THE ASSOCIATION BETWEEN DRUSEN EXTENT AND FOVEOLAR CHOROIDAL BLOOD FLOW IN AGE-RELATED MACULAR DEGENERATION

Purpose: To investigate the relationship between drusen extent and foveolar choroidal blood flow in nonexudative age-related macular degeneration. Methods: Total drusen area, average druse area, and total drusen number were determined using a computer program developed to quantify the extent of manually outlined drusen from fundus photographs of 157 patients (239 eyes) with nonexudative age-related macular degeneration. Laser Doppler flowmetry was used to assess relative choroidal blood velocity (ChB(Vel)), volume (ChB(Vol)), and flow (ChB(Flow)) in the center of the fovea. Results: We found a significant inverse relationship between total drusen area and ChB(Vol) or ChB(Flow). For every 1-mm(2) increase in total drusen area, ChB(Vol) decreased by 0.0061 arbitrary units (P = 0.03) and ChB(Flow) decreased by 0.23 arbitrary units (P = 0.049). Average druse area was also significantly inversely related to ChB(Vol) and ChB(Flow). For every 0.01-mm(2) increase in average druse area, the ChB(Vol) decreased by 0.0149 arbitrary units (P = 0.001) and the ChB(Flow) decreased by 0.4951 arbitrary units (P = 0.003). Adjustment for age weakened the significance, although it remained strong for average druse area versus ChB(Flow) (P = 0.017) and ChB(Vol) (P = 0.004). The computer-aided quantification of drusen used in this study showed high intra- and intergrader agreement. Conclusion: In patients with nonexudative age-related macular degeneration, there is an association between increased drusen extent and decreased ChB(Vol) and ChB(Flow). This suggests the presence of ischemia and possibly the reason why patients with high-risk drusen are prone to advanced disease. RETINA 32:25-31, 2012