Retinal Layer Research Articles

Inter-eye asymmetry of microvascular density in patients on hydroxychloroquine therapy by optical coherence tomography angiography

AimsTo explore the inter-eye retinal microvascular density asymmetry of patients on hydroxychloroquine (HCQ) therapy through optical coherence tomography angiography (OCTA). Methods40 subjects were enrolled in this cross-sectional study, including 20 systemic lupus erythematasus patients currently treated with HCQ (40 eyes) and 20 age- and sex-matched normal controls (NCs, 40 eyes). OCTA images were obtained to measure macular and peripapillary mircrovasculatures and microstructures, including vessel density, retinal nerver fiber layer thickness, and peripapillary ganglion cell-inner plexiform layer thickness. The absolute values of the difference between right and left eyes were taken as a measure of inter-eye asymmetry. ResultsMacular whole image vessel density (wiVD-M) and perifoveal vessel density (pfVD) of superficial capillary plexus (SCP) were notably reduced in both the right and left eyes of the HCQ treatment group compared with NCs. Specifically, SLE patients treated with HCQ have higher inter-eye asymmetry of wiVD-M of SCP (2.28 ± 1.03 vs 1.27 ± 0.79, p < 0.01) and pfVD of SCP (2.55 ± 1.26 vs 1.78 ± 1.06, p = 0.04) compared with NCs. There were no significant differences in inter-eye asymmetry of structure parameters. Inter-eye asymmetry of wiVD-M of SCP (AUC = 0.80, p < 0.01) and pfVD of SCP (AUC = 0.71, p = 0.02) exhibited greater discrimination power. ConclusionSLE Patients treated with HCQ exhibited a notably higher inter-eye vessel density asymmetry compared to that of NCs. Thus, inter-eye vessel density asymmetry could be used to screen for HCQ retinal toxicity.

CLINICOPATHOLOGIC CHANGES OF VITREOMACULAR INTERFACE IN IDIOPATHIC EPIRETINAL MEMBRANE WITH DISORGANIZATION OF RETINAL INNER LAYERS.

To compare the pathological characteristics of the vitreomacular interface of the idiopathic epiretinal membrane with and without disorganization of retinal inner layers (DRIL) and to correlate with clinical data. In this clinicopathologic study, the samples of epiretinal membrane and internal limiting membrane were extracted from DRIL(+) (19 eyes) and DRIL(-) (22 eyes) idiopathic epiretinal membrane eyes. Ultrathin series sectioning for transmission electron microscopy was observed and correlated with surgery status and prognosis. All idiopathic epiretinal membrane eyes presented fibrocellular membranes accompanied by vitreous collagen, glial cells, and myofibroblasts, regardless of association with DRIL. A robust signal indicative of Collagen Type VI was observed in eyes DRIL(-), whereas Collagen Type I was discovered in DRIL eyes. Cell debris and microvascular basement membrane were seen on the retinal side of DRIL eyes and a larger cell count on the vitreous side. These have more intraoperative complications and less surgery benefit. Although internal limiting membrane peeling seems important, the histopathologic findings underscore the potential for retinal injury in DRIL(+) idiopathic epiretinal membrane eyes. This suggests that further research is needed to investigate individual preoperative assessment and to modify surgical procedures.

Individual Prognostication of Disease Activity and Disability Worsening in Multiple Sclerosis With Retinal Layer Thickness z Scores

Individual Prognostication of Disease Activity and Disability Worsening in Multiple Sclerosis With Retinal Layer Thickness <i>z</i> Scores

Visual prognostic factors following surgery for stage 3 idiopathic epiretinal membrane by Govetto classification.

