Domain Optical Coherence Tomography Scans Research Articles

Focal Choroidal Excavation in Retinal Dystrophies

ABSTRACTAim: To investigate the presence of focal choroidal excavation (FCE) in patients with retinitis pigmentosa (RP), Stargardt’s disease (STGD), and Best disease in the Indian population. Methods: This retrospective consecutive case series included 309 eyes of 157 patients with RP (183 eyes), STGD (93 eyes), and Best disease (33 eyes) with good-quality, enhanced-depth spectral domain optical coherence tomography scans. Comprehensive ophthalmic examination data were collected. Characteristics of FCE, including location of FCE, type (conforming and non-conforming), maximal width, and depth, were noted. Results: FCE was found in 2 out of 33 (6%) eyes with Best disease and no FCE was found in eyes with RP or STGD. The location of the FCE was extrafoveal in both cases. The first case had non-conforming FCE while the second case had the conforming type and the FCE occurred in association with choroidal neovascularization in the second case. The first case maintained good visual acuity of 20/20 over the entire period of follow-up (14 months), while the second case had a visual acuity of 20/200 at the last follow-up (three years) due to scarred choroidal neovascular membranes. The FCE showed no change in both eyes over the entire duration of follow-up. Conclusion: Focal choroidal excavation was found in 6% of eyes with Best disease, which remained stable throughout follow up. Eyes with RP and STGD did not have any FCE. Further studies are required to determine the role of vitelliform material in FCE development in Best disease.

Change of macular structure after cataract surgery observed with spectral domain optical coherence tomography scanning

Objective To observe the change of structure of the macular after cataract surgery. Methods The data of 98 eyes of 68 cases with age related cataract who received phacoemulsification and intraocular lens implantation from Aug. 2013 to Sep. 2015 in our hospital were retrospectively analyzed.The results of visual acuity, anterior segment of eye and fundus were recorded. Spectral domain optical coherence tomography (SD-OCT) was used to measure the fundus 1 month after the surgery. Results The cataract surgery was performed successfully in all 98 eyes and the postoperative best corrected visual acuity(BCVA) was improved compared with preoperative one.No abnormal change of macular area was found by direct and indirect ophthalmoscopy 1 month after the surgery .The spectralis SD-OCT showed no significant change of the macular thickness except for slight increase of the central macular thickness, which was (209.28±25.16)μm compared with(187.71±31.65)μm of normal people at the same age, and the difference was not statistically significant. However, the slightly abnormal continuity of the IS/OS layer and integrity of the RPE layer appeared in some patients with poor visual acuity recovery.Epimacular membrane formed in 5 eyes. Conclusion The macular thickness 1 month after phacoemulsification in age-related cataract patients without other general or ocular diseases is similar to the normal one. A few patients with poor visual acuity recovery is probably due to the changes of continuity of the IS/OS layer or the integrity of the RPE layer. Key words: Cataract; Phacoemulsification; Lens, intraocular; Visual acuity; Optical coherence tomography, spectral domain

Age-dependent vitreous separation from the macula in a clinic population.

BackgroundVitreous degeneration begins soon after birth and accelerates throughout life. Vitreous liquefaction with a slowly progressive separation of the posterior hyaloid from the peripheral macula usually leads to complete posterior vitreous detachment. The purpose of this study is to measure the age-related prevalence of partial vitreous separation and the length of residual vitreous adhesion in an ophthalmology clinic population.MethodsPatients examined by the senior author (MWS) during a 6-month period were included in a retrospective chart review. Demographic data and spectral domain optical coherence tomography scan results were gathered. Data analysis with descriptive statistics focused on the prevalence and extent of partial vitreous separation.ResultsThe mean age of the study patients was 69.9 years, and 62% were phakic. The highest prevalence of partial posterior hyaloid separation from the internal limiting membrane (71.2%) was seen in the 50- to 54-year age group. This prevalence rate steadily decreased to 5.6% in the 95- to 99-year age group. The prevalence of complete vitreous detachment as determined by slit-lamp biomicroscopy increased from 1.7% in the <50-year age group to a maximum of 29.2% in the 75- to 79-year group. The length of vitreomacular adhesion averaged 4.6 mm in the 50- to 54-year age group and steadily decreased to 2.1 mm in the 90- to 95-year group.ConclusionVitreomacular separation affects the majority of eyes in the sixth decade of life. The prevalence of partial vitreous separation decreases with advancing age, probably because an increasing number of these patients progress to complete posterior vitreous detachment.

