Spectral-domain Optical Coherence Tomography Scans Research Articles

Post-operative visual outcomes based on morphological staging of idiopathic epiretinal membranes on OCT.

To evaluate the recently described optical coherence tomography (OCT) based classification of epiretinal membrane (ERM) and its usefulness in predicting the functional outcome. A retrospective observational review of OCT scans of patients with the diagnosis of idiopathic ERM was carried out from January 2016 to June 2021. All consecutive images diagnosed with any stage of idiopathic ERM and fulfilled the eligibility criteria were included in the analysis. ERM was identified on OCT scans as a thin hyperreflective layer over the inner layers of retina. OCT scans of patients with ERM who underwent vitrectomy, were independently staged as per the new classification by two independent retinal surgeons to form a consensus on stage. Best corrected visual acuity (BCVA) in logMAR scale and central subfield thickness (CST) on pre- and post-operative spectral domain OCT scans were the variables noted for all patients at the time of diagnosis and at 6 and 12mo follow up visit after undergoing intervention. Partial correlation coefficient was computed between BCVA (logMAR) and CST by ERM stage adjusting by baseline measures. Clinical charts of 74 patients with idiopathic ERM were assessed. Clinically significant improvement in BCVA overtime was observed with significant difference in median visual acuity of patients with Stage II-IV ERM with P<0.001. The median CST of all patients with stage II-IV ERM showed similar consistent improvement with P<0.001 from baseline to 12th month. Our results showed not only gain in visual acuity but also shift from baseline to anatomical normalization of CST in stage II. We found a decrease in CST with difference of 166 µm and 151 µm in stage III and stage IV respectively. Our results remained consistent with the hypothesis of improved visual outcomes with all stages of ERM with adjusted moderate linear correlation between visual acuity and CST in stage II-IV (r>0.3). Equally significant visual outcomes of patients with ERM staged II-IV and therefore can be counselled for improved visual acuity after surgical removal of ERM with improvement up to 5 lines on Snellen's chart from the baseline.

Central macular thickness and subfoveal choroidal thickness changes on spectral domain optical coherence tomography after cataract surgery in pediatric population.

To evaluate the central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) changes on spectral domain optical coherence tomography (SD-OCT) after cataract surgery with intraocular lens (IOL) implantation in a pediatric population. This was a longitudinal, prospective, interventional study which included 90 pediatric patients who underwent cataract extraction with IOL implantation. Serial SD-OCT scans were done at postoperative day 1, 1-month, and 3-month follow-up. CMT and SFCT were measured at each visit. A statistically significant increase in CMT was noted at 1 month (from 199.3 μm to 210.04 μm) post surgery, which declined over a 3-month period (202.70 μm, P = 0.0001). In case of SFCT, a constant increase was observed for over 3 months of follow-up (baseline: 296.52 μm; 1 month: 309.04 μm; and 3 months: 319.03 μm, P = 0.0001). The traumatic cataract group showed more pronounced changes in CMT and SFCT than the non-traumatic cataract group. No significant difference was observed regarding these parameters between those who underwent primary posterior capsulotomy (PPC) versus those who did not. None of the patients in the study group developed cystoid macular edema. These posterior segment-related anatomical changes did not affect the final visual outcomes. Cataract surgery induces potential inflammatory changes in the macula and choroid in pediatric patients. Such changes are more pronounced in trauma-related cases; however, they are not significant enough to affect the visual outcomes. Similarly, the additional surgical step of PPC does not induce significant anatomical or functional changes.

Evaluation of the segmented inner retinal layers in exfoliation glaucoma.

To investigate the macular spectral domain optical coherence tomography (SD-OCT) measurements of the segmented inner retinal layers in patients with exfoliation syndrome (XFS), exfoliation glaucoma (XFG). This prospective cross-sectional study included 28 eyes with XFS, 47 eyes with XFG, and 29 healthy controls. Thickness of the inner retinal layers, including retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and inner plexiform layer (IPL) was obtained from the horizontal SD-OCT scans. Functional correlation of structural parameters was analyzed using the mean sensitivity (MS) values on 10-2 visual fields. The RNFL, GCL, and IPL were thinnest in eyes with XFG. Among these retinal layers, IPL was significantly thinner in eyes with XFS than healthy controls (p = 0.02) and the IPL thickness was significantly correlated with the corresponding MS scores on 10-2 visual fields (r = 0.492, p = 0.02) in eyes with XFS. Neither GCL nor RNFL thickness values demonstrated significant correlations with functional parameters in eyes with XFS (r = 0.377, p = 0.08; r = 0.212, p = 0.34). In eyes with XFG, the IPL thickness correlated with the visual field MS scores (r = 0.572, p = 0.0007), similar to the correlation of GCL (r = 0.585, p = 0.0005) thickness with visual field scores. Segmented analysis of the macular IPL thickness presented a significant correlation with the 10-2 visual field scores not only in eyes with XFG but also in eyes with XFS. With respect to early dendritic/synaptic alterations in animal models, larger and longitudinal studies are encouraged to determine the predictive value of the IPL thickness for conversion of XFS to XFG.