To investigate the visual prognosis of metamorphopsia in patients undergoing surgery for stage 3 idiopathic epiretinal membrane (ERM) by Govetto classification using preoperative optical coherence tomography (OCT) parameters. Retrospective clinical study. This study included 45 eyes of 45 patients with a minimum follow-up period of 3 months. The best-corrected visual acuity (BCVA) and metamorphopsia score using the M-CHARTS were recorded. Central foveal thickness (CFT), inner nuclear layer thickness (INL), ectopic inner retinal layer thickness (EIFL), outer retinal layer thickness, disruption of the ellipsoid zone, cotton ball sign, and intraretinal cystoid changes were measured based on spectral domain OCT. Preoperative and postoperative values and conditions were compared, and correlations between the preoperative values or conditions and postoperative metamorphopsia scores or BCVA were analyzed. After surgery, the horizontal, vertical, and mean metamorphopsia scores, as well as BCVA, CFT, INL, and EIFL significantly improved (p < 0.001). Using multivariate analysis, only preoperative CFT was a significant explanatory parameter for both the postoperative horizontal metamorphopsia scores and mean values of the postoperative horizontal and vertical metamorphopsia scores (p = 0.019 and p = 0.011, respectively). Age (p = 0.011) and preoperative CFT (p = 0.026) were significant explanatory parameters of postoperative BCVA. Preoperative CFT significantly correlated with postoperative metamorphopsia in patients undergoing surgery for stage 3 idiopathic ERM. This finding might help surgeons predict postoperative visual outcomes and make timely surgical decisions.

Differential Expression of Branched-Chain Aminotransferase in the Rat Ocular Tissues.

Branched-chain amino acids (BCAAs) play vital roles in metabolic and physiological processes, with their catabolism initiated by two branched-chain aminotransferase isozymes: cytosolic (BCATc) and mitochondrial (BCATm). These enzymes have tissue and cell-specific compartmentalization and are believed to shuttle metabolites between cells and tissues. Although their expression and localization have been established in most tissues, ocular tissues remain unknown. In this study, we used immunohistochemical analyses to investigate the expression and localization of BCAT enzymes in the normal eye tissues. As expected, BCATc was highly expressed in the neuronal cells of the retina, particularly in the ganglion cell layers, inner nuclear layer, and plexiform layer, with little to no expression in Müller cells. BCATc was also present in the cornea, retinal pigment epithelium (RPE), choroid, ciliary body, and iris but not in the lens. In contrast, BCATm was expressed across all ocular tissues, with strong expression in the Muller cells of the retina, the endothelial and epithelial layers of the cornea, the choroid and iris, and the epithelial cells at the lens's front. The extensive expression and distribution of BCAT isozymes in the ocular tissue, suggests that BCAA transamination is widespread in the eye, potentially aiding in metabolite transport between ocular tissues. The findings provide new insights into the physiological role of BCATs in the eye, particularly within the neuronal retina.

Age-related effects of optineurin deficiency in the mouse eye

Optineurin (OPTN) is a gene associated with familial normal tension glaucoma (NTG). While NTG involves intraocular pressure (IOP)-independent neurodegeneration of the visual pathway that progresses with age, how OPTN dysfunction leads to NTG remains unclear. Here, we generated an OPTN knockout mouse (Optn−/−) model to test the hypothesis that a loss-of-function mechanism induces structural and functional eye deterioration with aging. Eye anatomy, visual function, IOP, retinal histology, and retinal ganglion cell survival were compared to littermate wild-type (WT) control mice. Consistent with OPTN’s role in NTG, loss of OPTN did not increase IOP or alter gross eye anatomy in young (2–3 months) or aged (12 months) mice. When retinal layers were quantitated, young Optn−/− mice had thinner retina in the peripheral regions than young WT mice, primarily due to thinner ganglion cell-inner plexiform layers. Despite this, visual function in Optn−/− mice was not severely impaired, even with aging. We also assessed relative abundance of retinal cell subtypes, including amacrine cells, bipolar cells, cone photoreceptors, microglia, and astrocytes. While many of these cellular subtypes were unaffected by Optn deletion, more dopaminergic amacrine cells were observed in aged Optn−/− mice. Taken together, our findings showed that complete loss of Optn resulted in mild retinal changes and less visual function impairment, supporting the possibility that OPTN-associated glaucoma does not result from a loss-of-function disease mechanism. Further research using these Optn mice will elucidate detailed molecular pathways involved in NTG and identify clinical or environmental risk factors that can be targeted for glaucoma treatment.