New appraisals of Kyrieleis plaques: a multimodal imaging study.

Kyrieleis retinal periarteritis reflects the severe intraocular inflammation experienced by the eye. Its aetiology has not been well established, since only nine cases have been reported and there is no pathological study available in the literature. We determine the pathogenesis of Kyrieleis periarteritis based on interpretation of multimodal imaging findings. Charts of patients with Kyrieleis arteritis seen between 2006 and 2014 were retrieved from eight uveitis referral centres throughout the world. Follow-up ranged from 5 to 12 months. Twenty-five eyes with Kyrieleis arteritis from 25 patients were included in the study. Nineteen patients (72%) were male and six (28%) were female. Twenty-three patients were diagnosed with toxoplasmosis retinochoroiditis and two patients had cytomegalovirus retinitis. Fluorescein angiography, fundus autofluorescence and indocyanine green angiography were performed on 25/25 (100%) eyes. In eight eyes (32%), baseline spectral domain optical coherence tomography (SD-OCT) scans were performed along the segmental Kyrieleis arteritis. Fluorescein angiography showed early hypofluorescence and intermediate hyperfluorescence associated with the areas of focal arteritis, whereas indocyanine green angiography of these accumulations showed early hypofluorescence and late hyperfluorescence. Fundus autofluorescence revealed an increased autofluorescence of the vessels corresponding to the Kyrieleis plaques, while SD-OCT scans along the segmental Kyrieleis arteritis showed hyperreflectivity of the vessel wall. These imaging modalities provide in vivo, quasi-histologic images demonstrating that Kyrieleis plaques are characterised by an inflammatory involvement within the vessels' endothelium.

Optical Coherence Tomography Features Of Active And Inactive Retinal Neovascularization In Proliferative Diabetic Retinopathy.

To describe spectral domain-optical coherence tomography features of retinal neovascularization in proliferative diabetic retinopathy and thus to identify novel signs of new vessel activity. Retrospective, cross-sectional study. Data were collected over a 9-month period. Spectral domain optical coherence tomography scans were performed over areas of new vessel complexes (NVC) in both the disk and elsewhere, and were qualitatively graded by two masked observers. New vessel complexes activity was determined using clinical and angiographic criteria and correlated with spectral domain optical coherence tomography features. Forty-three eyes of 30 patients with proliferative diabetic retinopathy were included. Sixty-one NVC lesions (neovascularization of the disk-37.7%, neovascularization elsewhere-62.3%) were captured by spectral domain-optical coherence tomography and analyzed. Among them, 63.9% were classified as active and 36.1% as quiescent. Five distinctive features were identified as significantly different between active and quiescent NVC: the presence of vitreous hyperreflective dots in active NVC (P = 0.002) and the presence of epiretinal membrane (P = 0.04), inner retinal tissue contracture (P = 0.03), vitreous invasion (P = 0.02), and protrusion towards vitreous (P = 0.002) in quiescent NVC. In this exploratory study, the presence of vitreous hyperreflective dots, epiretinal membrane, inner retinal tissue contracture, vitreous invasion, and vitreous protrusion were identified as distinct signs of disease activity. Such parameters may be useful as a noninvasive imaging modality in eyes undergoing treatment for proliferative diabetic retinopathy.

