Detection Of Reticular Drusen Using Autofluorescence Imaging In A Population-based Setting: The Alienor Study

Abstract

Purpose: : Reticular drusen are associated with high risk of progression to late age-related maculopathy (ARM). We investigated the potential value of autofluorescence (AF) imaging for the detection of reticular drusen in a population-based setting.

Methods: : 963 residents of Bordeaux (France), aged 73 years or more, were included in 2006-2008. About 18 months later, a complementary eye examination was proposed to all subjects diagnosed with early ARM at baseline, and an equal number of subjects without early ARM. It included AF imagining with measurement of macular pigment (Modified HRA I, Heidelberg Engineering, Heidelberg, Germany) and colour photographs. A total of 360 subjects (677 eyes) had gradable photographs and AF imaging, after exclusion of 15 cases of incident late ARM. ARM was graded from colour photographs in 3 exclusive groups: large soft indistinct drusen and/or reticular drusen and/or large distinct drusen with pigment abnormalities (early ARM2); large soft distinct drusen alone or pigment abnormalities alone (early ARM1); no ARM. Colour photographs and AF images were graded by different people, in a masked fashion.

Results: : Of 24 eyes classified as definite reticular drusen on colour photographs, 22 (91.7 %) were also classified as definite on AF images, 1 (4.2 %) as questionable and only 1 (4.2 %) as absent. In addition, among 8 eyes classified as questionable reticular drusen on colour photographs, 5 (62.5 %) were classified as definite from AF images, 1 (12.5%) as questionable and 2 (25 %) as absent. Conversely, 42 of 69 eyes (69.9 %) with definite reticular drusen on AF images were not detected on colour photographs. Using AF classification, 29.3 % of eyes with early ARM2, 10.8 % of those of early ARM1 and 3.4 % of those without ARM had definite reticular drusen, versus 17.1 %, 0 % and 0 % according to colour photographs, respectively.

Conclusions: : AF imaging appears much more sensitive than colour photographs for the detection of reticular drusen. Previous epidemiological studies relying on colour photographs may have seriously underestimated the frequency of reticular drusen

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • age-related macular degeneration