Abstract
Abstract: :
Purpose: We have described a feline model of PVR (Sethi C S et al. Invest Ophthalmol Vis Sci 2000;41:S344) to elucidate the pathology of this visually devastating complication of retinal detachment (RD). We have now characterised the effect of anatomical reattachment in this system. Methods: Experimental RD was supplemented with basic FGF and TGF beta according to our PVR protocol, with reattachment of the retina using SF6 gas after 3 days, for a further 28 days before sacrifice (n=3). Controls received identical surgery and growth factors but no retinal detachment (n=3). Retinal sections were labelled with a panel of 10 antibodies for immunohistochemical analysis by confocal microscopy. Results: In our previously described feline model of PVR, experimental RD for 28 days supplemented with basic FGF and TGF beta produces epiretinal and subretinal glial membranes similar to human PVR. Reattachment of the retina after 3 days does not inhibit this process entirely, but does prevent focal glial breaches of inner and outer limiting membranes from progressing to more extensive, contractile gliosis as seen in established human PVR. Reattached retinas demonstrate more redistribution of rod opsin protein and rod axon retraction than controls that have received the same growth factors but without retinal detachment / reattachment. Reattachment of the retina at day 3 preserves photoreceptor morphology and «aborted’ neurite extensions can be seen at the level of first, second and third order neurons, with injury-induced expression of growth-associated proteins in ganglion cells. Control animals did not develop PVR or exhibit significant neuronal remodelling. Conclusion: Reattachment of the retina is the primary intervention in complicated retinal detachment surgery. We have examined the anatomical consequences of this procedure using an experimental model and demonstrated that reattachment of the retina at day 3 abrogates deleterious remodeling of glial and neuronal retinal components, even in the presence of the biologically hostile environment that we know will induce these changes in detached feline retina. Retinal reattachment at time points beyond 3 days will define the therapeutic window in which anatomically successful surgery can best achieve a good functional outcome
Keywords: 524 proliferative vitreoretinopathy • 563 retinal detachment • 316 animal model