[Pars plana vitrectomy in patients with acute retinal necrosis syndrome: surgical results in 52 patients].

PURPOSE: To analyze results of pars plana vitrectomy for acute retinal necrosis (ARN) syndrome. METHODS: We reviewed the records of 52 eyes with ARN syndrome who underwent pars plana vitrectomy at the Tokyo Medical University Hospital from 1989 to 2007. The mean age was 50.1 +/- 10.2 years and the mean follow-up duration was 75.3 months. The causative virus was herpes simplex virus in 7 cases and varicella zoster virus in 45 cases. In all cases, treatment with acyclovir and corticosteroids was started from presentation. During the follow-up period, vitrectomy was done in patients who developed retinal detachment, and in those who developed posterior vitreous detachment exerting marked traction on the retina, even though retinal detachment had not occurred. In these cases, preoperative and postoperative visual acuities were compared and reoperation, retinal detachment preventive surgery and age-stratified visual prognosis after vitrectomy were analyzed. RESULTS: Visual acuity was improved by 2 lines or more in 13 eyes (25.0%), remained unchanged in 16 eyes (30.8%), and deteriorated by 2 lines or more in 23 eyes (44.2%). Thirty-seven of 52 eyes (71.2%) required re-operation. No significant differences were detected when the patients were stratified according to whether they were treated either with or without combined use of silicon oil, or according to whether they were treated either with or without prophylactic surgery for retinal detachment, as well as by age of vitrectomy. A combination of lens extraction, silicon oil and encircling sclera buckling procedure was associated with a significantly higher frequency of final visual acuity. CONCLUSION: Despite the advances in vitrectomy achieved today, the visual prognosis of acute retinal necrosis remains unsatisfactory. The present study found no significant improvement in the prognostic relevance of prophylactic vitrectomy. Improvement in pharmacotherapy may help improve the prognosis. Further prospective large-scale studies to compare other treatment modalities are also required.