Probing Deposit-Driven Age-Related Macular Degeneration Via Thicknesses of Outer Retinal Bands and Choroid: ALSTAR2 Baseline.

Purpose: We aimed to identify structural differences in normal eyes, early age-related macular degeneration (AMD), and intermediate AMD eyes using optical coherence tomography (OCT) in a well-characterized, large cross-sectional cohort. Methods: Subjects ≥ 60 years with healthy normal eyes, as well as early or intermediate AMD were enrolled in the Alabama Study on Age-related Macular Degeneration 2 (ALSTAR2; NCT04112667). Using Spectralis HRA + OCT2, we obtained macular volumes for each participant. An auto-segmentation software was used to segment six layers and sublayers: photoreceptor inner and outer segments, subretinal drusenoid deposits (SDDs), retinal pigment epithelium + basal lamina (RPE + BL), drusen, and choroid. After manually refining the segmentations of all B-scans, mean thicknesses in whole, central, inner and outer rings of the ETDRS grid were calculated and compared among groups. Results: This study involved 502 patients, 252 were healthy, 147 had early AMD, and 103 had intermediate AMD eyes (per Age-Related Eye Disease Study [AREDS] 9-step). Intermediate AMD eyes exhibited thicker SDD and drusen, thinner photoreceptor inner segments, and RPE compared to healthy and early AMD eyes. They also had thicker photoreceptor outer segments than early AMD eyes. Early AMD eyes had thinner photoreceptor outer segments than normal eyes but a thicker choroid than intermediate AMD eyes. Using the Beckman scale, 42% of the eyes initially classified as early AMD shifted to intermediate AMD, making thickness differences for photoreceptor outer segments and choroid insignificant. Conclusions: With AMD stages, the most consistent structural differences involve appearance of drusen and SDD, followed by RPE + BL thickness, and then thickness of photoreceptor inner and outer segments. Structural changes in the transition from aging to intermediate AMD include alterations in the outer retinal bands, including the appearance of deposits on either side of the RPE.

Automated classification of choroidal neovascularization, diabetic macular edema, and drusen from retinal OCT images using vision transformers: a comparative study.

Classifying retinal diseases is a complex problem because the early problematic areas of retinal disorders are quite small and conservative. In recent years, Transformer architectures have been successfully applied to solve various retinal related health problems. Age-related macular degeneration (AMD) and diabetic macular edema (DME), two prevalent retinal diseases, can cause partial or total blindness. Diseases therefore require an early and accurate detection. In this study, we proposed Vision Transformer (ViT), Tokens-To-Token Vision Transformer (T2T-ViT) and Mobile Vision Transformer (Mobile-ViT) algorithms to detect choroidal neovascularization (CNV), drusen, and diabetic macular edema (DME), and normal using optical coherence tomography (OCT) images. The predictive accuracies of ViT, T2T-ViT and Mobile-ViT achieved on the dataset for the classification of OCT images are 95.14%, 96.07% and 99.17% respectively. Experimental results obtained from ViT approaches showed that Mobile-ViT have superior performance with regard to classification accuracy in comparison with the others. Overall, it has been observed that ViT architectures have the capacity to classify with high accuracy in the diagnosis of retinal diseases.

Age-Related Macular Degeneration and Extramacular Drusen: Genetic Associations in the Coimbra Eye Study.

