions: Schizophrenia patients had a reduction of peripapillary RNFL thickness evaluated by OCT. To our knowledge, neither reduced RNFL thickness nor macular thickness and volume have been previously documented in patients diagnosed with schizophrenia. These findings suggest that neuronal degeneration could be present in the retina of schizophrenic patients as previously observed in neurodegenerative disorders.

  7. CHOROIDAL IMAGING USING SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY

    Science.gov (United States)

    Regatieri, Caio V.; Branchini, Lauren; Fujimoto, James G.; Duker, Jay S.

    2012-01-01

    Background A structurally and functionally normal choroidal vasculature is essential for retinal function. Therefore, a precise clinical understanding of choroidal morphology should be important for understanding many retinal and choroidal diseases. Methods PUBMED (http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed) was used for most of the literature search for this article. The criterion for inclusion of an article in the references for this review was that it included materials about both the clinical and the basic properties of choroidal imaging using spectral-domain optical coherence tomography. Results Recent reports show successful examination and accurate measurement of choroidal thickness in normal and pathologic states using spectral-domain optical coherence tomography systems. This review focuses on the principles of the new technology that make choroidal imaging using optical coherence tomography possible and on the changes that subsequently have been documented to occur in the choroid in various diseases. Additionally, it outlines future directions in choroidal imaging. Conclusion Optical coherence tomography is now proven to be an effective noninvasive tool to evaluate the choroid and to detect choroidal changes in pathologic states. Additionally, choroidal evaluation using optical coherence tomography can be used as a parameter for diagnosis and follow-up. PMID:22487582

  8. Non-invasive in vivo measurement of macular carotenoids

    Science.gov (United States)

    Lambert, James L. (Inventor); Borchert, Mark S. (Inventor)

    2009-01-01

    A non-invasive in vivo method for assessing macular carotenoids includes performing Optical Coherence Tomography (OCT) on a retina of a subject. A spatial representation of carotenoid levels in the macula based on data from the OCT of the retina can be generated.

  9. In-vivo imaging of blood flow in human retinal vessels using color Doppler optical coherence tomography

    Science.gov (United States)

    Yazdanfar, Siavash; Rollins, Andrew M.; Izatt, Joseph A.

    1999-04-01

    Quantification of retinal blood flow may lead to a better understanding of the progression and treatment of several ocular disorders, including diabetic retinopathy, age- related macular degeneration, and glaucoma. Current techniques, such as fluorescein angiography and laser Doppler velocimetry are limited, failing to provide sufficient information to the clinician. Color Doppler optical coherence tomography (CDOCT) is a novel technique using coherent heterodyne detection for simultaneous cross- sectional imaging of tissue microstructure and blood flow. This technique is capable of high spatial and velocity resolution imaging in highly scattering media. We implemented CDOCT for retinal blood flow mapping in human subjects. No dilation of the pupil was necessary. CDOCT is demonstrated for determining bidirectional flow in sub- 100micrometers diameter vessels in the retina. Additionally, we calculated Doppler broadening using the variance of depth- resolved spectra to identify regions with large velocity gradients within the Xenopus heart. This technique may be useful in quantifying local tissue perfusion in highly vascular retinal tissue.

  10. Accuracy of optical navigation systems for automatic head surgery: optical tracking versus optical coherence tomography

    Science.gov (United States)

    Díaz Díaz, Jesús; Riva, Mauro H.; Majdani, Omid; Ortmaier, Tobias

    2014-03-01

    The choice of a navigation system highly depends on the medical intervention and its accuracy demands. The most commonly used systems for image guided surgery (IGS) are based on optical and magnetic tracking systems. This paper compares two optical systems in terms of accuracy: state of the art triangulation-based optical tracking (OT) and optical coherence tomography (OCT). We use an experimental setup with a combined OCT and cutting laser, and an external OT. We simulate a robotic assisted surgical intervention, including planning, navigation, and processing, and compare the accuracies reached at a specific target with each navigation system.

  11. Optical probe design with extended depth-of-focus for optical coherence microscopy and optical coherence tomography

    Science.gov (United States)

    Lee, Seungwan; Choi, Minseog; Lee, Eunsung; Jung, Kyu-Dong; Chang, Jong-hyeon; Kim, Woonbae

    2013-03-01

    In this report, Optical probe system for modality, optical coherence tomography (OCT) and optical coherence microscope (OCM), is presented. In order to control the back focal length from 2.2 mm to 27 mm, optical probe is designed using two liquid lenses and several lenses. The narrow depth of focus (DOF) in microscope is extended by phase filter such as cubic filter. The filter is modified so that DOF is extended only In the OCM mode. The section for the extended DOF of probe is controlled by iris. Therefore in OCT mode, the phase filter does not affect on the DOF of lens. In OCM mode, the Gaussian light and modified light will affect the DOF. The probe dimension is less than 4 mm diameter and less than 60 mm long. The scan range of system is 0.88 mm wide, 1 mm deep in the OCT and 510 μm wide, 1 mm deep in the OCM mode. The lens curvature and iris aperture are operated by digital microelectrofluidic lens and iris.

  12. Artifacts in spectral-domain optical coherence tomography measurements in glaucoma.

    Science.gov (United States)

    Asrani, Sanjay; Essaid, Luma; Alder, Brian D; Santiago-Turla, Cecilia

    2014-04-01

    IMPORTANCE Spectral-domain optical coherence tomography (SD-OCT) has an integral role in the diagnosis and treatment of glaucoma. Understanding the types of artifacts commonly seen in the imaging of patients being evaluated for glaucoma will help physicians better implement these data in the care of patients. OBJECTIVES To determine the frequency and distribution of SD-OCT imaging artifacts in patients being evaluated for glaucoma and to provide examples of common artifacts. DESIGN, SETTING, AND PARTICIPANTS A retrospective cross-sectional study design was used to examine SD-OCT images (using Spectralis SD-OCT) of 277 consecutive patients who had a diagnosis of glaucoma of any stage or had suspected glaucoma. Retinal nerve fiber layer (RNFL) and macular thickness scans were included. For each scan, the final printout and the source images that generated the final printout were examined. If present, artifacts were classified as evident on the final printout or not and were categorized as to the primary source of the artifact (eg, ocular pathologic features or technician errors). Examples of common artifacts are provided. MAIN OUTCOMES AND MEASURES The presence of imaging artifacts. RESULTS In 277 consecutive patients, 131 macular thickness scans were obtained, and 277 RNFL scans were obtained. Of the macular thickness scans, 37 (28.2%; 95% CI, 20.8%-36.1%) had imaging artifacts. Six of these artifacts were not obvious on the final printout. Of the RNFL scans, 55 (19.9%; 95% CI, 15.2%-24.6%) contained artifacts. Seven of these artifacts were not evident on the final printout. The most common cause of artifacts for macular thickness and RNFL scans was ocular pathologic features, primarily the presence of an epiretinal membrane. CONCLUSIONS AND RELEVANCE It is likely that SD-OCT-related imaging artifacts occur in 15.2% to 36.1% of scans obtained in patients being evaluated for glaucoma. Some of these artifacts may not be evident on the final printout. Physicians should

  13. Optical coherence tomography of the prostate nerves

    Science.gov (United States)

    Chitchian, Shahab

    Preservation of the cavernous nerves during prostate cancer surgery is critical in preserving a man's ability to have spontaneous erections following surgery. These microscopic nerves course along the surface of the prostate within a few millimeters of the prostate capsule, and they vary in size and location from one patient to another, making preservation of the nerves difficult during dissection and removal of a cancerous prostate gland. These observations may explain in part the wide variability in reported sexual potency rates (9--86%) following prostate cancer surgery. Any technology capable of providing improved identification, imaging, and visualization of the cavernous nerves during prostate cancer surgery would be of great assistance in improving sexual function after surgery, and result in direct patient benefit. Optical coherence tomography (OCT) is a noninvasive optical imaging technique capable of performing high-resolution cross-sectional in vivo and in situ imaging of microstructures in biological tissues. OCT imaging of the cavernous nerves in the rat and human prostate has recently been demonstrated. However, improvements in the OCT system and the quality of the images for identification of the cavernous nerves is necessary before clinical use. The following chapters describe complementary approaches to improving identification and imaging of the cavernous nerves during OCT of the prostate gland. After the introduction to OCT imaging of the prostate gland, the optimal wavelength for deep imaging of the prostate is studied in Chapter 2. An oblique-incidence single point measurement technique using a normal-detector scanning system was implemented to determine the absorption and reduced scattering coefficients, mua and m's , of fresh canine prostate tissue, ex vivo, from the diffuse reflectance profile of near-IR light as a function of source-detector distance. The effective attenuation coefficient, mueff, and the Optical Penetration Depth (OPD) were

  14. Coherent optical transitions in implanted nitrogen vacancy centers.

    Science.gov (United States)

    Chu, Y; de Leon, N P; Shields, B J; Hausmann, B; Evans, R; Togan, E; Burek, M J; Markham, M; Stacey, A; Zibrov, A S; Yacoby, A; Twitchen, D J; Loncar, M; Park, H; Maletinsky, P; Lukin, M D

    2014-01-01

    We report the observation of stable optical transitions in nitrogen-vacancy (NV) centers created by ion implantation. Using a combination of high temperature annealing and subsequent surface treatment, we reproducibly create NV centers with zero-phonon lines (ZPL) exhibiting spectral diffusion that is close to the lifetime-limited optical line width. The residual spectral diffusion is further reduced by using resonant optical pumping to maintain the NV(-) charge state. This approach allows for placement of NV centers with excellent optical coherence in a well-defined device layer, which is a crucial step in the development of diamond-based devices for quantum optics, nanophotonics, and quantum information science.

  15. Coherent feedback control of multipartite quantum entanglement for optical fields

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Zhihui; Jia, Xiaojun; Xie, Changde; Peng, Kunchi [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan, 030006 (China)

    2011-12-15

    Coherent feedback control (CFC) of multipartite optical entangled states produced by a nondegenerate optical parametric amplifier is theoretically studied. The features of the quantum correlations of amplitude and phase quadratures among more than two entangled optical modes can be controlled by tuning the transmissivity of the optical beam splitter in the CFC loop. The physical conditions to enhance continuous variable multipartite entanglement of optical fields utilizing the CFC loop are obtained. The numeric calculations based on feasible physical parameters of realistic systems provide direct references for the design of experimental devices.

  16. The Development, Commercialization, and Impact of Optical Coherence Tomography.

    Science.gov (United States)

    Fujimoto, James; Swanson, Eric

    2016-07-01

    This review was written for the special issue of IOVS to describe the history of optical coherence tomography (OCT) and its evolution from a nonscientific, historic perspective. Optical coherence tomography has become a standard of care in ophthalmology, providing real-time information on structure and function - diagnosing disease, evaluating progression, and assessing response to therapy, as well as helping to understand disease pathogenesis and create new therapies. Optical coherence tomography also has applications in multiple clinical specialties, fundamental research, and manufacturing. We review the early history of OCT describing how research and development evolves and the important role of multidisciplinary collaboration and expertise. Optical coherence tomography had its origin in femtosecond optics, but used optical communications technologies and required advanced engineering for early OCT prototypes, clinical feasibility studies, entrepreneurship, and corporate development in order to achieve clinical acceptance and clinical impact. Critical advances were made by early career researchers, clinician scientists, engineering experts, and business leaders, which enabled OCT to have a worldwide impact on health care. We introduce the concept of an "ecosystem" consisting of research, government funding, collaboration and competition, clinical studies, innovation, entrepreneurship and industry, and impact - all of which must work synergistically. The process that we recount is long and challenging, but it is our hope that it might inspire early career professionals in science, engineering, and medicine, and that the clinical and research community will find this review of interest.

  17. Structural Alterations of Segmented Macular Inner Layers in Aquaporin4-Antibody-Positive Optic Neuritis Patients in a Chinese Population.

    Directory of Open Access Journals (Sweden)

    Chunxia Peng

    Full Text Available This study aimed to analyse the structural injury of the peripapillary retinal nerve fibre layer (pRNFL and segmented macular layers in optic neuritis (ON in aquaporin4-antibody (AQP4-Ab seropositivity(AQP4-Ab-positiveON patients and in AQP4-Ab seronegativity (AQP4-Ab-negative ON patients in order to evaluate their correlations with the best-corrected visual acuity (BCVA and the value of the early diagnosis of neuromyelitis optica (NMO.This is a retrospective, cross-sectional and control observational study.In total, 213 ON patients (291 eyes and 50 healthy controls (HC (100 eyes were recruited in this study. According to a serum AQP4-Ab assay, 98 ON patients (132 eyes were grouped as AQP4-Ab-positive ON and 115 ON patients (159 eyes were grouped as AQP4-Ab-negative ON cohorts. All subjects underwent scanning with spectralis optical coherence tomography (OCT and BCVA tests. pRNFL and segmented macular layer measurements were analysed.The pRNFL thickness in AQP4-Ab-positive ON eyes showed a more serious loss during 0-2 months (-27.61μm versus -14.47 μm and ≥6 months (-57.91μm versus -47.19μm when compared with AQP4-Ab-negative ON eyes. AQP4-Ab-positive ON preferentially damaged the nasal lateral pRNFL. The alterations in the macular ganglion cell layer plus the inner plexiform layer (GCIP in AQP4-Ab-positive ON eyes were similar to those in AQP4-Ab-negative ON eyes. AQP4-Ab-positive ON eyes had entirely different injury patterns in the inner nuclear layer (INL compared with AQP4-Ab-negative ON eyes during the first 6 months after the initial ON attack. These differences were as follows: the INL volume of AQP4-Ab-positive ON eyes had a gradual growing trend compared with AQP4-Ab-negative ON eyes, and it increased rapidly during 0-2 months, reached its peak during 2-4 months, and then decreased gradually. The pRNFL and GCIP in AQP4-Ab-positive ON eyes had positive correlations with BCVA. When the pRNFL thickness decreased to 95%CI (50.77

  18. Structural Alterations of Segmented Macular Inner Layers in Aquaporin4-Antibody-Positive Optic Neuritis Patients in a Chinese Population

    Science.gov (United States)

    Peng, Chunxia; Wang, Wei; Xu, Quangang; Zhao, Shuo; Li, Hongyang; Yang, Mo; Cao, Shanshan; Zhou, Huanfen; Wei, Shihui

    2016-01-01

    Objectives This study aimed to analyse the structural injury of the peripapillary retinal nerve fibre layer (pRNFL) and segmented macular layers in optic neuritis (ON) in aquaporin4-antibody (AQP4-Ab) seropositivity(AQP4-Ab-positiveON) patients and in AQP4-Ab seronegativity (AQP4-Ab-negative ON) patients in order to evaluate their correlations with the best-corrected visual acuity (BCVA) and the value of the early diagnosis of neuromyelitis optica (NMO). Design This is a retrospective, cross-sectional and control observational study. Methods In total, 213 ON patients (291 eyes) and 50 healthy controls (HC) (100 eyes) were recruited in this study. According to a serum AQP4-Ab assay, 98 ON patients (132 eyes) were grouped as AQP4-Ab-positive ON and 115 ON patients (159 eyes) were grouped as AQP4-Ab-negative ON cohorts. All subjects underwent scanning with spectralis optical coherence tomography (OCT) and BCVA tests. pRNFL and segmented macular layer measurements were analysed. Results The pRNFL thickness in AQP4-Ab-positive ON eyes showed a more serious loss during 0–2 months (-27.61μm versus -14.47 μm) and ≥6 months (-57.91μm versus -47.19μm) when compared with AQP4-Ab-negative ON eyes. AQP4-Ab-positive ON preferentially damaged the nasal lateral pRNFL. The alterations in the macular ganglion cell layer plus the inner plexiform layer (GCIP) in AQP4-Ab-positive ON eyes were similar to those in AQP4-Ab-negative ON eyes. AQP4-Ab-positive ON eyes had entirely different injury patterns in the inner nuclear layer (INL) compared with AQP4-Ab-negative ON eyes during the first 6 months after the initial ON attack. These differences were as follows: the INL volume of AQP4-Ab-positive ON eyes had a gradual growing trend compared with AQP4-Ab-negative ON eyes, and it increased rapidly during 0–2 months, reached its peak during 2–4 months, and then decreased gradually. The pRNFL and GCIP in AQP4-Ab-positive ON eyes had positive correlations with BCVA. When the p

  19. A comparison between amblyopic and fellow eyes in unilateral amblyopia using spectral-domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Araki S

    2014-11-01

    Full Text Available Syunsuke Araki,1 Atsushi Miki,1,2 Tsutomu Yamashita,1,2 Katsutoshi Goto,1,2 Kazuko Haruishi,1 Yoshiaki Ieki,1 Junichi Kiryu1 1Department of Ophthalmology, Kawasaki Medical School, Kurashiki, Japan; 2Department of Sensory Science, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, Kurashiki, Japan Purpose: To compare the macular retinal thickness and characteristics of optic nerve head (ONH parameters in amblyopic and fellow eyes in patients with unilateral amblyopia.Patients and methods: A total of 21 patients with unilateral amblyopia (14 patients with anisometropic amblyopia, four patients with strabismic amblyopia, and three patients with both were examined using spectral-domain optical coherence tomography. The mean age of the patients was 8.5±3.5 years. The examined parameters included the mean macular (full, inner, and outer, ganglion cell complex and circumpapillary retinal nerve fiber layer (cpRNFL thicknesses, and ONH parameters (rim volume, nerve head volume, cup volume, rim area, optic disc area, cup area, and cup-to-disc area ratio.Results: The amblyopic eyes were significantly more hyperopic than the fellow eyes (P<0.001. Among the macular retinal thickness parameters, the cpRNFL thickness (P<0.01, macular full retinal thickness (3 mm region (P<0.01, and macular outer retinal thickness (1 and 3 mm regions (P<0.05 were significantly thicker in the amblyopic eyes than in the fellow eyes, while the ganglion cell complex thickness, macular full retinal thickness (1 mm region, and macular inner retinal thickness (1 and 3 mm regions were not significantly different. Among the ONH parameters, the rim area was significantly larger and the cup-to-disc area ratio was smaller in the amblyopic eyes than in the fellow eyes (P<0.05. None of the other ONH parameters were significantly different between the investigated eyes. The differences in the cpRNFL thickness and macular outer retinal thickness in the 1 mm

  20. Optical coherent technologies in next generation access networks

    Science.gov (United States)

    Iwatsuki, Katsumi; Tsukamoto, Katsutoshi

    2012-01-01

    This paper reviews optical coherent technologies in next generation access networks with the use of radio over fiber (RoF), which offer key enabling technologies of wired and wireless integrated and/or converged broadband access networks to accommodate rapidly widespread cloud computing services. We describe technical issues on conventional RoF based on subcarrier modulation (SCM) and their countermeasures. Two examples of RoF access networks with optical coherent technologies to solve the technical issues are introduced; a video distribution system with FM conversion and wired and wireless integrated wide-area access network with photonic up- and down-conversion.

  1. High-resolution second harmonic optical coherence tomography

    Science.gov (United States)

    Jiang, Yi; Tomov, Ivan V.; Wang, Yimin; Chen, Zhongping

    2005-04-01

    A high-resolution Second Harmonic Optical Coherence Tomography (SH-OCT) system is demonstrated using a spectrum broadened femtosecond Ti:sapphire laser. An axial resolution of 4.2 μm at the second harmonic wave center wavelength of 400 nm has been achieved. Because the SH-OCT system uses the second harmonic generation signals that strongly depend on the orientation, polarization and local symmetry properties of chiral molecules, this technique provides unique contrast enhancement to conventional optical coherence tomography. The system is applied to image biological tissues like the rat-tail tendon. Images of highly organized collagen fibrils in the rat-tail tendon have been demonstrated.

  2. The Contribution of Optical Coherence Tomography in Neuromyelitis Optica Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Javier Mateo

    2017-09-01

    Full Text Available Neuromyelitis optica spectrum disorders (NMOSD comprises a group of central nervous system disorders of inflammatory autoimmune origin that mainly affect the optic nerves and the spinal cord and can cause severe visual and general disability. The clinical signs are similar to those of multiple sclerosis (MS, with the result that it is often difficult to differentiate between the two, thus leading to misdiagnosis. As the treatment and prognosis of NMOSD and MS are different, it is important to make an accurate and early diagnosis of NMOSD. Optical coherence tomography (OCT is a non-invasive technique that enables a quantitative study of the changes that the optic nerve and the macula undergo in several neurodegenerative diseases. Many studies have shown that some of these changes, such as retinal nerve fiber layer thinning or microcystic macular edema, can be related to alterations in the brain due to neurodegenerative disorders. The purpose of this mini-review is to show how OCT can be useful for the diagnosis of NMOSD and follow-up of affected patients, as well as for the differential diagnosis with MS.

  3. Reversible quantum optical data storage based on resonant Raman optical field excited spin coherence.

    Science.gov (United States)

    Ham, Byoung S

    2008-09-01

    A method of reversible quantum optical data storage is presented using resonant Raman field excited spin coherence, where the spin coherence is stored in an inhomogeneously broadened spin ensemble. Unlike the photon echo method, in the present technique, a 2pi Raman optical rephasing pulse area is used and multimode (parallel) optical channels are available in which the multimode access gives a great benefit to quantum information processors such as quantum repeaters.

  4. [Applications of optical coherence tomography (OCT) in neuro-ophthalmology].

    Science.gov (United States)

    Kernstock, C; Friebe, K; Tonagel, F

    2013-11-01

    Optical coherence tomography (OCT) has revolutionised ophthalmology. Due to modern instruments with extremely high resolution there are more and more applications also in neuro-ophthalmological disorders. This review gives an overview on typical changes in OCT for the following diseases: autosomal dominant optic atrophy, Leber hereditary optic neuropathy, toxic, traumatic and compressive optic neuropathy, optic nerve drusen, anterior ischaemic optic neuropathy, optic disc pit, papilledema, optic neuritis (isolated or associated with multiple sclerosis or neuromyelitis optica), neurodegenerative diseases and hereditary retinal diseases. A diagnosis exclusively based on an OCT examination is not always possible, but in several diseases there are pathognomonic changes that directly lead to the correct diagnosis. Particularly with the often complex settings in neuro-ophtalmology the OCT should be seen as a supplementary modality and not as a replacement for other techniques.

  5. The effect of BCMO1 gene variants on macular pigment optical density in young healthy Caucasians

    Directory of Open Access Journals (Sweden)

    Zachary eKyle-Little

    2014-12-01

    Full Text Available Background: Serum lutein (L and zeaxanthin (Z positively correlate with macular pigment optical density (MPOD, hence the latter is a valuable indirect tool for measuring L and Z content in the macula. L and Z have been attributed antioxidant capacity and protection from certain retinal diseases but their uptake within the eye is thought to depend on genetic, age and environmental factors. In particular gene variants within beta-carotene monooxygenase (BCMO1 are thought to modulate MPOD in the macula.Objectives: To determine the effect of BCMO1 single nucleotide polymorphisms (SNPs rs11645428, rs6420424 and rs6464851 on macular pigment optical density (MPOD in a cohort of young healthy participants of Caucasian origin with normal ocular health.Design: In this cohort study, MPOD was assessed in 46 healthy participants (22 male and 24 female with a mean age of 24 ± 4.0 years (range 19-33. The three SNPs, rs11645428, rs6420424, rs6564851 that have established associations with MPOD were determined using MassEXTEND (hME Sequenom assay. One-way analysis of variance (ANOVA was performed on groups segregated into homozygous and heterozygous BCMO1 genotypes. Correlations between body mass index (BMI, iris colour, gender, central retinal thickness (CRT, diet and MPOD were investigated.Results: MPOD did not significantly vary with BCMO1 rs11645428 (F2,41 = 0.700, p = 0.503, rs6420424 (F2,41 = 0.210, p = 0.801 nor rs6464851 homozygous or heterozygous genotypes (F2,41 = 0,13, p = 0.88, in this young healthy cohort. The combination of these three SNPs into triple genotypes based on plasma conversion efficiency did not affect MPOD (F2,41 = 0.07, p = 0.9. There was a significant negative correlation with MPOD and central retinal thickness (r = - 0.39, p = 0.01 but no significant correlation between BMI, iris colour, gender and MPOD. Conclusion: Our results indicate that macular pigment deposition within the central retina is not dependent on BCMO1 gene variant

  6. Investigation of optical currents in coherent and partially coherent vector fields

    DEFF Research Database (Denmark)

    Angelsky, O. V.; Gorsky, M. P.; Maksimyak, P. P.

