Abstract: Objective To analyze the treatment timing and efficacy of acute retinal necrosis (ARN) syndrome. Methods 35 patients (52 eyes) diagnosed with ARN syndrome undergoing systemic medication, retinal photocoagulation and vitreous surgery were reviewed retrospectively to evaluate the timing and efficacy of the treatment. Results In the patients who took medicine atthe first 2 weeks, 17 of 22 eyes (77%) avoided retinal detachment and 14 eyes had a final visual acuity better than 0.3. Nevertheless, only 12 of 31 eyes (39%) with medicine and retinal photocoagulation were spared from retinal detachment, and 4 eyes underwent vitrectomy for sever proliferative vitreoretinopathy. Retinal reattachment was achieved in 20 of the 24 eyes with vitrectomy. 18 eyes of those with retinal detachment before surgery had visual acuity from light perception to 0.05, others from 0.05 to 0.2. Conclusion It is suggested that prompt treatments, such as medication, retinal photocoagulation and vitrectomy are important managements to ARN syndrome. The visual outcome suggests that the eyes without retinal detachment have better effect. Vitrectomy should be considered before retinal detachment.

Key words: acute retinal necrosis syndrome, vitrectomy, virus infect