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Updated: Aug 17, 2026

Efficient and Consistent Generation of Retinal Pigment Epithelium/Choroid Flatmounts from Human Eyes for Histological Analysis
Published on: October 28, 2022
Phenotypic variation of retinal pigment epithelium in age-related macular degeneration
Clyde Guidry1, Nancy E Medeiros, Christine A Curcio
1Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0009, USA.
Purpose:
To determine whether retinal pigment epithelium (RPE) in eyes with age-related macular degeneration (ARMD) express vimentin and alpha smooth muscle actin (alphaSMA), two cytoskeletal proteins associated with phenotypic variation in culture.
Methods:
Six eyes with late ARMD and three age-matched control eyes were preserved in buffered 4% paraformaldehyde and cryosectioned at 10 microm. Stages of RPE morphology and pigmentation were assessed by the Alabama Age-Related Macular Degeneration Grading System. Vimentin, alphaSMA, and glial fibrillary acidic protein (GFAP) expression was detected by indirect immunofluorescence. These results were compared with regional variations in disease severity.
Results:
RPE changes in ARMD included acquired expression of vimentin, but alphaSMA-positive cells were rare. GFAP expression increased in Müller cells in the neural retina in association with RPE changes and photoreceptor degeneration.
Conclusions:
The initial stages of RPE changes in eyes with ARMD mimic those reported for cultured RPE cells. The absence of alphaSMA-positive cells in regions of RPE atrophy suggests that RPE are lost rather than persist in a dedifferentiated state.