    2011-01-01

    in the arrangements of two-wave and four-wave superposition on the characteris-tics of the microparticle’s motion has been analyzed. The prospects of stud-ying temporal coherence using the proposed approach are made. For the first time, the possibility of diagnostics of optical currents in liquids caused...

  7. Analysis of morphological features and vascular layers of choroid in diabetic retinopathy using spectral-domain optical coherence tomography.

    Science.gov (United States)

    Adhi, Mehreen; Brewer, Erika; Waheed, Nadia K; Duker, Jay S

    2013-10-01

    Diabetic retinopathy (DR) is characterized by microaneurysms, capillary nonperfusion, and ischemia within the retina, ultimately leading to neovascularization and/or macular edema. Evidence suggests that choroidal angiopathy may coexist with retinal vascular damage. Recent advances in spectral-domain optical coherence tomography (SD-OCT) permit an efficient visualization of the choroid. To analyze the morphological features and vascular layers of the choroid in patients with DR using SD-OCT. A cross-sectional retrospective review identified patients with DR and healthy (control) subjects who underwent 1-line raster scanning from February 1, 2010, through June 30, 2012. Patients were classified into the following 3 groups: nonproliferative DR without macular edema (9 eyes), proliferative DR without macular edema (PDR) (10 eyes), and diabetic macular edema (DME) (14 eyes). Two independent raters experienced in analyzing OCT images evaluated the morphological features and vasculature of the choroid. New England Eye Center. Thirty-three eyes of 33 patients with DR and 24 eyes of 24 controls. Diabetic retinopathy. Choroidal morphological features and vasculature analysis. The choroidoscleral interface had an irregular contour in 8 of 9 eyes with nonproliferative DR (89%), 9 of 10 eyes with PDR (90%), and 13 of 14 eyes with DME (93%) compared with 0 of 24 controls. The thickest point of the choroid was displaced from under the fovea, and focal choroidal thinning was observed in eyes with DR. Mean subfoveal choroidal thickness and mean subfoveal medium choroidal vessel layer and choriocapillaris layer thickness were significantly reduced in eyes with PDR (P Choroidal morphological features are altered in patients with moderate to severe DR. The subfoveal choroidal thickness and the subfoveal medium choroidal vessel layer and choriocapillaris layer thicknesses are significantly reduced in patients with PDR and DME. To our knowledge, this is the first study to analyze the

  8. Coherence-Gated Sensorless Adaptive Optics Multiphoton Retinal Imaging

    Science.gov (United States)

    Cua, Michelle; Wahl, Daniel J.; Zhao, Yuan; Lee, Sujin; Bonora, Stefano; Zawadzki, Robert J.; Jian, Yifan; Sarunic, Marinko V.

    2016-09-01

    Multiphoton microscopy enables imaging deep into scattering tissues. The efficient generation of non-linear optical effects is related to both the pulse duration (typically on the order of femtoseconds) and the size of the focused spot. Aberrations introduced by refractive index inhomogeneity in the sample distort the wavefront and enlarge the focal spot, which reduces the multiphoton signal. Traditional approaches to adaptive optics wavefront correction are not effective in thick or multi-layered scattering media. In this report, we present sensorless adaptive optics (SAO) using low-coherence interferometric detection of the excitation light for depth-resolved aberration correction of two-photon excited fluorescence (TPEF) in biological tissue. We demonstrate coherence-gated SAO TPEF using a transmissive multi-actuator adaptive lens for in vivo imaging in a mouse retina. This configuration has significant potential for reducing the laser power required for adaptive optics multiphoton imaging, and for facilitating integration with existing systems.

  9. Coherence-Gated Sensorless Adaptive Optics Multiphoton Retinal Imaging.

    Science.gov (United States)

    Cua, Michelle; Wahl, Daniel J; Zhao, Yuan; Lee, Sujin; Bonora, Stefano; Zawadzki, Robert J; Jian, Yifan; Sarunic, Marinko V

    2016-09-07

    Multiphoton microscopy enables imaging deep into scattering tissues. The efficient generation of non-linear optical effects is related to both the pulse duration (typically on the order of femtoseconds) and the size of the focused spot. Aberrations introduced by refractive index inhomogeneity in the sample distort the wavefront and enlarge the focal spot, which reduces the multiphoton signal. Traditional approaches to adaptive optics wavefront correction are not effective in thick or multi-layered scattering media. In this report, we present sensorless adaptive optics (SAO) using low-coherence interferometric detection of the excitation light for depth-resolved aberration correction of two-photon excited fluorescence (TPEF) in biological tissue. We demonstrate coherence-gated SAO TPEF using a transmissive multi-actuator adaptive lens for in vivo imaging in a mouse retina. This configuration has significant potential for reducing the laser power required for adaptive optics multiphoton imaging, and for facilitating integration with existing systems.

  10. Interconnection of polarization properties and coherence of optical fields.

    Science.gov (United States)

    Zenkova, Claudia Yu

    2014-04-01

    Theoretical and experimental approaches to diagnosing internal spin and orbital optical flows and the corresponding optical forces caused by these flows are offered. These approaches are based on the investigation of the motion of the particles tested in the formed optical field. The dependence of the above-mentioned forces upon the size and optical properties of the particles is demonstrated. The possibility of using kinematic values defining the motion dynamics of particles of the Rayleigh light scattering mechanism to make a quantitative assessment of the degree of coherence of mutually orthogonal waves that are linearly polarized in the incidence plane is demonstrated. The feasibility of using the above mentioned approach, its shortcomings, and its advantages over the interfering method for estimating the degree of coherence are analyzed.

  11. Coherent conversion between optical and microwave photons in Rydberg gases

    CERN Document Server

    Kiffner, Martin; Kaczmarek, Krzysztof T; Jaksch, Dieter; Nunn, Joshua

    2016-01-01

    Quantum information encoded in optical photons can be transmitted over long distances with very high information density, and suffers from negligible thermal noise at room temperature. On the other hand, microwave photons at cryogenic temperatures can be confined in high quality resonators and strongly coupled to solid-state qubits, providing a quantum bus to connect qubits and a route to deterministic photonic non-linearities. The coherent interconversion of microwave and optical photons has therefore recently emerged as a highly desirable capability that would enable freely-scalable networks of optically-linked qubits, or large-scale photonic information processing with multi-photon interactions mediated by microwaves. Here, we propose a route to efficient and coherent microwave-optical conversion based on frequency mixing in Rydberg atoms. The interaction requires no microfabricated components or cavities, and is tunable, broadband, and both spatially and spectrally multimode.

  12. Analog signal processing for optical coherence imaging systems

    Science.gov (United States)

    Xu, Wei

    Optical coherence tomography (OCT) and optical coherence microscopy (OCM) are non-invasive optical coherence imaging techniques, which enable micron-scale resolution, depth resolved imaging capability. Both OCT and OCM are based on Michelson interferometer theory. They are widely used in ophthalmology, gastroenterology and dermatology, because of their high resolution, safety and low cost. OCT creates cross sectional images whereas OCM obtains en face images. In this dissertation, the design and development of three increasingly complicated analog signal processing (ASP) solutions for optical coherence imaging are presented. The first ASP solution was implemented for a time domain OCT system with a Rapid Scanning Optical Delay line (RSOD)-based optical signal modulation and logarithmic amplifier (Log amp) based demodulation. This OCT system can acquire up to 1600 A-scans per second. The measured dynamic range is 106dB at 200A-scan per second. This OCT signal processing electronics includes an off-the-shelf filter box with a Log amp circuit implemented on a PCB board. The second ASP solution was developed for an OCM system with synchronized modulation and demodulation and compensation for interferometer phase drift. This OCM acquired micron-scale resolution, high dynamic range images at acquisition speeds up to 45,000 pixels/second. This OCM ASP solution is fully custom designed on a perforated circuit board. The third ASP solution was implemented on a single 2.2 mm x 2.2 mm complementary metal oxide semiconductor (CMOS) chip. This design is expandable to a multiple channel OCT system. A single on-chip CMOS photodetector and ASP channel was used for coherent demodulation in a time domain OCT system. Cross-sectional images were acquired with a dynamic range of 76dB (limited by photodetector responsivity). When incorporated with a bump-bonded InGaAs photodiode with higher responsivity, the expected dynamic range is close to 100dB.

  13. Quantum filtering of optical coherent states

    DEFF Research Database (Denmark)

    Wittmann, C.; Elser, D.; Andersen, Ulrik Lund

    2008-01-01

    We propose and experimentally demonstrate nondestructive and noiseless removal (filtering) of vacuum states from an arbitrary set of coherent states of continuous variable systems. Errors, i.e., vacuum states in the quantum information are diagnosed through a weak measurement, and on that basis......, probabilistically filtered out. We consider three different filters based on on-off detection, phase stabilized, and phase randomized homodyne detection. We find that on-off detection, optimal in the ideal theoretical setting, is superior to the homodyne strategy also in a practical setting....

  14. All-optical coherent control of vacuum Rabi oscillations

    CERN Document Server

    Bose, Ranojoy; Choudhury, Kaushik Roy; Solomon, Glenn S; Waks, Edo

    2014-01-01

    When an atom strongly couples to a cavity, it can undergo coherent vacuum Rabi oscillations. Controlling these oscillatory dynamics quickly relative to the vacuum Rabi frequency enables remarkable capabilities such as Fock state generation and deterministic synthesis of quantum states of light, as demonstrated using microwave frequency devices. At optical frequencies, however, dynamical control of single-atom vacuum Rabi oscillations remains challenging. Here, we demonstrate coherent transfer of optical frequency excitation between a single quantum dot and a cavity by controlling vacuum Rabi oscillations. We utilize a photonic molecule to simultaneously attain strong coupling and a cavity-enhanced AC Stark shift. The Stark shift modulates the detuning between the two systems on picosecond timescales, faster than the vacuum Rabi frequency. We demonstrate the ability to add and remove excitation from the cavity, and perform coherent control of light-matter states. These results enable ultra-fast control of atom...

  15. Choroidal Thickness Measured by Spectral Domain Optical Coherence Tomography: Factors Affecting Thickness in Glaucoma Patients

    Science.gov (United States)

    Maul, Eugenio A.; Friedman, David S.; Chang, Dolly S.; Boland, Michael V.; Ramulu, Pradeep Y.; Jampel, Henry D.; Quigley, Harry A.

    2011-01-01

    Purpose To measure choroidal thickness and to determine parameters associated with it. Design Cross-sectional study. Participants Seventy-four glaucoma patients and glaucoma suspects. Methods Spectral domain optical coherence tomography (SDOCT) scans were obtained to estimate average choroidal thickness in a group of glaucoma suspects and glaucoma patients. Average thickness was calculated from enhanced depth SDOCT images and manually analyzed with Image J software. Open angle glaucoma, open angle glaucoma suspect, primary angle closure glaucoma, primary angle closure, and primary angle closure suspect were defined by published criteria. Glaucoma suspects had normal visual fields bilaterally. Glaucoma was defined by specific criteria for optic disc damage and visual field loss in at least one eye. The most affected eye was analyzed for comparisons across individuals, while right/left and upper half/lower half comparisons were made to compare thickness against degree of visual field damage. Main Outcome Measured Average macular and peripapillary choroidal thickness measured using SDOCT. Results The choroidal-scleral interface (CSI) was visualized in 86% and 96% of the macular and peripapillary scans, respectively. In multivariable linear regression analysis, the macular choroid was significantly thinner in association with 4 features: longer eyes (22 µm per mm longer [95% confidence Interval (CI): −33, −11]), older individuals (31 µm thinner per decade older [95% CI: −44 −17]), lower diastolic ocular perfusion pressure (26 µm thinner per 10 mmHg lower [95% CI: 8, 44]), and thicker central corneas (6 µm per 10 µm thicker cornea [95% CI: −10, 0]). The choroid was not significantly thinner in glaucoma patients than in suspects (14 µm [95% CI: −54, 26], p=0.5). Peripapillary choroidal thickness was not significantly different between glaucomaand suspect patients. Thickness was not associated with damage severity as estimated by visual field mean

  16. Enhancement of Optical Coherence Tomography Axial Resolution by Spectral Shaping

    Institute of Scientific and Technical Information of China (English)

    孙汕; 郭继华; 高湔松; 薛平

    2002-01-01

    We propose a new method of changing the spectrum shape to improve the axial resolution of optical coherencetomography (OCT). Theoretical analysis shows that certain spectral shaping can shorten the coherence length.Comparisons of the simulation and experimental measurements of spectral shape and axial resolution of OCTare given, showing that the axial resolution of OCT is enhanced by a factor of 1.4.

  17. Optical coherent tomography in diagnoses of peripheral retinal degenarations

    Directory of Open Access Journals (Sweden)

    O. G. Pozdeyeva

    2013-01-01

    Full Text Available Purpose: Studying the capabilities of optical coherence tomography (RTVue-100, OPTOVUE, USA in evaluation of peripheral retinal degenerations, vitreoretinal adhesions, adjacent vitreous body as well as measurement of morphometric data.Methods: The study included 189 patients (239 eyes with peripheral retinal degeneration. 77 men and 112 women aged 18 to 84 underwent an ophthalmologic examination since November 2012 until October 2013. The peripheral retina was visualized with the help of optical coherence tomography («RTVue-100,» USA. The fundography was carried out using a Nikon NF505‑AF (Japan fundus camera. All patients were examined with a Goldmann lens.Results: Optical coherence tomography was used to evaluate different kinds of peripheral retinal degenerations, such as lattice and snail track degeneration, isolated retinal tears, cystoid retinal degeneration, pathological hyperpigmentation, retinoschisis and cobblestone degeneration. The following morphometric data were studied: dimensions of the lesion (average length, retinal thickness along the edge of the lesion, retinal thickness at the base of the lesion and the vitreoretinal interface.Conclusion: Optical coherence tomography is a promising in vivo visualization method which is useful in evaluation of peripheral retinal degenerations, vitreoretinal adhesions and tractions. It also provides a comprehensive protocolling system and monitoring. It will enable ophthalmologists to better define laser and surgical treatment indications and evaluate therapy effectiveness.

  18. Optical coherent tomography in diagnoses of peripheral retinal degenarations

    Directory of Open Access Journals (Sweden)

    O. G. Pozdeyeva

    2014-07-01

    Full Text Available Purpose: Studying the capabilities of optical coherence tomography (RTVue-100, OPTOVUE, USA in evaluation of peripheral retinal degenerations, vitreoretinal adhesions, adjacent vitreous body as well as measurement of morphometric data.Methods: The study included 189 patients (239 eyes with peripheral retinal degeneration. 77 men and 112 women aged 18 to 84 underwent an ophthalmologic examination since November 2012 until October 2013. The peripheral retina was visualized with the help of optical coherence tomography («RTVue-100,» USA. The fundography was carried out using a Nikon NF505‑AF (Japan fundus camera. All patients were examined with a Goldmann lens.Results: Optical coherence tomography was used to evaluate different kinds of peripheral retinal degenerations, such as lattice and snail track degeneration, isolated retinal tears, cystoid retinal degeneration, pathological hyperpigmentation, retinoschisis and cobblestone degeneration. The following morphometric data were studied: dimensions of the lesion (average length, retinal thickness along the edge of the lesion, retinal thickness at the base of the lesion and the vitreoretinal interface.Conclusion: Optical coherence tomography is a promising in vivo visualization method which is useful in evaluation of peripheral retinal degenerations, vitreoretinal adhesions and tractions. It also provides a comprehensive protocolling system and monitoring. It will enable ophthalmologists to better define laser and surgical treatment indications and evaluate therapy effectiveness.

  19. Complex sine-Gordon Equation in Coherent Optical Pulse Propagation

    CERN Document Server

    Park, Q H

    1999-01-01

    It is shown that the McCall-Hahn theory of self-induced transparency in coherent optical pulse propagation can be identified with the complex sine-Gordon theory in the sharp line limit. We reformulate the theory in terms of the deformed gauged Wess-Zumino-Witten sigma model and address various new aspects of self-induced transparency.

  20. Heartbeat OCT: In vivo intravascular megahertz-optical coherence tomography

    NARCIS (Netherlands)

    T. Wang (Tianshi); A.F.H. Pfeiffer (Andreas); E.S. Regar (Eveline); W. Wieser (Wolfgang); H.M.M. van Beusekom (Heleen); C.T. Lancée (Charles); T. Springeling (Tirza); I. Krabbendam (Ilona); A.F.W. van der Steen (Ton); R. Huber (Roman); G. van Soest (Gijs)

    2015-01-01

    textabstractCardiac motion artifacts, non-uniform rotational distortion and undersampling affect the image quality and the diagnostic impact of intravascular optical coherence tomography (IV-OCT). In this study we demonstrate how these limitations of IV-OCT can be addressed by using an imaging syste

  1. Generation of optical coherent state superpositions for quantum information processing

    DEFF Research Database (Denmark)

    Tipsmark, Anders

    2012-01-01

    I dette projektarbejde med titlen “Generation of optical coherent state superpositions for quantum information processing” har målet været at generere optiske kat-tilstande. Dette er en kvantemekanisk superpositions tilstand af to koherente tilstande med stor amplitude. Sådan en tilstand er...

  2. Internal fingerprint zone detection in optical coherence tomography fingertip scans

    CSIR Research Space (South Africa)

    Darlow, LN

    2015-04-01

    Full Text Available Optical coherence tomography (OCT) is a high-resolution imaging technology capable of capturing a three-dimensional (3-D) representation of fingertip skin. The papillary junction—a junction layer of skin containing the same topographical features...

  3. Ultrahigh resolution optical coherence tomography using a superluminescent light source

    NARCIS (Netherlands)

    Kowalevicz, Andrew M.; Ko, Tony; Hartl, Ingmar; Fujimoto, James G.; Pollnau, Markus; Salathé, René P.

    2002-01-01

    A superluminescent Ti:Al2O3 crystal is demonstrated as a light source for ultrahigh resolution optical coherence tomography (OCT). Single spatial mode, fiber coupled output powers of ~40 μW can be generated with 138 nm bandwidth using a 5 W frequency doubled, diode pumped laser, pumping a thin Ti:Al

  4. Spectral domain optical coherence tomography and microperimetry in foveal hypoplasia

    Directory of Open Access Journals (Sweden)

    Swakshyar Saumya Pal

    2011-01-01

    Full Text Available A case of foveal hypoplasia associated with ocular albinism with anatomic and functional changes by various techniques using spectral domain optical coherence tomography (SD-OCT, microperimeter and confocal scanning laser ophthalmoscope is described. This case highlights the importance of microperimeter in detecting the functional abnormalities of vision and SD-OCT in identifying the retinal laminar abnormalities in foveal hypoplasia.

  5. Unsuccessful vitrectomy without gas tamponade for macular retinal detachment and retinoschisis without optic disc pit.

    Science.gov (United States)

    Hotta, Kazuki

    2004-01-01

    The mechanism of subretinal fluid accumulation in optic disc pit maculopathy is unknown. A 67-year-old Japanese woman complaining of blurred vision in her right eye presented with a best-corrected visual acuity of 20/200. Slit-lamp biomicroscopy and optical coherence tomography examination showed maculopathy typically associated with optic disc pits, except that the patient had no optic disc pit. Long-acting gas tamponade was required to achieve reattachment of the retina and retinoschisis after initial failure of surgery using surgically induced vitreous detachment without either fluid-air exchange or gas injection. Vitreous traction may not have played a major role in introducing fluid into the submacular space in this case. Gas tamponade may be indispensable to achieve surgical success. This may also pertain to some cases of optic nerve pits.

  6. Simultaneous measurement of group refractive index and thickness of optical samples using optical coherence tomography.

    Science.gov (United States)

    Cheng, Hsu-Chih; Liu, Yi-Cheng

    2010-02-10

    Optical coherence tomography (OCT), based on a Michelson interferometer and utilizing low coherence light as the optical source, is a novel technique for the noninvasive imaging of optical scattering media. A simple OCT scheme based on a 3 x 3 fiber coupler is presented for the simultaneous measurement of the refractive index and thickness of optical samples. The proposed system enables the refractive index and thickness to be determined without any prior knowledge of the sample parameters and is characterized by a simple and compact configuration, a straightforward measurement procedure, and a low cost. The feasibility of the proposed approach is demonstrated experimentally using BK7 and B270 optical glass samples.

  7. Simultaneous measurement of group refractive index and thickness of optical samples using optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Hsu-Chih; Liu, Yi-Cheng

    2010-02-10

    Optical coherence tomography (OCT), based on a Michelson interferometer and utilizing low coherence light as the optical source, is a novel technique for the noninvasive imaging of optical scattering media. A simple OCT scheme based on a 3x3 fiber coupler is presented for the simultaneous measurement of the refractive index and thickness of optical samples. The proposed system enables the refractive index and thickness to be determined without any prior knowledge of the sample parameters and is characterized by a simple and compact configuration, a straightforward measurement procedure, and a low cost. The feasibility of the proposed approach is demonstrated experimentally using BK7 and B270 optical glass samples.

  8. Local retinal sensitivity in relation to specific retinopathy lesions in diabetic macular oedema

    DEFF Research Database (Denmark)

    Soliman, Wael; Hasler, Pascal; Sander, Birgit;

    2012-01-01

    with nonproliferative diabetic retinopathy and recently diagnosed untreated DMO. Investigations included microperimetry, fluorescein angiography, colour fundus photography, and OCT. All measures and gradings were made for each of the nine fields of an early treatment diabetic retinopathy study macula template......Purpose: To study microperimetric macular sensitivity in diabetic macular oedema (DMO) in relation to lesion characteristics obtained by optical coherence tomography (OCT), colour fundus photography, and fluorescein angiography (FA). Methods: The study comprised 20 eyes in 15 patients...

  9. Comparison of life quality scores of ranibizumab-treated patients with age-related macular degeneration

    OpenAIRE

    Saadet Arslan; Merih Soylu; ilter Varinli

    2016-01-01

    Purpose: To evaluate the visual acuity, fluorescein angiography, optic coherence tomography and life quality of patients diagnosed with exudative age-related macular degeneration and administered with intravitreal Ranibizumab injection. Material and Methods: This study included of 48 different patients who were diagnosed as exudative age-related macular degeneration and administered with ranibizumab injection. In this study, demographic characteristics, pre- and post-injection corrected v...

