REATTACHMENT RATE OF HUMAN RETINAL-PIGMENT EPITHELIUM TO LAYERS OF HUMAN BRUCHS MEMBRANE

Objectives: To determine the reattachment rate of human retinal pigmen t epithelium (RPE) to different layers of human Bruch's membrane (BM). Methods: Explants of BM were prepared from 10 human cadaver eyes by r emoving native RPE. The RPE basal lamina, inner collagenous layer, ela stin layer, and outer collagenous layer were exposed by sequentially r emoving each apical layer by mechanical or enzymatic means. First-pass age human RPE was plated onto the surface and the RPE reattachment rat e to each layer of BM was determined. Results: Retinal pigment epithel ial cell reattachment was highest to the inner aspects of BM and decre ased as deeper layers of BM were exposed (ie, reattachment rate to bas al lamina was higher than to the inner collagenous layer, which was hi gher than to the elastin layer, which was higher than to the outer col lagenous layer). The reattachment rate to the inner collagenous layer, elastin layer, and outer collagenous layer harvested from elderly don ors (age > 60 years) was less than the reattachment rate to correspond ing layers harvested from younger (age < 50 years) donors. Conclusions : Retinal pigment epithelial cell reattachment depends on the anatomic al layer of BM present in the host tissue. Age-related changes in BM m ay interfere with RPE reattachment. Our observations may have implicat ions for understanding the pathogenesis of age-related macular degener ation and its potential treatment with RPE transplantation techniques.