Purpose: To explore the association between the genetics of age-related macular degeneration (AMD) and extramacular drusen (EMD) in patients with and without AMD. Methods: We included 1753 eyes (912 subjects) with phenotypic characterization regarding AMD and EMD. Genetic sequencing and the genetic risk score (GRS) for AMD were performed according to the EYE-RISK consortium methodology. To test for differences in the GRS from EMD cases, AMD cases, and controls, a clustered Wilcoxon rank-sum test was used. The association of AMD, EMD, and the GRS was evaluated using logistic regression models adjusted for age and sex. Individual associations of common risk variants for AMD with EMD were explored. Results: EMD were found in 755 eyes: 252 (14.4%) with AMD and 503 (28.7%) without. In total, 122 eyes (7.0%) had only AMD, and 876 (50.0%) were controls. EMD were strongly associated with AMD (odds ratio [OR], 3.333; 95% confidence interval [CI], 2.356-4.623; P < 0.001). The GRS was associated with an increased risk of AMD (OR, 1.416; 95% CI, 1.218-1.646; P < 0.001) but not with EMD. Individually, the common risk variants ARMS2 rs10490924 (P = 0.042), C3 rs2230199 (P = 0.042), and CETP rs5817082 (P = 0.042) were associated with EMD, after adjustment for AMD, sex, and age. Conclusions: We found a strong association between EMD and AMD, suggesting a common pathogenesis. The GRS for AMD was not associated with EMD, but a partially overlapping genetic basis was suggested when assessing individual risk variants. We propose that EMD per se do not represent an increase in the global genetic risk for AMD.

CFH Haploinsufficiency and Complement Alterations in Early-Onset Macular Degeneration.

Purpose: Complement dysregulation is a key component in the pathogenesis of age-related macular degeneration (AMD) and related diseases such as early-onset macular drusen (EOMD). Although genetic variants of complement factor H (CFH) are associated with AMD risk, the impact of CFH and factor H-like protein 1 (FHL-1) expression on local complement activity in human retinal pigment epithelium (RPE) remains unclear. Methods: We identified a novel CFH variant in a family with EOMD and generated patient induced pluripotent stem cell (iPSC)-derived RPE cells. We assessed CFH and FHL-1 co-factor activity through C3b breakdown assays and measured complement activation by immunostaining for membrane attack complex (MAC) formation. Expression of CFH, FHL-1, local alternative pathway (AP) components, and regulators of complement activation (RCA) in EOMD RPE cells was determined by quantitative PCR, western blot, and immunostaining. Isogenic EOMD (cEOMD) RPE was generated using CRISPR/Cas9 gene editing. Results: The CFH variant (c.351-2A>G) resulted in loss of CFH and FHL-1 expression and significantly reduced CFH and FHL-1 protein expression (∼50%) in EOMD iPSC RPE cells. These cells exhibited increased MAC deposition upon exposure to normal human serum. Under inflammatory or oxidative stress conditions, CFH and FHL-1 expression in EOMD RPE cells paralleled that of controls, whereas RCA expression, including MAC formation inhibitors, was elevated. CRISPR/Cas9 correction restored CFH/FHL-1 expression and mitigated alternative pathway complement activity in cEOMD RPE cells. Conclusions: Identification of a novel CFH variant in patients with EOMD resulting in reduced CFH and FHL-1 and increased local complement activity in EOMD iPSC RPE supports the involvement of CFH haploinsufficiency in EOMD pathogenesis.

Spatially Resolved Association of Structural Biomarkers on Retinal Function in Non-Exudative Age-Related Macular Degeneration Over 4 Years.

Purpose: To longitudinally assess the impact of high-risk structural biomarkers for natural disease progression in non-exudative age-related macular degeneration (AMD) on spatially resolved mesopic and scotopic fundus-controlled perimetry testing. Methods: Multimodal retinal imaging data and fundus-controlled perimetry stimuli points were semiautomatically registered according to landmark correspondences at each annual visit over a period of up to 4 years. The presence of sub-RPE drusen, subretinal drusenoid deposits, pigment epithelium detachments (PEDs), hyper-reflective foci (HRF), vitelliform lesions, refractile deposits, and incomplete RPE and outer retinal atrophy (iRORA) and complete RPE and outer retinal atrophy (cRORA) were graded at each stimulus position and visit. Localized retinal layer thicknesses were extracted. Mixed-effect models were used for structure-function correlation. Results: Fifty-four eyes of 49 patients with non-exudative AMD (mean age, 70.7 ± 9.1 years) and 27 eyes of 27 healthy controls (mean age, 63.4 ± 8.9 years) were included. During study course, presence of PED had the highest functional impact with a mean estimated loss of -1.30 dB (P < 0.001) for mesopic and -1.23 dB (P < 0.001) for scotopic testing, followed by HRF with -0.89 dB (mesopic, P = 0.001) and -0.87 dB (scotopic, P = 0.005). Subretinal drusenoid deposits were associated with a stronger visual impairment (mesopic, -0.38 dB; P = 0.128; scotopic, -0.37 dB; P = 0.172) compared with sub-RPE drusen (-0.22 dB, P = 0.0004; -0.18 dB, P = 0.006). With development of c-RORA, scotopic retinal sensitivity further significantly decreased (-2.15 dB; P = 0.02). Thickening of the RPE-drusen-complex and thinning of the outer nuclear layer negatively impacted spatially resolved retinal sensitivity. Conclusions: The presence of PED and HRF had the greatest prognostic impact on progressive point-wise sensitivity losses. Higher predominant rod than cone-mediated localized retinal sensitivity losses with early signs of retinal atrophy development indicate photoreceptor preservation as a potential therapeutic target for future interventional AMD trials.