Deep learning aided measurement of outer retinal layer metrics as biomarkers for inherited retinal degenerations: opportunities and challenges.

The purpose of this review was to provide a summary of currently available retinal imaging and visual function testing methods for assessing inherited retinal degenerations (IRDs), with the emphasis on the application of deep learning (DL) approaches to assist the determination of structural biomarkers for IRDs. (clinical trials for IRDs; discover effective biomarkers as endpoints; DL applications in processing retinal images to detect disease-related structural changes). Assessing photoreceptor loss is a direct way to evaluate IRDs. Outer retinal layer structures, including outer nuclear layer, ellipsoid zone, photoreceptor outer segment, RPE, are potential structural biomarkers for IRDs. More work may be needed on structure and function relationship.

Vessel density, macula thickness and foveal avascular zone measurements in young African adults with moderate myopia: A pilot study.

The aim of this study was to investigate the association between macula thickness and vessel density in African myopic and emmetropic eyes through the use of Spectral Domain Optical Coherence Tomography (OCT). The study population comprised African adults aged 18-35 years old. The study was conducted at a University eye clinic located in Durban, South Africa. Purposive sampling was utilised to obtain 59 participants of whom 24 were myopes and 35 were emmetropes. Vessel density (VD), foveal avascular zone (FAZ) and retinal thickness (RT) were obtained using the Heidelberg Spectralis OCT with angiography. Thereafter, a multivariate linear regression was used to investigate associations between the spherical equivalent myopic refractive error and VD, FAZ and RT for the myopic group only. Myopic participants had a mean spherical equivalent (MSE) and standard deviation (SD) of -4.79 D (1.27) while the emmetropic group had an MSE (SD) of -0.32 D (0.46). Both superficial and deep VD were significantly decreased at the central fovea (radius (r) = 0.4 mm), peri-foveal (r = 1.10-1.45 mm) and para-foveal (r = 0.75-1.10 mm) sectors in myopes when compared with emmetropes. Myopes showed a significant reduction in RT in the inner retinal layer across the inferior and temporal zones of the peri-foveal region as well as the inferior and temporal zones of the para-foveal region when compared with emmetropes. A significantly smaller FAZ was found at both the superficial and deep vascular plexuses (p < 0.001). In African myopes, significant associations were not found between MSE and VD or FAZ and macula retinal thickness. Retinal vascular and thickness reduction may occur in young African adults with moderate myopia. A broad-based study targeting VD and IRT in African myopes is proposed to confirm preclinical myopic macula disruptions in adults of African ethnicity. OCT angiography should be considered when monitoring progressive myopia.

Differences in macular thickness associated with peripheral retinal vessel whitening in diabetic patients

This study aimed to determine the difference in macular thickness among patients with diabetes mellitus (DM) with and without peripheral retinal vessel whitening (PRVW). PRVW was defined by retinal vessel whitening outside the standard seven ETDRS fields. Subjects were divided into DM with PRVW, DM without PRVW, and normal age-matched controls. Optical coherence tomography scans were divided into total, inner, and outer retinal layer thicknesses and were compared in the macula's central, inner, and outer rings. Forty-seven eyes were included: DM with PRVW = 15, DM without PRVW = 16, and Controls = 16. Overall, the mean retinal thickness in patients with DM with PRVW was lower than in patients with DM without PRVW and controls. In the inner macula, DM patients with PRVW showed a significantly lower mean inner superior, nasal, inferior, and temporal macula compared to DM patients without PRVW (p = 0.014, 0.008, 0.005, < 0.001, respectively). DM patients with PRVW also showed a significantly lower mean outer superior, nasal, inferior, and temporal macula than controls (p = 0.005, 0.005, 0.016, 0.025, respectively). This study demonstrates that PRVW in DM patients may be associated with global structural changes to the macular region, promoting a decrease in inner and outer retinal thickness. Further studies should investigate the functional correlation with PRVW in DM patients in order to better understand its potential implications in diabetic patients.