Prevalence and Distribution of Segmentation Errors in Macular Ganglion Cell Analysis of Healthy Eyes Using Cirrus HD-OCT.

PurposeTo determine the frequency of different types of spectral domain optical coherence tomography (SD-OCT) scan artifacts and errors in ganglion cell algorithm (GCA) in healthy eyes.MethodsInfrared image, color-coded map and each of the 128 horizontal b-scans acquired in the macular ganglion cell-inner plexiform layer scans using the Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA) macular cube 512 × 128 protocol in 30 healthy normal eyes were evaluated. The frequency and pattern of each artifact was determined. Deviation of the segmentation line was classified into mild (less than 10 microns), moderate (10–50 microns) and severe (more than 50 microns). Each deviation, if present, was noted as upward or downward deviation. Each artifact was further described as per location on the scan and zones in the total scan area.ResultsA total of 1029 (26.8%) out of total 3840 scans had scan errors. The most common scan error was segmentation error (100%), followed by degraded images (6.70%), blink artifacts (0.09%) and out of register artifacts (3.3%). Misidentification of the inner retinal layers was most frequent (62%). Upward Deviation of the segmentation line (47.91%) and severe deviation (40.3%) were more often noted. Artifacts were mostly located in the central scan area (16.8%). The average number of scans with artifacts per eye was 34.3% and was not related to signal strength on Spearman correlation (p = 0.36).ConclusionsThis study reveals that image artifacts and scan errors in SD-OCT GCA analysis are common and frequently involve segmentation errors. These errors may affect inner retinal thickness measurements in a clinically significant manner. Careful review of scans for artifacts is important when using this feature of SD-OCT device.

Reliability of a Manual Procedure for Marking the EZ Endpoint Location in Patients with Retinitis Pigmentosa.

PurposeWe developed and evaluated a training procedure for marking the endpoints of the ellipsoid zone (EZ), also known as the inner segment/outer segment (IS/OS) border, on frequency domain optical coherence tomography (fdOCT) scans from patients with retinitis pigmentosa (RP).MethodsA manual for marking EZ endpoints was developed and used to train 2 inexperienced graders. After training, an experienced grader and the 2 trained graders marked the endpoints on fdOCT horizontal line scans through the macula from 45 patients with RP. They marked the endpoints on these same scans again 1 month later.ResultsIntragrader agreement was excellent. The intraclass correlation coefficient (ICC) was 0.99, the average difference of endpoint locations (19.6 μm) was close to 0 μm, and the 95% limits were between −284 and 323 μm, approximately ±1.1°. Intergrader agreement also was excellent. The ICC values were 0.98 (time 1) and 0.97 (time 2), the average difference among graders was close to zero, and the 95% limits of these differences was less than 350 μm, approximately 1.2°, for both test times.ConclusionsWhile automated algorithms are becoming increasingly accurate, EZ endpoints still have to be verified manually and corrected when necessary. With training, the inter- and intragrader agreement of manually marked endpoints is excellent.Translational RelevanceFor clinical studies, the EZ endpoints can be marked by hand if a training procedure, including a manual, is used. The endpoint confidence intervals, well under ±2.0°, are considerably smaller than the 6° spacing for the typically used static visual field.

Prevalence of vitreomacular adhesion: an optical coherence tomography analysis in the retina clinic setting