Advanced age-related macular degeneration and risk factors in eyes with pachydrusen.

The risk of progression to advanced age-related macular degeneration (AMD) varies depending on the type of drusen. This retrospective longitudinal study included 248 eyes of 156 patients with pachydrusen without advanced AMD at baseline. Macular neovascularization (MNV) and geographic atrophy (GA) were evaluated. Risk factors for progression to advanced AMD were determined using multivariate Cox regression analysis. The mean age at baseline was 65.4 ± 9.1 years, and the mean follow-up duration was 6.40 ± 3.58 years. The mean total number of pachydrusen and macular pachydrusen were 4.10 ± 2.85 and 2.27 ± 1.81 per eye, respectively. Pachydrusen was accompanied by other types of drusen in 4.8% (12 eyes) of eyes at baseline. During follow-up, MNVs occurred in 2.8% (seven eyes), including polypoidal choroidal vasculopathy (PCV six eyes); however, no GA occurred. Regarding risk factors for progression to neovascular AMD, age (p = 0.023) and macular pigmentary changes (p = 0.014) were significantly associated with MNV development. The cumulative incidence of MNV was significantly higher in the group with macular pigmentary changes (17.39% vs. 0.57% at 10 years; p = 0.0005). The number of macular pachydrusen and the presence of MNV in the fellow eye did not show a statistically significant relationship with MNV development. Age and macular pigmentary changes are risk factors for MNV development in the eyes with pachydrusen. Eyes with pachydrusen appear to have a risk profile for advanced AMD that is different from that of AMD eyes with drusen or drusenoid deposits other than pachydrusen.

Correlation between ellipsoid zone thickness and the presence of subretinal drusenoid deposits in age-related macular degeneration.

PURPOSE: Subretinal drusenoid deposits (SDDs) in age-related macular degeneration (AMD) are associated with systemic vascular diseases that compromise ocular perfusion. We demonstrate that SDDs are associated with decreased ellipsoid zone (EZ) thickness, further evidence of hypoxic damage. METHODS: Post hoc analysis of a cross-sectional study. 165 AMD subjects (aged 51-100; 61% women). Spectral-domain optical coherence tomography was obtained in both eyes. Masked readers assigned subjects to three groups: drusen only, SDD+drusen (SDD+D) and SDD only. EZ thickness was measured subfoveally and 2000 µm nasally, temporally, superiorly and inferiorly from the fovea. Univariate testing was performed using two-tailed t-tests with Bonferroni correction. RESULTS: The mean EZ thickness differences between the SDD+D and drusen-only groups were (in µm) 1.10, 0.67, 1.21, 1.10 and 0.50 at the foveal, nasal, temporal, superior and inferior locations, respectively (p=0.08 inferiorly, otherwise p≤0.01); between the SDD-only and drusen-only groups, the differences were 3.48, 2.48, 2.42, 2.08 and 1.42 (p≤0.0002). Differences in EZ thicknesses across all subjects and between groups were not significantly different based on gender, race or age. CONCLUSION: Subjects with SDDs (±drusen) had thinner EZs than those with drusen only, and the inferior EZ was least affected. EZs were thinnest in SDD-only subjects. This thinning gradation is consistent with progressive destruction of highly oxygen-sensitive mitochondria in the EZ from hypoxia. These findings support the reduced ophthalmic perfusion hypothesis for the formation of SDDs secondary to high-risk systemic vasculopathy.