Impact of systemic hypertension on inner retinal layer thickness and macular microvasculature in patients with diabetic retinopathy.

To investigate the effects of hypertension (HTN) on inner retinal thickness and macular microvasculature in patients with diabetic retinopathy (DR). Subjects were classified into three groups: patients with type 2 diabetes mellitus (T2DM) (T2DM group), patients with DR (DR-HTN group), and patients with DR and HTN (DR + HTN group). The ganglion cell complex (GCC) thicknesses and the macular vessel density (VD) were compared. Linear regression analyses were performed to identify factors associated with the VD in the DR + HTN group. The mean GCC thicknesses were 112.2 ± 12.3, 109.2 ± 13.7, and 106.2 ± 11.2μm in the T2DM, DR-HTN, and DR + HTN groups, respectively (P = 0.045). The mean VDs were 25.4 ± 5.0, 24.3 ± 8.9, and 21.2 ± 7.1% (P = 0.014) for the superficial capillary plexus (SCP) and 25.9 ± 4.3, 22.9 ± 8.5, and 20.2 ± 6.6% (P < 0.001) for the deep capillary plexus (DCP) in the T2DM, DR-HTN, and DR + HTN groups, respectively. In multivariate analyses, the duration of HTN was a significant factor associated with the VD of both SCP (B = -0.24, P = 0.010) and DCP (B = -0.21, P = 0.016). Patients with both DR and HTN had a thinner GCC and lower VDs of SCP and DCP than those with DR alone. These outcomes could be associated with the synergistic ischemic effects in DR patients with HTN. Moreover, the duration of HTN in DR patients was significantly associated with macular VD in both SCP and DCP.

Vitrectomy in Small idiopathic MAcuLar hoLe (SMALL) study: conventional internal limiting membrane peeling versus inverted flap.

To compare conventional internal limiting membrane (ILM) peeling versus inverted flap technique in small idiopathic macular hole. Retrospective, multicentre cohort study including consecutive eyes with a ≤250 μm idiopathic macular hole treated with primary vitrectomy. The primary outcome was best-corrected visual acuity (BCVA) change and macular hole closure rate. Closure patterns on optical coherence tomography (OCT) and rates of external limiting membrane (ELM) and ellipsoid zone (EZ) recovery were considered as secondary outcomes. A total of 389 and 250 eyes were included in the conventional ILM peeling group and in the inverted flap group, respectively. Hole closure rate was comparable between the two groups (98.5% in the ILM peeling group and 97.6% in the inverted flap group). Mean BCVA was comparable between the two groups at baseline (p = 0.331). At 12 months, mean BCVA was 0.14 ± 0.19 logMAR in the conventional ILM peeling group and 0.17 ± 0.18 logMAR in the inverted flap group (p = 0.08). At 12 months, 73% of eyes had a U-shape closure morphology in the conventional ILM peeling group versus 55% in the inverted flap group. At 12 months, ELM recovery rate was 96% and 86% in the conventional ILM peeling group and in the inverted flap group, respectively (p < 0.001); EZ recovery rate was 78% and 69%, respectively (p = 0.04). The inverted flap technique provides no advantages in terms of visual outcome and closure rate in small idiopathic macular hole surgery. Additionally, this technique seems to impair postoperative restoration of external retinal layers compared with conventional peeling.

Optical Coherence Tomography Angiography Assessment of Optic Nerve Head and Macula across the Primary Angle Closure Disease Spectrum.