PurposeThe aims of this study were to determine the prevalence of vitreomacular adhesion (VMA) in a random sample of clinical patients at three US retina clinics and to assess comorbid retinal conditions, ocular diseases, prior treatment history, and other medical histories.Patients and methodsThis observational, retrospective cohort study was based on patients from the Doheny Eye Centers, Duke Eye Center, and Tufts Medical Center who received a bilateral spectral domain optical coherence tomography (SD-OCT) scan (one scan/eye) for clinical evaluation with available medical records. The study had three phases: 1) collection of retrospective patient data; 2) review of OCT scans at a reading center to assess VMA and associated conditions; and 3) analyses and reporting of data on the prevalence of VMA, patient demographics, and comorbid conditions. Data were obtained from electronic health records and OCT grading forms. Outcome measures from bilateral SD-OCT scans and medical records included OCT evaluation of VMA and retinal comorbid conditions.ResultsIn 719 patients with 1,483 reviewable OCT scans, the prevalence of VMA was estimated at 14.74% (90% CI, 12.58%–16.92%). The prevalence of unilateral VMA was estimated at 12.39%, while bilateral VMA was 2.36%. In patients with VMA, 34 out of 123 eyes with VMA (27.64%) also had fovea deformed by vitreomacular traction. Macular hole (MH) was significantly more prevalent in VMA-diagnosed eyes versus non-VMA-diagnosed eyes (6.5% versus 1.9%; P=0.02). There was a significantly higher incidence of full-thickness MH (P=0.008), operculum/flaps (P<0.0001), and lamellar or pseudo-holes (P=0.048) in VMA-diagnosed versus non-VMA-diagnosed eyes. Age, MH as a comorbid condition, full-thickness MH, lamellar or pseudo-holes, and operculum were predictive of a VMA diagnosis.ConclusionThe prevalence of VMA was estimated at 14.74% in a random sample of patients from three retina clinics. VMA diagnosis can be predicted by factors, including age, MH as a comorbid condition, and lamellar or pseudo-holes.

A novel benchmark model for intelligent annotation of spectral-domain optical coherence tomography scans using the example of cyst annotation

Background and objectivesThe lack of benchmark data in computational ophthalmology contributes to the challenging task of applying disease assessment and evaluate performance of machine learning based methods on retinal spectral domain optical coherence tomography (SD-OCT) scans. Presented here is a general framework for constructing a benchmark dataset for retinal image processing tasks such as cyst, vessel, and subretinal fluid segmentation and as a result, a benchmark dataset for cyst segmentation has been developed. MethodFirst, a dataset captured by different SD-OCT vendors with different numbers of scans and pathology qualities are selected. Then a robust and intelligent method is used to evaluate performance of readers, partitioning the dataset into subsets. Subsets are then assigned to complementary readers for annotation with respect to a novel confidence based annotation protocol. Finally, reader annotations are combined based on their performance to generate final annotations. ResultThe generated benchmark dataset for cyst segmentation comprises 26 SD-OCT scans with differing cyst qualities, collected from 4 different SD-OCT vendors to cover a wide variety of data. The dataset is partitioned into three subsets which are annotated by complementary readers based on a confidence based annotation protocol. Experimental results show annotations of complementary readers are combined efficiently with respect to their performance, generating accurate annotations. ConclusionOur results facilitate the process of generating benchmark datasets. Moreover the generated benchmark data set for cyst segmentation can be used reliably to train and test machine learning based methods.

CORRELATION OF OPTICAL COHERENCE TOMOGRAPHY AND MACULAR PIGMENT OPTICAL DENSITY MEASUREMENTS IN TYPE 2 IDIOPATHIC MACULAR TELANGIECTASIA.

Macular telangiectasia is associated with neurodegenerative changes including focal outer retinal atrophy and a loss of macular pigment (MP). We aimed to investigate whether an association between spectral domain optical coherence tomography neurodegenerative signs and MP abnormalities can be detected. Forty-seven eyes of 27 macular telangiectasia Type 2 patients (mean age 66.7 years, range 50-82 years, 12 male) were investigated. An MP pattern was recorded using a dual-wavelength autofluorescence method and classified according to severity (I-III). Outer plexiform, inner nuclear, and photoreceptor layer thickness values were measured in Spectralis spectral domain optical coherence tomography scans. Thickness values were compared with those of a control group of 14 healthy age-matched eyes. Macular pigment redistribution was found to be Class I in 11 eyes, Class II in 28 eyes, and Class III in 8 eyes. More advanced stages of MP loss were associated with a greater, statistically significant thinning of the outer plexiform and inner nuclear layer complex and photoreceptor layers (P ≤ 0.001). Lower absolute levels of MP were also associated with a thinning of the photoreceptor layer. Thinning was restricted to within the parafovea, more severe at temporal eccentricities. Our findings support the hypothesis that in macular telangiectasia Type 2 cellular degenerative processes leading to a thinning of these layers also result in reduction and redistribution of MP.

