Histopathology of Age-Related Macular Degeneration

Pathologic changes in age-related macular degener- ation (AMD) occur in the various structures in the posterior pole, such as the outer retina, the retinal pigment epithelium (RPE), Bruch’s membrane and the choriocapillaries (1,2). Early lesions of AMD are located either between the RPE and its basement membrane [e.g., basal laminar deposits (BlamD)] or between the basement membrane of the RPE and the remainder of Bruch’s membrane [e.g., basal linear deposits (BlinD)] (2-5). Focal and diffuse deposition between the RPE and Bruch’s membrane is called drusen. Alterations of RPE such as hypopigmentation, depigmentation or atrophy as well as attenuation of photoreceptor cells are also observed. This form of macular degeneration is known as dry AMD (non-exudative AMD), whereas choroidal neovascu- larization (CNV) is the main feature of wet AMD (exudative AMD), which ultimately results in a disci- form scar in end stage AMD.