Prevalence and natural course of refractile drusen in eyes with intermediate age-related macular degeneration

Abstract

Purpose : Refractile drusen represent a phenotypic feature in various stages of age-related macular degeneration (AMD). Aim of this analysis was to evaluate prevalence, natural course, and clinical significance of refractile druse associated with intermediate AMD in a prospective, longitudinal natural history study.

Methods : Ninety-eight eyes of 98 subjects (mean age 73.1 ± 7.1 years) with intermediate AMD were included. At baseline and at each year, multimodal retinal imaging including infrared reflectance (IR), blue reflectance (BR), fundus autofluorescence, and optical coherence tomography (OCT) over a review period of up to 4 years was performed. Refractile drusen were identified in color fundus photographs and longitudinal changes of individual lesions were analyzed in different imaging modalities. Incidence of late atrophic and neovascular AMD was compared between eyes with and without refractile drusen.

Results : Twenty of 98 eyes had refractile drusen at baseline with a total lesion number of 115. Lesions were bilateral in 14 subjects. Refractile drusen showed a hyperreflective appearance on IR (80.9%) and BR (93.9%). Corresponding hyperreflective material at the level of Bruch’s membrane by OCT was noted in 33 %. Longitudinal observations revealed both spontaneous regression of refractile drusen (n = 10) as well as progression to geographic atrophy (n = 30) or exudative changes (n = 25). If refractile drusen were present at baseline, the development of central GA was more frequently observed as compared to eyes with no refractile drusen at baseline (9/15 vs 6/57, excluding patients who dropped out). The presence of refractile drusen resulted in similar rates for the incidence of choroidal neovascularization (3/15 vs 16/57).

Conclusions : The results indicate that refractile drusen in eyes with intermediate AMD may represent a predictive marker for the progression towards GA rather than CNV. Expanded future natural history as well as interventional studies should record the presence of refractile drusen for further validation of these initial observations.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.