Optic Nerve Sheath Fenestration for Progressive Visual Loss in Cerebral Venous Sinus Thrombosis: A Long-Term Retrospective Observational Study.

ABSTRACT

INTRODUCTION: Progressive cerebral venous sinus thrombosis (CVST)-induced visual loss remains problematic, despite decreasing overall mortality owing to early diagnosis and aggressive treatment. Optic nerve sheath fenestration (ONSF) improves or stabilizes visual function in patients with idiopathic intracranial hypertension; however, its role in CVST awaits elucidation. We evaluated the efficacy and safety of ONSF in resolving CVST-induced visual impairment based on long-term observation. METHODS: This observational study included 18 patients with progressive CVST-induced visual loss, who had undergone ONSF between 2012 and 2021. Patients received maximum medical therapy, including anticoagulants and intracranial pressure (ICP)-lowering medications. The best-corrected visual acuity (BCVA), visual fields (VFs), and optic nerve head were assessed at baseline, at 1 week after ONSF, and over 6 months after ONSF. Activities of daily living (ADL) and National Eye Institute Visual Function Questionnaire-25 (VFQ-25) scores were assessed at final follow-up. RESULTS: Thirty-one ONSF-treated eyes of 18 patients were included. The mean follow-up duration was 35.6 months (range 1 week-8 years). Two patients were lost to follow-up. Before ONSF, all patients were still experiencing progressive visual loss despite receiving adequate anticoagulation and ICP-lowering therapy. Postoperative BCVA remained stable or improved in 25/31 eyes (80.6%) 1 week postoperatively and 17/28 eyes (60.7%) upon final follow-up. All papilledema resolved postoperatively. No complications were reported except for one transient postoperative diplopia. The median ADL score was 100 (range 25-100), and the mean total VFQ-25 score was 40.6 (range 9.5-87.3). CONCLUSION: This was the largest study to describe ONSF's role in CVST based on a long-term follow-up. Considering its efficacy and favorable safety, ONSF can be considered an important adjunctive approach to resolving progressive visual loss of CVST patients, on the basis of anticoagulation and ICP-lowering therapy.

Cerebral venous sinus thrombosis (CVST) is a cerebrovascular disease that generally affects young patients. Medical treatments include anticoagulants, intracranial pressure (ICP)-lowering medications, and repeated lumbar punctures, effectively reducing CVST's mortality rate. However, CVST still carries a potential risk of progressive vision loss. Optic nerve sheath fenestration (ONSF) has been reported to be effective and safe in protecting visual function of patients with idiopathic intracranial hypertension. However, its efficacy and safety have not been evaluated in visual loss caused by CVST. We were the first to evaluate the efficacy and safety of ONSF in CVST-induced progressive visual loss based on long-term follow-ups. Before ONSF, all patients were still experiencing progressive visual loss despite receiving adequate anticoagulation and ICP-lowering therapy. We found ONSF to be 80.6% (1 week postoperatively) and 60.7% (after long-term follow-up of over 6 months) effective in stabilizing and/or improving visual function as well as 100% effective in papilledema resolution. Moreover, ONSF exhibited a favorable safety profile, with an extremely low complication rate of 5.6% despite under perioperative anticoagulation. Although visual impairment in CVST was reported to be uncommon, it often significantly affects quality of life and social value of patients. Thus, visual loss in CVST deserves more attention from neurologists, neurosurgeons, and ophthalmologists. Considering its efficacy and favorable safety, ONSF could be regarded a potentially important adjunctive approach to resolving progressive visual loss in CVST patients, on the basis of anticoagulation and ICP-lowering therapy.Procedural videos available for this article.