Abstract
Abstract: :
Dystrophic RCS rats undergo progressive photoreceptor degeneration over the first months of life, providing a model of human retinal degenerative disease. Transplantation of a human retinal pigment epithelial cell line, ARPE19, into the sub-retinal space of these rats early in life limits subsequent retinal degeneration. Purpose: In this study, we investigated whether limiting retinal degeneration with ARPE19 transplantation is an effective long-term method of preserving visual function. Method: We first characterized the spatial vision of non-dystrophic RCS rats, using the Visual Water Task, to determine whether the RCS strain itself has normal visual function. Next, we measured the visual acuity of dystrophic RCS rats, over time, to quantify the effect retinal deterioration has on cortical vision. Finally, we measured the visual acuity of monocularly and binocularly transplanted dystrophic RCS rats at various times after the surgery. Results: We found that non-dystrophic RCS rats had a grating acuity and contrast sensitivity that was normal for a pigmented rat. We also found that the acuity of dystrophic RCS rats declined from ~0.8 cycles/degree (cpd) at one month postnatal, to ~0.3 cpd by four months postnatal. There was a much slower decline in acuity thereafter. In addition, we found that both monocular and binocular transplants resulted in significantly improved vision over sham-operated controls, up to seven months of age. Conclusions: The results indicate that the RCS rat strain has no inherent spatial vision deficits, that dystrophic RCS rats lose cortical vision as their retinas degenerate, and that retinal transplantation of ARPE19 cells limits the progressive loss of visual function in dystrophic RCS rats for a significant period of time. Consequently, RPE cell transplantation may have therapeutic benefit for human retinal degenerative disease.
Keywords: transplantation • retinal pigment epithelium • age-related macular degeneration