Reticular drusen associated with geographic atrophy in age-related macular degeneration

PURPOSE: To characterize reticular drusen (RDR) in patients with geographic atrophy (GA) secondary to age-related macular degeneration (AMD) in a prospective, multicenter, natural history study.

METHODS: Confocal scanning laser ophthalmoscopy (cSLO) three-field fundus autofluorescence (FAF; exc., 488; em., 500-700 nm), near-infrared reflectance (IR; 820 nm), and blue reflectance (BR; 488 nm) images as well as red-free (RF) and color fundus (CF) camera photographs were recorded in 458 GA patients. The digital images were evaluated by two independent readers with subsequent senior reader arbitration for prevalence and topographic distribution of RDR using a modified Early Treatment Diabetic Retinopathy Study grid.

RESULTS: RDR were detected with at least one cSLO modality in 286 of 458 (62%) patients in either eye (bilateral 207 [45%]) and were visible in fundus camera photographs in 66 of 371 (18%) patients (bilateral 48 [13%]). Prevalence of RDR by cSLO imaging was associated with increasing age (P = 0.007) and female sex (P = 0.007), but not with GA total lesion area (P = 0.38). Cohen kappa statistics showed good interobserver agreement for FAF (0.81) and IR (0.82) imaging modes, and moderate agreement was found for BR (0.48), RF (0.48), and CF (0.40). On three-field FAF images RDR were present most frequently superior to the fovea (99%).

CONCLUSIONS: RDR represent a common phenotypic hallmark in GA eyes. RDR are readily identified using cSLO imaging technology. These observations may explain the high prevalence determined herein, in contrast to previous reports based on fundus photographs. Incorporation of these novel imaging modalities in future natural history studies may facilitate efforts aimed at defining the role and predictive value of RDR in the progression of AMD. (ClinicalTrials.gov number, NCT00599846.)