Retinal sensitivity over drusen and nondrusen areas. A study using fundus perimetry.

Elderly patients with drusen and good visual acuity have a decrease in dark-adapted retinal sensitivity in the central retina. We used the fundus camera stimulator to determine whether this sensitivity loss is caused directly by the presence of drusen. We measured retinal sensitivity over drusen and in drusen-free areas in eight patients with drusen and age-related macular degeneration (AMD). There was no significant difference in sensitivity between drusen and nondrusen areas in each patient. The sensitivity loss seen in patients with drusen thus seems to reflect a more diffuse disease of the retina and retinal pigment epithelium and is not a direct effect of drusen. More marked sensitivity losses are found in even small areas of more advanced AMD changes, suggesting that a large focal loss in retinal sensitivity may be an indicator of developing AMD changes.