  10. Acute macular edema following intracorporeal prostaglandin injection for erectile dysfunction

    Directory of Open Access Journals (Sweden)

    Asahi MG

    2015-07-01

    Full Text Available Masumi G Asahi, Calvin Chou, Ron P Gallemore Retina Macula Institute, Torrance, CA, USA Purpose: We aimed to describe the first case of macular edema following intracorporeal injection of alprostadil, a prostaglandin E1. Methods: This was a retrospective case report followed with optical coherence tomography, fundus photos, and fluorescein angiography images. Results: A patient developed bilateral cystoid macular edema following intracorporeal injection of alprostadil, a prostaglandin E1 for treatment of erectile dysfunction. The edema resolved following treatment with nonsteroidal anti-inflammatory drugs (NSAIDs and corticosteroids, with subsequent recovery in visual acuity. Discussion: Systemic prostaglandin administration can cause macular edema and vision loss, indicating that elevated systemic prostaglandin levels may affect visual function. This has potential implications for other systemic disorders and treatments that could affect macular function. Keywords: alprostadil, inflammation

  11. Serous macular detachment, yellow macular deposits, and prominent middle limiting membrane in multiple myeloma

    Directory of Open Access Journals (Sweden)

    Dogan B

    2015-04-01

    Full Text Available Berna Dogan,1 Muhammet Kazim Erol,1 Devrim Toslak,1 Deniz Turgut Coban,1 Mehmet Bulut,1 Ayse Cengiz,1 Esin Sogutlu Sari2 1Antalya Training and Research Hospital, Eye Clinic, Antalya, Turkey; 2Balikesir University Medicine Faculty, Eye Clinic, Balikesir, Turkey Abstract: Bone marrow-derived multiple myeloma is a type of plasma cell tumor that may be associated with ocular complications. A 52-year-old male patient was admitted to our eye clinic with the complaint of sudden visual loss and a visual acuity of 20/50 in the right eye and 20/800 in the left eye. Fundus examination revealed common flame-shaped hemorrhages, venous dilatation and tortuosity, Roth spots, serous macular detachment, and yellow macular deposits in both eyes. Evaluation with fundus fluorescein angiography, fundus autofluorescence, and spectral-domain optical coherence tomography resulted in suspicion of hyperviscosity retinopathy and referral to the hematology clinic. After hematology consultation confirmed a diagnosis of multiple myeloma, chemotherapy and plasmapheresis were initiated. Four months after presentation, best-corrected visual acuity was 20/20 in both eyes and improvement in hyperviscosity retinopathy, serous macular detachment, and yellow macular deposits was observed. Keywords: serous macular detachment, yellow macular deposit, prominent middle limiting membrane, multiple myeloma

  12. Use of Prescribed Optical Devices in Age-Related Macular Degeneration

    Science.gov (United States)

    DeCarlo, Dawn K.; McGwin, Gerald; Searcey, Karen; Gao, Liyan; Snow, Marsha; Stevens, Lynne; Owsley, Cynthia

    2012-01-01

    Purpose To evaluate prescribed optical device use in terms of frequency and perceived usefulness among people with age-related macular degeneration (AMD). We also sought to determine the tasks for which they were using their prescribed low vision device. Methods 199 patients with AMD presenting for the first time to the low vision service were recruited from a university-based clinic. Prior to the low vision evaluation and device prescription, they completed the NEI-VFQ 25, Center for Epidemiological Studies Depression Scale, Short Portable Mental Status Questionnaire and a general health questionnaire. The low vision evaluation included best-corrected ETDRS visual acuity, MNRead testing, microperimetry, prescription and dispensing of optical low vision devices. Telephone follow-up interviews were conducted about device usage 1-week, 1-month and 3-months post-intervention. Results 181 participants were prescribed low vision devices. 93% completed all 3 follow-up interviews. Intensive users (≥ 1hour/day) of devices were similar in demographic and visual characteristics to non-intensive users (AMD who are provided with prescribed optical low vision devices do use them and perceive them as useful, especially for leisure reading activities. High rates of usage were maintained over 3 months. PMID:22902420

  13. Design and characterization of SiON integrated optics components for optical coherence tomography

    NARCIS (Netherlands)

    Nguyen, V. Duc; Kalkman, J.; Ismail, N.; Sun, F.; Worhoff, Kerstin; Driessen, A.; Pollnau, Markus; van Leeuwen, Ton

    2009-01-01

    Optical coherence tomography (OCT) is a technique for high resolution imaging of biological tissues with a depth range of a few millimeters. OCT is based on interferometry to enable depth ranging. Currently, optical components for OCT are rather bulky and expensive; the use of integrated optical

  14. In Vivo Confocal Microscopy and Anterior Segment Optic Coherence Tomography Findings in Ocular Ochronosis

    Directory of Open Access Journals (Sweden)

    Elif Demirkilinc Biler

    2015-01-01

    Full Text Available Purpose. To report clinical and in vivo confocal microscopy (IVCM findings of two patients with ocular ochronosis secondary due to alkaptonuria. Materials and Methods. Complete ophthalmologic examinations, including IVCM (HRT II/Rostock Cornea Module, Heidelberg, Germany, anterior segment optical coherence tomography (AS-OCT (Topcon 3D spectral-domain OCT 2000, Topcon Medical Systems, Paramus, NJ, USA, corneal topography (Pentacam, OCULUS Optikgeräte GmbH, Wetzlar, Germany, and anterior segment photography, were performed. Results. Biomicroscopic examination showed bilateral darkly pigmented lesions of the nasal and temporal conjunctiva and episclera in both patients. In vivo confocal microscopy of the lesions revealed prominent degenerative changes, including vacuoles and fragmentation of collagen fibers in the affected conjunctival lamina propria and episclera. Hyperreflective pigment granules in different shapes were demonstrated in the substantia propria beneath the basement membrane. AS-OCT of Case 1 demonstrated hyporeflective areas. Fundus examination was within normal limits in both patients, except tilted optic discs with peripapillary atrophy in one of the patients. Corneal topography, thickness, and macular OCT were normal bilaterally in both cases. Conclusion. The degenerative and anatomic changes due to ochronotic pigment deposition in alkaptonuria can be demonstrated in detail with IVCM and AS-OCT. Confocal microscopic analysis in ocular ochronosis may serve as a useful adjunct in diagnosis and monitoring of the disease progression.

  15. Choroidal structure determined by binarizing optical coherence tomography images in eyes with reticular pseudodrusen

    Directory of Open Access Journals (Sweden)

    Masuda N

    2017-04-01

    Full Text Available Naonori Masuda, Masashi Kojima, Mariko Yamashita, Tomo Nishi, Nahoko Ogata Department of Ophthalmology, Nara Medical University, Nara, Japan Purpose: To compare the choroidal structure beneath the macular area in eyes with reticular pseudodrusen (RPD and age-matched controls.Methods: This study was performed at Nara Medical University Hospital, Japan. Twenty eyes of 14 patients (82.3±4.2 years, mean ± standard deviation with RPD and 35 eyes of 20 age-matched controls (81.5±6.0 years were studied. The choroidal structure was determined by binarizing the images obtained by enhanced depth imaging optical coherence tomography in all patients and controls. The total, luminal, and stromal choroidal areas were quantified by the binarization method.Results: The total choroidal area of the eyes with RPD was significantly smaller than that of control eyes (P=0.001, unpaired t-test. Both the luminal and stromal areas in eyes with RPD were significantly smaller than that of control eyes (P=0.001, paired t-test, but there was no significant difference in the luminal/stromal ratio between eyes with RPD and control eyes.Conclusion: The total, luminal, and stromal choroidal areas in eyes with RPD were smaller than those of the control eyes. The reduction of the choroidal luminal and stromal areas may be due to a loss of the oxygen demand of the choroid due to RPE dysfunction. Keywords: reticular pseudodrusen, age-related macular degeneration, choroidal structure, binarization method

  16. Assessment of choroidal thickness in healthy and glaucomatous eyes using swept source optical coherence tomography.

    Directory of Open Access Journals (Sweden)

    Chunwei Zhang

    Full Text Available PURPOSE: To evaluate choroidal thickness (CT in healthy and glaucomatous eyes using Swept Source Optical Coherence Tomography (SS-OCT. METHODS: A cross-sectional observational study of 216 eyes of 140 subjects with glaucoma and 106 eyes of 67 healthy subjects enrolled in the Diagnostic Innovations in Glaucoma Study. CT was assessed from wide-field (12×9 mm SS-OCT scans. The association between CT and potential confounding variables including age, gender, axial length, intraocular pressure, central corneal thickness and ocular perfusion pressure was examined using univariable and multivariable regression analyses. RESULTS: Overall CT was thinner in glaucomatous eyes with a mean (± standard deviation of 157.7±48.5 µm in glaucoma compared to 179.9±36.1 µm in healthy eyes (P<0.001. The choroid was thinner in both the peripapillary and macular regions in glaucoma compared to controls. Mean peripapillary CT was 154.1±44.1 µm and 134.0±56.9 µm (P<0.001 and macular CT 199.3±46.1 µm and 176.2±57.5 µm (P<0.001 for healthy and glaucomatous eyes respectively. However, older age (P<0.001 and longer axial length (P<0.001 were also associated with thinner choroid and when differences in age and axial length between glaucomatous and healthy subjects were accounted for, glaucoma was not significantly associated with CT. There was also no association between glaucoma severity and CT. CONCLUSIONS: Glaucoma was not associated with CT measured using SS-OCT; however, older age and longer axial length were associated with thinner choroid so should be considered when interpreting CT measurements.

  17. Choroidal thickness measurements with optical coherence tomography in branch retinal vein occlusion

    Directory of Open Access Journals (Sweden)

    Muge Coban-Karatas

    2016-05-01

    Full Text Available AIM: To evaluate central macular thickness (CMT and mean choroidal thickness (MCT in eyes with branch retinal vein occlusion (BRVO, before and after ranibizumab treatment using spectral domain-optical coherence tomography (SD-OCT. METHODS: Forty-two patients with unilateral BRVO and macular edema were included in this study. There were 25 men and 17 women. Using SD-OCT, choroidal thickness was measured at 500 µm intervals up to 1500 µm temporal and nasal to the fovea. MCT was calculated based on the average of the 7 locations. All the eyes with BRVO were treated with intravitreal ranibizumab (0.5 mg/0.05 mL. Comparisons between the BRVO and fellow eyes were analyzed using Mann-Whitney U test. Pre-injection and post-injection measurements were analyzed using Wilcoxon test and repeated measure analysis. RESULTS: At baseline, there was a significant difference between the BRVO and fellow eyes in MCT [BRVO eyes 245 (165-330 µm, fellow eyes 229 (157-327 µm] and CMT [BRVO eyes 463 (266-899 µm, fellow eyes 235 (148-378 µm (P=0.041, 0.0001, respectively]. Following treatment, CMT [295 (141-558 µm] and MCT [229 (157-329 µm] decreased significantly compared to the baseline measurements (P=0.001, 0.006, respectively. Also BCVA (logMAR improved significantly (P=0.0001 in the BRVO eyes following treatment. After treatment CMT [BRVO eyes 295 (141-558 µm, fellow eyes 234 (157-351 µm] and MCT [BRVO eyes 229 (157-329 µm, fellow eyes 233 (162-286 µm] values did not reveal any significant difference in BRVO eyes and fellow eyes (P=0.051, 0.824, respectively. CONCLUSION: In eyes with BRVO, CMT and MCT values are greater than the fellow eyes, and decrease significantly following ranibizumab injection.

  18. Lamellar macular hole formation following vitrectomy for rhegmatogenous retinal detachment repair

    Directory of Open Access Journals (Sweden)

    Kabanarou SA

    2012-04-01

    Full Text Available Tina Xirou, Andrej Kidess, Christina Kourentis, Vasiliki Xirou, Elias Feretis, Stamatina A KabanarouRetina Department, Hellenic Red Cross General Hospital, Athens, GreeceBackground: The purpose of this study was to investigate lamellar macular hole formation in six patients after rhegmatogenous retinal detachment repair.Methods: A retrospective review of medical records of patients who underwent primary pars plana vitrectomy for rhegmatogenous retinal detachment repair was performed. Optical coherence tomography characteristics and best-corrected visual acuity were evaluated. Patients who developed lamellar macular hole after pars plana vitrectomy for rhegmatogenous retinal detachment repair were identified.Results: A total of 1185 eyes underwent pars plana vitrectomy for retinal detachment between 2004 and 2009. Optical coherence tomography evaluation was available in 450 cases. Six of these cases demonstrated lamellar macular hole formation, which was diagnosed by OCT-3. The mean time from retinal detachment surgery to lamellar hole diagnosis was 4.1 months. The presence of an epiretinal membrane on the surface of the juxtafoveal retina was a common finding in all six patients. Visual acuity was improved after successful retinal reattachment and remained unchanged after lamellar hole formation.Conclusion: Lamellar macular holes developing after pars plana vitrectomy is a rare complication. Stability of optical coherence tomography findings and best-corrected visual acuity after lamellar macular hole formation may be observed for at least two years.Keywords: lamellar macular hole, rhegmatogenous retinal detachment

  19. Coherent DWDM technology for high speed optical communications

    Science.gov (United States)

    Saunders, Ross

    2011-10-01

    The introduction of coherent digital optical transmission enables a new generation of high speed optical data transport and fiber impairment mitigation. An initial implementation of 40 Gb/s coherent systems using Dual Polarization Quadrature Phase Shift Keying (DP-QPSK) is already being installed in carrier networks. New systems running at 100 Gb/s DP-QPSK data rate are in development and early technology lab and field trial phase. Significant investment in the 100 Gb/s ecosystem (optical components, ASICs, transponders and systems) bodes well for commercial application in 2012 and beyond. Following in the footsteps of other telecommunications fields such as wireless and DSL, we can expect coherent optical transmission to evolve from QPSK to higher order modulations schemes such as Mary PSK and/or QAM. This will be an interesting area of research in coming years and poses significant challenges in terms of electro-optic, DSP, ADC/DAC design and fiber nonlinearity mitigation to reach practical implementation ready for real network deployments.

  20. Retinal layer location of increased retinal thickness in eyes with subclinical and clinical macular edema in diabetes type 2

    DEFF Research Database (Denmark)

    Bandello, Francesco; Tejerina, Amparo Navea; Vujosevic, Stela

    2015-01-01

    PURPOSE: To identify the retinal layer predominantly affected in eyes with subclinical and clinical macular edema in diabetes type 2. METHODS: A cohort of 194 type 2 diabetic eyes/patients with mild nonproliferative diabetic retinopathy (ETDRS levels 20/35) were examined with Cirrus spectral......-domain optical coherence tomography (OCT) at the baseline visit (ClinicalTrials.gov identifier: NCT01145599). Automated segmentation of the retinal layers of the eyes with subclinical and clinical macular edema was compared with a sample of 31 eyes from diabetic patients with normal OCT and an age......-matched control group of 58 healthy eyes. RESULTS: From the 194 eyes in the study, 62 had subclinical macular edema and 12 had clinical macular edema. The highest increases in retinal thickness (RT) were found in the inner nuclear layer (INL; 33.6% in subclinical macular edema and 81.8% in clinical macular edema...

  1. Characterization of the dental pulp using optical coherence tomography

    Science.gov (United States)

    Kauffman, C. M. F.; Carvalho, M. T.; Araujo, R. E.; Freitas, A. Z.; Zezell, D. M.; Gomes, A. S. L.

    2006-02-01

    The inner structure of teeth, i.e. the root canal anatomy, is very complex. However a good knowledge of endodontic architecture is the first step towards successful endodontic treatment. Optical coherence tomography (OCT) is a powerful technique to generate images of hard and soft tissue. Its images show dependency on the optical properties of the tissue under analysis. Changes in the scattering and absorption of tissues can be observed through the OCT images. In this work, we used optical coherence tomography to perform in vitro studies of the inner structure of the first molar of albino rats (Rattus norvegicus). Focusing on the pulp chamber and in the root canal, we compare the images generated with the OCT technique to the histology. We are analyzing the feasibility of OCT to help on the diagnostic of endodontic diseases.

  2. Quantum optical coherence in cytoskeletal microtubules: implications for brain function.

    Science.gov (United States)

    Jibu, M; Hagan, S; Hameroff, S R; Pribram, K H; Yasue, K

    1994-01-01

    'Laser-like,' long-range coherent quantum phenomena may occur biologically within cytoskeletal microtubules. This paper presents a theoretical prediction of the occurrence in biological media of the phenomena which we term 'superradiance' and 'self-induced transparency'. Interactions between the electric dipole field of water molecules confined within the hollow core of microtubules and the quantized electromagnetic radiation field are considered, and microtubules are theorized to play the roles of non-linear coherent optical devices. Superradiance is a specific quantum mechanical ordering phenomenon with characteristic times much shorter than those of thermal interaction. Consequently, optical signalling (and computation) in microtubules would be free from both thermal noise and loss. Superradiant optical computing in networks of microtubules and other cytoskeletal structures may provide a basis for biomolecular cognition and a substrate for consciousness.

  3. Optical phase estimation via coherent state and displaced photon counting

    CERN Document Server

    Izumi, Shuro; Wakui, Kentaro; Fujiwara, Mikio; Ema, Kazuhiro; Sasaki, Masahide

    2016-01-01

    We consider the phase sensing via weak optical coherent state at quantum limit precision. A new detection scheme for the phase estimation is proposed which is inspired by the suboptimal quantum measurement in coherent optical communication. We theoretically analyze a performance of our detection scheme, which we call the displaced-photon counting, for phase sensing in terms of the Fisher information and show that the displaced-photon counting outperforms the static homodyne and heterodyne detections in wide range of the target phase. The proof-of-principle experiment is performed with linear optics and a superconducting nanowire single photon detector. The result shows that our scheme overcomes the limit of the ideal homodyne measurement even under practical imperfections.

  4. Coherent control of optical activity and optical anisotropy of thin metamaterials

    CERN Document Server

    Mousavi, Seyedmohammad A; Shi, Jinhui; Zheludev, Nikolay I

    2013-01-01

    The future fibre optic communications network will rely on photons as carriers of information, which may be stored in intensity, polarization or phase of light. However, processing of such optical information usually relies on electronics. Aiming to avoid the conversion between optical and electronic signals, modulation of light with light based on optical nonlinearity has become a major research field, but real integrated all-optical systems face thermal management and energy challenges. On the other hand, it has recently been demonstrated that the interaction of two coherent light beams on a thin, lossy, linear material can lead to large and ultrafast intensity modulation at arbitrarily low power resulting from coherent absorption. Here we demonstrate that birefringence and optical activity (linear and circular birefringence and dichroism) of functional materials can be coherently controlled by placing a thin material slab into a standing wave formed by the signal and control waves. Efficient control of the...

  5. Polarization-Sensitive Quantum Optical Coherence Tomography: Experiment

    CERN Document Server

    Booth, Mark C; Teich, Malvin Carl

    2010-01-01

    Polarization-sensitive quantum optical coherence tomography (PS-QOCT) makes use of a Type-II twin-photon light source for carrying out optical sectioning with polarization sensitivity. A BBO nonlinear optical crystal pumped by a Ti:sapphire psec-pulsed laser is used to confirm the theoretical underpinnings of this imaging paradigm. PS-QOCT offers even-order dispersion cancellation with simultaneous access to the group-velocity dispersion characteristics of the interstitial medium between the reflecting surfaces of the sample.

  6. Fourier phase in Fourier-domain optical coherence tomography.

    Science.gov (United States)

    Uttam, Shikhar; Liu, Yang

    2015-12-01

    Phase of an electromagnetic wave propagating through a sample-of-interest is well understood in the context of quantitative phase imaging in transmission-mode microscopy. In the past decade, Fourier-domain optical coherence tomography has been used to extend quantitative phase imaging to the reflection-mode. Unlike transmission-mode electromagnetic phase, however, the origin and characteristics of reflection-mode Fourier phase are poorly understood, especially in samples with a slowly varying refractive index. In this paper, the general theory of Fourier phase from first principles is presented, and it is shown that Fourier phase is a joint estimate of subresolution offset and mean spatial frequency of the coherence-gated sample refractive index. It is also shown that both spectral-domain phase microscopy and depth-resolved spatial-domain low-coherence quantitative phase microscopy are special cases of this general theory. Analytical expressions are provided for both, and simulations are presented to explain and support the theoretical results. These results are further used to show how Fourier phase allows the estimation of an axial mean spatial frequency profile of the sample, along with depth-resolved characterization of localized optical density change and sample heterogeneity. Finally, a Fourier phase-based explanation of Doppler optical coherence tomography is also provided.

  7. Multiple Scattering Model for Optical Coherence Tomography with Rytov Approximation

    KAUST Repository

    Li, Muxingzi

    2017-04-24

    Optical Coherence Tomography (OCT) is a coherence-gated, micrometer-resolution imaging technique that focuses a broadband near-infrared laser beam to penetrate into optical scattering media, e.g. biological tissues. The OCT resolution is split into two parts, with the axial resolution defined by half the coherence length, and the depth-dependent lateral resolution determined by the beam geometry, which is well described by a Gaussian beam model. The depth dependence of lateral resolution directly results in the defocusing effect outside the confocal region and restricts current OCT probes to small numerical aperture (NA) at the expense of lateral resolution near the focus. Another limitation on OCT development is the presence of a mixture of speckles due to multiple scatterers within the coherence length, and other random noise. Motivated by the above two challenges, a multiple scattering model based on Rytov approximation and Gaussian beam optics is proposed for the OCT setup. Some previous papers have adopted the first Born approximation with the assumption of small perturbation of the incident field in inhomogeneous media. The Rytov method of the same order with smooth phase perturbation assumption benefits from a wider spatial range of validity. A deconvolution method for solving the inverse problem associated with the first Rytov approximation is developed, significantly reducing the defocusing effect through depth and therefore extending the feasible range of NA.

  8. Reproducibility of Perfusion Parameters of Optic Disc and Macula in Rhesus Monkeys by Optical Coherence Tomography Angiography

    Directory of Open Access Journals (Sweden)

    Jing Li

    2016-01-01

    Conclusions: The study is about the reproducibility of optic disc and macular perfusion parameters as measured by OCT angiography in healthy rhesus monkeys. Flow index measurement reproducibility is high for both the optic disc and macula of normal monkey eyes. OCT angiography might be a useful technique to assess changes when examining monkeys with experimental ocular diseases.

  9. Surgical treatment of lamellar macular holes.

    Science.gov (United States)

    Michalewska, Zofia; Michalewski, Janusz; Odrobina, Dominik; Pikulski, Zbigniew; Cisiecki, Sławomir; Dziegielewski, Krzysztof; Nawrocki, Jerzy

    2010-10-01

    The aim of this study is to present functional and anatomical results of pars plana vitrectomy without gas tamponade in lamellar macular holes. Additionally, the study determines factors influencing final outcome. Twenty-six eyes of 26 patients with lamellar macular hole were diagnosed using spectral domain optical coherence tomography (SD-OCT). The diameters of the lamellar defects were measured. Pars plana vitrectomy with epiretinal membrane (ERM) removal and internal limiting membrane (ILM) peeling without endotamponade followed. Follow-up examinations were conducted with SD-OCT for a period of 12 months after surgery. The following factors were examined: maximum and minimum diameter of the lamellar defect, maximum diameter of the disruption of the photoreceptors, representing the photoreceptor layer, central macular thickness, paracentral macular thickness 1000 microm from the centre of the fovea, and maximum paracentral retinal thickness. Retina thickness was measured manually from the inner retina surface to the upper line of retinal pigment epithelium. Prior to surgery, mean visual acuity was 0.2. Twelve months after surgery, the mean visual acuity was 0.51. Lower visual acuity was observed in patients with photoreceptor layer defects localized under the fovea. Epiretinal membranes and complete or partial posterior hyaloid detachment were observed in all cases. The size of the lamellar defect had no influence on final visual acuity. The results obtained show that intraocular gas tamponade is not a crucial step in achieving closure and visual improvement in lamellar macular holes.

  10. Spontaneously resolving macular cyst in an infant

    Directory of Open Access Journals (Sweden)

    Anuradha Ganesh

    2013-01-01

    Full Text Available The purpose of this study is to describe transient macular cysts in an infant and correlate their occurrence with normal development events. A newborn Caucasian girl presented with a protruding corneal mass in her left eye at birth. She underwent a complete ophthalmic examination. A keratinized staphylomatous malformation involving the entire cornea and precluding further visualization of the anterior and posterior segment was observed in the left eye. Spectral domain optical coherence tomography (SD-OCT of the right eye performed when the child was approximately 6-week-old had revealed an unexpected finding of macular cysts involving the inner nuclear and outer retinal layers. Corneal transplant in the left eye was performed a month later. Ocular examination under anesthesia just prior to surgery revealed normal intraocular pressure, anterior segment and retina in the right eye. SD-OCT was normal in both eyes and showed complete resolution of the cysts in the right eye. The patient had not been on any medications at that time. Although clinical retinal examination might be unremarkable, SD-OCT may reveal cystic spaces in the macula. In the absence of conditions known to be associated with macular edema, transient macular cysts may arise due to a developmental incompetence of the blood-retinal barrier or may represent transient spaces created during normal migration of retinal cells. Further study is warranted to delineate the entity of transient macular cysts in infancy.

