Drusen characteristics in patients with exudative versus non-exudative age-related macular degeneration.

The drusen characteristics of 38 eyes from 38 patients with bilateral drusen associated with age-related macular degeneration (AMD) were compared in a masked fashion to 89 fellow eyes from 89 patients with unilateral exudative AMD (disciform scarring or choroidal neovascularization). The average age of the drusen group (67.4 years) was significantly less (P = 0.01) than the average age of the unilateral exudative group (72.6 years). Multiple logistic regression was used to compare the drusen characteristics in the two groups, controlling for the age and sex of the patients. Among patients 75 years of age and younger, patients with confluent drusen had an increased risk of having a fellow eye with exudative AMD compared with patients without confluent drusen. Among patients older than 75 years of age, confluent drusen did not significantly differentiate the two study groups, although confluent drusen in this older age group were more often associated with the bilateral drusen group. Focal hyperpigmentation of the retinal pigment epithelium was also associated with the unilateral exudative group. These drusen characteristics should be evaluated in future prospective studies designed to determine which eyes with drusen are at greatest risk for developing the blinding complications of choroidal neovascularization.