A Natural History Study of RP2-Related Retinopathy.

X-linked retinitis pigmentosa (RP) is a severe form of RP, often with early macular involvement. This study aimed to characterise the natural history of patients with a diagnosis of X-linked RP due to RP2 mutations. Clinical details, best-corrected visual acuity (BCVA) and multimodal retinal imaging were retrospectively collected from patients with RP2 variants from Moorfields Eye Hospital (London, UK). Measures of the ellipsoid-zone (EZ) width, central retinal thickness (CRT), and thickness of the photoreceptor and retinal pigment epithelium complex (PR+RPE, taken between the external limiting membrane and RPE) were extracted from spectral-domain optical coherence tomography (SD-OCT) scans. A total of 47 affected males (median baseline age: 20 years, IQR: 12.5−36.5) were included, and 41 had two or more visits (median follow-up: 8.0 years, IQR: 3.2−14.5). A total of 24 RP2 variants were identified, 13 of which were novel. BCVA dropped from 0.66 LogMAR at baseline (IQR, 0.35−1.4) to 1.3 LogMAR at the most recent visit (IQR: 0.6−1.4). SD-OCT revealed a prevalent outer retinal atrophy (n = 23/35, 65.7%), and measurable EZ width at baseline in 34.3% of patients (n = 12). Age significantly affected all quantitative measures (p < 0.001) except EZ width (p = 0.58), with exponential decays of 46−49% and 12.6−33.9% per decade for BCVA and SD-OCT measures, respectively. RP2 patients exhibited rapid progression to outer retina atrophy and early macular involvement with substantial vision loss by age 30−40.

Microperimetry assessment in foveal hypoplasia: functional results in a series of pediatric patients

ObjectifÉtudier le lien entre les paramètres fonctionnels et morphologiques de la rétine chez des enfants présentant différents degrés d'hypoplasie fovéale (HF). NatureÉtude d'observation rétrospective réalisée dans un seul centre. ParticipantsSur les 21 enfants, 16 répondaient aux critères d'inclusion et présentaient une HF confirmée par tomographie par cohérence optique en domaine spectral (SD-OCT). MéthodesLes données ont été analysées de manière rétrospective. Les patients qui étaient en mesure de subir une micropérimétrie maculaire (MPM) et une SD-OCT ont été inclus dans l'analyse. La corrélation de Pearson a servi à comparer les résultats de la MPM et de la SD-OCT en fonction du degré d'HF et de la meilleure acuité visuelle corrigée (MAVC). RésultatsOnt été analysés 31 yeux de 16 patients (âge moyen : 12,4 ans) présentant différents degrés d'HF : grade 1 chez 2 patients; grade 2 chez 7 patients; grade 3 chez 5 patients et grade 4 chez 2 patients. De ce nombre, 8 patients présentaient un nystagmus clinique. La corrélation entre la MAVC et les données obtenues à la SD-OCT (–0,31) était plus faible que celle entre la MAVC et le nystagmus (0,64), l'indice de fixation P1 (–0,60) et la sensibilité maculaire (–0,63). ConclusionsMalgré les limites que présente notre petit échantillonnage, notre étude confirme la faisabilité de l’évaluation par MPM automatisée chez des enfants qui présentent une HF. Elle est d'autant plus intéressante qu'elle fournit des données sur les liens entre les mesures maculaires anatomiques et fonctionnelles obtenues grâce à la SD-OCT et à la MPM, d'une part, et la MAVC, d'autre part, dans des yeux qui présentent différents degrés d'HF. Des études prospectives de plus grande envergure permettront de confirmer nos résultats.

