DISEASE EXPRESSION IN NONEXUDATIVE AGE-RELATED MACULAR DEGENERATION VARIES WITH CHOROIDAL THICKNESS

Abstract

Purpose: To investigate the relationship between subfoveal choroidal thickness and disease manifestation in a series of eyes with nonexudative age-related macular degeneration (AMD).

Methods: Retrospective study of eyes with nonexudative AMD. The extracellular deposits present, drusen and subretinal drusenoid deposits (SDD, pseudodrusen) along with a newly recognized form of drusen, pachydrusen, were graded and compared with choroidal thickness as determined by optical coherence tomography. Demographic and imaging information was evaluated with descriptive statistics and generalized estimating equations.

Results: There were 94 eyes of 71 patients, who had a mean age of 78.1 years. Soft drusen alone were found in 45 eyes (47.9%) and subretinal drusenoid deposit with or without drusen in 38 (40.4%). Pachydrusen, which were typically larger than 125 μm, often had an irregular outer contour, showed a scattered distribution over the posterior pole and occurred in isolation or in groups of only a few drusen were found in 11 (11.7%). The mean subfoveal choroidal thickness in the soft drusen group was 227.9 μm, in the subretinal drusenoid deposit group 167.3 μm, and in the pachydrusen group 419 μm. The differences between the groups were highly significant.

Conclusion: Extracellular deposits, subretinal drusenoid deposits and drusen, which are on either side of the retinal pigment epithelium, respectively, are common in nonexudative AMD. A new form of drusen presentation could be differentiated from typical soft drusen and was associated with thicker choroids. Disease manifestation in nonexudative AMD seems to be associated with choroidal thickness. Each of these has potential to lead to specific forms of late AMD.