WIDE-FIELD SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY.

To describe wide-field spectral domain optical coherence tomography morphologic relationships of the vitreous, retina, and choroid in healthy and pathologic eyes. Standardized horizontal, vertical, and two oblique (supertemporal to inferonasal and supranasal to inferotemporal) spectral domain optical coherence tomography sections were collected for each patient. For extramacular imaging, images were obtained from 8 locations: (1) nasal to the optic disk, (2) extreme nasal periphery, (3) superior to the superotemporal vascular arcade, (4) extreme superior periphery, (5) inferior to the inferotemporal vascular arcade, (6) extreme inferior periphery, (7) temporal to the macula, and (8) extreme temporal periphery. Wide-angle montage images of optical coherence tomography from equator-to-equator were composed with a montaging software. Wide-field spectral domain optical coherence tomography scans were obtained in 10 healthy subjects, in 7 patients with central serous chorioretinopathy, in 5 patients with wet age-related macular degenerations, in 5 patients with dry age-related macular degenerations, in 4 patients with retinitis pigmentosa, and in 1 patient with acute exudative polymorphous vitelliform maculopathy. The novel approach of montaging spectral domain optical coherence tomography images to examine relationships between the choroid, retina, and associated structures adjacent to and outside of the macula may have a number of relevant applications in the study of vitreoretinal interface, paramacular and macular pathologic features.

Homonymous hemimacular thinning in retrochiasmal lesions

PurposeTo evaluate the thickness of macular retina and determine which retinal layers are most affected by retrochiasmal visual pathways lesions.MethodsMean retinal thickness utilizing automated intraretinal layer segmentation of spectral domain optical coherence tomography scans was performed in 40 eyes of 40 patients with retrochiasmal visual pathways lesions and compared with 60 eyes of control subjects. Multiple linear regression analysis was used to determine the relationship between retinal thickness and follow‐up, age and gender.ResultsGanglion cell and inner plexiform layer was thinner in the temporal hemiretina ipsilateral and in the nasal hemiretina contralateral than in healthy controls.The mean thickness was significantly reduced in lesions over 6 months of duration, with no differences in correlations with age or gender.ConclusionsThis study demonstrate ganglion cell and inner plexiform thinning in the hemimacular area. These results support the concept that transneuronal retrograde degeneration of the retinal ganglion cells can be detected by OCT in humans with retrochiasmal visual pathways lesions.This homonymous hemimacular thinning in OCT represents an imaging biomarker that can be of valu in diagnosis, prognosis and clinical trials of neuroprotectives therapies.

Assessment of Retinal Structural and Functional Characteristics in Eyes with Autoimmune Retinopathy.

