A study of the retinal vascular pathology in the Royal College of Surgeons rat : a model of human retinal degeneration
The leading causes of loss of vision in the developed world are the degenerative diseases of photoreceptors in particular, age-related macular degeneration (AMD) and retinitis pigmentosa (RP). A common characteristic of these diseases is secondary damage affecting the vascular network, which is apparently initiated by photoreceptor loss. One problem with investigating the vascular consequences of these diseases has been the lack of a suitable animal model that can be used to investigate various potential treatments. This study has developed methods of quantifying retinal vascular damage in the pigmented Royal College of Surgeons (RCS) rat, which is characterised by the formation of vascular complexes and these methods have been used to explore strategies to retard or reverse this damage. This was done with the view to improving the retinal environment, thereby assisting other therapeutic strategies that target the primary defect causing the loss of photoreceptors. The work was divided into three areas: 1) investigation of the vascular effects of progressive photoreceptor loss and development of computerised image analysis to quantify changes, 2) pharmaceutical intervention to modify the normal sequence of events, 3) examination of the effects of RPE sub-retinal transplantation on the vascular network to determine how the retinal vasculature would react to the presence of transplanted human RPE cells at different time-points. These three areas of study validate the use of naturally occurring events in the RCS rat to provide a model of vascular pathology in human retinal degenerative diseases. This contrasts with previous models, which have relied on creating wounds to simulate conditions that occurring in the diseased human retina.