Reattachment Rate of Human Retinal Pigment Epithelium to Layers of Human Bruch's Membrane

Objectives: To determine the reattachment rate of human retinal pigment epithelium (RPE) to different layers of human Bruch’s membrane (BM). Methods: Explants of BM were prepared from 10 human cadaver eyes by removing native RPE. The RPE basal lamina, inner collagenous layer, elastin layer, and outer collagenous layer were exposed by sequentially removing each apical layer by mechanical or enzymatic means. First-passage human RPE was plated onto the surface and the RPE reattachment rate to each layer of BM was determined. Results: Retinal pigment epithelial cell reattachment was highest to the inner aspects of BM and decreased as deeper layers of BM were exposed (ie, reattachment rate to basal lamina was higher than to the inner collagenous layer, which was higher than to the elastin layer, which was higher than to the outer collagenous layer). The reattachment rate to the inner collagenous layer, elastin layer, and outer collagenous layer harvested from elderly donors (age .60 years) was less than the reattachment rate to corresponding layers harvested from younger (age ,50 years) donors. Conclusions: Retinal pigment epithelial cell reattachment depends on the anatomical layer of BM present in the host tissue. Age-related changes in BM may interfere with RPE reattachment. Our observations may have implications for understanding the pathogenesis of agerelated macular degeneration and its potential treatment with RPE transplantation techniques.