Origins of Ghost Drusen: A follow-up Analysis

Purpose Ghost drusen (GD) are pyramidal or dome-shaped retinal pigment epithelium elevations observed in some geographic atrophy (GA) areas in the context of age-related macular degeneration (AMD). The purpose was to investigate the first morphologic features preceding GD on spectral-domain optical coherence tomography (SD-OCT) on patients with GA associated with AMD. Methods A retrospective observational study was performed on a series of patients with GA that had at least 3 years of follow-up. Using the follow-up tool of SD-OCT, we tracked the initial lesions that could lead to GD. Results Among 442 patients with GA, 37 had well defined GD (8%). We included the 17/37 patients (31 eyes) with at least 3 years of follow-up for analysis, which led to a total of 582 counted GD. Most GD were already present at the first visit, and remained stable. However, on 13 of the 582 analyzed GD (2.2%), soft drusen were shown as the initial lesion, which progressively turned into GD. Conclusions GD were observed in less than 10% of eyes with GA. None of the ghost drusen turned into another shaped lesion, suggesting that GD is a possible final stage of evolution. In a few cases, large drusen were shown as the primary lesion that progressed into GD.