  11. Correlation between optical coherence tomography and multifocal electroretinogram findings with visual acuity in retinitis pigmentosa

    Directory of Open Access Journals (Sweden)

    Moschos MM

    2013-10-01

    Full Text Available Marilita M Moschos, Irini P Chatziralli, George Verriopoulos, Aristeides Triglianos, Dimitrios S Ladas, Dimitrios BrouzasLaboratory of Electrophysiology, First Department of Ophthalmology, University of Athens, Athens, GreeceIntroduction: Our purpose was to study the correlation between the macular morphology and function in eyes with retinitis pigmentosa (RP.Methods: Sixty-six eyes from 33 patients with RP and with different visual acuity (VA were studied using optical coherence tomography (OCT and multifocal electroretinogram (mfERG. Correlation analysis was performed between VA, macular thickness, mfERG amplitude, and latency.Results: Retinal thickness, retinal response density, and latency of the mfERG in the foveal area were independently and positively associated with VA (P = 0.002; P < 0.0001; P = 0.029; and P = 0.002, respectively, whereas there was no evidence for a correlation between VA and the amplitude of mfERG in the parafoveal area. Evidence of a correlation between the OCT and the mfERG evaluation was of borderline significance (P = 0.047. Also, there was evidence for an inverse association of VA with latency in ring 1 and ring 2 (b = -0.138; 95% confidence interval: -0.261, -0.015; P = 0.029. In accordance with the univariate findings, when foveal retinal thickness, mfERG amplitude, and latency in ring 1 were inserted simultaneously in the same model, all the three variables remained significantly associated with VA (P = 0.016; P < 0.0001; and P = 0.031, respectively. Nevertheless, some individual values deviated from the expected range. More specifically, 15 eyes showed a normal retinal thickness, whereas the respective VA was relatively low and the mfERG values were abnormal. Conversely, in seven eyes, despite the low retinal thickness, the respective VA was high.Conclusion: The combined use of OCT with mfERG appears to be more appropriate for the estimation of macular function.Keywords: retinitis pigmentosa, OCT, mfERG, VA

  12. Retinal neurodegeneration in Wilson's disease revealed by spectral domain optical coherence tomography.

    Directory of Open Access Journals (Sweden)

    Philipp Albrecht

    Full Text Available BACKGROUND/OBJECTIVE: In addition to cirrhosis of the liver, Wilson's disease leads to copper accumulation and widespread degeneration of the nervous system. Delayed visual evoked potentials (VEPs suggest changes to the visual system and potential structural changes of the retina. METHODS: We used the latest generation of spectral domain optical coherence tomography to assess the retinal morphology of 42 patients with Wilson's disease and 76 age- and sex-matched controls. We measured peripapillary retinal nerve fiber layer (RNFL thickness and total macular thickness and manually segmented all retinal layers in foveal scans of 42 patients with Wilson's disease and 76 age- and sex-matched controls. The results were compared with VEPs and clinical parameters. RESULTS: The mean thickness of the RNFL, paramacular region, retinal ganglion cell/inner plexiform layer and inner nuclear layer was reduced in Wilson's disease. VEPs were altered with delayed N75 and P100 latencies, but the N140 latency and amplitude was unchanged. An analysis of the laboratory parameters indicated that the serum concentrations of copper and caeruloplasmin positively correlated with the thickness of the outer plexiform layer and with N75 and P100 VEP latencies. CONCLUSION: Neuronal degeneration in Wilson's disease involves the retina and changes can be quantified by optical coherence tomography. While the VEPs and the thickness of the outer plexiform layer appear to reflect the current copper metabolism, the thicknesses of the RNFL, ganglion cell/inner plexiform layer, inner nuclear layer and the total paramacular thickness may be the best indicators of chronic neuronal degeneration.

  13. Probing myocardium biomechanics using quantitative optical coherence elastography

    Science.gov (United States)

    Wang, Shang; Lopez, Andrew L.; Morikawa, Yuka; Tao, Ge; Li, Jiasong; Larina, Irina V.; Martin, James F.; Larin, Kirill V.

    2015-03-01

    We present a quantitative optical coherence elastographic method for noncontact assessment of the myocardium elasticity. The method is based on shear wave imaging optical coherence tomography (SWI-OCT), where a focused air-puff system is used to induce localized tissue deformation through a low-pressure short-duration air stream and a phase-sensitive OCT system is utilized to monitor the propagation of the induced tissue displacement with nanoscale sensitivity. The 1-D scanning of M-mode OCT imaging and the application of optical phase retrieval and mapping techniques enable the reconstruction and visualization of 2-D depth-resolved shear wave propagation in tissue with ultra-high frame rate. The feasibility of this method in quantitative elasticity measurement is demonstrated on tissue-mimicking phantoms with the estimated Young's modulus compared with uniaxial compression tests. We also performed pilot experiments on ex vivo mouse cardiac muscle tissues with normal and genetically altered cardiomyocytes. Our results indicate this noncontact quantitative optical coherence elastographic method can be a useful tool for the cardiac muscle research and studies.

  14. Coherent optical photons from shock waves in crystals.

    Science.gov (United States)

    Reed, Evan J; Soljacić, Marin; Gee, Richard; Joannopoulos, J D

    2006-01-13

    We predict that coherent electromagnetic radiation in the 1-100 THz frequency range can be generated in crystalline materials when subject to a shock wave or soliton-like propagating excitation. To our knowledge, this phenomenon represents a fundamentally new form of coherent optical radiation source that is distinct from lasers and free-electron lasers. The radiation is generated by the synchronized motion of large numbers of atoms when a shock wave propagates through a crystal. General analytical theory and NaCl molecular dynamics simulations demonstrate coherence lengths on the order of mm (around 20 THz) and potentially greater. The emission frequencies are determined by the shock speed and the lattice constants of the crystal and can potentially be used to determine atomic-scale properties of the shocked material.

  15. Estudo da síndrome de tração macular vítreo-retiniana idiopática por meio da tomografia de coerência óptica: relato de casos A study of idiophatic vitreomacular traction syndrome with optical coherence tomography images: cases report

    OpenAIRE

    Hélio Paulo Primiano Júnior; Aloísio Fumio Nakashima; Otacílio de Oliveira Maia Júnior; Maria Teresa Brizzi Bonanomi; Yoshitaka Nakashima

    2007-01-01

    OBJETIVOS: Avaliar alterações estruturais observadas na síndrome de tração macular vítreo-retiniana idiopática (STMI) pela tomografia de coerência óptica (OCT), antes e depois da vitrectomia; identificar situações em que a tomografia de coerência óptica fornece informações adicionais da morfologia e patogênese desta doença. MÉTODOS: Imagens tomográficas (OCT Stratus) comparativas da estrutura vítreo-retiniana foram realizadas em quatro pacientes, em estágios variados da síndrome de tração mac...

  16. Gabor-based fusion technique for Optical Coherence Microscopy.

    Science.gov (United States)

    Rolland, Jannick P; Meemon, Panomsak; Murali, Supraja; Thompson, Kevin P; Lee, Kye-sung

    2010-02-15

    We recently reported on an Optical Coherence Microscopy technique, whose innovation intrinsically builds on a recently reported - 2 microm invariant lateral resolution by design throughout a 2 mm cubic full-field of view - liquid-lens-based dynamic focusing optical probe [Murali et al., Optics Letters 34, 145-147, 2009]. We shall report in this paper on the image acquisition enabled by this optical probe when combined with an automatic data fusion method developed and described here to produce an in-focus high resolution image throughout the imaging depth of the sample. An African frog tadpole (Xenopus laevis) was imaged with the novel probe and the Gabor-based fusion technique, demonstrating subcellular resolution in a 0.5 mm (lateral) x 0.5 mm (axial) without the need, for the first time, for x-y translation stages, depth scanning, high-cost adaptive optics, or manual intervention. In vivo images of human skin are also presented.

  17. Retinal thickness measured with optical coherence tomography and risk of disability worsening in multiple sclerosis

    DEFF Research Database (Denmark)

    Martinez-Lapiscina, Elena H; Arnow, Sam; Wilson, James A

    2016-01-01

    BACKGROUND: Most patients with multiple sclerosis without previous optic neuritis have thinner retinal layers than healthy controls. We assessed the role of peripapillary retinal nerve fibre layer (pRNFL) thickness and macular volume in eyes with no history of optic neuritis as a biomarker of dis...

  18. Digital signal processing techniques for coherent optical communication

    Science.gov (United States)

    Goldfarb, Gilad

    Coherent detection with subsequent digital signal processing (DSP) is developed, analyzed theoretically and numerically and experimentally demonstrated in various fiber-optic transmission scenarios. The use of DSP in conjunction with coherent detection unleashes the benefits of coherent detection which rely on the preservaton of full information of the incoming field. These benefits include high receiver sensitivity, the ability to achieve high spectral-efficiency and the use of advanced modulation formats. With the immense advancements in DSP speeds, many of the problems hindering the use of coherent detection in optical transmission systems have been eliminated. Most notably, DSP alleviates the need for hardware phase-locking and polarization tracking, which can now be achieved in the digital domain. The complexity previously associated with coherent detection is hence significantly diminished and coherent detection is once gain considered a feasible detection alternative. In this thesis, several aspects of coherent detection (with or without subsequent DSP) are addressed. Coherent detection is presented as a means to extend the dispersion limit of a duobinary signal using an analog decision-directed phase-lock loop. Analytical bit-error ratio estimation for quadrature phase-shift keying signals is derived. To validate the promise for high spectral efficiency, the orthogonal-wavelength-division multiplexing scheme is suggested. In this scheme the WDM channels are spaced at the symbol rate, thus achieving the spectral efficiency limit. Theory, simulation and experimental results demonstrate the feasibility of this approach. Infinite impulse response filtering is shown to be an efficient alternative to finite impulse response filtering for chromatic dispersion compensation. Theory, design considerations, simulation and experimental results relating to this topic are presented. Interaction between fiber dispersion and nonlinearity remains the last major challenge

  19. Field Theory for Coherent Optical Pulse Propagation

    CERN Document Server

    Park, Q H

    1997-01-01

    We introduce a new notion of "matrix potential" to nonlinear optical systems. In terms of a matrix potential $g$, we present a gauge field theoretic formulation of the Maxwell-Bloch equation that provides a semiclassical description of the propagation of optical pulses through resonant multi-level media. We show that the Bloch part of the equation can solved identically through $g$ and the remaining Maxwell equation becomes a second order differential equation with reduced set of variables due to the gauge invariance of the system. Our formulation clarifies the (nonabelian) symmetry structure of the Maxwell-Bloch equations for various multi-level media in association with symmetric spaces $G/H$. In particular, we associate nondegenerate two-level system for self-induced transparency with $G/H=SU(2)/U(1)$ and three-level $\\L $- or V-systems with $G/H = SU(3)/U(2)$. We give a detailed analysis for the two-level case in the matrix potential formalism, and address various new properties of the system including so...

  20. Optical Coherence Tomography in Pulmonary Medicine

    Science.gov (United States)

    Murgu, Septimiu Dan; Brenner, Matthew; Chen, Zhongping; Suter, Melissa J.

    Advances in pulmonary diagnostics and therapeutics offer a major potential for optical imaging applications both in clinical practice and research settings. Complexities of pulmonary structures and function have restricted widespread OCT investigations and clinical applications, but these will likely be overcome by developments in OCT technology [1]. Some factors that have limited adaptation of OCT into the pulmonary setting in the past have been the shallow depth of penetration, resolution limitations, relatively slow access times, need to examine large surface areas with numerous branching airways, motion artifacts, as well as a need for development of practical imaging probes to reach the relevant locations in a minimally invasive way. Considerable recent engineering and analytical advances in OCT technology [2-8] have already overcome several of these obstacles and will enable much more extensive investigations into the role for structural and functional pulmonary OCT imaging [1].

  1. Optical Coherence Tomography: Modeling and Applications

    DEFF Research Database (Denmark)

    Thrane, Lars

    in previous theoretical models of OCT systems. It is demonstrated that the shower curtain effect is of utmost importance in the theoretical description of an OCT system. The analytical model, together with proper noise analysis of the OCT system, enables calculation of the SNR, where the optical properties...... geometry, i.e., reflection geometry, is developed. As in the new OCT model, multiple scattered photons has been taken into account together with multiple scattering effects. As an important result, a novel method of creating images based on measurements of the momentum width of the Wigner phase......An analytical model is presented that is able to describe the performance of OCT systems in both the single and multiple scattering regimes simultaneously. This model inherently includes the shower curtain effect, well-known for light propagation through the atmosphere. This effect has been omitted...

  2. Parametric imaging of viscoelasticity using optical coherence elastography

    Science.gov (United States)

    Wijesinghe, Philip; McLaughlin, Robert A.; Sampson, David D.; Kennedy, Brendan F.

    2015-03-01

    We demonstrate imaging of soft tissue viscoelasticity using optical coherence elastography. Viscoelastic creep deformation is induced in tissue using step-like compressive loading and the resulting time-varying deformation is measured using phase-sensitive optical coherence tomography. From a series of co-located B-scans, we estimate the local strain rate as a function of time, and parameterize it using a four-parameter Kelvin-Voigt model of viscoelastic creep. The estimated viscoelastic strain and time constant are used to visualize viscoelastic creep in 2D, dual-parameter viscoelastograms. We demonstrate our technique on six silicone tissue-simulating phantoms spanning a range of viscoelastic parameters. As an example in soft tissue, we report viscoelastic contrast between muscle and connective tissue in fresh, ex vivo rat gastrocnemius muscle and mouse abdominal transection. Imaging viscoelastic creep deformation has the potential to provide complementary contrast to existing imaging modalities, and may provide greater insight into disease pathology.

  3. Optical Coherence Tomography in Spontaneous Resolution of Vitreomacular Traction Syndrome

    Directory of Open Access Journals (Sweden)

    Kuo-Hsuan Hung

    2010-06-01

    Full Text Available Vitreomacular traction syndrome (VTS is a vitreoretinal interface abnormality. The disorder is caused by incomplete posterior vitreous detachment with persistent traction on the macula that produces symptoms and decreased vision. Most symptomatic eyes with VTS undergo a further decrease in visual acuity. Spontaneous complete vitreomacular separation occurs infrequently in eyes with VTS. Surgical intervention may be considered if severe metamorphopsia and decreased visual quality occur. Herein, we report 2 typical cases of idiopathic VTS with spontaneous resolution of vitreo-retinal traction demonstrated by optical coherence tomography. Optical coherence tomography is a sensitive and useful tool for the confirmation of diagnosis and for the serial anatomical evaluation of patients with VTS.

  4. Control of coherent backscattering by breaking optical reciprocity

    CERN Document Server

    Bromberg, Y; Popoff, S M; Cao, H

    2015-01-01

    Reciprocity is a universal principle that has a profound impact on many areas of physics. A fundamental phenomenon in condensed-matter physics, optical physics and acoustics, arising from reciprocity, is the constructive interference of quantum or classical waves which propagate along time-reversed paths in disordered media, leading to, for example, weak localization and metal-insulator transition. Previous studies have shown that such coherent effects are suppressed when reciprocity is broken. Here we show that by breaking reciprocity in a controlled manner, we can tune, rather than simply suppress, these phenomena. In particular, we manipulate coherent backscattering of light, also known as weak localization. By utilizing a non-reciprocal magneto-optical effect, we control the interference between time-reversed paths inside a multimode fiber with strong mode mixing, and realize a continuous transition from the well-known peak to a dip in the backscattered intensity. Our results may open new possibilities fo...

  5. Optical coherence tomography a clinical and technical update

    CERN Document Server

    Cunha-Vaz, José

    2012-01-01

    Optical Coherence Tomography represents the ultimate noninvasive  ocular imaging technique although being in the field for over two-decades. This book encompasses both medical and technical developments and recent achievements. Here, the authors cover the field of application from the anterior to the posterior ocular segments (Part I) and present a comprehensive review on the development of OCT. Important developments towards  clinical applications are covered in Part II, ranging from the adaptive optics to the integration on a slit-lamp, and passing through new structural  and functional information extraction from OCT data. The book is intended to be informative, coherent and comprehensive for both the medical and technical communities and aims at easing the communication between the two fields and bridging the gap between the two scientific communities.

  6. Imaging cutaneous T-Cell lymphoma with optical coherence tomography

    DEFF Research Database (Denmark)

    Ring, H.C.; Hansen Stamp, I.M.; Jemec, G.B.E.

    2012-01-01

    Aim: To investigate the presentation of a patch-stage cutaneous T-cell lymphoma (CTCL) using optical coherence tomography (OCT). Methods: A patient with a patch caused by CTCL was photographed digitally, OCT-scanned and biopsied. A normal skin area adjacent to the patch was OCT-scanned for compar......Aim: To investigate the presentation of a patch-stage cutaneous T-cell lymphoma (CTCL) using optical coherence tomography (OCT). Methods: A patient with a patch caused by CTCL was photographed digitally, OCT-scanned and biopsied. A normal skin area adjacent to the patch was OCT.......13 mm. A good immediate correlation was found between histology and OCT imaging of the sample. Conclusion: The aetiology of the elongated structures is thought to be lymphomatous infiltrates. Similar findings have been described in ocular lymphoma and may therefore be an important characteristic...

  7. Topology optimization for optical microlithography with partially coherent illumination

    DEFF Research Database (Denmark)

    Zhou, Mingdong; Lazarov, Boyan Stefanov; Sigmund, Ole

    2017-01-01

    This article revisits a topology optimization design approach for micro-manufacturing and extends it to optical microlithography with partially coherent illumination. The solution is based on a combination of two technologies, the topology optimization and the proximity error correction in microl......This article revisits a topology optimization design approach for micro-manufacturing and extends it to optical microlithography with partially coherent illumination. The solution is based on a combination of two technologies, the topology optimization and the proximity error correction...... in microlithography/nanolithography. The key steps include (i) modeling the physical inputs of the fabrication process, including the ultraviolet light illumination source and the mask, as the design variables in optimization and (ii) applying physical filtering and heaviside projection for topology optimization...

  8. All-optically integrated multimodality imaging system: combined photoacoustic microscopy, optical coherence tomography, and fluorescence imaging

    Science.gov (United States)

    Chen, Zhongjiang; Yang, Sihua; Xing, Da

    2016-10-01

    We have developed a multimodality imaging system by optically integrating all-optical photoacoustic microscopy (AOPAM), optical coherence tomography (OCT) and fluorescence microscopy (FLM) to provide complementary information including optical absorption, optical back-scattering and fluorescence contrast of biological tissue. By sharing the same low-coherence Michelson interferometer, AOPAM and OCT could be organically optically combined to obtain the absorption and scattering information of the biological tissues. Also, owing to using the same laser source and objective lens, intrinsically registered photoacoustic and fluorescence signals are obtained to present the radiative and nonradiative transition process of absorption. Simultaneously photoacoustic angiography, tissue structure and fluorescence molecular in vivo images of mouse ear were acquired to demonstrate the capabilities of the optically integrated trimodality imaging system, which can present more information to study tumor angiogenesis, vasculature, anatomical structure and microenvironments in vivo.

  9. Strong electronic correlation effects in coherent multidimensional nonlinear optical spectroscopy.

    Science.gov (United States)

    Karadimitriou, M E; Kavousanaki, E G; Dani, K M; Fromer, N A; Perakis, I E

    2011-05-12

    We discuss a many-body theory of the coherent ultrafast nonlinear optical response of systems with a strongly correlated electronic ground state that responds unadiabatically to photoexcitation. We introduce a truncation of quantum kinetic density matrix equations of motion that does not rely on an expansion in terms of the interactions and thus applies to strongly correlated systems. For this we expand in terms of the optical field, separate out contributions to the time-evolved many-body state due to correlated and uncorrelated multiple optical transitions, and use "Hubbard operator" density matrices to describe the exact dynamics of the individual contributions within a subspace of strongly coupled states, including "pure dephasing". Our purpose is to develop a quantum mechanical tool capable of exploring how, by coherently photoexciting selected modes, one can trigger nonlinear dynamics of strongly coupled degrees of freedom. Such dynamics could lead to photoinduced phase transitions. We apply our theory to the nonlinear response of a two-dimensional electron gas (2DEG) in a magnetic field. We coherently photoexcite the two lowest Landau level (LL) excitations using three time-delayed optical pulses. We identify some striking temporal and spectral features due to dynamical coupling of the two LLs facilitated by inter-Landau-level magnetoplasmon and magnetoroton excitations and compare to three-pulse four-wave-mixing (FWM) experiments. We show that these features depend sensitively on the dynamics of four-particle correlations between an electron-hole pair and a magnetoplasmon/magnetoroton, reminiscent of exciton-exciton correlations in undoped semiconductors. Our results shed light into unexplored coherent dynamics and relaxation of the quantum Hall system (QHS) and can provide new insight into non-equilibrium co-operative phenomena in strongly correlated systems.

  10. Multifocal cysticercosis with optical coherence tomography findings in a child

    Directory of Open Access Journals (Sweden)

    Manisha Agarwal

    2012-01-01

    Full Text Available We herein report a case with multifocal cysticercosis - sub-conjunctival cysticercus cyst, sub-retinal cysticercosis, and neurocysticercosis in a child. The optical coherence tomography (OCT findings of the sub-retinal cysticercus cyst are reported. He was treated with anti-helminthic drugs and oral prednisolone followed by surgical removal of the sub-retinal cyst. He subsequently underwent silicone oil removal with lens aspiration and intraocular lens implantation maintaining stable vision

  11. Demonstration of Near-Optimal Discrimination of Optical Coherent States

    DEFF Research Database (Denmark)

    Wittmann, Christoffer; Takeoka, Masahiro; Cassemiro, Katiuscia N

    2008-01-01

    The optimal discrimination of nonorthogonal quantum states with minimum error probability is a fundamental task in quantum measurement theory as well as an important primitive in optical communication. In this work, we propose and experimentally realize a new and simple quantum measurement strategy...... capable of discriminating two coherent states with smaller error probabilities than can be obtained using the standard measurement devices: the Kennedy receiver and the homodyne receiver....

  12. Submicron Resolution Spectral-Domain Optical Coherence Tomography

    KAUST Repository

    Alarousu, Erkki

    2013-11-14

    Apparatuses and systems for submicron resolution spectral-domain optical coherence tomography (OCT) are disclosed. The system may use white light sources having wavelengths within 400-1000 nanometers, and achieve resolution below 1 .mu.m. The apparatus is aggregated into a unitary piece, and a user can connect the apparatus to a user provided controller and/or light source. The light source may be a supercontinuum source.

  13. Parallel optical coherence tomography using a CCD camera

    Institute of Scientific and Technical Information of China (English)

    Junle Qu(屈军乐); Ravi S.Jonnal; Donald T. Miller

    2004-01-01

    Parallel optical coherence tomography is demonstrated using a 12-bit scientific-grade charge-coupled device array.A superluminescent diode in combination with a free-space Michelson interferometer was employed to achieve 10-μm axial resolution and 1.1-μm transverse resolution on a 902×575 μm2 field of view.We imaged a test mirror and bovine retinal tissue using a four-step phase shift method.

  14. Optical coherence tomography-based micro-particle image velocimetry.

    Science.gov (United States)

    Mujat, Mircea; Ferguson, R Daniel; Iftimia, Nicusor; Hammer, Daniel X; Nedyalkov, Ivaylo; Wosnik, Martin; Legner, Hartmut

    2013-11-15

    We present a new application of optical coherence tomography (OCT), widely used in biomedical imaging, to flow analysis in near-wall hydrodynamics for marine research. This unique capability, called OCT micro-particle image velocimetry, provides a high-resolution view of microscopic flow phenomena and measurement of flow statistics within the first millimeter of a boundary layer. The technique is demonstrated in a small flow cuvette and in a water tunnel.

  15. Polarimetry noise in fiber-based optical coherence tomography instrumentation

    Science.gov (United States)

    Zhang, Ellen Ziyi; Vakoc, Benjamin J.

