Optic nerve sheath fenestration for salvaging acutely threatened vision in Idiopathic Intracranial Hypertension - A two-year completed follow up

Abstract

Objectives: To determine the efficacy and safety of Optic Nerve Sheath Fenestration (ONSF) for salvaging acutely threatened vision in patients of Idiopathic Intracranial Hypertension (IIH). Methods: This retrospective, interventional case series study was performed at Institute of Ophthalmology Mayo Hospital Lahore from September 2017 to September 2019. Nine patients diagnosed with Idiopathic Intracranial Hypertension as per Modified Dandy Criteria, underwent medial trans-conjunctival ONSF. Pre-operative and 1st day, 1st week, 1st month, 1st year, and 2nd year postoperative best-corrected logMAR visual acuities (BCVA) were recorded. Mean BCVA were calculated and compared using paired t-test. P-value <0.05 was taken as significant. Results: All nine patients were female with a mean age of 24 years. The average best-correctedpre-operative logMAR visual acuity (BCVA) in the better eye was 0.5 ± 0.28 and in the worse eye was 1.0 ± 0.57. After the worse eye ONSF, at 1st week mean BCVA in better eyes was 0.27 ± 0.32 (p-value=0.001), while it was 0.43 ± 0.63 (p-value=0.006) in the worse eyes. At 2nd year follow-up after optic nerve sheath fenestration mean BCVA in better eyes was 0.30 ± 0.30 (p-value=0.002) and in worse eyes was 0.44 ± 0.63 (p-value=0.007). Four patients (44.4%) had a subconjunctival hemorrhage, two patients (22.2%) had binocular diplopia, one patient (11.1%) pre-septal cellulitis, and one patient (11.1%) had no improvement in vision because of pre-operative secondary optic atrophy. All patients had unilateral fenestration and bilateral improvement, six patients (66.67%) reported improvement in headache and successful tapering of medical therapy. Conclusion: Optic nerve sheath fenestration is effective as well as a safe surgical procedure to salvage acutely threatened vision in patients of Idiopathic Intracranial Hypertension on maximal medical treatment. doi: https://doi.org/10.12669/pjms.39.6.6441 How to cite this: Latif S, Rizwan A, Khan AA, Zahra S. Optic nerve sheath fenestration for salvaging acutely threatened vision in Idiopathic Intracranial Hypertension - A two-year completed follow up. Pak J Med Sci. 2023;39(6):---------. doi: https://doi.org/10.12669/pjms.39.6.6441 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.