Vessel density and choroidal vascularity index in patients with Bietti crystalline dystrophy and retinitis pigmentosa

ObjectiveTo evaluate and compare the vessel density (VD) using swept-source optical coherence tomography angiography (OCT-A) and the choroidal vascularity index (CVI) using spectral-domain optical coherence tomography (SD-OCT) in patients with Bietti crystalline dystrophy (BCD) and retinitis pigmentosa (RP). Materials and methodsA cross-sectional retrospective study was conducted on 26 eyes of 13 BCD patients, 26 eyes of 13 RP patients, and 26 eyes of 13 age- and gender-matched healthy individuals. BCD patients were further staged as having early, intermediate, and advanced disease. VD was assessed in five quadrants of the macula (superior, temporal, inferior, nasal, and center) using a modified ETDRS technique with OCT-A. SD-OCT scans were binarized using Niblack's autolocal threshold, and CVI was determined as the ratio of the luminal area to the total choroidal area. ResultsA significant difference was found in VD in all quadrants of the superficial capillary plexus (SCP) and the deep capillary plexus (DCP) slabs among the three groups (p < 0.001). A statistically significant difference was noted in the mean VD of temporal and inferior quadrants of the SCP and between the BCD and RP groups (p = 0.005, p = 0.015, respectively). A statistically significant difference was observed in the mean VD of the temporal, inferior, and nasal quadrants between the BCD and RP groups on DCP slabs (p = 0.002, p = 0.003, p = 0.003, respectively). The mean central choroidal thickness was 214.65±87.10 μm in the BCD group, 351.69±67.94 μm in the RP group, and 320.92±59.26 μm in the control group (p < 0.001). We found that CVI was significantly higher in the control group than BCD group (p < 0.001), and it was significantly lower in the BCD group when compared to the RP group (p < 0.001).There was no difference in CVI between RP and control groups (p = 0.948). Furthermore, the CVI was significantly lower in the intermediate and advanced disease stages than the early disease stage in the subgroup analysis of BCD patients (p < 0.001, p < 0.001, respectively). ConclusionCVI is a novel investigative tool to monitor disease progression. The CVI value was lower in BCD and RP patients than in the healthy subjects, and lower CVI values seem to be related to the disease severity in BCD patients. VD was also significantly lower in BCD patients when compared to RP patients, and VD analysis may help clinicians better understand the disease pathophysiology.

Deep Learning Estimation of 10-2 Visual Field Map Based on Circumpapillary Retinal Nerve Fiber Layer Thickness Measurements

To estimate central 10-degree visual field (VF) map from spectral-domain optical coherence tomography (SD-OCT) retinal nerve fiber layer thickness (RNFL) measurements in glaucoma with artificial intelligence. Artificial intelligence (convolutional neural networks) study. This study included 5352 SD-OCT scans and 10-2 VF pairs from 1365 eyes of 724 healthy patients, patients with suspected glaucoma, and patients with glaucoma. Convolutional neural networks (CNNs) were developed to estimate the 68 individual sensitivity thresholds of 10-2 VF map using all-sectors (CNNA) and temporal-sectors (CNNT) RNFL thickness information of the SD-OCT circle scan (768 thickness points). 10-2 indices including pointwise total deviation (TD) values, mean deviation (MD), and pattern standard deviation (PSD) were generated using the CNN-estimated sensitivity thresholds at individual test locations. Linear regression (LR) models with the same input were used for comparison. The CNNA model achieved an average pointwise mean absolute error of 4.04 dB (95% confidence interval [CI] 3.76-4.35) and correlation coefficient (r) of 0.59 (95% CI 0.52-0.64) over 10-2 map and the mean absolute error and r of 2.88 dB (95% CI 2.63-3.15) and 0.74 (95% CI 0.67-0.80) for MD, and 2.31 dB (95% CI 2.03-2.61) and 0.59 (95% CI 0.51-0.65) for PSD estimations, respectively, significantly outperforming the LRA model. The proposed CNNA model improved the estimation of 10-2 VF map based on circumpapillary SD-OCT RNFL thickness measurements. These artificial intelligence methods using SD-OCT structural data show promise to individualize the frequency of central VF assessment in patients with glaucoma and would enable the reallocation of resources from patients at lowest risk to those at highest risk of central VF damage.

