Surgery for nonarteritic anterior ischemic optic neuropathy.

BACKGROUND: Nonarteritic ischemic optic neuropathy is characterized by sudden and painless loss of vision in the eye, accompanied by pallid swelling of the optic disc. No medical therapy has been proven effective in treating this condition. OBJECTIVES: The objective of this review is to assess the safety and efficacy of surgery compared with other treatment or usual care in people with nonarteritic ischemic optic neuropathy. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Group Trials Register, in The Cochrane Library, MEDLINE, EMBASE and the UK National Research Register (NRR). The last search was on 13 July 2005. SELECTION CRITERIA: We included randomized controlled trials. DATA COLLECTION AND ANALYSIS: We obtained full copies of all potentially relevant articles. One randomized trial was eligible for inclusion. One author extracted data which was verified by another author. No synthesis was required. MAIN RESULTS: The one included trial randomized 258 participants and was stopped early. At the time of the 24-month report the follow-up rate was 95.3% for six months and 67.4% for 24 months (174 participants, 89 careful follow up and 85 surgery). There was no evidence of a benefit of surgery on visual acuity. At six months 32.0% of the surgery group had improved visual acuity by three or more lines compared with 42.6% of the careful follow up group (unadjusted risk ratio (RR) 0.75, 95% confidence interval (CI) 0.54 to 1.04). At 24 months 29.4% of the surgery group had improved compared with 31.0% of the careful follow up group (unadjusted RR 0.95, 95% CI 0.60 to 1.49). Participants who underwent surgery had a greater risk of losing three or more lines of vision. At six months 18.9% in the surgery group had worsened compared with 14.8% in the careful follow up group (RR 1.28; 95% CI 0.73 to 2.24). At 24 months 20.0% in the surgery group had worsened compared with 21.8% in the careful follow up group (RR 0.92; 95% CI 0.51 to 1.64). AUTHORS' CONCLUSIONS: Results from the single trial indicate no evidence of a beneficial effect of optic nerve decompression surgery for nonarteritic ischemic optic neuropathy.