    2011-01-01

    High noise levels in fiber-based polarization-sensitive optical coherence tomography (PS-OCT) have broadly limited its clinical utility. In this study we investigate contribution of polarization mode dispersion (PMD) to the polarimetry noise. We develop numerical models of the PS-OCT system including PMD and validate these models with empirical data. Using these models, we provide a framework for predicting noise levels, for processing signals to reduce noise, and for designing an optimized system. PMID:21935044

  16. Clinical Observation on Juvenile Macular Hole without Trauma and Hypermyopia

    Institute of Scientific and Technical Information of China (English)

    Tieying Zhao; Qingshan Chen; Ming Li; Xunqing Gu; Rulong Gao; Feng Wen

    2005-01-01

    Purpose: To investigate the clinical characteristics of juvenile macular hole without trauma and hypermyopia, and research the mechanism of macular hole.Methods: Sixty-seven patients less than 40 years of age were studied retrospectively from June 1998 to March 2003. Five cases (7 eyes) aged from 22 to 38 years were reported and the clinical characteristics that had macular hole without trauma or hypermyopia were summed up.Results: There was 1 male and 4 females with visual acuity from 0.08 to 0.8. The images of optical coherence tomography (OCT) showed full thickness macular hole in 5 patients (7 eyes), and the diameters were from 87 to 1043 μm. Among them, 2 cases were combined with retina pigmentosa; 1 case with binocular Coat's disease; 1 case had bilateral macular hole combined with Eagles' disease; 1 case was combined with 2-2.5PD old retinochoroidal lesion under middle-peripheral fundus, and 1.5 PD retinal pigment epithelium (RPE) defect on the optical disk.Conclusion: The juvenile macular hole without trauma and hypermyopia combined the different retina vascular damages and the RPE defects.

  17. Optical Coherence Tomography as a Tool for Ocular Dynamics Estimation

    Directory of Open Access Journals (Sweden)

    Damian Siedlecki

    2015-01-01

    Full Text Available Purpose. The aim of the study is to demonstrate that the ocular dynamics of the anterior chamber of the eye can be estimated quantitatively by means of optical coherence tomography (OCT. Methods. A commercial high speed, high resolution optical coherence tomographer was used. The sequences of tomographic images of the iridocorneal angle of three subjects were captured and each image from the sequence was processed in MATLAB environment in order to detect and identify the contours of the cornea and iris. The data on pulsatile displacements of the cornea and iris and the changes of the depth of the gap between them were retrieved from the sequences. Finally, the spectral analysis of the changes of these parameters was performed. Results. The results of the temporal and spectral analysis manifest the ocular microfluctuation that might be associated with breathing (manifested by 0.25 Hz peak in the power spectra, heart rate (1–1.5 Hz peak, and ocular hemodynamics (3.75–4.5 Hz peak. Conclusions. This paper shows that the optical coherence tomography can be used as a tool for noninvasive estimation of the ocular dynamics of the anterior segment of the eye, but its usability in diagnostics of the ocular hemodynamics needs further investigations.

  18. Automatic detection of subretinal fluid and sub-retinal pigment epithelium fluid in optical coherence tomography images.

    Science.gov (United States)

    Ding, Weiguang; Young, Mei; Bourgault, Serge; Lee, Sieun; Albiani, David A; Kirker, Andrew W; Forooghian, Farzin; Sarunic, Marinko V; Merkur, Andrew B; Beg, Mirza Faisal

    2013-01-01

    Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries. Subretinal fluid (SRF) and sub-retinal pigment epithelium (sub-RPE) fluid are signs of AMD and can be detected in optical coherence tomography images. However, manual detection and segmentation of SRFs and sub-RPE fluids are laborious and time consuming. In this paper, a novel pipeline is proposed for automatic detection of SRFs and sub-RPE fluids. First, top and bottom layers of retina are segmented using a graph cut method. Then, a Split Bregman-based segmentation method is used to segment dark regions between layers. These segmented regions are considered as potential fluid candidates, on which a set of features are generated. After that, a random forest classifier is trained to distinguish between the true fluid regions from the falsely detected fluid regions. This method shows reasonable performance in a leave-one-out evaluation using a dataset from 21 patients.

  19. A comparison of two methods to measure choroidal thickness by enhanced depth imaging optical coherence tomography -Letter to the Editor

    DEFF Research Database (Denmark)

    Lundberg, Kristian; Vergmann, Anna Stage; Vestergaard, Anders Højslet;

    2016-01-01

    -domain optical coherence tomography (EDI-SD OCT) has made it possible to visualize the choroid, and it is generally accepted that Heidelberg Spectralis OCT provides valid measurements of choroidal thickness (CT) (Li et al. 2014), although no fully automated software is commercially available. In the literature...... different approaches and software programs are described for manual measurement of the CT. Unfortunately many investigators do not report in details which method they use. Two methods for CT-measurement are available in the Heidelberg software, but to our knowledge these methods have not been compared....... Hence, the purpose of this study was to evaluate and validate the Segmentation method and the Ruler method for CT-measurement. We obtained data from 10 healthy subjects, aged 15 to 17 years (mean 16.3) and 10 patients with macular pathology, aged 59 to 79 years (mean 71.8). The diseases included wet age...

  20. Variable-time-delay optical coherent transient signal processing.

    Science.gov (United States)

    Merkel, K D; Babbitt, W R; Anderson, K E; Wagner, K H

    1999-10-15

    A technique is proposed and experimentally demonstrated that achieves simultaneous optical pattern waveform storage and programmable time delay for continuous real-time signal processing by use of optical coherent transient technology. We achieve variable-time-delay and broadband signal processing by frequency shifting of two chirped programming pulses, the chirp rate of one being twice that of the other, without using brief reference pulses and without changing the timing of the programming sequence. We demonstrate the technique experimentally in Tm(3+): YAG at 5 K for 40-MHz chirps by performing temporal signal convolution with true-time delays that vary over a 250-ns range.

  1. High efficiency coherent beam combining of semiconductor optical amplifiers.

    Science.gov (United States)

    Creedon, Kevin J; Redmond, Shawn M; Smith, Gary M; Missaggia, Leo J; Connors, Michael K; Kansky, Jan E; Fan, Tso Yee; Turner, George W; Sanchez-Rubio, Antonio

    2012-12-01

    We demonstrate 40 W coherently combined output power in a single diffraction-limited beam from a one-dimensional 47-element array of angled-facet slab-coupled optical waveguide amplifiers at 1064 nm. The output from each emitter was collimated and overlapped onto a diffractive optical element combiner using a common transform lens. Phase locking was achieved via active feedback on each amplifier's drive current to maximize the power in the combined beam. The combining efficiency at all current levels was nearly constant at 87%.

  2. Three-dimensional multifunctional optical coherence tomography for skin imaging

    Science.gov (United States)

    Li, En; Makita, Shuichi; Hong, Young-Joo; Kasaragod, Deepa; Sasaoka, Tomoko; Yamanari, Masahiro; Sugiyama, Satoshi; Yasuno, Yoshiaki

    2016-02-01

    Optical coherence tomography (OCT) visualizes cross-sectional microstructures of biological tissues. Recent developments of multifunctional OCT (MF-OCT) provides multiple optical contrasts which can reveal currently unknown tissue properties. In this contribution we demonstrate multifunctional OCT specially designed for dermatological investigation. And by utilizing it to measure four different body parts of in vivo human skin, three-dimensional scattering OCT, OCT angiography, polarization uniformity tomography, and local birefringence tomography images were obtained by a single scan. They respectively contrast the structure and morphology, vasculature, melanin content and collagen traits of the tissue.

  3. Quantum theory of optical coherence selected papers and lectures

    CERN Document Server

    Glauber, Roy J

    2007-01-01

    A summary of the pioneering work of Glauber in the field of optical coherence phenomena and photon statistics, this book describes the fundamental ideas of modern quantum optics and photonics in a tutorial style. It is thus not only intended as a reference for researchers in the field, but also to give graduate students an insight into the basic theories of the field. Written by the Nobel Laureate himself, the concepts described in this book have formed the basis for three further Nobel Prizes in Physics within the last decade

  4. The diagnosis of nasopharyngeal carcinoma by optical coherence tomography (OCT)

    Science.gov (United States)

    Li, J. H.; Du, Y.

    2016-06-01

    We have attempted to explore the intrinsic differences in the optical properties of the nasopharyngeal carcinoma (NPC) and normal tissue by optical coherence tomography (OCT). OCT imaging of normal tissue provided three layers of epithelium, lamina propria, and the brighter interface of basement membrane; while carcinomas disrupted the layered construction embedded in signal-poor images. The morphologies were consistent with histological findings. Sensitivity and specificity were 90% and 100%, respectively. This pilot study demonstrates that NPC could be diagnosed by visualization, which implies that OCT might be potentially used to differentiate normal from NPC tissue in the early stage as an invasive biopsy.

  5. Modeling light–tissue interaction in optical coherence tomography systems

    DEFF Research Database (Denmark)

    Andersen, Peter E.; Jørgensen, Thomas Martini; Thrane, Lars

    2015-01-01

    Optical coherence tomography (OCT) performs high-resolution, cross-sectional tomographic imaging of the internal tissue microstructure by measuring backscattered or backreflected light. The scope of this chapter is to present analytical and numerical models that are able to describe light......-tissue interactions and its influence on the performance of OCT systems including multiple scattering effects in heterogeneous media. In general, these models, analytical as well as numerical, may serve as important tools for improving interpretation of OCT images and also serve as prerequisites for extraction...... of tissue optical scattering parameters....

  6. Novel coherent optical OFDM-based transponder for optical slot switched networks

    DEFF Research Database (Denmark)

    Mestre, Miquel A.; Estaran, Jose M.; Jenneve, Philippe

    2016-01-01

    We report a novel coherent optical OFDM transponder approach capable of recovering microsecond-scale data-burst while adapting to tight filtering constraints present in optical slot switched intradatacenter networks. Filtering effects in such large node-count environments are reviewed. The CO...

  7. Effectiveness of adaptive optics system in satellite-to-ground coherent optical communication.

    Science.gov (United States)

    Jian, Huang; Ke, Deng; Chao, Liu; Peng, Zhang; Dagang, Jiang; Zhoushi, Yao

    2014-06-30

    Adaptive optics (AO) systems can suppress the signal fade induced by atmospheric turbulence in satellite-to-ground coherent optical communication. The lower bound of the signal fade under AO compensation was investigated by analyzing the pattern of aberration modes for a one-stage imaging AO system. The distribution of the root mean square of the residual aberration is discussed on the basis of the spatial and temporal characteristics of the residual aberration of the AO system. The effectiveness of the AO system for improving the performance of coherent optical communication is presented in terms of the bit error rate and system availability.

  8. Optical Coherence Tomography for Brain Imaging

    Science.gov (United States)

    Liu, Gangjun; Chen, Zhongping

    Recently, there has been growing interest in using OCT for brain imaging. A feasibility study of OCT for guiding deep brain probes has found that OCT can differentiate the white matter and gray matter because the white matter tends to have a higher peak reflectivity and steeper attenuation rate compared to gray matter. In vivo 3D visualization of the layered organization of a rat olfactory bulb with OCT has been demonstrated. OCT has been used for single myelin fiber imaging in living rodents without labeling. The refractive index in the rat somatosensory cortex has also been measured with OCT. In addition, functional extension of OCT, such as Doppler-OCT (D-OCT), polarization sensitive-OCT (PS-OCT), and phase-resolved-OCT (PR-OCT), can image and quantify physiological parameters in addition to the morphological structure image. Based on the scattering changes during neural activity, OCT has been used to measure the functional activation in neuronal tissues. PS-OCT, which combines polarization sensitive detection with OCT to determine tissue birefringence, has been used for the localization of nerve fiber bundles and the mapping of micrometer-scale fiber pathways in the brain. D-OCT, also named optical Doppler tomography (ODT), combines the Doppler principle with OCT to obtain high resolution tomographic images of moving constituents in highly scattering biological tissues. D-OCT has been successfully used to image cortical blood flow and map the blood vessel network for brain research. In this chapter, the principle and technology of OCT and D-OCT are reviewed and examples of potential applications are described.

  9. Reliability of Heterochromatic Flicker Photometry in Measuring Macular Pigment Optical Density among Preadolescent Children

    Directory of Open Access Journals (Sweden)

    Sasha M. McCorkle

    2015-10-01

    Full Text Available Macular pigment optical density (MPOD—assessed using customized heterochromatic flicker photometry (cHFP—is related to better cognition and brain lutein among adults. However, the reliability of MPOD assessed by cHFP has not been investigated in children. We assessed inter-session reliability of MPOD using modified cHFP. 7–10-year-olds (n = 66 underwent cHFP over 2 visits using 11 examiners. Reliability was also assessed in a subsample (n = 46 with only 2 examiners. Among all participants, there was no significant difference between the two sessions (p = 0.59—session 1: 0.61 ± 0.28; session 2: 0.62 ± 0.27. There was no significant difference in the MPOD of boys vs. girls (p = 0.56. There was a significant correlation between sessions (Y = 0.52x + 0.31; R2 = 0.29, p ≤ 0.005, with a reliability of 0.70 (Cronbach’s α. Among the subsample with 2 examiners, there was a significant correlation between sessions (Y = 0.54x + 0.31; R2 = 0.32, p < 0.005, with a reliability of 0.72 (Cronbach’s α. In conclusion, there is moderate reliability for modified cHFP to measure MPOD in preadolescents. These findings provide support for future studies aiming to conduct noninvasive assessments of retinal xanthophylls and study their association with cognition during childhood.

  10. Macular pigment optical density is positively associated with academic performance among preadolescent children.

    Science.gov (United States)

    Barnett, Sasha M; Khan, Naiman A; Walk, Anne M; Raine, Lauren B; Moulton, Christopher; Cohen, Neal J; Kramer, Arthur F; Hammond, Billy R; Renzi-Hammond, Lisa; Hillman, Charles H

    2017-05-23

    Macular pigment optical density (MPOD) - a non-invasive indicator of retinal xanthophylls and correlate of brain lutein - has been associated with superior cognitive function among adult populations. Given that lutein accumulation in the brain occurs in early life, it is possible that the cognitive implications of greater MPOD may be evident in childhood. Participants aged 8-9 years (n = 56) completed MPOD measurements via heterochromatic flicker photometry. Academic performance was assessed using the Kaufman Test of Academic and Educational Achievement II (KTEA). Habitual dietary intake of L and Z was measured among a subsample of participants (n = 35) using averaged 3-day food records. Stepwise hierarchical regression models were developed to determine the relationship between MPOD and academic achievement tests, following the adjustment of key covariates including sex, aerobic fitness, body composition, and intelligence quotient (IQ). The regression analyses revealed that MPOD improved the model, beyond the covariates, for overall academic achievement (ΔR(2) = 0.10, P academic achievement in children, even after accounting for the robust effects of IQ and other demographic factors. These findings extend the positive associations observed between MPOD and cognitive abilities to a pediatric population. Trail registration: The Fitness Improves Thinking in Kids 2 (FITKids2) trial was registered at www.clinicaltrials.gov as NCT01619826.

  11. Choroidal structure determined by binarizing optical coherence tomography images in eyes with reticular pseudodrusen

    Science.gov (United States)

    Masuda, Naonori; Kojima, Masashi; Yamashita, Mariko; Nishi, Tomo; Ogata, Nahoko

    2017-01-01

    Purpose To compare the choroidal structure beneath the macular area in eyes with reticular pseudodrusen (RPD) and age-matched controls. Methods This study was performed at Nara Medical University Hospital, Japan. Twenty eyes of 14 patients (82.3±4.2 years, mean ± standard deviation) with RPD and 35 eyes of 20 age-matched controls (81.5±6.0 years) were studied. The choroidal structure was determined by binarizing the images obtained by enhanced depth imaging optical coherence tomography in all patients and controls. The total, luminal, and stromal choroidal areas were quantified by the binarization method. Results The total choroidal area of the eyes with RPD was significantly smaller than that of control eyes (P=0.001, unpaired t-test). Both the luminal and stromal areas in eyes with RPD were significantly smaller than that of control eyes (P=0.001, paired t-test), but there was no significant difference in the luminal/stromal ratio between eyes with RPD and control eyes. Conclusion The total, luminal, and stromal choroidal areas in eyes with RPD were smaller than those of the control eyes. The reduction of the choroidal luminal and stromal areas may be due to a loss of the oxygen demand of the choroid due to RPE dysfunction. PMID:28490860

  12. Acute Retinal Pigment Epitheliitis: Spectral Domain Optical Coherence Tomography, Fluorescein Angiography, and Autofluorescence Findings

    Directory of Open Access Journals (Sweden)

    Tuğba Aydoğan

    2015-01-01

    Full Text Available A 17-year-old presented with central and paracentral scotomas in his right eye for one week. There was no remarkable medical or ocular history. Blood analyses were within normal range. At presentation both eyes’ best-corrected visual acuities were 20/20. Slit-lamp examination result was normal. Fundus examination revealed yellow-white hypopigmented areas in the macula. Fluorescein angiography (FA showed hypofluorescence surrounded by ring of hyperfluorescence. Fundus autofluorescence (FAF was slightly increased. Spectral domain optical coherence tomography (SD-OCT showed disruption of IS/OS junction with expansion of abnormal hyperreflectivity from retinal pigment epithelium to the outer nuclear layer (ONL. One month later fundus examination showed disappearance of the lesions. FA revealed transmission hyperfluorescence. FAF showed increased autofluorescence and pigment clumping. Hyperreflective band in SD-OCT disappeared. Loss of photoreceptor segment layers was observed in some of the macular lesions. The diagnosis of acute retinal pigment epitheliitis can be challenging after disappearance of fundus findings. FA, FAF, and SD-OCT are important tests for diagnosis after resolution of the disease.

  13. Optical coherence tomography and electrophysiology of retinal and visual pathways in Wilson's disease.

    Science.gov (United States)

    Langwińska-Wośko, Ewa; Litwin, Tomasz; Szulborski, Kamil; Członkowska, Anna

    2016-04-01

    We evaluated correlations between positive findings of changes on brain magnetic resonance imaging (MRI) and selected morphological and electrophysiological parameters of the retinal and visual systems in Wilson's disease. Fifty-eight Wilson's disease symptomatic patients were divided according to whether they displayed brain changes on MRI (positive, n = 39; negative, n = 19). All participants and healthy control group (n = 30), underwent retinal optical coherence tomography to assess the thickness of macula and the total retinal nerve fiber layer. Visual evoked potentials were measured and electroretinography was performed. Macular and retinal nerve fibers were thinner in participants with changes on MRI than in participants without changes. Electrophysiological parameters were markedly different in the MRI positive group compared with the negative group and 30 healthy controls; however, some abnormalities were evident in cases without visible brain pathology. Morphological and electrophysiological changes of retinal and visual pathways are associated with MRI visualized brain injury in Wilson's disease and may be useful for detecting the degree of neurodegeneration.

  14. Choroidal structure determined by binarizing optical coherence tomography images in eyes with reticular pseudodrusen.

    Science.gov (United States)

    Masuda, Naonori; Kojima, Masashi; Yamashita, Mariko; Nishi, Tomo; Ogata, Nahoko

    2017-01-01

    To compare the choroidal structure beneath the macular area in eyes with reticular pseudodrusen (RPD) and age-matched controls. This study was performed at Nara Medical University Hospital, Japan. Twenty eyes of 14 patients (82.3±4.2 years, mean ± standard deviation) with RPD and 35 eyes of 20 age-matched controls (81.5±6.0 years) were studied. The choroidal structure was determined by binarizing the images obtained by enhanced depth imaging optical coherence tomography in all patients and controls. The total, luminal, and stromal choroidal areas were quantified by the binarization method. The total choroidal area of the eyes with RPD was significantly smaller than that of control eyes (P=0.001, unpaired t-test). Both the luminal and stromal areas in eyes with RPD were significantly smaller than that of control eyes (P=0.001, paired t-test), but there was no significant difference in the luminal/stromal ratio between eyes with RPD and control eyes. The total, luminal, and stromal choroidal areas in eyes with RPD were smaller than those of the control eyes. The reduction of the choroidal luminal and stromal areas may be due to a loss of the oxygen demand of the choroid due to RPE dysfunction.

  15. Foveal dysplasia evident by optical coherence tomography in patients with a history of retinopathy of prematurity.

    Science.gov (United States)

    Recchia, Franco M; Recchia, Cynthia C

    2007-01-01

    To describe the optical coherence tomography (OCT) findings for patients with a history of retinopathy of prematurity (ROP). Clinical records, fundus photographs, and OCT findings for consecutive patients aged 8 years and older who had a history of ROP were reviewed. The main outcome measures were best-corrected visual acuity, central foveal thickness (CFT), macular anatomy, and foveal contour by OCT. Twenty eyes of 12 patients (median age, 15 years) were studied. Median gestational age at birth was 25 weeks. Six eyes had received peripheral retinal ablation for threshold ROP. Median best-corrected visual acuity was 20/40 (range, 20/20 to counting fingers). CFT was >220 microm in 70% of eyes and >240 microm in 35% of eyes. In all eyes, foveal contour was abnormal, with foveal depression either absent (n = 7 [35%]) or shallow (n = 13 [65%]). Preservation of multiple inner retinal layers within the fovea was seen in 14 eyes (70%). Vitreomacular traction or subretinal fluid was not seen in any eye. Anomalies in foveal anatomy by OCT may be a vestige of prematurity, appear to be independent of prior retinopexy, and can still be associated with excellent visual acuity.

  16. Flat Choroidal Nevus Inaccessible to Ultrasound Sonography Evaluated by Enhanced Depth Imaging Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Chrysanthi Basdekidou

    2011-06-01

    Full Text Available Purpose: To demonstrate the usefulness of enhanced depth imaging optical coherence tomography (EDI-OCT in investigating choroidal lesions inaccessible to ultrasound sonography. Methods: In a 60-year-old woman with an asymptomatic choroidal nevus, normal OCT was used to observe the macula and EDI-OCT to image the choroidal nevus that was inaccessible to ultrasound. The exact location of the lesion in the choroid and the dimensions of the nevus were measured. Results: The lesion was located in the superior macula, and the nevus was homogeneous in its reflectivity. We observed a thickened choroid delineated by the shadow cone behind it, measuring 1,376 × 325 µm in the larger vertical cut and 1,220 × 325 µm in the larger horizontal cut in an image with a 1:1 pixel mapping and automatic zoom. The macular profile and thickness were both normal. Conclusions: EDI-OCT appears to be an excellent technique for measuring choroidal nevi and all choroidal lesions accessible to OCT imaging by depicting their exact location in the choroid, their dimensions, and their demarcation from the surrounding healthy tissue, thus allowing for a more efficient and accurate follow-up.

  17. Choroid thickness in central serous chorioretinopathy using enhanced depth imaging optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Xiao-Long Yu

    2013-04-01

    Full Text Available AIM: To observe the choroidal thickness in the macular area in affected and unaffected fellow eyes with central serous chorio retinopathy(CSCand in healthy controls. METHODS: Twenty-six cases with unilateral CSC and controls were recruited in this study. All eyes were divided into three groups: 26 eyes in Group A(affected eyes with CSC, 26 eyes in group B(unaffected fellow eyesand 26 eyes in group C(right eyes of age and sex matched control. Enhanced depth imaging was obtained by using spectral-domain optical coherence tomography. Subfoveal choroidal thickness and choroidal thickness at 1mm/3mm nasal, temporal, superior and inferior to the fovea were measured. RESULTS: Choroidal thickness was significantly increased in affected eyes with CSC than unaffected fellow eyes(t=5.57, P<0.01.The mean subfoveal choroidal thickness(SFCTwas 528.31±91.24μm in group A, 413.71±79.35μm in group B, and 301.31±52.46 in group C. The subfoveal choroid was significantly thicker in group A than Group C(P<0.01. SFCT in unaffected fellow eyes were thicker than the controls(P<0.01. CONCLUSION:Choroidal thickness is thicker in affected eyes with CSC and also in fellow unaffected eyes, indicating that the choroid blood vessels are high and perfusion state, may be one of the factors of the disease CSC.

  18. Assessment of Choroidal Thickness in Healthy and Glaucomatous Eyes Using Swept Source Optical Coherence Tomography

    Science.gov (United States)

    Zhang, Chunwei; Tatham, Andrew J.; Medeiros, Felipe A.; Zangwill, Linda M.; Yang, Zhiyong; Weinreb, Robert N.