Visual function and retinal changes after voretigene neparvovec treatment in children with biallelic RPE65-related inherited retinal dystrophy

To report quantitative retinal changes assessed by spectral-domain optical coherence tomography (SD-OCT) in children treated with voretigene neparvovec (VN) at a single center in Italy. Retrospective review of six consecutive pediatric patients with biallelic RPE65-related dystrophy treated bilaterally with VN. SD-OCT scans were analyzed to extract Early Treatment Diabetic Retinopathy Study (ETDRS) thickness maps of the whole retina and the outer nuclear layer (ONL). Changes in visual function were assessed by best-corrected visual acuity (BCVA) and retinal morphology at Days 30/45 and 180. BCVA significantly improved at Day 30/45 and 6 months (both P < 0.001). Central foveal retinal thickness and central foveal ONL thickness tended to increase (6.4 ± 19.2 µm; P = 0.080 and 3.42 ± 7.68 µm; P = 0.091, respectively). ONL thickness of the internal ETDRS-ring significantly increased at day 30/45 (4.7 ± 8.4 µm; P < 0.001) and day 180 (5.0 ± 5.7 µm; P = 0.009). Intra-operative foveal detachment was not associated with a higher function gain in terms of BCVA, but with a mild thinning of foveal ONL after treatment. The improvement of BCVA and thickening of the ONL layer suggest that improvement of visual acuity could be related to partial recovery of retinal morphology in the perifoveal ring.

Vitrectomy for macular retinoschisis associated with peripapillary intrachoroidal cavitations in a moderately myopic eye

BackgroundPeripapillary intrachoroidal cavitation (PICC), a cavernous change in the peripapillary choroid, may present with macular lesions. Here, we present a rare case of PICC with outer lamellar macular hole and macular retinoschisis.Case presentationA 69-year-old man presented with metamorphopsia in the left eye. Fundus examination revealed macular retinoschisis and PICCs. Pars plana vitrectomy with fovea sparing internal limiting membrane peeling (FSIP) was performed. Three weeks postoperatively, the patient developed rhegmatogenous retinal detachment and underwent a second vitrectomy. The macular retinoschisis resolved without macular hole formation and the patient’s visual acuity improved. There were no recurrent macular lesions over the three years of postoperative follow-up. Postoperative spectral-domain optical coherence tomography scan revealed a communication between the PICC and the vitreous cavity.ConclusionsThis case shed light on understanding development of PICC in non-highly myopic eyes and a rare complication of macular retinoschisis. Vitrectomy with FSIP may effectively resolve macular retinoschisis.

Total retinal thickness: a neglected factor in the evaluation of inner retinal thickness.

AimTo determine whether macular retinal nerve fibre layer (mRNFL) and ganglion cell-inner plexiform layer (GC-IPL) thicknesses vary by ethnicity after accounting for total retinal thickness.MethodsWe included healthy participants from the UK Biobank cohort who underwent macula-centred spectral domain-optical coherence tomography scans. mRNFL and GC-IPL thicknesses were determined for groups from different self-reported ethnic backgrounds. Multivariable regression models adjusting for covariables including age, gender, ethnicity and refractive error were built, with and without adjusting for total retinal thickness.Results20237 participants were analysed. Prior to accounting for total retinal thickness, mRNFL thickness was on average 0.9 μm (−1.2, –0.6; p<0.001) lower among Asians and 1.5 μm (−2.3, –0.6; p<0.001) lower among black participants compared with white participants. Prior to accounting for total retinal thickness, the average GC-IPL thickness was 1.9 μm (−2.5, –1.4; p<0.001) lower among Asians compared with white participants, and 2.4 μm (−3.9, –1.0; p=0.001) lower among black participants compared with white participants. After accounting for total retinal thickness, the layer thicknesses were not significantly different among ethnic groups. When considered as a proportion of total retinal thickness, mRNFL thickness was ~0.1 and GC-IPL thickness was ~0.2 across age, gender and ethnic groups.ConclusionsThe previously reported ethnic differences in layer thickness among groups are likely driven by differences in total retinal thickness. Our results suggest using layer thickness ratio (retinal layer thicknesses/total retinal thickness) rather than absolute thickness values when comparing retinal layer thicknesses across groups.

Persistent subfoveal fluid in pneumatic retinopexy versus pars plana vitrectomy for rhegmatogenous retinal detachment: posthoc analysis of the PIVOT randomised trial

PurposeTo assess the incidence of persistent subfoveal fluid (PSFF) in pneumatic retinopexy (PnR) versus pars plana vitrectomy (PPV) following rhegmatogenous retinal detachment (RRD) repair and to determine its association with...

The Effect of Latanoprost on Choroidal Vascularity Index in Glaucoma and Ocular Hypertension.