Spatial Analysis Reveals Vascular Changes in Retinal and Choroidal Vessel Perfusion in Intermediate AMD With Reticular Pseudodrusen.

Purpose: To examine the effect of reticular pseudodrusen (RPD) on retinal and choroidal vessel perfusion (VP) topography in intermediate age-related macular degeneration (iAMD) using refined spatial analyses. Methods: This was a retrospective cross-sectional study of 120 individuals with 30 iAMDRPD, 60 iAMDno_RPD, and 30 normal eyes, propensity-score matched by age, sex, and presence of cardiovascular-related disease. VP of the superficial and deep retinal and choriocapillaris vascular slabs was assessed from 6 × 6-mm optical coherence tomography angiography (OCTA) scans divided into 126 × 126 grids, with adjustment for various person- and eye-level factors. Grid-wise VP differences (%) among the groups were spatially assessed according to analyses based on the Early Treatment for Diabetic Retinopathy Study (ETDRS), eccentricity (µm), and degree (°). Results: VP was significantly decreased between iAMDRPD and iAMDno_RPD, across all vascular slabs in various ETDRS sectors (up to -2.16%; 95% confidence interval, -2.99 to -1.34; P < 0.05). Eccentricity analyses revealed more complex patterns: a bisegmented relationship where VP in iAMDRPD eyes decreased linearly toward 1000 µm then returned toward similar values as iAMDno_RPD, plateauing around 2000 µm in the superficial and 3000 µm in the deep retina (R2 = 0.57-0.9; P < 0.001). Degree-based analysis further showed that the greatest VP differences in iAMDRPD eyes were commonly located superiorly and nasally across all vascular slabs (P < 0.05). Conclusions: RPD appears to compound the vascular impact of iAMD, displaying complex spatial patterns beyond the ETDRS sectors. This highlights the importance of considering spatial delineations for future work regarding the role of RPD and vascular dysfunction.

En Face Optical Coherence Tomography Illustrates the Trizonal Distribution of Drusen and Subretinal Drusenoid Deposits in the Macula.

PURPOSE: To analyze the topographic distribution of macular drusen and subretinal drusenoid deposits (SDDs) using single-capture en face spectral domain optical coherence tomography (SD-OCT) imaging. DESIGN: Retrospective case series. METHODS: Analysis of 33 eyes of 20 patients with evidence of SDDs. Structural en face OCT images were reconstructed using a 40-µm-thick slab positioned from 48 to 88 µm above the Bruch membrane. The Early Treatment of Diabetic Retinopathy Study (ETDRS) grid and a rod/cone density map were overlaid on the en face OCT images, and the distribution of different subtypes of SDDs and macular drusen were assessed. RESULTS: A total of 31 eyes (94%) showed a trizonal distribution pattern of drusen and SDDs. Whereas small to large drusen tended to aggregate in the central circle, dot SDDs predominated in the inner ring and the inner portion of the outer ring of the ETDRS grid and ribbon SDDs localized to the outer ring and outside the ETDRS grid. Of note, drusen colocalized to the region of greatest cone density, whereas ribbon SDDs colocalized to the area of greatest rod density. The dot SDDs mapped to the intermediate region with mixed rod and cone representation. CONCLUSION: Dot and ribbon subtypes of SDDs and macular drusen show a characteristic trizonal distribution. The locations of these lesions colocalize according to the different densities of the cones and rods in the retina and may reflect varying pathophysiological activities of these photoreceptor subtypes.

Choroidal signal hypertransmission on optical coherence tomography imaging: Association with development of geographic atrophy in age-related macular degeneration.

