THERAPEUTIC EFFECT OF PERIOCULAR CORTICOSTEROIDS IN EXPERIMENTAL PROLIFERATIVE VITREORETINOPATHY

Objective: To test the therapeutic effect of periocular corticosteroid injection on outcome, vitreous cellular infiltrate, and vitreous solu ble growth-stimulating activity in an experimental model of tractional retinal detachment resulting from proliferative vitreoretinopathy. Me thods: An experimental model of proliferative vitreoretinopathy was in duced in rabbits, which then were selected randomly to receive either periocular methylprednisolone acetate injection treatment or a placebo injection (control). Animals were examined and monitored to determine the degree of retinal detachment and proliferative vitreoretinopathy at weekly intervals for 4 weeks. Vitreous specimens were obtained each week and analyzed for cell number by flow cytometry and for soluble g rowth-stimulating activity using a bioassay. Results: Eighty-six perce nt (12 of 14) of the rabbits receiving periocular steroid injection ha d retinas that remained attached, whereas only 13 percent (2 of 15) of control animals had retinas that remained attached, Periocular steroi d injections were associated with a significant decrease in the vitreo us soluble proliferation stimulating activity at all times during expe rimental proliferative vitreoretinopathy. Vitreous cellular infiltrati on also was reduced significantly in steroid-treated animals compared with that of control animals. Finally, the magnitude of the soluble gr owth-stimulating activity at day 7, before onset of proliferative vitr eoretinopathy, was highly predictive of outcome 3 weeks later. Conclus ion: Periocular steroids decreased the incidence of complicated retina l detachment caused by proliferative vitreoretinopathy in this rabbit model. Decreased vitreous cellular infiltrate and soluble proliferatio n stimulating activity within the vitreous microenvironment also was o bserved to be associated with successful outcome.