Basal laminar deposit in the aging peripheral human retina.

A basal laminar deposit (BLD) in the human macula has been described as an early sign of age-related macular degeneration. In some eyes with a BLD in the macula, light microscopic sections of the peripheral retina revealed almost similar deposits between the retinal pigment epithelium and Bruch's membrane. Because the exact pathogenesis of age-related macular degeneration and the origin of the BLD are unknown, we studied the ultrastructure of these peripheral sub-RPE deposits. Parts of the equatorial and peripheral regions of the retina of ten human eyes, with BLD-like deposits between the retinal pigment epithelium and Bruch's membrane, were examined by electron microscopy. In eight of these ten eyes the ultrastructure of these deposits was amorphous and finely granular. Five of the eight deposits also contained small amounts of long-spacing collagen. Ultrastructurally, the deposits were similar to an early type BLD in the macula. In the remaining two eyes, the deposits appeared to consist of flat, elongated drusen. Our findings indicate that a BLD can develop not only in the macula but also in the peripheral region of the retina.