BACKGROUND: To examine the association between large choroidal signal hypertransmission ≥250 µm (LHyperT) on optical coherence tomography (OCT) with the risk of developing geographic atrophy (GA) and compare this risk with those associated with nascent geographic atrophy (nGA). METHODS: Two hundred and eighty eyes from 140 participants with bilateral large drusen and without late age-related macular degeneration (AMD) or nGA at baseline underwent OCT imaging and colour fundus photography (CFP) at 6-monthly intervals up to 5 years. OCT scans were graded for the presence of LHyperT and nGA, and CFPs were graded for the presence of GA. RESULTS: The five-year incidence of LHyperT and nGA were 37% and 27% respectively (p = 0.003), and the two-year probability of their progression to GA were 17% and 40%, respectively (p = 0.002). LHyperT and nGA explained 81% and 91% of the variance in the time to develop GA, respectively (p = 0.032), and they were both associated with a significantly higher rate of GA development compared to eyes without these lesions (adjusted hazard ratio = 110.8 and 183.2, respectively; p < 0.001 for both). CONCLUSIONS: LHyperT and nGA were both high-risk features for GA development, but the latter showed a higher rate of GA progression and explained a significantly greater proportion of the variance in the time to develop GA. As such, nGA may be a more robust surrogate endpoint than LHyperT for the conventional clinical endpoint of CFP-defined GA for intervention trials in the early stages of AMD.

Subretinal drusenoid deposits, age-related macular degeneration, and cardiovascular disease.

Decades of studies on age-related macular degeneration (AMD), cardiovascular disease and stroke have not found consistent associations between AMD and systemic vascular disease. This study suggests that there is in fact no general relationship, but instead a strong, specific association between only the subretinal drusenoid deposit (SDD) phenotype of AMD on retinal imaging and certain co-existent vascular diseases that are high risk for compromised cardiac output or internal carotid artery stenosis. Future screening initiatives for these high -risk vascular diseases (HRVDs) with fast, inexpensive retinal imaging could make a significant contribution to public health and save lives. Likewise, screening patients with known HRVDs for unrecognized AMD of the SDD form could enable needed treatment and save vision.

Optical coherence tomography biomarkers in early and intermediate age-related macular degeneration: A clinical guide.

Advanced forms of age-related macular degeneration (AMD), characterised by atrophic and neovascular changes, are a leading cause of vision loss in the elderly population worldwide. Prior to the development of advanced AMD, a myriad of risk factors from the early and intermediate stages of AMD have been published in the scientific literature over the last years. The ability to precisely recognise structural and anatomical changes in the ageing macula, altogether with the understanding of the individual risk implications of each one of them is key for an accurate and personalised diagnostic assessment. The present review aims to summarise updated evidence of the relative risk conferred by diverse macular signs, commonly seen on optical coherence tomography, in terms of progression to geographic atrophy or macular neovascularization. This information may also serve as a basis for tailored follow-up monitoring visits.

Application of artificial intelligence system for screening multiple fundus diseases in Chinese primary healthcare settings: a real-world, multicentre and cross-sectional study of 4795 cases.

BACKGROUND/AIMS: This study evaluates the performance of the Airdoc retinal artificial intelligence system (ARAS) for detecting multiple fundus diseases in real-world scenarios in primary healthcare settings and investigates the fundus disease spectrum based on ARAS. METHODS: This real-world, multicentre, cross-sectional study was conducted in Shanghai and Xinjiang, China. Six primary healthcare settings were included in this study. Colour fundus photographs were taken and graded by ARAS and retinal specialists. The performance of ARAS is described by its accuracy, sensitivity, specificity and positive and negative predictive values. The spectrum of fundus diseases in primary healthcare settings has also been investigated. RESULTS: A total of 4795 participants were included. The median age was 57.0 (IQR 39.0-66.0) years, and 3175 (66.2%) participants were female. The accuracy, specificity and negative predictive value of ARAS for detecting normal fundus and 14 retinal abnormalities were high, whereas the sensitivity and positive predictive value varied in detecting different abnormalities. The proportion of retinal drusen, pathological myopia and glaucomatous optic neuropathy was significantly higher in Shanghai than in Xinjiang. Moreover, the percentages of referable diabetic retinopathy, retinal vein occlusion and macular oedema in middle-aged and elderly people in Xinjiang were significantly higher than in Shanghai. CONCLUSION: This study demonstrated the dependability of ARAS for detecting multiple retinal diseases in primary healthcare settings. Implementing the AI-assisted fundus disease screening system in primary healthcare settings might be beneficial in reducing regional disparities in medical resources. However, the ARAS algorithm must be improved to achieve better performance. TRIAL REGISTRATION NUMBER: NCT04592068.