    2014-01-01

    Purpose To evaluate choroidal thickness (CT) in healthy and glaucomatous eyes using Swept Source Optical Coherence Tomography (SS-OCT). Methods A cross-sectional observational study of 216 eyes of 140 subjects with glaucoma and 106 eyes of 67 healthy subjects enrolled in the Diagnostic Innovations in Glaucoma Study. CT was assessed from wide-field (12×9 mm) SS-OCT scans. The association between CT and potential confounding variables including age, gender, axial length, intraocular pressure, central corneal thickness and ocular perfusion pressure was examined using univariable and multivariable regression analyses. Results Overall CT was thinner in glaucomatous eyes with a mean (± standard deviation) of 157.7±48.5 µm in glaucoma compared to 179.9±36.1 µm in healthy eyes (Pchoroid was thinner in both the peripapillary and macular regions in glaucoma compared to controls. Mean peripapillary CT was 154.1±44.1 µm and 134.0±56.9 µm (Pchoroid and when differences in age and axial length between glaucomatous and healthy subjects were accounted for, glaucoma was not significantly associated with CT. There was also no association between glaucoma severity and CT. Conclusions Glaucoma was not associated with CT measured using SS-OCT; however, older age and longer axial length were associated with thinner choroid so should be considered when interpreting CT measurements. PMID:25295876

  19. Investigation of alterations in multifractality in optical coherence tomographic images of in vivo human retina

    Science.gov (United States)

    Das, Nandan Kumar; Mukhopadhyay, Sabyasachi; Ghosh, Nirmalya; Chhablani, Jay; Richhariya, Ashutosh; Divakar Rao, Kompalli; Sahoo, Naba Kishore

    2016-09-01

    Optical coherence tomography (OCT) enables us to monitor alterations in the thickness of the retinal layer as disease progresses in the human retina. However, subtle morphological changes in the retinal layers due to early disease progression often may not lead to detectable alterations in the thickness. OCT images encode depth-dependent backscattered intensity distribution arising due to the depth distributions of the refractive index from tissue microstructures. Here, such depth-resolved refractive index variations of different retinal layers were analyzed using multifractal detrended fluctuation analysis, a special class of multiresolution analysis tools. The analysis extracted and quantified microstructural multifractal information encoded in normal as well as diseased human retinal OCT images acquired in vivo. Interestingly, different layers of the retina exhibited different degrees of multifractality in a particular retina, and the individual layers displayed consistent multifractal trends in healthy retinas of different human subjects. In the retinal layers of diabetic macular edema (DME) subjects, the change in multifractality manifested prominently near the boundary of the DME as compared to the normal retinal layers. The demonstrated ability to quantify depth-resolved information on multifractality encoded in OCT images appears promising for the early diagnosis of diseases of the human eye, which may also prove useful for detecting other types of tissue abnormalities from OCT images.

  20. 3D Curvelet-Based Segmentation and Quantification of Drusen in Optical Coherence Tomography Images

    Directory of Open Access Journals (Sweden)

    M. Esmaeili

    2017-01-01

    Full Text Available Spectral-Domain Optical Coherence Tomography (SD-OCT is a widely used interferometric diagnostic technique in ophthalmology that provides novel in vivo information of depth-resolved inner and outer retinal structures. This imaging modality can assist clinicians in monitoring the progression of Age-related Macular Degeneration (AMD by providing high-resolution visualization of drusen. Quantitative tools for assessing drusen volume that are indicative of AMD progression may lead to appropriate metrics for selecting treatment protocols. To address this need, a fully automated algorithm was developed to segment drusen area and volume from SD-OCT images. The proposed algorithm consists of three parts: (1 preprocessing, which includes creating binary mask and removing possible highly reflective posterior hyaloid that is used in accurate detection of inner segment/outer segment (IS/OS junction layer and Bruch’s membrane (BM retinal layers; (2 coarse segmentation, in which 3D curvelet transform and graph theory are employed to get the possible candidate drusenoid regions; (3 fine segmentation, in which morphological operators are used to remove falsely extracted elongated structures and get the refined segmentation results. The proposed method was evaluated in 20 publically available volumetric scans acquired by using Bioptigen spectral-domain ophthalmic imaging system. The average true positive and false positive volume fractions (TPVF and FPVF for the segmentation of drusenoid regions were found to be 89.15% ± 3.76 and 0.17% ± .18%, respectively.

  1. Visualization of vitreoretinal surgical manipulations using intraoperative spectral domain optical coherence tomography

    Science.gov (United States)

    Tao, Yuankai K.; Ehlers, Justis P.; Toth, Cynthia A.; Izatt, Joseph A.

    2011-03-01

    Vitreoretinal surgical visualization by ophthalmic microscopy is limited in its ability to distinguish thin translucent tissues from other retinal substructures. Conventional methods for supplementing poor contrast, such as with increased illumination and application of exogenous contrast agents, have been limited by the risks of toxicity at the retina. Spectral domain optical coherence tomography (SDOCT) has demonstrated strong clinical success in retinal imaging, enabling high-resolution, motion-artifact-free cross-sectional imaging and rapid accumulation of volumetric macular datasets. Current generation SDOCT systems achieve surgical microscope to concurrently acquire high-resolution, high-contrast SDOCT volumetric datasets. Here, we demonstrated the utility of intraoperative MMOCT for the visualization of vitreoretinal surgical procedures. Vitreoretinal surgery was simulated by performing procedures, through an ophthalmic surgical microscope, on cadaveric porcine eyes. The datasets acquired with the MMOCT show both instrument-tissue interaction as well as the ability of OCT to image certain surgical tools, which would directly translate to better surgical visualization and impact the treatment of ocular diseases.

  2. Optical coherent detection Brillouin distributed optical fiber sensor based on orthogonal polarization diversity reception

    Institute of Scientific and Technical Information of China (English)

    Muping Song; Bin Zhao; Xianmin Zhang

    2005-01-01

    In Brillouin distributed optical fiber sensor, using optical coherent detection to detect Brillouin scattering optical signal is a good method, but there exists the polarization correlated detection problem. A novel detecting scheme is presented and demonstrated experimentally, which adopts orthogonal polarization diversity reception to resolve the polarization correlated detection problem. A laser is used as pump and reference light sources, a microwave electric-optical modulator (EOM) is adopted to produce frequency shift reference light, a polarization controller is used to control the polarization of the reference light which is changed into two orthogonal polarization for two adjacent acquisition periods. The Brillouin scattering light is coherently detected with the reference light, and the Brillouin scattering optical signal is taken out based on Brillouin frequency shift. After electronic processing, better Brillouin distributed sensing signal is obtained. A 25-km Brillouin distributed optical fiber sensor is achieved.

  3. Effect of Hydroxychloroquine on the Retinal Layers: A Quantitative Evaluation with Spectral-Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Hasim Uslu

    2016-01-01

    Full Text Available Purpose. To evaluate the effect of hydroxychloroquine on retinal pigment epithelium- (RPE- Bruch’s membrane complex, photoreceptor outer segment, and macular ganglion cell-inner plexiform layer (GCIPL thicknesses using spectral-domain optical coherence tomography (SD-OCT. Methods. In this prospective case-control study, 51 eyes of 51 hydroxychloroquine patients and 30 eyes of 30 healthy subjects were included. High-quality images were obtained using a Cirrus HD-OCT with 5-line raster mode; the photoreceptor inner segment (IS and outer segment (OS, sum of the segments (IS + OS, and RPE-Bruch’s membrane complex were analyzed. Results. The thicknesses of the IS + OS and OS layers were significantly lower in the hydroxychloroquine subjects compared to the control subjects (P<0.05. RPE-Bruch’s membrane complex thicknesses were significantly higher in the hydroxychloroquine subjects than for those of the control subjects (P<0.05. The minimum and temporal-inferior macular GCIPL thicknesses were significantly different between the patients with hydroxychloroquine use and the control subjects (P=0.04 and P=0.03, resp.. Conclusions. The foveal photoreceptor OS thinning, loss of GCIPL, and RPE-Bruch’s membrane thickening were detected in patients with hydroxychloroquine therapy. This quantitative approach using SD-OCT images may have important implications to use as an early indicator of retinal toxicity without any visible signs of hydroxychloroquine retinopathy.

  4. Long-term changes of macular retinal thickness after idiopathic macular hole surgery

    Directory of Open Access Journals (Sweden)

    Yan Yang

    2014-12-01

    Full Text Available AIM:To determine the changes of regional macular retinal thickness(RTwith spectral domain optical coherence tomography(SD-OCTafter successful pars plana vitrectomy(PPVsurgery with inner limiting membrane(ILMpeeling in patients with idiopathic macular hole.METHODS:A non-randomized retrospective case study on 17 patients(17 eyeswho were hospitalized between March 1, 2011 and June 30, 2013. All 17 eyes had been diagnosed with idiopathic macular hole and thereafter underwent 25G-PPV surgeries performed by the same surgeon with ILM peeling and short-term gas tamponade. In the 6mo-plus follow-up after surgery, these eyes were found to have successful closure in the macular hole. The macular RT of the nine areas in the Early Treatment Diabetic Retinopathy Study was measured by SD-OCT. All patients were applied by SD-OCT with linear scan of the macular. At least four examinations on the operated eye were conducted in contrast to the other normal eye: before the surgery, 3~5wk after the surgery(stage A, 2~3mo after the surgery(stage B, and >6mo after the surgery(stage C.RESULTS:In stage A, the macular RT of operated eyes in the areas of C, IS, II, IN, OS, OI, ON(263.00±39.48, 313.92±18.35, 311.00±18.02, 335.67±19.91, 280.83±33.74, 269.92±23.32, 307.00±28.40were significantly thicker than the corresponding areas of the normal fellow eyes(220.51±23.94, 292.08±21.93, 282.50±20.30, 288.33±20.76, 251.25±17.60, 247.75±21.48, 265.17±24.76μm(PP>0.01. In Stage B, the macular RT in the areas of II, IN, OS(335.67±19.20,319.75±19.20, 273.50±16.89μmwere significantly thicker than the corresponding areas of the normal fellow eyes(286.33±20.46, 293.42±17.64, 252.50±16.32μm(PP> 0.01. In Stage C, the macular RT of operated eyes with the areas of IN(321.17±19.71μmwere significantly thicker than the corresponding areas of the normal fellow eyes(296.25±19.57μm(PP>0.01. Moreover, the macular RT of operated eyes in the areas of ON, IT(307.00±28

  5. Optical coherence tomography for retinal imaging in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Zimmermann H

    2014-12-01

    Full Text Available Hanna Zimmermann,1 Timm Oberwahrenbrock,1 Alexander U Brandt,1 Friedemann Paul,1–3 Jan Dörr1,2 1NeuroCure Clinical Research Center, 2Clinical and Experimental Multiple Sclerosis Research Center, 3Department of Neurology, Charité – Universitätsmedizin Berlin, Berlin, Germany Abstract: Visual disturbances caused by inflammatory and demyelinating processes of the visual system, mainly in the optic nerve, are a common symptom in multiple sclerosis (MS. Optical coherence tomography (OCT is a tool that is increasingly used for quantifying retinal damage in MS and other neurologic diseases. Based on spectral interferometry, it uses low-coherent infrared light to generate high-resolution spatial images of the retina. The retinal nerve fiber layer (RNFL consists of unmyelinated axons that form the optic nerve, and thus represents a part of the central nervous system. OCT allows for noninvasive measurements of RNFL thickness in micrometer resolution. With the help of OCT, researchers have managed to demonstrate that eyes of MS patients show distinct RNFL thinning after an event of acute optic neuritis in MS, and even subclinical damage in eyes with no previous optic neuritis. OCT is also a useful tool in terms of providing a differential diagnosis of MS toward, for example, neuromyelitis optica, a disease that usually shows stronger retinal thinning, or Susac syndrome, which is characterized by distinct patchy thinning of the inner retinal layers. RNFL thinning is associated with magnetic resonance imaging-derived measurements of the brain, such as whole-brain atrophy, gray and white matter atrophy, and optic radiation damage. These features suggest that OCT-derived retinal measurements are a complement for measuring central nervous system neurodegeneration in the context of clinical trials – for example, with neuroprotective substances. Keywords: visual function, multiple sclerosis, optic neuritis, retinal nerve fiber layer, neuromyelitis optica

  6. Analysis and follow-up of type 1 choroidal neovascularisation with optical coherence tomography-angiography after antiangiogenic treatment.

    Science.gov (United States)

    Torrecillas-Picazo, R; Cerdà-Ibáñez, M; Almor Palacios, I; Hervás Hernandis, J M; Ramón-Cosín, R; Ruiz Del Rio, N; Duch-Samper, A

    2017-06-01

    To describe the characteristics of type 1 choroidal neovascularisation (CNV) in age-related macular degeneration (ARMD) using two different optical coherence tomography angiography (OCT-A) devices sequentially during a standard protocol of three intravitreal injections of an anti-vascular endothelial growth factor (anti-VEGF). The study included 6 eyes with naïve neovascular ARMD. Macular OCT-A images were acquired using AngioPlex Cirrus HD-OCT 5000 (Carl Zeiss Meditec, Inc., Dublin, USA) and DRI OCT Triton SS-OCT Angio (Topcon, Medical Systems, Inc. Oakland, NJ, USA). The macular OCT-A scan covered an area of 3×3mm. Distinct morphological patterns and quantifiable features of the neovascular membranes were studied on en face projection images, which were taken at different stages of the follow-up. Treatment response could be estimated using the OCT-A criteria of CNV activity. Higher activity scores before treatment resulted in a greater decrease in the membrane area. The estimated net decline in area ranged from 83.5% to 1.4%. The OCT-A performed one-week after treatment revealed the greatest area reductions. OCT-A provides new possibilities for the non-invasive assessment of features of neovascular networks and CNV structural morphology. Newly described activity criteria can also guide therapeutic decisions, and help in evaluating responses. Quantitative and qualitative information can be provided with this technique. However, further software development and future investigation are essential to define the role of this tool on a daily basis. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Evaluation of Retinal Nerve Fiber Layer and Ganglion Cell Complex in Patients with Optic Neuritis or Neuromyelitis Optica Spectrum Disorders Using Optical Coherence Tomography in a Chinese Cohort

    OpenAIRE

    Guohong Tian; Zhenxin Li; Guixian Zhao; Chaoyi Feng; Mengwei Li; Yongheng Huang; Xinghuai Sun

    2015-01-01

    We evaluate a cohort of optic neuritis and neuromyelitis optica (NMO) spectrum disorders patients in a territory hospital in China. The peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell complex (GCC) were measured using spectral-domain OCT after 6 months of acute onset. The results showed that both the peripapillary RNFL and macular GCC were significantly thinner in all optic neuritis subtypes compared to controls. In addition, the recurrent optic neuritis and NMO group...

  8. Invited Article: A compact optically coherent fiber frequency comb.

    Science.gov (United States)

    Sinclair, L C; Deschênes, J-D; Sonderhouse, L; Swann, W C; Khader, I H; Baumann, E; Newbury, N R; Coddington, I

    2015-08-01

    We describe the design, fabrication, and performance of a self-referenced, optically coherent frequency comb. The system robustness is derived from a combination of an optics package based on polarization-maintaining fiber, saturable absorbers for mode-locking, high signal-to-noise ratio (SNR) detection of the control signals, and digital feedback control for frequency stabilization. The output is phase-coherent over a 1-2 μm octave-spanning spectrum with a pulse repetition rate of ∼200 MHz and a residual pulse-to-pulse timing jitter <3 fs well within the requirements of most frequency-comb applications. Digital control enables phase coherent operation for over 90 h, critical for phase-sensitive applications such as timekeeping. We show that this phase-slip free operation follows the fundamental limit set by the SNR of the control signals. Performance metrics from three nearly identical combs are presented. This laptop-sized comb should enable a wide-range of applications beyond the laboratory.

  9. PREFACE: XVIII International Youth Scientific School "Coherent Optics and Optical Spectroscopy"

    Science.gov (United States)

    Salakhov, M. Kh; Samartsev, V. V.; Gainutdinov, R. Kh

    2015-05-01

    Kazan Federal University has held the annual International Youth School "Coherent Optics and Optical Spectroscopy" since 1997. The choice of the topic is not accidental. Kazan is the home of photon echo which was predicted at Kazan Physical-Technical Institute in 1963 by Prof. U.G. Kopvil'em and V.R. Nagibarov and observed in Columbia University by N.A. Kurnit, I.D. Abella, and S.R. Hartmann in 1964. Since then, photon echo has become a powerful tool of coherent optical spectroscopy and optical information processing, which have been developed here in Kazan in close collaboration between Kazan Physical-Technical Institute and Kazan Federal University. The main subjects of the XVIII International Youth School are: Nonlinear and coherent optics; Atomic and molecular spectroscopy; Coherent laser spectroscopy; Problems of quantum optics; Quantum theory of radiation; and Nanophotonics and Scanning Probe Microscopy. The unchallenged organizers of that school are Kazan Federal University and Kazan E.K. Zavoisky Physical-Technical Institute. The rector of the School is Professor Myakzyum Salakhov, and the vice-rector is Professor Vitaly Samartsev. The International Youth Scientific School "Coherent Optics and Optical Spectroscopy" follows the global pattern of comprehensive studies of matter properties and their interaction with electromagnetic fields. Since 1997 more than 100 famous scientists from the USA, Germany, Ukraine, Belarus and Russia have given plenary lecture presentations. Here over 1000 young scientists had an opportunity to participate in lively discussions about the latest scientific news. Many young people have submitted interesting reports on photonics, quantum electronics, laser physics, quantum optics, traditional optical and laser spectroscopy, non-linear optics, material science and nanotechnology. Here we are publishing the fullsize papers prepared from the most interesting lectures and reports selected by the Program Committee of the School. The

  10. Advanced Equalization Techniques for Digital Coherent Optical Receivers

    DEFF Research Database (Denmark)

    Arlunno, Valeria

    This PhD thesis addresses the design and performance evaluation of advanced Digital Signal Processing (DSP) algorithms for coherent optical fiber transmission systems. The research results presented in this thesis report on transmission of highly spectrally efficient optical communication systems...... employing multiplexing techniques with polarization multiplexing and multi-level modulations format. Advanced digital signal processing techniques offer robustness and flexibility for next generation high capacity optical fibre networks and are therefore considered as key building blocks in next generation...... format detection. Feedback equalization structure have been investigated in high order modulation formats transmission, when combined with coding techniques, and for closed spaced multiplexing scenario. Highlight results presented in this PhD thesis include evaluation and implementation of a novel...

  11. Few-photon coherent nonlinear optics with a single molecule

    CERN Document Server

    Maser, Andreas; Utikal, Tobias; Götzinger, Stephan; Sandoghdar, Vahid

    2015-01-01

    The pioneering experiments of linear spectroscopy were performed using flames in the 1800s, but nonlinear optical measurements had to wait until lasers became available in the twentieth century. Because the nonlinear cross section of materials is very small, usually macroscopic bulk samples and pulsed lasers are used. Numerous efforts have explored coherent nonlinear signal generation from individual nanoparticles or small atomic ensembles with millions of atoms. Experiments on a single semiconductor quantum dot have also been reported, albeit with a very small yield. Here, we report on coherent nonlinear spectroscopy of a single molecule under continuous-wave single-pass illumination, where efficient photon-molecule coupling in a tight focus allows switching of a laser beam by less than a handful of pump photons nearly resonant with the sharp molecular transition. Aside from their fundamental importance, our results emphasize the potential of organic molecules for applications such as quantum information pro...

  12. Passive endoscopic polarization sensitive optical coherence tomography with completely fiber based optical components

    Science.gov (United States)

    Cahill, Lucas; Lee, Anthony M. D.; Pahlevaninezhad, Hamid; Ng, Samson; MacAulay, Calum E.; Poh, Catherine; Lane, Pierre

    2015-03-01

    Polarization Sensitive Optical Coherence Tomography (PSOCT) is a functional extension of Optical Coherence Tomography (OCT) that is sensitive to well-structured, birefringent tissue such as scars, smooth muscle and cartilage. In this work, we present a novel completely fiber based swept source PSOCT system using a fiber-optic rotary pullback catheter. This PSOCT implementation uses only passive optical components and requires no calibration while adding minimal additional cost to a standard structural OCT imaging system. Due to its complete fiber construction, the system can be made compact and robust, while the fiber-optic catheter allows access to most endoscopic imaging sites. The 1.5mm diameter endoscopic probe can capture 100 frames per second at pullback speeds up to 15 mm/s allowing rapid traversal of large imaging fields. We validate the PSOCT system with known birefringent tissues and demonstrate in vivo PSOCT imaging of human oral scar tissue.

  13. Cystoid macular edema

    Directory of Open Access Journals (Sweden)

    Tryfon G Rotsos

    2008-10-01

    Full Text Available Tryfon G Rotsos1, Marilita M Moschos21Medical Retina Service, Moorfields Eye Hospital, London, UK; 2Department of Ophthalmology, University of Athens, GreeceAbstract: We review the epidemiology, pathophysiology, and etiology of cystoid macular edema (CME. Inflammatory, diabetic, post-cataract, and macular edema due to age-related macular degeneration is described. The role of chronic inflammation and hypoxia and direct macular traction is evaluated in each case according to different views from the literature. The different diagnostic methods for evaluating the edema are described. Special attention is given to fluoroangiography and the most modern methods of macula examination, such as ocular coherence tomography and multifocal electroretinography. Finally, we discuss the treatment of cystoid macular edema in relation to its etiology. In this chapter we briefly refer to the therapeutic value of laser treatment especially in diabetic maculopathy or vitrectomy in some selected cases. Our paper is focused mainly on recent therapeutic treatment with intravitreal injection of triamcinolone acetonide and anti-VEGF factors like bevacizumab (Avastin, ranibizumab (Lucentis, pegaptamid (Macugen, and others. The goal of this paper is to review the current status of this treatment for macular edema due to diabetic maculopathy, central retinal vein occlusion and post-cataract surgery. For this reason the results of recent multicenter clinical trials are quoted, as also our experience on the use of intravitreal injections of anti-VEGF factors and we discuss its value in clinical practice.Keywords: cystoid macular edema, anti-VEGF, fluoroangiography, OCT, multifocal electroretinography

  14. Invited Article: The coherent optical laser beam recombination technique (COLBERT) spectrometer: Coherent multidimensional spectroscopy made easier

    Science.gov (United States)

    Turner, Daniel B.; Stone, Katherine W.; Gundogdu, Kenan; Nelson, Keith A.

    2011-08-01

    We have developed an efficient spectrometer capable of performing a wide variety of coherent multidimensional measurements at optical wavelengths. The two major components of the largely automated device are a spatial beam shaper which controls the beam geometry and a spatiotemporal pulse shaper which controls the temporal waveform of the femtosecond pulse in each beam. We describe how to construct, calibrate, and operate the device, and we discuss its limitations. We use the exciton states of a semiconductor nanostructure as a working example. A series of complex multidimensional spectra—displayed in amplitude and real parts—reveals increasingly intricate correlations among the excitons.

  15. Resultado funcional e índice macular em portadores de buraco macular submetidos à cirurgia com remoção da membrana limitante interna Functional outcome and macular index in macular hole patients who underwent surgery with internal limiting membrane removal

    Directory of Open Access Journals (Sweden)

    José Ricardo Diniz

    2008-04-01

    Full Text Available OBJETIVOS: Avaliar o resultado funcional e o índice macular dos portadores de buraco macular submetidos à cirurgia com remoção da membrana limitante interna. MÉTODOS: Quinze olhos de 15 pacientes com buraco macular estágios 2, 3 e 4 foram incluídos no estudo. Todos foram submetidos à cirurgia de buraco macular convencional com remoção da membrana limitante interna corada pelo azul de tripan. Melhor acuidade visual com correção e cortes transversais medidos por tomografia de coerência óptica (OCT foram avaliados no pré- e pós-operatório. O índice macular (razão entre a altura e base do buraco macular foi calculado e correlacionado com o diâmetro mínimo do buraco macular e o ganho de acuidade visual pós-operatória. RESULTADOS: Obteve-se fechamento do buraco macular em todos pacientes operados. Em 86,7%, houve ganho de pelo menos três linhas de visão. O índice macular demonstrou correlação negativa significante com o diâmetro mínimo (r=0,811. Não foi observada correlação significante entre o índice macular e o ganho de acuidade visual pós-operatória (r=0,351. CONCLUSÃO: Os resultados funcionais na cirurgia do buraco macular com remoção da membrana limitante interna foram bons neste grupo de pacientes. O índice macular demonstrou ser compatível com a configuração espacial do buraco macular, porém não foi preditor de resultados visuais.PURPOSE: To evaluate the functional outcome and macular index in patients with macular hole who underwent surgery with internal limiting membrane removal. METHODS: Fifteen eyes of 15 patients with idiopathic macular hole stages 2, 3 or 4 were enrolled in this study. All patients underwent conventional macular hole surgery with trypan blue staining to remove the internal limiting membrane. The best-corrected visual acuity and cross-sectional images of macular hole measured by optical coherence tomography (OCT were evaluated pre- and postoperatively. The macular hole index

  16. Retinal thickness measured with optical coherence tomography and risk of disability worsening in multiple sclerosis: a cohort study.

