Abstract
Purpose: :
To analyze the relationship between morphologic characteristics of drusen ultrastructure, revealed by Spectral domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) changes of drusen, exposed by Heidelberg Retina Angiograph 2 (HRA2), in dry AMD patients.
Methods: :
Dry AMD patients were images with SD-OCT and HRA2 on the same day. Thereafter, SD-OCT B-scans were precisely overlaid on HRA2 image and the SD-OCT morphologic characteristics of drusen were correlated with corresponding notable changes of FAF. The analyzed drusen and drusen-related morphologic characteristics were as follows: size, status of IS-OS junctional layer above the drusen, shape of drusen, internal reflectivity, homogeneity, presence of overlaying hyperreflective foci. For each drusen the FAF changes were rated as hyperautofluorescent, hypoautofluorescent changes or normal autofluorescence. Drusen phenotypic patterns of FAF were also noted in all studied eyes. Spearman’s correlation coefficient was used to analyze the correlation between the two primary outcomes: SD-OCT morphologic characteristics of drusen ultrastructure and HRA2 notable autofluorescence changes of correspondent drusen.
Results: :
431 drusen in 32 eyes of sixteen dry AMD patients were evaluated. Out of seven morphologic characteristics assessed by SD-OCT, only drusen size and the status of IS-OS layer above the drusen were found to be strongly correlated with notable FAF findings (r=0.78 and r=0.58, respectively). The correlation coefficients of other parameters are followed in a decreasing order of correlation strength: homogeneity (r=0.38), shape (r=0.29), reflectivity (r=0.28), presence of overlaying foci (r=0.25).Minimal change pattern was found to be the most common phenotypic among eight patterns and was observed in 10 (31.3%) out of 32 eyes.
Conclusions: :
A strong relationship between the presence of large drusen, the status of IS/OS layer and correspondent notable FAF changes. Monitoring FAF changes may give additional information regarding the status of drusen and the status of photoreceptors in dry AMD patients, although long-term longitudinal studies are warranted in order to evaluate the additional value of performing FAF examination during the follow-up of dry AMD patients with drusen.
Keywords: drusen • imaging/image analysis: clinical • age-related macular degeneration