Purpose: In an earlier study, the authors reported that foveolar choroidal blood flow (ChBFlow) decreases in patients with AMD and drusen. To explore further the choroidal circulatory changes in patients with AMD, the relationship between ChBFlow and fundus features associated with increased risk of choroidal neovascularization (CNV) were investigated.
Methods: The study included 26 control eyes of 17 normal subjects and 163 eyes with early AMD characteristics of 123 patients with AMD. The AMD study eyes were divided into three groups according to increasing risk for development of CNV: (1) drusen > or =63 microm, no RPE hyperpigmentary changes in the study eye, and no CNV in the fellow eye; (2) drusen > or =63 microm, RPE hyperpigmentary changes in the study eye, and no CNV in the fellow eye; and (3) eyes with CNV in the fellow eye. Laser Doppler flowmetry was used to assess relative foveolar choroidal blood velocity (ChBVel), volume (ChBVol), and flow (ChBFlow). Differences in the mean circulatory parameters were assessed by analysis of variance (ANOVA) and test of linear trend.
Results: Mean ChBVel, ChBVol, and ChBFlow decreased with increased risk for CNV (linear trend, P < 0.05). The lowest circulatory parameters were observed in the eyes with the highest risk for CNV development. Trends for ChBVel and ChBFlow were still significant after adjustment for multiple factors.
Conclusions: There is a systematic decrease in choroidal circulatory parameters with an increase in the severity of AMD features associated with risk for the development of CNV, suggesting a role for ischemia in the development of CNV.