Parapapillary drusen of the retinal pigment epithelium.

PURPOSE: To describe the occurrence, morphology and associations of parapapillary drusen of the retinal pigment epithelium (RPE-drusen). METHODS: Using light microscopy, we histomorphometrically examined enucleated human eyes. RESULTS: The study included 83 eyes (axial length: 25.9 ± 3.2 mm; range: 20.0-35.0 mm). Eyes with parapapillary RPE-drusen (n = 29 (35%) eyes) as compared to those without drusen had a significantly shorter axial length (24.0 ± 1.8 mm vs 27.0 ± 3.3 mm; p < 0.001), higher prevalence (27/29 vs 12/54; p < 0.001) and longer width (213 ± 125 µm vs 96 ± 282 µm; p < 0.0001) of parapapillary alpha zone, and thicker BM in parapapillary beta zone (8.4 ± 2.7 µm vs 3.9 ± 2.0 µm; p < 0.001) and alpha zone (6.6 ± 3.9 µm vs 4.4 ± 1.5 µm; p = 0.02). Prevalence of parapapillary RPE-drusen was 27 (69%) out of 39 eyes with alpha zone. Beneath the RPE-drusen and in total alpha zone, choriocapillaris was open, while it was closed in the central part of parapapillary beta zone. BM thickness was thicker (p = 0.001) in alpha zone than beta zone, where it was thicker (p < 0.001) than in the region outside of alpha/beta zone. BM thickness outside of alpha/beta zone was not correlated with prevalence of parapapillary RPE-drusen (p = 0.47) or axial length (p = 0.31). RPE cell density was higher in alpha zone than in the region adjacent to alpha zone (22.7 ± 7.3 cells/240 µm vs 18.3 ± 4.1 cells/240 µm; p < 0.001). In the parapapillary RPE-drusen, RPE cells were connected with a PAS-positive basal membrane. CONCLUSIONS: Parapapillary RPE-drusen as fibrous pseudo-metaplasia of the RPE were associated with shorter axial length, higher prevalence and larger size of alpha zone, and thicker BM in alpha zone and beta zone. The RPE-drusen may be helpful to differentiate glaucomatous parapapillary beta zone from myopic beta zone.

Fundus autofluorescence of retinal atrophy progression between fundus flavimaculatus and extensive macular atrophy with pseudo-drusen.

OBJECTIVE: To analyze the progression of macular atrophy in Fundus Flavimaculatus (FFM) versus Extensive Macular Atrophy with Pseudo-drusen (EMAP), using Spectralis® RegionFinder™ tool. METHODS: Retrospective review of patients diagnosed with FFM and EMAP. Ophthalmic imaging features were reviewed by retina specialists for each patient in both eyes. The atrophic zones were measured on fundus autofluorescence acquisitions using the RegionFinder™ tool. RESULTS: FFM group included 16 eyes of 8 patients, whose mean age was 61.42 ± 10.76 years, with a mean 4.54 ± 2.73 years of follow-up. EMAP group contained 16 eyes of 8 patients, whose mean age was 67.81 ± 3.03 years (p = 0.12), with a mean 3.62 ± 2.49 years of follow-up (P = 0.63). The atrophy progression rates were 3.73 ± 6.75 and 0.70 ± 0.98 mm2/year, for EMAP and FFM respectively. The yearly rate of progression of the atrophic areas in EMAP was 5.3 times higher than in FFM (mm2/year) (p = 0.03). CONCLUSION: The progression of the atrophy in eyes with Extensive Macular Atrophy with Pseudo-drusen (EMAP) is significantly more rapid than in eyes with Fundus Flavimaculatus (FFM).

Prevalence and determinants of subretinal drusenoid deposits in patients' first-degree relatives.