The microvasculature of the optic disc and macula in eyes with acute primary angle closure and primary angle closure glaucoma was lower across the disease spectrum, but the significant difference was only observed in primary angle closure glaucoma. To assess the microvasculature in the optic nerve head (ONH) and macula across primary angle-closure disease (PACD) spectrum using optical coherence tomography angiography (OCTA). OCTA (AngioVue, Fremont, CA) imaging was performed on 122 PACD subjects. Flow area (FA) and vessel density (VD) in the ONH, radial peripapillary capillary (RPC) network, and superficial and deep capillary plexuses of the macula were calculated and compared across the PACD spectrum using linear regression models with generalized estimating equations adjusted for inter-eye correlation. A total of 234 eyes including 44 primary angle-closure suspects (PACS), 93 primary angle-closure (PAC), 79 primary angle-closure glaucoma (PACG) and 18 PAC with history of previous acute primary angle-closure (APAC) were included in the analysis. Compared to other groups, PACG eyes showed smaller FA in the ONH (1.35±0.02mm2), RPC (0.78±0.03mm2), and the superficial retinal layer (1.08±0.03mm2) (all P<0.05). Lower VD was also observed in the "whole image", "inside disc", and "peripapillary" regions of the ONH and RPC, and the "whole image" and "parafoveal" regions of the retinal layer in the PACG group when compared with other groups (all P<0.05). No significant differences were found for the other groups (all P>0.05). Lower VD in the ONH, RPC, and superficial retinal layer significantly correlated with worse visual field loss in PACG eyes (all P<0.05). Significant reduction in the microvasculature of the optic disc and macula in PACG suggests that glaucoma development may contribute to lower VD in these regions.

Sources of Discrepancy between Retinal Nerve Fiber Layer and Bruch’s Membrane Opening-Minimum Rim Width Thickness in Eyes with Glaucoma

To compare the discrepancies between circumpapillary retinal nerve fiber layer (RNFL) and Bruch's membrane opening-minimum rim width (BMO-MRW) thickness in glaucoma eyes. A cross-sectional observational study. One hundred eighty-six eyes (118 patients) with glaucoma. OCT optic nerve head volume scans of patients enrolled in the Advanced Glaucoma Progression Study at the final available visit were exported. The RNFL and BMO-MRW measurements were averaged into corresponding 7.5° sectors, and the nasal sector data were excluded from analyses. A 2-stage screening process was used to identify true mismatches between the RNFL and BMO-MRW measurements, in which either the RNFL or BMO-MRW value was in the less than first percentile range while its counterpart was in the greater than first percentile range on the temporal-superior-nasal-inferior-temporal curve. The prevalence of these mismatches was mapped, and corresponding images were reviewed to determine the underlying cause of these discrepancies. Proportion of mismatches between RNFL and BMO-MRW, location of mismatches between RNFL and BMO-MRW, anatomical causes of mismatches between RNFL and BMO-MRW. Mismatch analysis revealed true mismatches between RNFL and BMO-MRW in 7.7% of sectors. High BMO-MRW with low corresponding RNFL mismatches were most frequently located at the 45° and 322.5° sectors, whereas high RNFL with corresponding low BMO-MRW mismatches peaked at the 75° sector. Large blood vessels accounted for 90.9% of high RNFL with low BMO-MRW mismatches. Small to large blood vessels accounted for 62.9% of high BMO-MRW with low RNFL mismatches; the remaining mismatches could be attributed to retinoschisis or inclusion of outer retinal layers in BMO-MRW measurements. Although overall agreement between RNFL and BMO-MRW measurements is good in areas with advanced damage, blood vessels and other anatomical factors can cause discrepancies between the 2 types of structural measurements and need to be considered when evaluating the utility of such measurements for detection of change. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Acute ocular hypertension in the living human eye: Model description and initial cellular responses to elevated intraocular pressure

