ORIGINAL ARTICLE Drusen, an Age Related Change in the Retina of the

The formation and progression of drusen was studied in the retinas of Fisher rats. The incidence of drusen in-creased with age. More numerous and advanced lesions were formed in males than in females. In general, there were more lesions in lower peripheral retina than upper peripheral retinas. Early lesions appeared as an ac-cumulation of amorphous material between the retina pigment epithelium and Brush's membrane, which later led to the separation and disruption of retinal pigment epithelium. Increased thickness of Bruch's membrane, areolar atrophy of retinal pigment epithelium, and choroidal neovascularization were evident in advanced le-sions. Drusen have been caused by many factors. To understand the etiology of these lesions, it is important to study the effect of each factor. The changes reported in this study are specifically age-related. Key words: Drusen; Bruch 's membrane; retinal pigment epithelium cells The pathogenesis of age-related retinal degenera-Lion has not been dearly understood. Clinical and ex-perimental findings suggest the involvemen t of many etiological factors, acting alone or in combination, to result in similar clinical manifestations known as ag-ing retinal or macular degeneration. The presence of drusen, localized depositions of hyaline-like material between the retinal pigmented epithelium and Bruch's membrane, has been shown to precede retinal degeneration, 1 • 2 areolar retinal pigmented epithelial atrophy,' • 2 • ' disciform scarring of th