PURPOSE: Subretinal drusenoid deposits (SDDs) are distinct extracellular alteration anterior to the retinal pigment epithelium (RPE). Given their commonly uniform phenotype, a hereditary predisposition seems likely. Hence, we aim to investigate prevalence and determinants in patients' first-degree relatives. METHODS: We recruited SDD outpatients at their visits to our clinic and invited their relatives. We performed a full ophthalmic examination including spectral domain-optical coherence tomography (SD-OCT) and graded presence, disease stage of SDD as well as percentage of infrared (IR) en face area affected by SDD. Moreover, we performed genetic sequencing and calculated a polygenic risk score (PRS) for AMD. We conducted multivariable regression models to assess potential determinants of SDD and associations of SDD with PRS. RESULTS: We included 195 participants, 123 patients (mean age 81.4 ± 7.2 years) and 72 relatives (mean age 52.2 ± 14.2 years), of which 7 presented SDD, resulting in a prevalence of 9.7%. We found older age to be associated with SDD presence and area in the total cohort and a borderline association of higher body mass index (BMI) with SDD presence in the relatives. Individuals with SDD tended to have a higher PRS, which, however, was not statistically significant in the multivariable regression. CONCLUSION: Our study indicates a potential hereditary aspect of SDD and confirms the strong association with age. Based on our results, relatives of SDD patients ought to be closely monitored for retinal alterations, particularly at an older age. Further longitudinal studies with larger sample size and older relatives are needed to confirm or refute our findings.

Central macular choriocapillaris impairment as a manifestation of microvascular disease in eyes with subretinal drusenoid deposits.

BACKGROUND/OBJECTIVES: Microvascular alterations and choroidal impairment are emerging as a pathologic pathway in age-related macular degeneration (AMD). This study aimed to evaluate the central macular choriocapillaris (CC) in eyes with subretinal drusenoid deposits (SDD) and the retinal microvasculature in patients with early AMD phenotypes. SUBJECTS/METHODS: This was an institutional, multicentric observational cross-sectional study. Ninety-nine eyes of 99 subjects; 33 eyes with SDD only, 33 eyes with conventional drusen (CD) only, and 33 eyes of healthy age-matched subjects were included. Comprehensive ophthalmologic examination and optical coherence tomography angiography (OCTA) was performed. The central macular flow area of the CC was analysed in the SDD group and the vessel density of the retinal superficial capillary plexus (SCP) and deep capillary plexus (DCP) was analysed in the SDD and CD groups using automated OCTA output parameters. RESULTS: The flow area of the CC in the SDD group was significantly reduced (p ≤ 0.001) with respect to the healthy control group. There was a trend of reduction of vessel density of the SCP and the DCP in the SDD and CD group with respect to controls, although this did not reach statistical significance. CONCLUSIONS: OCTA data in the present report corroborate the role of vascular damage in early AMD with CC impairment in the central macular area in eyes with SDD.

Calpain-specific breakdown fragment in human drusen.

PURPOSE: With aging and age-related macular dystrophy (AMD), proteolytic fragments are deposited in extracellular drusen located between the RPE and Bruch's membrane. Localized hypoxia may be a risk factor for AMD. Our hypothesis is that following hypoxia, activation of proteolytic enzymes called calpains may cause proteolysis/degeneration of retinal cells and RPE. No direct evidence has yet demonstrated activation of calpains in AMD. The purpose of the present study was to identify calpain-cleaved proteins in drusen. METHODS: Seventy-six (76) drusen were analyzed in human eye sections from six normal and twelve AMD human donor eyes. The sections were subjected to immunofluorescence for the calpain-specific 150 kDa breakdown product from α-spectrin, SBDP150 - a marker for calpain activation, and for recoverin - a marker for photoreceptor cells. RESULTS: Among 29 nodular drusen, 80% from normal eyes and 90% from AMD eyes stained positive for SBDP150. Among 47 soft drusen, mostly from AMD eyes, 72% stained positive for SBDP150. Thus, the majority of both soft and nodular drusen from AMD donors contained SBDP150. CONCLUSIONS: SBDP150 was detected for the first time in soft and nodular drusen from human donors. Our results suggest that calpain-induced proteolysis participates in the degeneration of photoreceptors and/or RPE cells during aging and AMD. Calpain inhibitors may ameliorate AMD progression.