The choroidal vascularity index (CVI) is a new marker for the choroid. The decrease in CVI following latanoprost use can provide a better understanding of the pathogenesis of the posterior segment side effects of latanoprost such as cystoid macular edema and central serous choroidopathy. The purpose of this paper is to evaluate the changes in the CVI, total choroidal area (TCA), stromal area (SA), luminal area (LA), and choroidal thickness (CT) following latanoprost therapy in patients with primary open angle glaucoma and ocular hypertension. Patients with newly diagnosed primary open angle glaucoma or ocular hypertension who had never received antiglaucoma therapy were included. Each patient received latanoprost 0.005% once daily. Enhanced depth imaging mode of spectral-domain optical coherence tomography scans was taken before the start of latanoprost therapy and in the first and third months. Subfoveal CT, CVI, TCA, LA, and SA for the submacular area, and 4 quadrants of the peripapillary area were calculated from the scans. A total of 36 eyes of 18 patients were analyzed. Subfoveal CT increased significantly ( P =0.007). Mean TCA ( P =0.008) and SA ( P <0.001) in the first and third months were higher than baseline in the submacular regions. Mean CVI was lower in the first and third months ( P <0.001). There was an increase in the mean TCA and SA in the peripapillary temporal ( P =0.001 and 0.028) and inferior ( P =0.002 and <0.001) quadrants and a decrease in mean CVI in the temporal ( P =0.027) and inferior ( P =0.003) peripapillary quadrants. A negative correlation was found between the rate of decrease in intraocular pressure and the macular region CVI. Following latanoprost use for several months, the CVI was significantly decreased in newly treated patients with glaucoma or ocular hypertension, among other changes to the choroid. These findings may contribute to a better understanding of the effects of prostaglandins on the posterior segment of the eye.

Predicting Topographic Disease Progression and Treatment Response of Pegcetacoplan in Geographic Atrophy Quantified by Deep Learning

To identify disease activity and effects of intravitreal pegcetacoplan treatment on the topographic progression of geographic atrophy (GA) secondary to age-related macular degeneration quantified in spectral-domain OCT (SD-OCT) by automated deep learning assessment. Retrospective analysis of a phase II clinical trial study evaluating pegcetacoplan in GA patients (FILLY, NCT02503332). SD-OCT scans of 57 eyes with monthly treatment, 46 eyes with every-other-month (EOM) treatment, and 53 eyes with sham injection from baseline and 12-month follow-ups were included, in a total of 312 scans. Retinal pigment epithelium loss, photoreceptor (PR) integrity, and hyperreflective foci (HRF) were automatically segmented using validated deep learning algorithms. Local progression rate (LPR) was determined from a growth model measuring the local expansion of GA margins between baseline and 1 year. For each individual margin point, the eccentricity to the foveal center, the progression direction, mean PR thickness, and HRF concentration in the junctional zone were computed. Mean LPR in disease activity and treatment effect conditioned on these properties were estimated by spatial generalized additive mixed-effect models. LPR of GA, PR thickness, and HRF concentration in μm. A total of 31,527 local GA margin locations were analyzed. LPR was higher for areas with low eccentricity to the fovea, thinner PR layer thickness, or higher HRF concentration in the GA junctional zone. When controlling for topographic and structural risk factors, we report on average a significantly lower LPR by -28.0% (95% confidence interval [CI], -42.8 to -9.4; P = 0.0051) and -23.9% (95% CI, -40.2 to -3.0; P = 0.027) for monthly and EOM-treated eyes, respectively, compared with sham. Assessing GA progression on a topographic level is essential to capture the pathognomonic heterogeneity in individual lesion growth and therapeutic response. Pegcetacoplan-treated eyes showed a significantly slower GA lesion progression rate compared with sham, and an even slower growth rate toward the fovea. This study may help to identify patient cohorts with faster progressing lesions, in which pegcetacoplan treatment would be particularly beneficial. Automated artificial intelligence-based tools will provide reliable guidance for the management of GA in clinical practice.

Retinal Layer Thinning After Optic Neuritis Is Associated With Future Relapse Remission in Relapsing Multiple Sclerosis.