This initial methods study presents the initial immunohistochemical and transcriptomic changes in the optic nerve head and retina from three research-consented brain-dead organ donors following prolonged and transient intraocular pressure (IOP) elevation. In this initial study, research-consented brain-dead organ donors were exposed to unilateral elevation of IOP for 7.5 h (Donor 1), 30 h (Donor 2), and 1 h (Donor 3) prior to organ procurement. Optic nerve tissue and retinal tissue was obtained following organ procurement for immunohistological and transcriptomic analysis.Optic nerve sections in Donor 1 exposed to 7.5-hours of unilateral sub-ischemic IOP elevation demonstrated higher levels of protein expression of the astrocytic marker, glial fibrillary acidic protein (GFAP), within the lamina cribrosa with greatest expression inferior temporally in the treated eye compared to control. Spatial transcriptomic analysis performed on optic nerve head tissues from Donor 2 exposed to 30 h of unilateral IOP elevation demonstrated differential transcription of mRNA across laminar and scleral regions. Immunohistochemistry of retinal sections from Donor 2 exhibited higher GFAP and IBA1 expression in the treated eye compared with control, but this was not observed in Donor 3, which was exposed to only 1-hour of IOP elevation. While there were no differences in GFAP protein expression in the retina following the 1-hour IOP elevation in Donor 3, there were higher levels of transcription of GFAP in the inner nuclear layer, and CD44 in the retinal ganglion cell layer, indicative of astrocytic and Müller glial reactivity as well as an early inflammatory response, respectively.We found that transcriptomic differences can be observed across treated and control eyes following unilateral elevation of IOP in brain dead organ donors. The continued development of this model affords the unique opportunity to define the acute mechanotranscriptomic response of the optic nerve head, evaluate the injury and repair mechanisms in the retina in response to IOP elevation, and enable correlation of in vivo imaging and functional testing with ex vivo cellular responses for the first time in the living human eye.

SPECTRAL-DOMAIN OCT INSIGHTS INTO IDIOPATHIC EPIRETINAL MEMBRANE SURGERY OUTCOMES.

This study aims to assess the prognostic value of a classification system that includes the presence of ectopic inner foveal layers (EIFL) and other anatomical variables identified in spectral-domain optical coherence tomography (SD-OCT) for idiopathic epiretinal membrane (ERM) surgery. A descriptive-analytic, longitudinal, retrospective study was conducted on patients with idiopathic ERMs treated with pars plana vitrectomy (PPV) from January 2017 to December 2021. Clinical data and SD-OCT images were reviewed pre-surgery and 12 months post-surgery. The primary outcome measured was best corrected visual acuity (BCVA) before and after surgery, analyzing the impact of anatomical factors on BCVA in patients undergoing ERM surgery. The study included 342 eyes from 323 patients. Post-surgical evaluations showed significant reductions in central foveal thickness (CFT) across all ERM stages, with most stage 4 ERMs regressing to stage 3. The mean improvement in BCVA was significant for all stages, with earlier stages showing better results. Presence of macular edema (ME) and ellipsoid zone (EZ) disruption were significant predictors of post-surgical BCVA, while disorganization of the retinal inner layer (DRIL) showed association with visual recovery but was not conclusively predictive. The study highlights the importance of SD-OCT in assessing retinal changes in idiopathic ERMs, demonstrating the prognostic value of EIFL stage scheme and other anatomical variables like EZ disruption and ME presence on BCVA. These findings offer insights for surgical prognostication and the potential for personalized treatment strategies.

Duration of face down positioning following full-thickness macular hole repair: A protocol for a randomized pilot study.