To evaluate the thicknesses of individual retinal layers, and the correlation between structural changes and functional loss using spectral domain optical coherence tomography (SD-OCT) scans and electroretinograms (ERG), in eyes with autoimmune retinopathy (AIR). SD-OCT raster scans of 12 eyes from 6 patients serologically diagnosed with AIR were evaluated. Retinal layers were segmented along a 5 mm horizontal scan passing through the fovea. Retinal layers analyzed include full retinal thickness (FRT), retinal pigment epithelium and Bruch's membrane complex (RPE+BM complex), photoreceptor layer (PRL), inner nuclear layer (INL), combined ganglion cell and inner plexiform layers (GCL+), nerve fiber layer (NFL), and combined GCL+ and NFL layers (GCL+/NFL). Changes in the thicknesses of the layers were assessed in 0.5 mm increments along the B-scan in the central, nasal, and temporal regions. These recorded values were compared to corresponding values of 51 eyes from 51 subjects with no known ocular pathology. Full-field ERGs were obtained at corresponding visits and were interpreted by a grader masked to the diagnoses and OCT findings. The mean age of the patients was 59.5 years (range, 33-83), with 4 males (66.6%). Within the control population of 51 subjects, mean age was 51.5 years (range, 40-75), with 25 males (49%). Eyes with AIR showed a loss of retinal tissue compared to eyes with no known ocular pathology at the fovea. Specifically, the FRT, RPE+BM complex, and PRL exhibited thinning of statistically significance. ERG findings demonstrated a functional deficit which showed a good correlation with structural loss. Fifty (50) percent of eyes experienced central photoreceptor (rod and cone) dysfunction and 75% of eyes displayed peripheral photoreceptor (rod and cone) dysfunction. Eyes with AIR show a loss of retinal tissue compared to eyes with no known ocular pathology. The greatest loss appears to occur in the RPE and PRL. ERG findings correlate strongly with the loss of tissue seen in these layers. Thus, therapeutic options may be targeted to preserve these regions of the retina.

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

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.

Macular Abnormalities in Chinese Patients with Uveitis.

To investigate the prevalence of macular abnormalities in Chinese patients affected by uveitis. A retrospective study was performed by reviewing the medical records and high-definition spectral domain optical coherence tomography (SD-OCT) scans in a cohort of 413 uveitis eyes to assess the presence of macular abnormalities. Macular abnormalities were observed in 242 (58.6%) of the 413 examined eyes with uveitis. The observed macular abnormalities include diffuse macular edema, cystoid macular edema (CME), and serous retinal detachment. In addition, vitreoretinal abnormalities in the patients with uveitis were evaluated through SD-OCT. The evaluated vitreoretinal abnormalities include epiretinal membrane, tractional CME, macular adhesions, macular hole, and choroidal neovascularization. The most frequent abnormality in the uveitis patients was CME, observed in 105 eyes (25.4%), and followed by epiretinal membrane, observed in 52 eyes (12.6%). Moreover, the percentage of uveitis patients with vitreoretinal abnormalities (23.1%) was significantly high. Macular abnormalities were more frequently observed in uveitis compared with those in the general population. Multiple patterns of macular abnormalities indicate lesions of multilayer of cells. Therefore, when following up uveitis patients, it is highly recommended to screen with SD-OCT to evaluate the macular alterations of those patients. Careful observation of the macular abnormalities using SD-OCT may help to identify patients who are at risk for visual loss secondary to foveal changes and provide preventive treatment.

MORPHOLOGY SCORE AS A MARKER OF RETINAL FUNCTION IN DRUSENOID PIGMENT EPITHELIAL DETACHMENT.

To evaluate a morphology score for drusenoid pigment epithelial detachment (dPED) regarding predictability of a decline in retinal function beyond best-corrected visual acuity. Thirteen eyes of 10 patients with dPED due to age-related macular degeneration (AMD) were included (age 72.8 ± 4.2 years). All underwent volume spectral domain optical coherence tomography, fluorescence angiography, and confocal scanning laser ophthalmoscopy infrared imaging as well as multifocal electroretinography and microperimetry. The dPED morphology score suggested consists of five parameters: hyperreflective spots in infrared, lesion diameter, lesion height, presence of vitelliform-like material in the subretinal space or subretinal fluid, and integrity of the ellipsoid zone in spectral domain optical coherence tomography. Subsequently, a score value between 0 and 1 according to the extent of morphologic changes was correlated to foveal multifocal electroretinography and microperimetry measurements. The mean best-corrected visual acuity was 20/40. The mean height and mean diameter of dPED were 312.2 ± 111 μm and 2,535 ± 805 μm. Two dPED showed no hyperreflective spots in confocal scanning laser ophthalmoscopy infrared images, three displayed a moderate stage of hyperreflective spots, and eight had severe hyperreflective spots. Two eyes showed subretinal fluid, and five patients showed vitelliform-like material in the subretinal space. Eight eyes revealed a severe disruption of the ellipsoid zone. Although no correlation was found between dPED morphology score and best-corrected visual acuity, eyes with a dPED morphology score >0.5 revealed distinctly decreased values in functional measurements compared with those with a score ≤0.5. The dPED morphology score aggregates all currently known morphologic changes in dPED and represents a valuable tool for clinical lesion evaluation. Furthermore, it allows for assessing an estimate of functional decline beyond best-corrected visual acuity.