Remission of relapses is an important contributor to both short- and long-term prognosis in relapsing multiple sclerosis (RMS). In MS-associated acute optic neuritis (MS-ON), retinal layer thinning measured by optical coherence tomography (OCT) is a reliable biomarker of both functional recovery and the degree of neuroaxonal damage. However, prediction of non-ON relapse remission is challenging. We aimed to investigate whether retinal thinning after ON is associated with relapse remission after subsequent non-ON relapses. For this longitudinal observational study from the Vienna MS database, we included patients with MS with (1) an episode of acute ON, (2) available spectral domain OCT scans within 12 months before ON onset (OCTbaseline), within 1 week after ON onset (OCTacute), and 3-6 months after ON (OCTfollow-up), and (3) at least 1 non-ON relapse after the ON episode. Subsequent non-ON relapses were classified as displaying either complete or incomplete remission based on change in the Expanded Disability Status Scale score assessed 6 months after relapse. Association of retinal thinning in the peripapillary retinal nerve fiber layer (ΔpRNFL) and macular ganglion cell and inner plexiform layer (ΔGCIPL) with incomplete remission was tested by multivariate logistic regression models adjusting for age, sex, disease duration, relapse severity, time to steroid treatment, and disease-modifying treatment status. We analyzed 167 patients with MS (mean age 36.5 years [SD 12.3], 71.3% women, mean disease duration 3.1 years [SD 4.5]) during a mean observation period of 3.4 years (SD 2.8) after the ON episode. In 61 patients (36.5%), at least 1 relapse showed incomplete remission. In the multivariable analyses, incomplete remission of non-ON relapse was associated with ΔGCIPL thinning both from OCTbaseline to OCTfollow-up and from OCTacute to OCTfollow-up (OR 2.4 per 5 μm, p < 0.001, respectively), independently explaining 29% and 27% of variance, respectively. ΔpRNFL was also associated with incomplete relapse remission when measured from OCTbaseline to OCTfollow-up (OR 1.9 per 10 μm, p < 0.001), independently accounting for 22% of variance, but not when measured from OCTacute to OCTfollow-up. DISCUSSION: Retinal layer thinning after optic neuritis may be useful as a marker of future relapse remission in RMS.

Temporal retinal thinning might be an early diagnostic indicator in male pediatric X-linked Alport syndrome.

To evaluate temporal retinal thinning changes in retinal layers using spectral-domain optical coherence tomography (SD-OCT) in pediatric X-linked Alport syndrome (XLAS) patients. A retrospective case-control study. SD-OCT scans of pediatric patients diagnosed with XLAS and age- and sex-matched healthy control participants were reviewed. Automated segmentation of SD-OCT scans was induced to analyze the retinal thickness (RT) of different layers. The temporal thinning index (TTI) was calculated for each layer and compared between the patients and the control group. Forty-three pediatric XLAS patients and 60 healthy controls were included. Temporal retinal thinning was present in 33 patients (76.74%), while 28 patients (65.11%) had severe pathological temporal retinal thinning and 5 patients (11.63%) had moderate thinning. The temporal inner sector RT (P<0.0001), the temporal outer sector RT (P<0.0001), and the nasal outer sector RT (P=0.0211) were significantly thinner in the XLAS male patients. The TTI of the total retina was significantly higher in the XLAS group than in the control group (P<0.0001). The TTI of the inner retina layers (P<0.0001), ganglion cell layer (P<0.0001), inner plexiform layer (P<0.0001), inner nuclear layer (P<0.0001), and outer nuclear layer (P<0.0001) were significantly higher in the XLAS group. The central RT of the XLAS group was significantly thinner than that of the control group (P<0.0001). Temporal retinal thinning appears early in XLAS patients, especially in male patients. The thinning is mainly caused by structural abnormalities of the inner retina. This suggests that temporal retinal thinning could be helpful for the early diagnosis and follow-up of XLAS with noninvasive SD-OCT examination.

Three-Dimensional Multi-Task Deep Learning Model to Detect Glaucomatous Optic Neuropathy and Myopic Features From Optical Coherence Tomography Scans: A Retrospective Multi-Centre Study

