Drusen Characteristics Revealed by Spectral-Domain Optical Coherence Tomography and Their Corresponding Fundus Autofluorescence Appearance in Dry Age-Related Macular Degeneration

Abstract

Purpose: To analyze the relationship between drusen morphology revealed by spectral-domain optical coherence tomography (SD-OCT) and corresponding fundus autofluorescence (FAF) features of the same drusen using the Heidelberg Retina Angiograph 2 (HRA2), in patients with dry age-related macular degeneration (AMD). Methods: Dry AMD patients were imaged with SD-OCT and HRA2 on the same day. SD-OCT B scans were then precisely overlaid onto the HRA2 images, and the SD-OCT morphological characteristics of the drusen were correlated with the corresponding FAF appearance. The analyzed morphological features of the drusen included: size, status of the inner segment/outer segment (IS-OS) junctional layer above the drusen, shape of the drusen, internal reflectivity, homogeneity and presence of overlaying hyperreflective foci. The FAF characteristics of each druse were rated as hyperautofluorescent, hypoautofluorescent or normally autofluorescent. Spearman’s correlation coefficient was used to analyze the correlation between the 2 primary outcomes: SD-OCT morphology of the drusen and their autofluorescent appearance. Results: 431 drusen in 32 eyes of 16 dry AMD patients were evaluated. Of the 7 morphological characteristics assessed by SD-OCT, only drusen size and the status of the IS-OS layer above the drusen were strongly correlated with the autofluorescent appearance (r = 0.78, p < 0.001, and r = 0.58, p < 0.001, respectively). The strength of correlation with other features appeared less robust: homogeneity (r = 0.38; p = 0.001), shape (r = 0.29; p = 0.004), reflectivity (r = 0.28; p = 0.004) and presence of overlaying foci (r = 0.25; p = 0.12). Conclusions: Autofluorescent changes most strongly correlate with drusen size and disruption of the IS-OS layer and may be useful as an additional functional-morphological feature by which drusen and their impact upon overlying photoreceptors may be judged.

Appearance of medium–large drusen and reticular pseudodrusen on adaptive optics in age-related macular degeneration

“…A hyper-reflective signal on cSLO IR reflectance has been previously described by our group for conventional drusen with RPE alterations 26. In a study of autofluorescence imaging in large drusen, Landa et al 27 suggested that hypoautofluorescent and hyperautofluorescent changes mostly correlate with the disruption of the overlying IS/OS layer. Current data from AO support the idea that different degrees of impairment in the RPE and photoreceptors could be responsible for the different imaging features recorded between medium–large drusen and reticular pseudodrusen.…”

Genetic Polymorphisms and the Phenotypic Characterization of Individuals with Early Age-Related Macular Degeneration

“…The measurements were performed subfoveally as well as 3,000 μm temporally and nasally of the fovea in the central horizontal OCT axis. Additionally, the frequencies of drusen, reticular drusen and RPE migrations, as well as presence and frequency of breaks of the ellipsoid portion of the inner segments of the photoreceptors (ISe) ≥ 50 μm were assessed [34,35] . Through the high-resolution OCT scans, a precise differentiation of the drusen ultrastructure with a qualitative discrimination via criteria established by Khanifar et al [29] could be accomplished.…”

In-vivo mapping of drusen by fundus autofluorescence and spectral-domain optical coherence tomography imaging

“…Several authors have specifically investigated SD-OCT characteristics at the site of visible drusen, including soft drusen by CFP [14,15,[17][18][19][27][28][29]. Khanifar et al demonstrated the existence of a wide variation in drusen morphology by SD-OCT, and differentiated 17 unique drusen patterns.…”

“…Landa et al recently performed an SD-OCT/confocal scanning laser ophthalmoscope (cSLO) FAF correlation in patients with bilateral early AMD in areas of drusen primarily detected by SD-OCT [19]. They found that disruptions in the outer retina (i.e., the inner segment/ outer segment [IS/OS] layer) were closely related to local FAF changes.…”