[Comparison of vitrectomy outcomes for eyes with proliferative vitreoretinopathy with and without prior vitrectomy].

PURPOSE: To compare the surgical outcomes of vitrectomy for eyes with proliferative vitreoretinopathy (PVR) with and without prior vitrectomy. METHODS: Eighty-two eyes of 81 patients (35 women and 46 men), who underwent vitrectomy for grade C PVR and had at least 6 months of follow-up, were studied retrospectively. The mean age of the cases was 50.8 years (range; 8-84 years). Twenty-eight eyes had undergone prior vitrectomy (vitrectomized group) and 54 eyes had no prior vitrectomy (primary vitrectomy group). The intraoperative technique of vitreous surgery, number of vitrectomy procedures, surgical success rate, visual acuity and intraocular pressure before and 6 months after the vitrectomy of the two groups were compared. RESULTS: The rate of the anterior (type 4 and 5) PVR cases was significantly higher in the vitrectomized group than in the primary vitrectomy group (p = 0.028), whereas the rate of the only subretinal cases (type 3) PVR was significantly higher in the primary vitrectomy group (p<0.001). There were no significant differences in the preoperative visual acuity and intraocular pressure between the two groups. The rate of the cases who underwent retinotomy/retinectomy was significantly higher (p< 0.001)in the vitrectomized group than in the primary vitrectomy group. The surgical success rate and postoperative visual acuity were significantly better in the primary vitrectomy group than in the vitrectomized group (p = 0.040, <0.001, respectively). The postoperative intraocular pressure was significantly lower (p = 0.017) in the vitrectomized group than in the primary vitrectomy group, and the rate of the cases with hypotony of less than 5mmHg was significantly higher (p<0.001) in the vitrectomized group than in the primary vitrectomy group. CONCLUSIONS: Compared to the PVR eyes that had had no prior vitrectomy, the PVR eyes that underwent prior vitrectomy had a significantly higher rate of complications of anterior PVR and a significantly higher rate of retinotomy/retinectomy, leading to a significantly poorer surgical outcomes.