OUTER RETINAL ATROPHY AFTER REGRESSION OF SUBRETINAL DRUSENOID DEPOSITS AS A NEWLY RECOGNIZED FORM OF LATE AGE-RELATED MACULAR DEGENERATION

Purpose: To investigate the long-term clinical course of eyes with pseudodrusen appearance caused by subretinal drusenoid deposits. Methods: Eyes from the original study identifying subretinal deposits of material as the cause of pseudodrusen appearance were evaluated in a retrospective study of outer retinal morphology. The distance between the inner plexiform layer and the retinal pigment epithelium, termed the photoreceptor length, was measured from optical coherence tomography approximately 2 mm superior to the fovea at baseline and at follow-up visits. The choroidal thickness was measured directly under this retinal area. Results: Of the 21 eyes available for follow-up, 9 (42.9%) eventually developed choroidal neovascularization over a mean 2.9-year follow-up period. Regression of subretinal drusenoid deposits was seen in 9 eyes (42.9%) as well. Those with regression of subretinal drusenoid deposits had a decrease in the photoreceptor length with the final photoreceptor length being 74.4% of the initial length (P < 0.001). In eyes with regression, the underlying choroid was 81.4% of its initial value (P = 0.01) at the final follow-up. Eyes with regression also showed loss of the ellipsoid band. Eyes without regression had no change in photoreceptor length, choroidal thickness, or outer retinal architecture. Conclusion: Eyes with regression of subretinal drusenoid deposits develop outer retinal atrophy and loss of the underlying choroidal thickness. This finding seems common in eyes having pseudodrusen and represents a late form of age-related macular degeneration that is not in current classification systems. Further study is needed to determine both the true prevalence and the effects on visual function.