Anna V Zarubina

Lipofuscin Redistribution and Loss Accompanied by Cytoskeletal Stress in Retinal Pigment Epithelium of Eyes With Age-Related Macular Degeneration

PURPOSE Lipofuscin (LF) and melanolipofuscin (MLF) of the retinal pigment epithelium (RPE) are the principal sources of autofluorescence (AF) signals in clinical fundus-AF imaging. Few details about the subcellular distribution of AF organelles in AMD are available. We describe the impact of aging and AMD on RPE morphology revealed by the distribution of AF LF/MLF granules and actin cytoskeleton in human tissues. METHODS Thirty-five RPE-Bruchs membrane flatmounts from 35 donors were prepared (postmortem: ≤4 hours). Ex vivo fundus examination at the time of accession revealed either absence of chorioretinal pathologies (10 tissues; mean age: 83.0 ± 2.6 years) or stages of AMD (25 tissues; 85.0 ± 5.8 years): early AMD, geographic atrophy, and late exudative AMD. Retinal pigment epithelium cytoskeleton was labeled with AlexaFluor647-Phalloidin. Tissues were imaged on a spinning-disk fluorescence microscope and a high-resolution structured illumination microscope. RESULTS Age-related macular degeneration impacts individual RPE cells by (1) lipofuscin redistribution by (i) degranulation (granule-by-granule loss) and/or (ii) aggregation and apparent shedding into the extracellular space; (2) enlarged RPE cell area and conversion from convex to irregular and sometimes concave polygons; and (3) cytoskeleton derangement including separations and breaks around subretinal deposits, thickening, and stress fibers. CONCLUSIONS We report an extensive and systematic en face analysis of LF/MLF-AF in AMD eyes. Redistribution and loss of AF granules are among the earliest AMD changes and could reduce fundus AF signal attributable to RPE at these locations. Data can enhance the interpretation of clinical fundus-AF and provide a basis for future quantitative studies.

The Association Between Subretinal Drusenoid Deposits in Older Adults in Normal Macular Health and Incident Age-Related Macular Degeneration.

Purpose Subretinal drusenoid deposits (SDD) have been associated with the progression to late age-related macular degeneration (AMD). To determine whether SDD in eyes in normal macular health increases risk for early AMD, this study examined the association between presence of SDD at baseline in a cohort of older adults in normal macular health and incident AMD 3 years later. Methods Subjects enrolled in the Alabama Study on Early Age-Related Macular Degeneration (ALSTAR) were assessed for the presence of SDD using color fundus photos, infrared reflectance and fundus autofluorescence images, and spectral-domain optical coherence tomography volumes. The study sample included 799 eyes from 455 participants in normal macular health per grading of color fundus photographs using the 9-step Age-Related Eye Disease Study (AREDS) classification system. Age-related macular degeneration was defined as eyes having an AREDS grade ≥2 at the 3-year follow-up. Results Twenty-five percent of participants had SDD in one or both eyes at baseline. At follow-up visit, 11.9% of eyes in the sample developed AMD. Compared to eyes without SDD, those with SDD were 2.24 (95% confidence interval [CI] 1.36–3.70) times more likely to have AMD at follow-up. After adjusting for age, C-reactive protein quartile, and family history of AMD, the association persisted. Conclusions Results suggest that SDD in older eyes with normal macular health as defined by the AREDS scale is a risk factor for the development of early AMD. Older adults in seemingly normal macular health yet having SDD may warrant closer clinical monitoring for the possible onset of early AMD.

Rod-Mediated Dark Adaptation and Macular Pigment Optical Density in Older Adults with Normal Maculas

ABSTRACT Purpose: To examine the association between macular pigment optical density (MPOD) and rod-mediated dark adaptation (RMDA) in persons ≥60 years old with normal maculas as determined by an accepted color fundus photography grading system. Methods: This cross-sectional analysis used baseline data from eyes in the Alabama Study on Early Age-Related Macular Degeneration. Eyes at step 1 in the AREDS 9-step grading system were considered normal. Eyes were additionally assessed by spectral domain optical coherence tomography (SD-OCT). Foveal MPOD was estimated via heterochromatic flicker photometry, and RMDA was assessed with a computerized dark adaptometer. The association between RMDA and MPOD was examined via Spearman correlation coefficients adjusted for age. Results: In 306 eyes from 306 persons (mean age 68.2 years) in normal macular health, MPOD was not associated with RMDA (age-adjusted rank correlation = 0.043, p = 0.45). After 81 eyes with incidental macular findings by SD-OCT evaluation were excluded, the association between MPOD and RMDA remained null (N = 225, age-adjusted r = 0.015, p = 0.82). Conclusion: In a large sample of normal aged eyes, RMDA, a visual function that is rate limited by retinoid availability to photoreceptors across the complex of retinal pigment epithelium, Bruch’s membrane, and choriocapillaris, is not related to MPOD in the neurosensory retina.

Macular Atrophy Development and Subretinal Drusenoid Deposits in Anti-Vascular Endothelial Growth Factor Treated Age-Related Macular Degeneration

Purpose To explore the association between presence of subretinal drusenoid deposits (SDD) at baseline in eyes with neovascular age-related macular degeneration (nAMD) with the development of macular atrophy (MA) during anti-vascular endothelial growth factor (VEGF) therapy. Methods There were 74 eyes without pre-existing MA receiving anti-VEGF therapy for nAMD for 2 years or longer analyzed. At least two image modalities that included spectral-domain optical coherence tomography, near-infrared reflectance, fluorescein angiography, and color fundus photos were used to assess for SDD presence, phenotype (dot and ribbon), and location, neovascularization type, and MA. Logistic regression models using generalized estimating equations assessed the association between SDD and the development of MA adjusting for age, neovascularization type, and choroidal thickness. Results SDD were present in 46 eyes (63%) at baseline. MA developed in 38 eyes (51%) during the mean of 4.7 ± 1.2 years of follow-up. Compared with eyes without SDD, those with SDD at baseline were 3.0 times (95% confidence interval [CI] 1.1–8.5, P = 0.0343) more likely to develop MA. Eyes with SDD present in the inferior macula and inferior extramacular fields at baseline were 3.0 times and 6.5 times more likely to develop MA at follow-up than eyes without SDD in these locations (95% CI 1.0–8.9, P = 0.0461 and 95% CI 1.3–32.4, P = 0.0218, respectively). MA development was not associated with a specific SDD phenotype. Conclusions MA frequently developed in eyes during anti-VEGF treatment. SDD were independently associated with MA development. The extension of SDD into the inferior fundus, particularly in the inferior extramacular field, conferred higher odds of subsequent MA development.