    Science.gov (United States)

    Martinez-Lapiscina, Elena H; Arnow, Sam; Wilson, James A; Saidha, Shiv; Preiningerova, Jana Lizrova; Oberwahrenbrock, Timm; Brandt, Alexander U; Pablo, Luis E; Guerrieri, Simone; Gonzalez, Ines; Outteryck, Olivier; Mueller, Ann-Kristin; Albrecht, Phillip; Chan, Wesley; Lukas, Sebastian; Balk, Lisanne J; Fraser, Clare; Frederiksen, Jette L; Resto, Jennifer; Frohman, Teresa; Cordano, Christian; Zubizarreta, Irati; Andorra, Magi; Sanchez-Dalmau, Bernardo; Saiz, Albert; Bermel, Robert; Klistorner, Alexander; Petzold, Axel; Schippling, Sven; Costello, Fiona; Aktas, Orhan; Vermersch, Patrick; Oreja-Guevara, Celia; Comi, Giancarlo; Leocani, Letizia; Garcia-Martin, Elena; Paul, Friedemann; Havrdova, Eva; Frohman, Elliot; Balcer, Laura J; Green, Ari J; Calabresi, Peter A; Villoslada, Pablo

    2016-05-01

    Most patients with multiple sclerosis without previous optic neuritis have thinner retinal layers than healthy controls. We assessed the role of peripapillary retinal nerve fibre layer (pRNFL) thickness and macular volume in eyes with no history of optic neuritis as a biomarker of disability worsening in a cohort of patients with multiple sclerosis who had at least one eye without optic neuritis available. In this multicentre, cohort study, we collected data about patients (age ≥16 years old) with clinically isolated syndrome, relapsing-remitting multiple sclerosis, and progressive multiple sclerosis. Patients were recruited from centres in Spain, Italy, France, Germany, Czech Republic, Netherlands, Canada, and the USA, with the first cohort starting in 2008 and the latest cohort starting in 2013. We assessed disability worsening using the Expanded Disability Status Scale (EDSS). The pRNFL thickness and macular volume were assessed once at study entry (baseline) by optical coherence tomography (OCT) and was calculated as the mean value of both eyes without optic neuritis for patients without a history of optic neuritis or the value of the non-optic neuritis eye for patients with previous unilateral optic neuritis. Researchers who did the OCT at baseline were masked to EDSS results and the researchers assessing disability with EDSS were masked to OCT results. We estimated the association of pRNFL thickness or macular volume at baseline in eyes without optic neuritis with the risk of subsequent disability worsening by use of proportional hazards models that included OCT metrics and age, disease duration, disability, presence of previous unilateral optic neuritis, and use of disease-modifying therapies as covariates. 879 patients with clinically isolated syndrome (n=74), relapsing-remitting multiple sclerosis (n=664), or progressive multiple sclerosis (n=141) were included in the primary analyses. Disability worsening occurred in 252 (29%) of 879 patients with

  17. Automated Segmentability Index for Layer Segmentation of Macular SD-OCT Images

    NARCIS (Netherlands)

    Lee, K.; Buitendijk, G.H.; Bogunovic, H.; Springelkamp, H.; Hofman, A.; Wahle, A.; Sonka, M.; Vingerling, J.R.; Klaver, C.C.W.; Abramoff, M.D.

    2016-01-01

    PURPOSE: To automatically identify which spectral-domain optical coherence tomography (SD-OCT) scans will provide reliable automated layer segmentations for more accurate layer thickness analyses in population studies. METHODS: Six hundred ninety macular SD-OCT image volumes (6.0 x 6.0 x 2.3 mm3) we

  18. Visual acuity and microperimetric mapping of lesion area in eyes with inflammatory cystoid macular oedema

    DEFF Research Database (Denmark)

    Munk, Marion R; Kiss, Christopher G; Huf, Wolfgang

    2014-01-01

    PURPOSE:   To evaluate the effect of fluid accumulation on local visual function in inflammatory cystoid-macular-edema (ICME). METHODS:   This cross-sectional study applied optical-coherence-tomography over a 12×12 fovea-centered field in 50 patients with ICME and mapped the extent of fluid-fille...

  19. Optical coherence tomography imaging of chorioretinal folds associated with hypotony maculopathy following pars plana vitrectomy

    Directory of Open Access Journals (Sweden)

    Williams Jr BK

    2015-09-01

    Full Text Available Basil K Williams Jr, Jonathan S Chang, Harry W Flynn Jr Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA Abstract: Chorioretinal folds may occur as a consequence of hypotony and can be a cause of vision loss when associated with macular involvement. In this report, the spectral domain ocular coherence tomography imaging of three patients with chorioretinal folds before and after management are presented. The cases had unique presentations and each underwent different management approaches, but the results included improved visual acuities and lessened chorioretinal folds. Keywords: hypotony, chorioretinal folds, ocular coherence tomography

  20. Spectral Domain Optical Coherence Tomography in Diffuse Unilateral Subacute Neuroretinitis

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre de A. Garcia Filho

    2011-01-01

    Full Text Available Purpose. To describe the SD-OCT findings in patients with diffuse unilateral subacute neuroretinitis (DUSN and evaluate CRT and RNFL thickness. Methods. Patients with clinical diagnosis of DUSN who were submitted to SD-OCT were included in the study. Complete ophthalmologic examination and SD-OCT were performed. Cirrus scan strategy protocols used were macular cube, optic nerve head cube, and HD-5 line raster. Results. Eight patients with DUSN were included. Mean RNFL thickness was 80.25 μm and 104.75 μm for affected and normal eyes, respectively. Late stage had mean RNFL thickness of 74.83 μm compared to 96.5 μm in early stage. Mean CMT was 205.5 μm for affected eyes and 255.13 μm for normal fellow eyes. Conclusion. RNFL and CMT were thinner in DUSN eyes compared to normal eyes. Late-stage disease had more pronounced thinning compared to early-stage patients. This thinning in RNFL and CMT may reflect the low visual acuity in patients with DUSN.

  1. Evaluation of dermal fillers with noncontact optical coherence elastography

    Science.gov (United States)

    Singh, Manmohan; Wang, Shang; Yee, Richard W.; Han, Zhaolong; Aglyamov, Salavat R.; Larin, Kirill V.

    2017-02-01

    Over 2 million dermal filler procedures are performed each year in the USA alone, and this figure is only expected to increase as the aging population continues to grow. Dermal filler treatments can last from a few months to years depending on the type of filler and its placement. Although adverse reactions are rare, they can be quite severe due to ischemic events and filler migration. Previously, techniques such as ultrasound or magnetic resonance imaging have been used to evaluate the filler injections. However, these techniques are not practical for real-time filler injection guidance due to limitations such as the physical presence of the transducer. In this work, we propose the use of optical coherence tomography (OCT) for image-guided dermal filler injections due to the high spatial and temporal resolution of OCT. In addition, we utilize a noncontact optical coherence elastography (OCE) technique, to evaluate the efficacy of the dermal filler injection. A grid of air-pulse OCE measurements was taken, and the dynamic response of the skin to the air-pulse was translated to the Young's modulus and shear viscosity. Our results show that OCT was able to visualize the dermal filler injection process, and that OCE was able to localize the dermal filler injection sites. Combined with functional techniques such as optical microangiography, and recent advanced in OCT hardware, OCT may be able to provide real-time injection guidance in 3D by visualizing blood vessels to prevent ischemic events.

  2. Polarization-sensitive optical coherence tomography applied to intervertebral disk

    Science.gov (United States)

    Matcher, Stephen J.; Winlove, Peter; Gangnus, Sergei V.

    2003-07-01

    Polarization-sensitive optical coherence tomography (PSOCT) is a powerful new optical imaging modality that is sensitive to the birefringence properties of tissues. It thus has potential applications in studying the large-scale ordering of collagen fibers within connective tisues and changes related to pathology. As a tissue for study by PSOCT, intervertebral disk respresents an interesting system as the collagen organization is believed to show pronounced variations with depth, on a spatial scale of about 100 μm. We have used a polarization-sensitive optical coherence tomography system to measure the birefringence properties of bovine caudal intervertebral disk and compared this with equine flexor tendon. The result for equine tendon, δ = (3.0 +/- 0.5)x10-3 at 1.3 μm, is in broad agreement with values reported for bovine tendon, while bovine intervertebral disk displays a birefringence of about half this, δ = 1.2 x 10-3 at 1.3 μm. While tendon appears to show a uniform fast-axis over 0.8 mm depth, intervertebral disk shows image contrast at all orientations relative to a linearly polarized input beam, suggesting a variation in fast-axis orientation with depth. These initial results suggest that PSOCT could be a useful tool to study collagen organization within this tissue and its variation with applied load and disease.

  3. Functional Doppler optical coherence tomography for cortical blood flow imaging

    Science.gov (United States)

    Yu, Lingfeng; Liu, Gangjun; Nguyen, Elaine; Choi, Bernard; Chen, Zhongping

    2010-02-01

    Optical methods have been widely used in basic neuroscience research to study the cerebral blood flow dynamics in order to overcome the low spatial resolution associated with magnetic resonance imaging and positron emission tomography. Although laser Doppler imaging and laser speckle imaging can map out en face cortical hemodynamics and columns, depth resolution is not available. Two-photon microscopy has been used for mapping cortical activity. However, flow measurement requires fluorescent dye injection, which can be problematic. The noninvasive and high resolution tomographic capabilities of optical coherence tomography make it a promising technique for mapping depth resolved cortical blood flow. Here, we present a functional Doppler optical coherence tomography (OCT) imaging modality for quantitative evaluation of cortical blood flow in a mouse model. Fast, repeated, Doppler OCT scans across a vessel of interest were performed to record flow dynamic information with a high temporal resolution of the cardiac cycles. Spectral Doppler analysis of continuous Doppler images demonstrates how the velocity components and longitudinally projected flow-volume-rate change over time, thereby providing complementary temporal flow information to the spatially distributed flow information of Doppler OCT. The proposed functional Doppler OCT imaging modality can be used to diagnose vessel stenosis/blockage or monitor blood flow changes due to pharmacological agents/neuronal activities. Non-invasive in-vivo mice experiments were performed to verify the capabilities of function Doppler OCT.

  4. Miniature endoscopic optical coherence tomography for calculus detection.

    Science.gov (United States)

    Kao, Meng-Chun; Lin, Chun-Li; Kung, Che-Yen; Huang, Yi-Fung; Kuo, Wen-Chuan

    2015-08-20

    The effective treatment of periodontitis involves the detection and removal of subgingival dental calculus. However, subgingival calculus is more difficult to detect than supragingival calculus because it is firmly attached to root surfaces within periodontal pockets. To achieve a smooth root surface, clinicians often remove excessive amounts of root structure because of decreased visibility. In addition, enamel pearl, a rare type of ectopic enamel formation on the root surface, can easily be confused with dental calculus in the subgingival environment. In this study, we developed a fiber-probe swept-source optical coherence tomography (SSOCT) technique and combined it with the quantitative measurement of an optical parameter [standard deviation (SD) of the optical coherence tomography (OCT) intensity] to differentiate subgingival calculus from sound enamel, including enamel pearl. Two-dimensional circumferential images were constructed by rotating the miniprobe (0.9 mm diameter) while acquiring image lines, and the adjacent lines in each rotation were stacked to generate a three-dimensional volume. In OCT images, compared to sound enamel and enamel pearls, dental calculus showed significant differences (Pcalculus.

  5. Coherent transport of matter waves in disordered optical potentials

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Robert

    2007-07-01

    The development of modern techniques for the cooling and the manipulation of atoms in recent years, and the possibility to create Bose-Einstein condensates and degenerate Fermi gases and to load them into regular optical lattices or disordered optical potentials, has evoked new interest for the disorder-induced localization of ultra-cold atoms. This work studies the transport properties of matter waves in disordered optical potentials, which are also known as speckle potentials. The effect of correlated disorder on localization is first studied numerically in the framework of the Anderson model. The relevant transport parameters in the configuration average over many different realizations of the speckle potential are then determined analytically, using self-consistent diagrammatic perturbation techniques. This allows to make predictions for a possible experimental observation of coherent transport phenomena for cold atoms in speckle potentials. Of particular importance are the spatial correlations of the speckle fluctuations, which are responsible for the anisotropic character of the single scattering processes in the effective medium. Coherent multiple scattering leads to quantum interference effects, which entail a renormalization of the diffusion constant as compared to the classical description. This so-called weak localization of matter waves is studied as the underlying mechanism for the disorder-driven transition to the Anderson-localization regime, explicitly taking into account the correlations of the speckle fluctuations. (orig.)

  6. Fiber optic low-coherence Michelson interferometer for silicon growth measurement

    Science.gov (United States)

    Michael, Robert R., Jr.; Lawson, Christopher M.

    1994-02-01

    We report on the use of optical low coherence reflectometry for silicon characterization. The measurement system uses a low coherence light source (edge-emitting LED) in conjunction with a fiber optic Michelson interferometer. This non-contact fiber optic measurement system has been used to measure silicon thickness and flatness to an accuracy of +/- 1.5 micrometers in the laboratory.

  7. Application of optical coherence tomography based microangiography for cerebral imaging

    Science.gov (United States)

    Baran, Utku; Wang, Ruikang K.

    2016-03-01

    Requirements of in vivo rodent brain imaging are hard to satisfy using traditional technologies such as magnetic resonance imaging and two-photon microscopy. Optical coherence tomography (OCT) is an emerging tool that can easily reach at high speeds and provide high resolution volumetric images with a relatively large field of view for rodent brain imaging. Here, we provide the overview of recent developments of functional OCT based imaging techniques for neuroscience applications on rodents. Moreover, a summary of OCT-based microangiography (OMAG) studies for stroke and traumatic brain injury cases on rodents are provided.

  8. Ultrahigh resolution optical coherence tomography using a superluminescent light source.

    Science.gov (United States)

    Kowalevicz, Andrew; Ko, Tony; Hartl, Ingmar; Fujimoto, James; Pollnau, Markus; Salathé, René

    2002-04-08

    A superluminescent Ti:Al2O(3) crystal is demonstrated as a light source for ultrahigh resolution optical coherence tomography (OCT). Single spatial mode, fiber coupled output powers of ~40 microW can be generated with 138 nm bandwidth using a 5 W frequency doubled, diode pumped laser, pumping a thin Ti:Al2O(3) crystal. Ultrahigh resolution OCT imaging is demonstrated with 2.2 microm axial resolution in air, or 1.7 microm in tissue, with >86 dB sensitivity. This light source provides a simple and robust alternative to femtosecond lasers for ultrahigh resolution OCT imaging.

  9. Probing beyond the laser coherence time in optical clock comparisons

    Science.gov (United States)

    Hume, David B.; Leibrandt, David R.

    2016-03-01

    We develop differential measurement protocols that circumvent the laser noise limit in the stability of optical clock comparisons by synchronous probing of two clocks using phase-locked local oscillators. This allows for probe times longer than the laser coherence time, avoids the Dick effect, and supports Heisenberg-limited measurement precision. We present protocols for such frequency comparisons and develop numerical simulations of the protocols with realistic noise sources. These methods provide a route to reduce frequency ratio measurement durations by more than an order of magnitude.

  10. Requirement of optical coherence for continuous-variable quantum teleportation.

    Science.gov (United States)

    Rudolph, T; Sanders, B C

    2001-08-13

    We show that the sender and the receiver each require coherent devices in order to achieve unconditional continuous variable quantum teleportation (CVQT), and this requirement cannot be achieved with conventional laser sources, linear optics, ideal photon detectors, and perfect Fock state sources. The appearance of successful CVQT in recent experiments is due to interpreting the measurement record fallaciously in terms of one preferred ensemble (or decomposition) of the correct density matrix describing the state. Our analysis is unrelated to technical problems such as laser phase drift or finite squeezing bandwidth.

  11. Quantum-optical coherence tomography with collinear entangled photons.

    Science.gov (United States)

    Lopez-Mago, Dorilian; Novotny, Lukas

    2012-10-01

    Quantum-optical coherence tomography (QOCT) combines the principles of classical OCT with the correlation properties of entangled photon pairs [Phys. Rev. A 65, 053817 (2002)]. The standard QOCT configuration is based on the Hong-Ou-Mandel interferometer, which uses entangled photons propagating in separate interferometer arms. This noncollinear configuration imposes practical limitations, e.g., misalignment due to drift and low signal-to-noise. Here, we introduce and implement QOCT based on collinear entangled photons. It makes use of a two-photon Michelson interferometer and offers several advantages, such as simplicity, robustness, and adaptability.

  12. The APOSTEL recommendations for reporting quantitative optical coherence tomography studies

    DEFF Research Database (Denmark)

    Cruz-Herranz, Andrés; Balk, Lisanne J; Oberwahrenbrock, Timm

    2016-01-01

    OBJECTIVE: To develop consensus recommendations for reporting of quantitative optical coherence tomography (OCT) study results. METHODS: A panel of experienced OCT researchers (including 11 neurologists, 2 ophthalmologists, and 2 neuroscientists) discussed requirements for performing and reporting...... quantitative analyses of retinal morphology and developed a list of initial recommendations based on experience and previous studies. The list of recommendations was subsequently revised during several meetings of the coordinating group. RESULTS: We provide a 9-point checklist encompassing aspects deemed...... relevant when reporting quantitative OCT studies. The areas covered are study protocol, acquisition device, acquisition settings, scanning protocol, funduscopic imaging, postacquisition data selection, postacquisition data analysis, recommended nomenclature, and statistical analysis. CONCLUSIONS...

  13. Optical coherence tomography imaging of ocular and periocular tumours

    Science.gov (United States)

    Medina, Carlos A; Plesec, Thomas; Singh, Arun D

    2014-01-01

    Optical coherence tomography (OCT) has become pivotal in the practice of ophthalmology. Similar to other ophthalmic subspecialties, ophthalmic oncology has also incorporated OCT into practice. Anterior segment OCT (AS-OCT), ultra-high resolution OCT (UHR-OCT), spectral domain OCT (SD-OCT) and enhanced depth imaging OCT (EDI-OCT), have all been described to be helpful in the diagnosis, treatment planning and monitoring response of ocular and periocular tumours. Herein we discuss the role of OCT including the advantages and limitations of its use in the setting of common intraocular and adnexal tumours. PMID:24599420

  14. Optical coherence tomography in the diagnosis of basal cell carcinoma

    DEFF Research Database (Denmark)

    Hussain, Alia Arif; Themstrup, Lotte; Jemec, Gregor Borut Ernst

    2015-01-01

    Since its introduction in dermatology in the late 1990s optical coherence tomography (OCT) has been used to study many skin diseases, in particular non-melanoma skin cancer and it s precursors. Special attention has been paid to superficial basal cell carcinoma (BCC), and a number of smaller...... observational studies have been published. The diagnostic criteria for BCC of these studies are systematically reviewed. A systemic review of English language studies was performed using PubMed, Google Scholar and Royal Danish Library, to search for primary papers on OCT and BCC. The references of retrieved...

  15. Single fiber perfusion phantom for optical coherence tomography

    Science.gov (United States)

    Podlipná, Petra; Kolář, Radim

    2013-06-01

    This paper presents the successful creation of new phantom for optical coherence tomography (OCT) aimed on perfusion simulation. The phantom is created from syringe pump and polypropylene hollow fiber with porous walls embeded in the glass capillary to provide small outer environment. Its function was tested by gold nanorods as a flowing medium and imaged by commercial swept-source OCT system. Results showed that the fiber is permeable for used gold nanorods which are frequently declared as possible contrast agents for OCT and this permeability can be displayed by OCT.

  16. [Optical coherence tomography in the diagnosis of achromatopsia].

    Science.gov (United States)

    Burgueño-Montañés, C; Colunga-Cueva, M

    2014-02-01

    The case of a fifty five year-old male with nyctalopia, photophobia, poor colour vision and nystagmus, is presented. The initial suspected diagnoses were achromatopsia and blue-cone monochromatism, since both are clinically indistinguishable. Optical coherence tomography (OCT) showed the characteristic foveal reflectivity pattern of achromatopsia. This diagnosis was subsequently confirmed by genetic study. OCT is a non-invasive diagnostic imaging method that allows tissue morphology to be observed with high resolution. Its use might be of great help to distinguish clinically similar diseases. Copyright © 2011 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  17. Optical coherence tomography in clinical examinations of nonpigmented skin malignancies

    Science.gov (United States)

    Jensen, Laura K.; Thrane, Lars; Andersen, Peter E.; Tycho, Andreas; Pedersen, Finn; Andersson-Engels, Stefan; Bendsoe, Niels; Svanberg, Sune; Svanberg, Katarina

    2003-10-01

    Optical coherence tomography (OCT) images of basal cell carcinomas (BCCs) have been acquired using a compact handheld proble with an integrated video camera allowing the OCT images to be correlated to a skin surface image. In general the healthy tissue of the skin has an obvious stratified structure, whereas the cancerous tissue shows a more homogeneous structure. Thus it was demonstrated that it is possible to distinguish BCCs from healthy tissue by means of OCT. Furthermore different histological types of BCC were identified. Comparison of OCT images taken prior to and immediately after photodynamic theory clearly shows the tissue response to the treatment, and indicates local oedema in the treated area.

  18. Primate retina imaging with polarization-sensitive optical coherence tomography

    Science.gov (United States)

    Ducros, Mathieu G.; Marsack, Jason D.; Rylander, H. Grady; Thomsen, Sharon L.; Milner, Thomas E.

    2001-12-01

    Polarization-sensitive optical coherence tomography (PSOCT) is applied to determine the depth-resolved polarization state of light backreflected from the eye. The birefringence of the retinal nerve fiber layer (RNFL) was observed and measured from PSOCT images recorded postmortem in a Rhesus monkey. An image-processing algorithm was developed to identify birefringent regions in acquired PSOCT retinal images and automatically determine the thickness of the RNFL. Values of the RNFL thickness determined from histology and PSOCT were compared. PSOCT may provide a new method to determine RNFL thickness and birefringence for glaucoma diagnostics.

  19. First characterization of coherent optical vortices from harmonic undulator radiation.

    Science.gov (United States)

    Hemsing, E; Dunning, M; Hast, C; Raubenheimer, T; Xiang, Dao

    2014-09-26

    We describe the experimental generation and measurement of coherent light that carries orbital angular momentum from a relativistic electron beam radiating at the second harmonic of a helical undulator. The measured helical phase of the light is shown to be in agreement with predictions of the sign and magnitude of the phase singularity and is more than 2 orders of magnitude greater than the incoherent signal. Our setup demonstrates that such optical vortices can be produced in modern free-electron lasers in a simple afterburner arrangement for novel two-mode pump-probe experiments.