Repeatability of Foveal Measurements Using Spectralis Optical Coherence Tomography Segmentation Software.

PurposeTo investigate repeatability and reproducibility of thickness of eight individual retinal layers at axial and lateral foveal locations, as well as foveal width, measured from Spectralis spectral domain optical coherence tomography (SD-OCT) scans using newly available retinal layer segmentation software.MethodsHigh-resolution SD-OCT scans were acquired for 40 eyes of 40 young healthy volunteers. Two scans were obtained in a single visit for each participant. Using new Spectralis segmentation software, two investigators independently obtained thickness of each of eight individual retinal layers at 0°, 2° and 5° eccentricities nasal and temporal to foveal centre, as well as foveal width measurements. Bland-Altman Coefficient of Repeatability (CoR) was calculated for inter-investigator and inter-scan agreement of all retinal measurements. Spearman's ρ indicated correlation of manually located central retinal thickness (RT0) with automated minimum foveal thickness (MFT) measurements. In addition, we investigated nasal-temporal symmetry of individual retinal layer thickness within the foveal pit.ResultsInter-scan CoR values ranged from 3.1μm for axial retinal nerve fibre layer thickness to 15.0μm for the ganglion cell layer at 5° eccentricity. Mean foveal width was 2550μm ± 322μm with a CoR of 13μm for inter-investigator and 40μm for inter-scan agreement. Correlation of RT0 and MFT was very good (ρ = 0.97, P < 0.0005). There were no significant differences in thickness of any individual retinal layers at 2° nasal compared to temporal to fovea (P > 0.05); however this symmetry could not be found at 5° eccentricity.ConclusionsWe demonstrate excellent repeatability and reproducibility of each of eight individual retinal layer thickness measurements within the fovea as well as foveal width using Spectralis SD-OCT segmentation software in a young, healthy cohort. Thickness of all individual retinal layers were symmetrical at 2°, but not at 5° eccentricity away from the fovea.

Computer-aided analyses of mouse retinal OCT images - an actual application report.

There is a need for automated retinal optical coherence tomography (OCT) image analysis tools for quantitative measurements in small animals. Some image processing techniques for retinal layer analysis have been developed, but reports about how useful those techniques are in actual animal studies are rare. This paper presents the use of a retinal layer detection method we developed in an actual mouse study that involves wild type and mutated mice carrying photoreceptor degeneration. Spectral domain OCT scanning was performed by four experimenters over 12 months on 45 mouse eyes that were wild-type, deficient for ephrin-A2 and ephrin-A3, deficient for rhodopsin, or deficient for rhodopsin, ephrin-A2 and ephrin-A3. The thickness of photoreceptor complex between the outer plexiform layer and retinal pigment epithelium was measured on two sides of the optic disc as the biomarker of retinal degeneration. All the layer detection results were visually confirmed. Overall, 96% (8519 out of 9000) of the half-side images were successfully processed using our technique in a semi-automatic manner. There was no significant difference in success rate between mouse lines (p = 0.91). Based on a human observer's rating of image quality for images successfully and unsuccessfully processed, the odds ratios for 'easily visible' images and 'not clear' images to be successfully processed is 62 and 4, respectively, against 'indistinguishable' images. Thickness of photoreceptor complex was significantly different across the quadrants compared (p < 0.001). It was also found that the average thickness based on 4-point sparse sampling was not significantly different from the full analysis, while the range of differences between the two methods could be up to about 6 μm or 16% for individual eyes. Differences between mouse lines and progressive thickness reduction were revealed by both sampling measures. Although the thickness of the photoreceptor complex layer is not even, manual sparse sampling may be as sufficiently accurate as full analysis in some studies such as ours, where the error of sparse sampling was much smaller than the effect size of rhodopsin deficiency. It is also suggested that the image processing method can be useful in actual animal studies. Even for images poorly visible to human eyes the image processing method still has a good chance to extract the complex layer.

