Optic nerve sheath fenestration for progressive ischemic optic neuropathy. Results in second series consisting of 21 eyes.

Objective: To determine the efficacy of optic nerve sheath fenestration in eyes with the progressive form of common anterior ischemic optic neuropathy. This investigation complements a previously reported initial series of 26 similar patients.
Patients and Methods: Optic nerve sheath fenestrations were performed in 21 eyes for treatment of common (nonarteritic) ischemic optic neuropathy with documented progressive deterioration of visual function. All patients underwent thorough preoperative and postoperative ocular evaluations by the Neuro-Ophthalmology Service at the Bascom Palmer Eye Institute, Miami, Fla.
Results: During a mean follow-up of 22.5 weeks (range, 3 to 104 weeks), results were as follows: visual acuity increased by 2 or more lines on the Snellen chart in two eyes (9.5%; the combined improvement rate for the two series was 14.9%); visual acuity decreased by 2 more lines in two eyes (9.5%).
Conclusions: Data from this series of 21 surgical procedures indicate no beneficial effect on visual morbidity in cases of common ischemic optic neuropathy and confirm the generally poor visual outcome implied from the results of optic nerve sheath decompression in our initial series. Based on this experience with a total of 47 eyes, we have discontinued optic nerve sheath decompression as a form of therapy for ischemic optic neuropathy.