PurposeWe aim to develop a multi-task three-dimensional (3D) deep learning (DL) model to detect glaucomatous optic neuropathy (GON) and myopic features (MF) simultaneously from spectral-domain optical coherence tomography (SDOCT) volumetric scans.MethodsEach volumetric scan was labelled as GON according to the criteria of retinal nerve fibre layer (RNFL) thinning, with a structural defect that correlated in position with the visual field defect (i.e., reference standard). MF were graded by the SDOCT en face images, defined as presence of peripapillary atrophy (PPA), optic disc tilting, or fundus tessellation. The multi-task DL model was developed by ResNet with output of Yes/No GON and Yes/No MF. SDOCT scans were collected in a tertiary eye hospital (Hong Kong SAR, China) for training (80%), tuning (10%), and internal validation (10%). External testing was performed on five independent datasets from eye centres in Hong Kong, the United States, and Singapore, respectively. For GON detection, we compared the model to the average RNFL thickness measurement generated from the SDOCT device. To investigate whether MF can affect the model’s performance on GON detection, we conducted subgroup analyses in groups stratified by Yes/No MF. The area under the receiver operating characteristic curve (AUROC), sensitivity, specificity, and accuracy were reported.ResultsA total of 8,151 SDOCT volumetric scans from 3,609 eyes were collected. For detecting GON, in the internal validation, the proposed 3D model had significantly higher AUROC (0.949 vs. 0.913, p < 0.001) than average RNFL thickness in discriminating GON from normal. In the external testing, the two approaches had comparable performance. In the subgroup analysis, the multi-task DL model performed significantly better in the group of “no MF” (0.883 vs. 0.965, p-value < 0.001) in one external testing dataset, but no significant difference in internal validation and other external testing datasets. The multi-task DL model’s performance to detect MF was also generalizable in all datasets, with the AUROC values ranging from 0.855 to 0.896.ConclusionThe proposed multi-task 3D DL model demonstrated high generalizability in all the datasets and the presence of MF did not affect the accuracy of GON detection generally.

Glaucoma Rose Plot Analysis: Detecting Early Structural Progression Using Angular Histograms

To evaluate the novel Rose Plot Analysis (RPA) in the analysis and presentation of glaucoma structural progression data. Case-control image analysis study using retrospective retinal imaging series. Subjects with open-angle glaucoma with at least 5 registered spectral-domain OCT scans. Glaucoma RPA was developed, combining a novel application of angular histograms and dynamic cluster analysis of circumpapillary retinal nerve fiber layer (cRNFL) OCT data. Rose Plot Analysis plots were created for each eye and each visit. Significant clusters of progression were indicated in red. Three masked clinicians categorized all RPA plots (progressing, not progressing), in addition to measuring the significant RPA area. A masked OCT series assessment with linear regression of averaged global and sectoral cRNFL thicknesses was conducted as the clinical imaging standard. Interobserver agreement was compared between RPA and the clinical imaging standard. Discriminative ability was assessed using receiver-operating characteristic curves. The time to detection of progression was compared using a Kaplan-Meier survival analysis, and the agreement of RPA with the clinical imaging standard was calculated. Seven hundred fourty-three scans from 98 eyes were included. Interobserver agreement was significantly greater when categorizing RPA (κ, 0.86; 95% confidence interval [CI], 0.81-0.91) compared with OCT image series (κ, 0.66; 95% CI, 0.54-0.77). The discriminative power of RPA to differentiate between eyes that were progressing and not progressing (area under the curve [AUC], 0.97; 95% CI, 0.92-1.00) was greater than that of global cRNFL thickness (AUC, 0.71; 95% CI, 0.59-0.82; P < 0.0001) and equivalent to that of sectoral cRNFL regression (AUC, 0.97; 95% CI, 0.92-1.00). A Kaplan-Meier survival analysis showed that progression was detected 8.7 months sooner by RPA than by global cRNFL linear regression (P < 0.0001) in progressing eyes but was not sooner than with sectoral cRNFL (P= 0.06). Rose Plot Analysis showed substantial agreement with the presence of significant thinning on sectoral cRNFL linear regression (κ, 0.715; 95% CI, 0.578-0.853). Rose Plot Analysis has been shown to provide accurate and intuitive, at-a-glance data analysis and presentation that improve interobserver agreement and may aid early diagnosis of glaucomatous disease progression.

Bacillary Detachment in Neovascular Age-Related Macular Degeneration: Incidence, Clinical Features, and Response to Anti-VEGF Therapy