Full-thickness macular holes (FTMH) are defects in the fovea involving all neural retinal layers. They reduce patients' visual acuity (VA) and impact their quality of life. FTMHs are repaired with pars plana vitrectomy (PPV) with intraocular gas tamponade and post-operative face-down positioning (FDP). There is no consensus regarding the ideal positioning requirements following FTMH repair and there lacks clear guidelines on the topic. While analysis of global practice patterns indicates that between 5-7 days is the most common duration suggested by surgeons, there is significant heterogeneity in surgeon preferences. There is, however, biological plausibility to support minimal or even no FDP following surgery and given the disabling nature of FDP for patients, there is a need to better assess key patient outcomes with different FDP durations. As such, this prospective randomized controlled pilot trial will compare 3-days of FDP to 7-days of FDP following PPV for FTMH. This single-centered, parallel-group randomized controlled pilot trial will randomize patients 1:1 following PPV to 3 days or 7 days of FDP. This investigation has been approved by the local ethics board (HiREB # 16100) and has been registered on clinicaltrials.gov (NCT06000111). The primary objective will be focused on assessing the feasibility of a larger trial; this will be determined through an assessment of the recruitment rate, retention rate, completion rate and recruitment time. The secondary outcomes involve assessment of the following patient-important outcomes a) macular hole closure rate, b) best-recorded VA, c) a general quality of life measure and vision-specific quality of life measure, d) patient compliance and e) complication rates. Outcomes will be evaluated at 3 months following surgery. The results of this pilot study will determine the feasibility of a larger-scale trial that will answer a patient important question with clinical equipoise.

Clinical and Multimodal Imaging Study to Differentiate Amelanotic Choroidal Lesions

Introduction: The aim of this study was to differentiate amelanotic choroidal lesions – amelanotic choroidal melanoma, choroidal metastasis, and choroidal granuloma using multimodal imaging. Methods: Retrospective comparative chart review was done. Patients diagnosed with the abovementioned choroidal lesions from 2015 to 2022 were included. Baseline lesion morphology and retinal layer changes on optical coherence tomography (OCT), lesion echogenicity and dimensions on ocular ultrasonography (USG), fundus autofluorescence (FAF), fundus fluorescein angiography (FFA), and indocyanine green angiography (ICG-A) patterns and findings were assessed. Results: Twelve eyes with melanoma, 22 eyes with metastasis, and 9 eyes with granuloma were included. On OCT, 83% of melanomas and 67% of granulomas, and 68% of metastasis had dome-shaped choroidal lesions. Presence of intraretinal fluid (IRF) and shaggy photoreceptors was 94% (95% CI: 79–99%) and 90% (95% CI: 74–98%) specific to differentiate melanomas from other choroidal lesions (AUC >0.75, p < 0.05). Similarly, presence of incomplete retinal pigment epithelium (RPE) and outer retinal atrophy (iRORA) was 77% (95% CI: 55–92%) sensitive and 77% (95% CI: 53–92%) specific (AUC = 0.8, p+ 0.03) and presence of lumpy-bumpy choroid was 55% (95% CI: 32–76%) sensitive and 95% (95% CI: 76–99%) specific (AUC = 0.75, p = 0.04) to distinguish metastasis from other choroidal lesions. Mean height: base ratio was more in melanoma compared to metastasis (0.54 ± 0.22 vs. 0.43 ± 0.12, p = 0.17) and both were hyperechoic on USG. On FAF, 100% metastasis and 60% granulomas were hypoAF, whereas 100% melanomas were hypoAF. Majority choroidal lesions were hyperfluorescent on FFA. Double vascular circulation was observed in melanomas (50%). On ICG-A, all choroidal lesions were hypofluorescent. Conclusion: Clinical and multimodal imaging features such as the presence of IRF, shaggy photoreceptors, iRORA, and lumpy-bumpy choroid can help diagnose and differentiate amelanotic choroidal lesions, thereby avoiding the need for choroidal biopsy. Further larger studies are needed to devise a standard imaging protocol to validate our findings.

Impact of cumulative dose of hydroxychloroquine on retinal structures.