Oral Rifampin treatment for longstanding chronic central serous chorioretinopathy.

To investigate the effect of oral Rifampin in patients with chronic central serous chorioretinoapthy (CSCR). This was a prospective pilot study of patients with chronic CSCR with persistent subretinal fluid (SRF) for at least 3 months, who were treated with oral Rifampin 300 mg twice per day for 3 months and had 6 months of follow-up. All patients underwent a complete ocular examination and a spectral domain optical coherence tomography (SD-OCT) scan monthly from baseline until month 4, and then at month 6. Fluorescein angiography (FA) was performed at baseline and at the end of the study. Fourteen eyes of 12 patients were included in the study, nine men and three women. Mean age was 58.5 years (range 32-80). Mean duration of SRF prior to study entry was 28.4 months. Forty-two percent of eyes were treated previously for CSR with thermal laser, PDT, or intravitreal bevacizumab. Mean best corrected visual acuity (BCVA) at presentation was 20/60 and improved to a mean of 20/50 at month 3 (P > 0.05). Retinal thickness was reduced by 25.3 %, 21.2 %, and 21 % on months 1, 2, 3, respectively (P < 0.05). Mean choroidal thickness at presentation was 476 μ (SD 188 μ) decreasing to 427 μ (SD 125 μ) after 3 months of treatment (P > 0.05). SRF was reduced in nine eyes (64 %) and completely resolved in six eyes (42.8 %) at month 3 following 3 months of treatment, and four out of these six eyes remained fluid free at month 6. Two patients stopped the treatment after 2 months due to adverse events. Oral Rifampin may be a therapeutic option in patients with longstanding chronic CSCR.

Autofluorescence and axial length as prognostic factors for outcomes of macular hole retinal detachment surgery in high myopia.

To evaluate the results of fundus autofluorescence and axial length as prognostic factors for surgical outcome of macular hole retinal detachment in high myopic patients. This is a retrospective, interventional, nonrandomized study. Patients were treated with posterior vitrectomy, internal limiting membrane peeling, and silicone oil tamponade. Best-corrected visual acuity, axial length, fundus autofluorescence, and spectral domain optical coherence tomography images were obtained. Fifteen eyes from 15 patients (mean age, 69.4 years) were evaluated. The mean refractive error was -19 diopters, and the mean axial length was 29.9 mm. The mean best-corrected visual acuity (logMAR) improved from 2.17 to 1.42 (P = 0.02) after a mean follow-up of 19.3 months. Spectral domain optical coherence tomography scans showed retinal detachment resolution in 13 eyes (86.6%) and macular hole closure in 9 eyes (60%). Fundus autofluorescence showed macular hypoautofluorescence with foveal involvement (mean area of 9.7 mm2) in 10 eyes (66.6%). Postoperative best-corrected visual acuity was significantly worse in these eyes (P = 0.009). Axial length >30 mm was found in the 2 cases with recurrent retinal detachment and in 4 of the 6 cases without macular hole closure (66.6%). Macular hole retinal detachment in high myopic patients can be successfully treated with vitrectomy, internal limiting membrane peeling, and silicone oil. Axial length >30 mm and macular hypoautofluorescence with foveal involvement seem to be prognostic factors for a worse anatomical and visual outcome.