Abstract
Abstract: :
Purpose:Previous studies indicate that platelet–derived growth factor (PDGF) receptor plays an important role in the development of proliferative vitreoretinopathy (PVR) in the rabbit model. We investigate whether STI571, an inhibitor of PDGF a and ß receptor, can be used intravitreally to inhibit PVR in the rabbit model. Methods: PVR was induced in the R–eye of 8 Dutch pigmented rabbits by injecting 2 x 105 conjunctival fibroblasts suspended in 0.1cc of serum free DMEM, in conjunction with 0.1 cc of platelet rich plasma. This was preceded by a gas vitrectomy with 0.1cc of 100% C3F8 three days prior. Four rabbits were concomitantly injected at the time of cell injection with 1mg of STI571 suspended in 0.1cc of BSS. These rabbits were injected with an additional dose of STI571 on Day 7. Rabbits were examined on Days 1, 5, 7, 14, 21, and 28 using indirect ophthalmoscopy by a single unmasked investigator. PVR was graded using the Fastenberg classification as follows: 0, no abnotmality; 1, vitreous strands, 2, traction of the retina, 3, retinal detachment (RD) involving less than two quadrants, 4, RD including more than two quadrants; 5, total RD. Results: Large intravitreal cell clusters were confirmed in all injected eyes on Day 1. On Day 7, the control rabbits demonstrated development of PVR, with one each achieving stage 2, stage 3, stage 4 and stage 5 disease. Eyes injected with STI571 showed less severe disease with three rabbits achieving stage 1, and one achieving stage 3 disease. Four weeks (28 days) after cell injection, control rabbits had achieved end–stage PVR with partial or complete RD (2 stage 4 and 2 stage 5 eyes). Of the eyes injected with STI571, one showed no abnormalities (stage 0), one showed minimal vitreous bands (stage 1), and two had progressed to complete RD (stage 5)Conclusions:Intravitreal STI571 is effective in suppressing the development of PVR in a small group of rabbits and could potentially be used as a locally administered therapeutic agent for this disease.
Keywords: proliferative vitreoretinopathy • inhibitory receptors