To evaluate the incidence of bacillary layer detachment among patients with neovascular age-related macular degeneration (nAMD) and their response to anti-VEGF therapy. Post hoc analysis of the OSPREY clinical trial, a prospective, double-masked, phase II study comparing 6-mg brolucizumab with 2-mg aflibercept over 56 weeks. Participants with treatment-naive nAMD at the initiation of the trial were included in the analysis (n= 81). Spectral-domain OCT (SD-OCT) scans were obtained at 4-week intervals throughout the OSPREY study and were segmented automatically using a proprietary, machine learning-enabled higher-order feature-extraction platform. The presence of bacillary detachment, and in these eyes the effect of anti-VEGF therapy on change from baseline in visual acuity (VA), central subfield thickness (CST), retinal fluid volumes, subretinal hyper-reflective material (SHRM) volume, subretinal pigment epithelium (sub-RPE) fluid volume, and ellipsoid zone (EZ) integrity at week56. Bacillary detachment was identified in 7.4% (6 of 81) eyes, which had higher fluid volumes, increased CST, EZ attenuation, and increased sub-RPE volume at baseline compared with eyes without bacillary detachment. Anti-VEGF treatment resulted in the resolution of bacillary detachment in 100% of the eyes. In eyes with bacillary detachment at baseline, the anti-VEGF treatment decreased CST, fluid burden, and SHRM volumes throughout the treatment course; however, there was no significant change from baseline in VA, sub-RPE volume, or EZ integrity throughout the 56-week course of anti-VEGF treatment. Bacillary detachment is an OCT signature that is identifiable in a notable proportion of nAMD eyes. Anti-VEGF therapy resulted in 100% resolution of bacillary detachment and significant decreases in CST and SHRM volume; however, improvements in VA may have been limited by persistent EZ attenuation.

Microstructural Deformations Within the Depth of the Lamina Cribrosa in Response to Acute In Vivo Intraocular Pressure Modulation.

PurposeThe lamina cribrosa (LC) is a leading target for initial glaucomatous damage. We investigated the in vivo microstructural deformation within the LC volume in response to acute IOP modulation while maintaining fixed intracranial pressure (ICP).MethodsIn vivo optic nerve head (ONH) spectral-domain optical coherence tomography (OCT) scans (Leica, Chicago, IL, USA) were obtained from eight eyes of healthy adult rhesus macaques (7 animals; ages = 7.9–14.4 years) in different IOP settings and fixed ICP (8–12 mm Hg). IOP and ICP were controlled by cannulation of the anterior chamber and the lateral ventricle of the brain, respectively, connected to a gravity-controlled reservoir. ONH images were acquired at baseline IOP, 30 mm Hg (H1-IOP), and 40 to 50 mm Hg (H2-IOP). Scans were registered in 3D, and LC microstructure measurements were obtained from shared regions and depths.ResultsOnly half of the eyes exhibited LC beam-to-pore ratio (BPR) and microstructure deformations. The maximal BPR change location within the LC volume varied between eyes. BPR deformer eyes had a significantly higher baseline connective tissue volume fraction (CTVF) and lower pore aspect ratio (P = 0.03 and P = 0.04, respectively) compared to BPR non-deformer. In all eyes, the magnitude of BPR changes in the anterior surface was significantly different (either larger or smaller) from the maximal change within the LC (H1-IOP: P = 0.02 and H2-IOP: P = 0.004).ConclusionsThe LC deforms unevenly throughout its depth in response to IOP modulation at fixed ICP. Therefore, analysis of merely the anterior LC surface microstructure will not fully capture the microstructure deformations within the LC. BPR deformer eyes have higher CTVF than BPR non-deformer eyes.

Outer retinal thickness and visibility of the choriocapillaris in four distinct retinal regions imaged with spectral domain optical coherence tomography in dogs and cats.

PurposeTo evaluate the outer retinal band thickness and choriocapillaris (CC) visibility in four distinct retinal regions in dogs and cats imaged with spectral domain optical coherence tomography (SD‐OCT). To attempt delineation of a fovea‐like region in canine and feline SD‐OCT scans, aided by the identification of outer retinal thickness differences between retinal regions.MethodsSpectralis® HRA + OCT SD‐OCT scans from healthy, anesthetized dogs (n = 10) and cats (n = 12) were analyzed. Scanlines on which the CC was identifiable were counted and CC visibility was scored. Outer nuclear layer (ONL) thickness and the distances from external limiting membrane (ELM) to retinal pigment epithelium/Bruch's membrane complex (RPE/BM) and ELM to CC were measured in the area centralis (AC), a visually identified fovea‐like region, and in regions superior and inferior to the optic nerve head (ONH). Measurements were analyzed using a multilevel regression.ResultsThe CC was visible in over 90% of scanlines from dogs and cats. The ONL was consistently thinnest in the fovea‐like region. The outer retina (ELM‐RPE and ELM‐CC) was thickest within the AC compared with superior and inferior to the ONH in dogs and cats (p < .001 for all comparisons).ConclusionsThe CC appears a valid, albeit less than ideal outer retinal boundary marker in tapetal species. The AC can be objectively differentiated from the surrounding retina on SD‐OCT images of dogs and cats; a fovea‐like region was identified in dogs and its presence was suggested in cats. These findings allow targeted imaging and image evaluation of these regions of retinal specialization.