FROM DRUSEN TO TYPE 3 MACULAR NEOVASCULARIZATION.

PURPOSE: To investigate the imaging features preceding the occurrence of type 3 (T3) macular neovascularization (MNV) using tracked spectral-domain optical coherence tomography. METHOD: From a cohort of eyes with T3 MNV and ≥ 12 months of previously tracked spectral-domain optical coherence tomography, T3 lesions that developed above soft drusen were selected for optical coherence tomography analysis. Retinal imaging findings at the location where type T3 MNV occurred were analyzed at each follow-up until the onset of T3 MNV. The following optical coherence tomography parameters were assessed: drusen size (height and width), outer nuclear layer/Henle fiber layer thickness at the drusen apex, and the presence of intraretinal hyperreflective foci, retinal pigment epithelium disruption, incomplete retinal pigment epithelium and outer retina atrophy, and complete retinal pigment epithelium and outer retina atrophy. RESULTS: From a cohort of 31 eyes with T3 MNV, T3 lesions developed above soft drusen in 20 eyes (64.5%). Drusen showed progressive growth ( P < 0.001) associated with outer nuclear layer/Henle fiber ( P < 0.001) thinning before T3 MNV. The following optical coherence tomography features were identified preceding the occurrence of T3 MNV, typically at the apex of the drusenoid lesion: disruption of the external limiting membrane/ellipsoid zone and/or the retinal pigment epithelium, hyperreflective foci, and incomplete retinal pigment epithelium and outer retina atrophy/complete retinal pigment epithelium and outer retina atrophy. CONCLUSION: The results demonstrate specific anatomic alterations preceding the occurrence of T3 MNV that most commonly originates above soft drusen. Drusen growth, reduced outer nuclear layer/Henle fiber thickness, and retinal pigment epithelium atrophy at the drusen apex precede the development of T3 MNV. Identifying these optical coherence tomography features should warrant close monitoring for identification of T3 MNV, which can benefit from prompt intravitreal anti-vascular endothelial growth factor therapy.

RETINAL OPTICAL COHERENCE TOMOGRAPHY IMAGING BIOMARKERS: A Review of the Literature.

PURPOSE: The aim of this literature review was to summarize novel optical coherence tomography (OCT) imaging biomarkers that have recently been described in the literature and are frequently encountered clinically. METHODS: The literature was reviewed to identify novel OCT biomarkers reported to date. A descriptive summary of all terms and representative illustrations were provided to highlight the most relevant features. RESULTS: Thirty-seven OCT terminologies were identified. The vitreomacular interface disorder group included the four stages of epiretinal membrane, macular pseudohole, tractional lamellar hole (LH), degenerative LH, cotton ball sign, and foveal crack sign. The age-related macular degeneration group included outer retinal tubulation, multilayered pigment epithelial detachment, prechoroidal cleft, onion sign, double-layer sign, complete outer retinal atrophy, complete retinal pigment epithelium and outer retinal atrophy, and reticular pseudodrusen. The uveitic disorder group consisted of bacillary layer detachment, syphilis placoid, rain-cloud sign, and pitchfork sign. The disorders relating to the toxicity group included flying saucer sign and mitogen-activated protein kinase (MEK) inhibitor-associated retinopathy. The disorders associated with the systemic condition group included choroidal nodules and needle sign. The pachychoroid spectrum group included pachychoroid and brush border pattern. The vascular disorder group included pearl necklace sign, diffuse retinal thickening, disorganization of retinal inner layers, inner nuclear layer microcysts, hyperreflective retinal spots, paracentral acute middle maculopathy, and acute macular neuroretinopathy. The miscellaneous group included omega sign (ω), macular telangiectasia (type 2), and omega sign (Ω). CONCLUSIONS: Thirty-seven OCT terminologies were summarized, and detailed illustrations consolidating the features of each biomarker were included. A nuanced understanding of OCT biomarkers and their clinical significance is essential because of their predictive and prognostic value.