Visual outcomes for optic nerve sheath fenestration in pseudotumour cerebri and related conditions

Background: To determine the efficacy and safety of optic nerve sheath fenestration, and to identify factors predicting visual field (VF) and visual acuity (VA) in patients with progressive pseudotumour cerebri syndrome. Methods: This retrospective observational case series studied 51 eyes of 32 patients with pseudotumour cerebri syndrome, by chart review and comparison of preoperative and postoperative examinations. Main outcome measures included VF, VA and complications. Results: Postoperative VF mean deviation scores improved (P = 0.03) within 6 months when compared with preoperative VF. Multiple regression analysis demonstrated that eyes with mean deviation≥-20 dB were associated with improved or stabilized VA at 6 months, odds ratio 7.5 and confidence interval (1.2, 46.1), P = 0.03. Eyes with VF defects outside 10° of fixation were associated with improved or stabilized VF at 6 months odds ratio 9.7, 95% confidence interval 1.1, 85.9, P = 0.04. Five patients developed self-limiting complications from surgery. Conclusions: Optic nerve sheath fenestration is safe and effective in stabilizing or improving VF and VA in the short to medium term. Patients with mild VF loss improved following surgery, and patients with severe VF loss stabilized following surgery.