  20. Optic coherence tomography measurement of choroidal and retinal thicknesses after uncomplicated YAG laser capsulotomy

    Directory of Open Access Journals (Sweden)

    İsa Yuvacı

    2015-12-01

    Full Text Available ABSTRACT Purpose: Optic coherence tomography (OCT evaluation of the choroid, retina, and retinal nerve fiber layer after uncomplicated yttrium-aluminum-garnet (YAG laser capsulotomy. Methods: OCT analysis of retinal and choroidal structures was performed in 28 eyes of 28 patients following routine examinations before and 24 h, 72 h, 2 weeks, 4 weeks, and 12 weeks after YAG laser capsulotomy. Data were analyzed using the SPSS software. Results: Data collected before YAG capsulotomy and at the above mentioned follow-up visits are summarized as follows. Mean central subfoveal choroidal thickness before YAG capsulotomy was 275.85 ± 74.78 µm; it was 278.46 ± 83.46 µm, 283.39 ± 82.84 µm, 280.00 ± 77.16 µm, 278.37 ± 76.95 µm, and 278.67 ± 76.20 µm after YAG capsulotomy, respectively. Central macular thickness was 272.14 ± 25.76 µm before YAG capsulotomy; it was 266.53 ± 26.47 µm, 269.14 ± 27.20 µm, 272.17 ± 26.97 µm, 270.91 ± 26.79 µm, and 273 ± 26.63 µm after YAG capsulotomy, respectively. Mean retinal nerve fiber layer thickness before YAG was 99.89 ± 7.61 µm; it was 98.50 ± 8.62 µm, 98.14 ± 8.69 µm, 99.60 ± 8.39 µm, 99.60 ± 8.39 µm, and 99.60 ± 8.35 µm after YAG capsulotomy, respectively. No observed change was statistically significant. No significant changes were observed with regard to mean intraocular pressure. Conclusions: After YAG laser capsulotomy, no statistically significant changes were found in choroidal, retinal, and optical nerve fiber layer thicknesses, although slight thickness changes in these structures were observed, particularly during the first days.

  1. Intra-retinal layer segmentation of 3D optical coherence tomography using coarse grained diffusion map.

    Science.gov (United States)

    Kafieh, Raheleh; Rabbani, Hossein; Abramoff, Michael D; Sonka, Milan

    2013-12-01

    Optical coherence tomography (OCT) is a powerful and noninvasive method for retinal imaging. In this paper, we introduce a fast segmentation method based on a new variant of spectral graph theory named diffusion maps. The research is performed on spectral domain (SD) OCT images depicting macular and optic nerve head appearance. The presented approach does not require edge-based image information in localizing most of boundaries and relies on regional image texture. Consequently, the proposed method demonstrates robustness in situations of low image contrast or poor layer-to-layer image gradients. Diffusion mapping applied to 2D and 3D OCT datasets is composed of two steps, one for partitioning the data into important and less important sections, and another one for localization of internal layers. In the first step, the pixels/voxels are grouped in rectangular/cubic sets to form a graph node. The weights of the graph are calculated based on geometric distances between pixels/voxels and differences of their mean intensity. The first diffusion map clusters the data into three parts, the second of which is the area of interest. The other two sections are eliminated from the remaining calculations. In the second step, the remaining area is subjected to another diffusion map assessment and the internal layers are localized based on their textural similarities. The proposed method was tested on 23 datasets from two patient groups (glaucoma and normals). The mean unsigned border positioning errors (mean ± SD) was 8.52 ± 3.13 and 7.56 ± 2.95 μm for the 2D and 3D methods, respectively.

  2. Optical Coherence Tomography Reveals Distinct Patterns of Retinal Damage in Neuromyelitis Optica and Multiple Sclerosis.

    Directory of Open Access Journals (Sweden)

    Elisa Schneider

    Full Text Available Neuromyelitis optica (NMO and relapsing-remitting multiple sclerosis (RRMS are difficult to differentiate solely on clinical grounds. Optical coherence tomography (OCT studies investigating retinal changes in both diseases focused primarily on the retinal nerve fiber layer (RNFL while rare data are available on deeper intra-retinal layers.To detect different patterns of intra-retinal layer alterations in patients with NMO spectrum disorders (NMOSD and RRMS with focus on the influence of a previous optic neuritis (ON.We applied spectral-domain OCT in eyes of NMOSD patients and compared them to matched RRMS patients and healthy controls (HC. Semi-automatic intra-retinal layer segmentation was used to quantify intra-retinal layer thicknesses. In a subgroup low contrast visual acuity (LCVA was assessed.NMOSD-, MS- and HC-groups, each comprising 17 subjects, were included in analysis. RNFL thickness was more severely reduced in NMOSD compared to MS following ON. In MS-ON eyes, RNFL thinning showed a clear temporal preponderance, whereas in NMOSD-ON eyes RNFL was more evenly reduced, resulting in a significantly lower ratio of the nasal versus temporal RNFL thickness. In comparison to HC, ganglion cell layer thickness was stronger reduced in NMOSD-ON than in MS-ON, accompanied by a more severe impairment of LCVA. The inner nuclear layer and the outer retinal layers were thicker in NMOSD-ON patients compared to NMOSD without ON and HC eyes while these differences were primarily driven by microcystic macular edema.Our study supports previous findings that ON in NMOSD leads to more pronounced retinal thinning and visual function impairment than in RRMS. The different retinal damage patterns in NMOSD versus RRMS support the current notion of distinct pathomechanisms of both conditions. However, OCT is still insufficient to help with the clinically relevant differentiation of both conditions in an individual patient.

  3. RETINAL MICROVASCULATURE AND VISUAL ACUITY AFTER INTRAVITREAL AFLIBERCEPT IN EYES WITH CENTRAL RETINAL VEIN OCCLUSION: An Optical Coherence Tomography Angiography Study.

    Science.gov (United States)

    Winegarner, Andrew; Wakabayashi, Taku; Hara-Ueno, Chikako; Sato, Tatsuhiko; Busch, Caleb; Fukushima, Yoko; Sayanagi, Kaori; Nishida, Kentaro; Sakaguchi, Hirokazu; Nishida, Kohji

    2017-09-07

    To investigate vascular perfusion and foveal avascular zone area in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) after intravitreal aflibercept therapy in central retinal vein occlusion eyes and their association with best-corrected visual acuity. Thirty-five subjects with central retinal vein occlusion and macular edema were evaluated. After macular edema resolution following intravitreal aflibercept, subjects underwent optical coherence tomography angiography to measure SCP and DCP perfusion and the foveal avascular zone within a 3 × 3-mm area. Correlations between best-corrected visual acuity and optical coherence tomography angiography measurements were examined. After intravitreal aflibercept therapy, mean retinal vascular area was 3.41 ± 0.74 mm in the SCP and 3.25 ± 0.91 mm in the DCP. Foveal avascular zone area was 1.03 ± 1.04 mm in the SCP and 1.78 ± 1.73 mm in the DCP. Improved best-corrected visual acuity was significantly associated with better SCP and DCP perfusion (both P retinal perfusion and less retinal ischemia are associated with better visual outcomes after aflibercept in eyes with central retinal vein occlusion.

  4. Late Closure of a Stage III Idiopathic Macular Hole after Pars Plana Vitrectomy

    Directory of Open Access Journals (Sweden)

    Filiz Afrashi

    2015-12-01

    Full Text Available A 57-year-old female presented to our hospital with decreased vision in her right eye. Detailed ocular examination was performed, and a macular hole was detected in the right eye. The presence of a full-thickness stage III macular hole was confirmed with optical coherence tomography (OCT imaging. Pars plana vitrectomy followed by long-acting gas tamponade (C3F8 was performed as treatment. One month after surgery, clinical examination revealed a persistent macular hole, confirmed by an OCT scan. Although the patient was scheduled for reoperation, the surgery was postponed due to personal reasons of the patient. Surprisingly, after five months, a closure pattern with accompanying epiretinal membrane was observed in the macular hole area. The closure of the macular hole was completed without any further intervention 8 months post-surgery. In cases of unclosed macular hole after the first surgery, if a second surgery cannot be performed, follow-up with OCT recommended due to the possibility of spontaneous closure. However, spontaneous closure of a persistent macular hole following PPV is rare, so early diagnosis and surgical repair of unclosed macular holes must remain the primary goal.

  5. Influence of ischemia on visual function in patients with branch retinal vein occlusion and macular edema

    Directory of Open Access Journals (Sweden)

    Noma H

    2011-05-01

    Full Text Available Hidetaka Noma¹, Hideharu Funatsu¹, Tatsuya Mimura², Katsunori Shimada³¹Department of Ophthalmology, Yachiyo Medical Center, Tokyo Women's Medical University, Owada-shinden, Chiba, Japan; ²Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan; ³Department of Hygiene and Public Health II, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, JapanAbstract: Visual function and retinal morphology were investigated to elucidate the influence of ischemia in patients with branch retinal vein occlusion (BRVO and macular edema. In 41 consecutive patients with BRVO aged 68.9 ± 10.0 years (22 women and 19 men, the area of capillary nonperfusion was measured by fluorescein angiography. Retinal thickness and retinal volume were measured by optical coherence tomography, and mean retinal sensitivity was calculated for each of 9 macular subfields. Mean visual acuity and macular sensitivity within the central subfield were not significantly correlated with the nonperfused area. However, the macular sensitivity within the central 5 subfields and all 9 subfields showed significant negative correlations with the nonperfused area. Also, macular thickness and volume within all 9 subfields were significantly correlated with the nonperfused area. In conclusion, evaluation of both the fovea and the entire macular region may be important in patients with ischemic BRVO.Keywords: branch retinal vein occlusion, macular edema, macular sensitivity, ischemia

  6. Characterizing matrix remodeling in collagen gels using optical coherence tomography

    Science.gov (United States)

    Levitz, David; Hinds, Monica T.; Hanson, Stephen R.; Jacques, Steven L.

    2010-02-01

    Optical coherence tomography (OCT) has shown promise at non-destructively characterizing engineered tissues such as collagen gels. However, as the collagen gels develop, the OCT images lose contrast of structures as the gels develop, making visual assessment difficult. Our group proposed quantitatively characterizing these gels by fitting the optical properties from the OCT signals. In this paper, we imaged collagen gels seeded with smooth muscle cells (SMCs) over a 5-day period and used the data to measure their optical properties. Our results showed that over time, the reflectivity of the samples increased 10-fold, corresponding to a decrease in anisotropy factor g, without much change in the scattering coefficient μs. Overall, the optical properties appeared to be dominated by scattering from the collagen matrix, not the cells. However, SMCs remodeled the collagen matrix, and this collagen remodeling by the cells is what causes the observed changes in optical properties. Moreover, the data showed that the optical properties were sensitive to the activity of matrix metalloproteinases (MMPs), enzymes that break down local collagen fibrils into smaller fragments. Blocking MMPs in the SMC gels greatly impeded both the remodeling process and change in optical properties at day 5. Treating day 1 acellular gels with MMP-8 for 3 hr managed to partially reproduce the remodeling observed in SMC gels at day 5. Altogether, we conclude that matrix remodeling in general, and MMPs specifically, greatly affect the local optical properties of the sample, and OCT is a unique tool that can assess MMP activity in collagen gels both non-destructively and label free.

  7. Quantitative characterization of developing collagen gels using optical coherence tomography

    Science.gov (United States)

    Levitz, David; Hinds, Monica T.; Choudhury, Niloy; Tran, Noi T.; Hanson, Stephen R.; Jacques, Steven L.

    2010-03-01

    Nondestructive optical imaging methods such as optical coherence tomography (OCT) have been proposed for characterizing engineered tissues such as collagen gels. In our study, OCT was used to image collagen gels with different seeding densities of smooth muscle cells (SMCs), including acellular gels, over a five-day period during which the gels contracted and became turbid with increased optical scattering. The gels were characterized quantitatively by their optical properties, specified by analysis of OCT data using a theoretical model. At 6 h, seeded cell density and scattering coefficient (μs) were correlated, with μs equal to 10.8 cm-1/(106 cells/mL). Seeded cell density and the scattering anisotropy (g) were uncorrelated. Over five days, the reflectivity in SMC gels gradually doubled with little change in optical attenuation, which indicated a decrease in g that increased backscatter, but only a small drop in μs. At five days, a subpopulation of sites on the gel showed substantially higher reflectivity (approximately a tenfold increase from the first 24 h). In summary, the increased turbidity of SMC gels that develops over time is due to a change in the structure of collagen, which affects g, and not simply due to a change in number density of collagen fibers due to contraction.

  8. Multiparametric, longitudinal optical coherence tomography imaging reveals acute injury and chronic recovery in experimental ischemic stroke

    National Research Council Canada - National Science Library

    Srinivasan, Vivek J; Mandeville, Emiri T; Can, Anil; Blasi, Francesco; Climov, Mihail; Daneshmand, Ali; Lee, Jeong Hyun; Yu, Esther; Radhakrishnan, Harsha; Lo, Eng H; Sakadžić, Sava; Eikermann-Haerter, Katharina; Ayata, Cenk

    2013-01-01

    .... A multi-parametric Optical Coherence Tomography (OCT) platform for longitudinal imaging of ischemic stroke in mice, through thinned-skull, reinforced cranial window surgical preparations, is described...

  9. Surgical removal of retained subfoveal perfluorocarbon liquid through a therapeutic macular hole with intravitreal PFCL injection and gas tamponade.

    Science.gov (United States)

    Kim, Jae Min; Woo, Se Joon; Park, Kyu Hyung; Chung, Hum

    2013-10-01

    We report two cases of surgical removal of a retained subfoveal perfluorocarbon liquid (PFCL) bubble through a therapeutic macular hole combined with intravitreal PFCL injection and gas tamponade. Two patients underwent pars plana vitrectomy with PFCL injection for rhegmatogenous retinal detachment. In both cases, a retained subfoveal PFCL bubble was noticed postoperatively by funduscopy and optical coherence tomography. Both patients underwent surgical removal of the subfoveal PFCL through a therapeutic macular hole and gas tamponade. The therapeutic macular holes were completely closed by gas tamponade and the procedure yielded a good visual outcome (best-corrected visual acuity of 20 / 40 in both cases). In one case, additional intravitreal PFCL injection onto the macula reduced the size of the therapeutic macular hole and preserved the retinal structures in the macula. Surgical removal of a retained subfoveal PFCL bubble through a therapeutic macular hole combined with intravitreal PFCL injection and gas tamponade provides an effective treatment option.

  10. Precision Spectral Manipulation: A Demonstration Using a Coherent Optical Memory

    Directory of Open Access Journals (Sweden)

    B. M. Sparkes

    2012-06-01

    Full Text Available The ability to coherently spectrally manipulate quantum information has the potential to improve qubit rates across quantum channels and find applications in optical quantum computing. In this paper, we present experiments that use a multielement solenoid combined with the three-level gradient echo memory scheme to perform precision spectral manipulation of optical pulses. These operations include separate bandwidth and frequency manipulation with precision down to tens of kHz, spectral filtering of up to three separate frequency components, as well as time-delayed interference between pulses with both the same, and different, frequencies. If applied in a quantum information network, these operations would enable frequency-based multiplexing of qubits.

  11. Polarization Drift Channel Model for Coherent Fibre-Optic Systems

    CERN Document Server

    Czegledi, Cristian B; Agrell, Erik; Johannisson, Pontus

    2015-01-01

    A theoretical framework is introduced to model the dynamical changes of the state of polarization during transmission in coherent fibre-optic systems. The model generalizes the one-dimensional phase noise random walk to higher dimensions, accounting for random polarization drifts. The model is described in the Jones, Stokes and real 4-dimensional formalisms, and the mapping between them is derived. Such a model will be increasingly important in simulating and optimizing future optical systems, which to a higher and higher degree rely on transmission and detection on both polarizations jointly using sophisticated digital signal processing. Such analysis cannot be carried out using the more rudimentary polarization drift models in use today, which only account for deterministic effects. The proposed polarization drift model is the first of its kind and will likely be useful in a wide-range of photonics applications where stochastic polarization fluctuation is an issue.

  12. Imaging of oral pathological tissue using optical coherence tomography

    Science.gov (United States)

    Canjau, Silvana; Todea, Carmen; Sinescu, Cosmin; Duma, Virgil-Florin; Topala, Florin I.; Podoleanu, Adrian G.

    2014-01-01

    Oral squamous cell carcinoma (OSCC) constitutes 90% of oral cancer. Early detection is a cornerstone to improve survival. Interaction of light with tissues may highlight changes in tissue structure and metabolism. We propose optical coherence tomography (OCT), as a non-invasive diagnosis method, being a new high-resolution optical technique that permits tri-dimensional (3-D), real-time imaging of near surface abnormalities in complex tissues. In this study half of the excisional biopsy was directed to the pathologist and the other half was assigned for OCT investigation. Histopathology validated the results. Areas of OSCC of the buccal mucosa were identified in the OCT images. The elements obserced included extensive epithelial down-growth, the disruption of the basement membrane, with areas of erosion, an epithelial layer that was highly variable in thickness and invasion into the sub-epithelial layers. Therefore, OCT appears to be a highly promising imaging modality.

  13. 8th Rochester Conference on Coherence and Quantum Optics

    CERN Document Server

    2001-01-01

    The Eighth Rochester Conference on Coherence and Quantum Optics was held on the campus of the University of Rochester during the period June 13-16,2001. This volume contains the proceedings of the meeting. The meeting was preceded by an affiliated conference, the International Conference on Quantum Information, with some overlapping sessions on June 13. The proceedings of the affiliated conference will be published separately by the Optical Society of America. A few papers that were presented in common plenary sessions of the two conferences will be published in both proceedings volumes. More than 268 scientists from 28 countries participated in the week long discussions and presentations. This Conference differed from the previous seven in the CQO series in several ways, the most important of which was the absence of Leonard Mandel. Professor Mandel died a few months before the conference. A special memorial symposium in his honor was held at the end of the conference. The presentations from that sym...

  14. Monte Carlo Simulations of Arterial Imaging with Optical Coherence Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Amendt, P.; Estabrook, K.; Everett, M.; London, R.A.; Maitland, D.; Zimmerman, G.; Colston, B.; da Silva, L.; Sathyam, U.

    2000-02-01

    The laser-tissue interaction code LATIS [London et al., Appl. Optics 36, 9068 ( 1998)] is used to analyze photon scattering histories representative of optical coherence tomography (OCT) experiment performed at Lawrence Livermore National Laboratory. Monte Carlo photonics with Henyey-Greenstein anisotropic scattering is implemented and used to simulate signal discrimination of intravascular structure. An analytic model is developed and used to obtain a scaling law relation for optimization of the OCT signal and to validate Monte Carlo photonics. The appropriateness of the Henyey-Greenstein phase function is studied by direct comparison with more detailed Mie scattering theory using an ensemble of spherical dielectric scatterers. Modest differences are found between the two prescriptions for describing photon angular scattering in tissue. In particular, the Mie scattering phase functions provide less overall reflectance signal but more signal contrast compared to the Henyey-Greenstein formulation.

  15. Gauss-Bonnet gravity, relic coherent gravitons and optical chaos

    CERN Document Server

    Crowell, Lawrence B

    2011-01-01

    We discuss the production of massive relic coherent gravitons in Gauss-Bonnet gravity and their possible imprint in Cosmic Microwave Background. In fact, in the very early universe these relic gravitons could have acted as slow gravity waves. They may have then acted to focus the geodesics of radiation and matter. Therefore, their imprint on the later evolution of the universe could appear as filaments and domain wall in the Universe today. In that case, the effect on Cosmic Microwave Background should be analogous to the effect of water waves, which, in focusing light, create optical caustics which are commonly seen on the bottom of swimming pools. We analyze this important issue by showing how relic massive GWs perturb the trajectories of Cosmic Microwave Background photons (gravitational lensing by relic GWs). The consequence of the type of physics discussed is outlined by illustrating an amplification of what might be called optical chaos.

  16. Cryosurgery treatment of actinic keratoses monitored by optical coherence tomography

    DEFF Research Database (Denmark)

    Themstrup, L.; Banzhaf, C.; Jemec, G.B.E.

    2013-01-01

    Background: Optical coherence tomography (OCT) is a non-invasive optical imaging technique providing high-resolution images. OCT may be useful as a monitoring tool during treatment of actinic keratoses (AK) and skin cancer. Objective: To examine and describe how OCT skin morphology changes when...... could not be monitored by OCT. Vesicle formation after cryotherapy could be identified in OCT images. In ex vivo skin no vesicle formation occurred. Conclusion: OCT cannot monitor the freezing depth, but OCT was able to visualise AK lesions and vesicle formation shortly after cryotherapy. Results add...... the tissue is exposed to the effects of cryotherapy. Methods: Normal ex vivo skin and in vivo AK lesions were examined. Cryotherapy was applied and OCT images were acquired at defined time points. OCT morphology was described. Results: Cryotherapy treatment produced an opaque iceball, and freezing depth...

  17. Optical Coherence Tomography: An Emerging Technology for Biomedical Imaging and Optical Biopsy

    OpenAIRE

    Fujimoto, James G.; Pitris, Costas; Boppart, Stephen A.; Brezinski, Mark E.

    2000-01-01

    Optical coherence tomography (OCT) is an emerging technology for performing high-resolution cross-sectional imaging. OCT is analogous to ultrasound imaging, except that it uses light instead of sound. OCT can provide cross-sectional images of tissue structure on the micron scale in situ and in real time. Using OCT in combination with catheters and endoscopes enables high-resolution intraluminal imaging of organ systems. OCT can function as a type of optical biopsy and is a powerful imaging te...

  18. Adaptive-optics Optical Coherence Tomography Processing Using a Graphics Processing Unit*

    Science.gov (United States)

    Shafer, Brandon A.; Kriske, Jeffery E.; Kocaoglu, Omer P.; Turner, Timothy L.; Liu, Zhuolin; Lee, John Jaehwan; Miller, Donald T.

    2015-01-01

    Graphics processing units are increasingly being used for scientific computing for their powerful parallel processing abilities, and moderate price compared to super computers and computing grids. In this paper we have used a general purpose graphics processing unit to process adaptive-optics optical coherence tomography (AOOCT) images in real time. Increasing the processing speed of AOOCT is an essential step in moving the super high resolution technology closer to clinical viability. PMID:25570838

  19. Adaptive-optics optical coherence tomography processing using a graphics processing unit.

    Science.gov (United States)

    Shafer, Brandon A; Kriske, Jeffery E; Kocaoglu, Omer P; Turner, Timothy L; Liu, Zhuolin; Lee, John Jaehwan; Miller, Donald T

    2014-01-01

    Graphics processing units are increasingly being used for scientific computing for their powerful parallel processing abilities, and moderate price compared to super computers and computing grids. In this paper we have used a general purpose graphics processing unit to process adaptive-optics optical coherence tomography (AOOCT) images in real time. Increasing the processing speed of AOOCT is an essential step in moving the super high resolution technology closer to clinical viability.

  20. Coherent optical array receiver for PPM signals under atmospheric turbulence

    Science.gov (United States)

    Munoz Fernandez, Michela

    The performance of a coherent free-space optical communications system operating in the presence of turbulence is investigated. Maximum Likelihood Detection techniques are employed to optimally detect Pulse Position Modulated signals with a focal-plane detector array and to reconstruct the turbulence-degraded signals. Laboratory equipment and experimental setup used to carry out these experiments at the Jet Propulsion Laboratory are described. The key components include two lasers operating at 1064 nm wavelength for use with coherent detection, a 16 element (4 X 4) InGaAs focal-plane detector array, and a data-acquisition and signal-processing assembly needed to sample and collect the data and analyze the results. The detected signals are combined using the least-mean-square (LMS) algorithm. In the first part of the experimental results we show convergence of the algorithm for experimentally obtained signal tones in the presence of atmospheric turbulence. The second part of the experimental results shows adaptive combining of experimentally obtained heterodyned pulse position modulated (PPM) signals with pulse-to-pulse coherence in the presence of simulated spatial distortions resembling atmospheric turbulence. The adaptively combined PPM signals are phased up via an LMS algorithm suitably optimized to operate with PPM in the presence of additive shot noise. A convergence analysis of the algorithm is presented, and results with both computer-simulated and experimentally obtained PPM signals are analyzed. The third part of the experimental results, in which the main goal of this thesis is achieved, includes an investigation of the performance of the Coherent Optical Receiver Experiment (CORE) at JPL. Bit Error Rate (BER) results are presented for single and multichannel optical receivers where quasi shot noise-limited performance is achieved under simulated turbulence conditions using noncoherent postdetection processing techniques. Theoretical BER expressions are