What is known • Hydroxychloroquine (HCQ) is widely used for autoimmune disorders but is associated with the risk of retinal toxicity. • Early detection of retinal structural changes due to HCQ toxicity remains challenging, and cumulative HCQ dose as a risk factor has conflicting clinical relevance. What Is New • Higher cumulative HCQ doses are significantly associated with thinner outer retinal layers (foveal, parafoveal, and perifoveal regions). • No significant associations were found between HCQ cumulative dose and inner retinal thickness or age.

The contribution of paramagnetic rim and cortical lesions to physical and cognitive disability at multiple sclerosis clinical onset: evaluating the power of MRI and OCT biomarkers.

In multiple sclerosis (MS), imaging biomarkers play a crucial role in characterizing the disease at the time of diagnosis. MRI and optical coherence tomography (OCT) provide readily available biomarkers that may help to define the patient's clinical profile. However, the evaluation of cortical and paramagnetic rim lesions (CL, PRL), as well as retinal atrophy, is not routinely performed in clinic. To identify the most significant MRI and OCT biomarkers associated with early clinical disability in MS. Brain, spinal cord (SC) MRI, and OCT scans were acquired from 45 patients at MS diagnosis to obtain: brain PRL and non-PRL, CL, SC lesion volumes and counts, brain volumetric metrics, SC C2-C3 cross-sectional area, and retinal layer thickness. Regression models assessed relationships with physical disability (Expanded Disability Status Scale [EDSS]) and cognitive performance (Brief International Cognitive Assessment for Multiple Sclerosis [BICAMS]). In a stepwise regression (R2 = 0.526), PRL (β = 0.001, p = 0.023) and SC lesion volumes (β = 0.001, p = 0.017) were the most significant predictors of EDSS, while CL volume and age were strongly associated with BICAMS scores. Moreover, in a model where PRL and non-PRL were pooled, only the contribution of SC lesion volume was retained in EDSS prediction. OCT measures did not show associations with disability at the onset. At MS onset, PRL and SC lesions exhibit the strongest association with physical disability, while CL strongly contribute to cognitive performance. Incorporating the evaluation of PRL and CL into the initial MS patient assessment could help define their clinical profile, thus supporting the treatment choice.

GCN-Enhanced Spatial-Spectral Dual-Encoder Network for Simultaneous Segmentation of Retinal Layers and Fluid in OCT Images

Changes in retinal thickness and the morphology of fluid provide valuable diagnostic information for Macular Edema (ME). Optical Coherence Tomography (OCT) is a pivotal diagnostic tool for ME, and the accurate segmentation of OCT retinal images aids ophthalmologists in monitoring disease progression. However, the unpredictable nature of ME’s occurrence poses significant challenges for existing methods in achieving precise segmentation of both retinal layers and fluids simultaneously. In this study, a novel U-shaped encoder-decoder architecture named GD-Net, is introduced for simultaneously segmenting retinal layers of diverse thicknesses and fluids. Specifically, a novel Fast Fourier Encoder is integrated within the encoder branch to capture spectral domain features overlooked by the spatial encoder. Additionally, Multi-scale Graph Convolution module is inserted between the encoder and decoder branches to leverage retinal layer topology for spatial reasoning. GD-Net is further optimized using a joint loss function, which includes a weighted version of region segmentation loss and contour loss, effectively mitigating the issues of blurred fluid edges and internal holes. The method was validated on three publicly available datasets: DUKE DME, Peripapillary OCT, and RETOUCH, achieving overall mean Dice score of 0.839, 0.826, and 0.872, respectively, outperforming the other state-of-the-art techniques. GD-Net demonstrated consistent high-precision segmentation on B-scans from different devices, proving its robustness and surpassing other methods in terms of visual quality, thus offering substantial support for clinical ophthalmologists in diagnosing ME. The code and weights are publicly available at: https://github.com/DBook111/GD-Net.