Abstract

Volume.125 Number.6

Original article : Case report

A Case of Optic Nerve Sheath Fenestration for Optic Neuropathy Caused by Congestion of Cerebrospinal Fluid
Yasushi Fujita, Masashi Mimura, Youhei Satou, Masahiro Tonari, Takahisa Hirokawa, Junko Matsuo, Hidehiro Oku, Atsushi Sugasawa, Tsunehiko Ikeda
Department of Ophthalmology, Osaka Medical and Pharmaceutical University

Background: Increasing cerebrospinal fluid (CSF) pressure in the optic nerve sheath can cause optic nerve damage. Herein, we report a case of optic neuropathy caused by CSF congestion speculated to originate from a skull base-optic nerve sheath meningioma, which was treated by optic nerve sheath fenestration.
Case: A 54-year-old male presented to our department due to vision in the left eye worsening for the past 3 years. Visual acuity was 20/100 OS, critical fusion frequency (CFF) was 10 Hz OS, dynamic visual field test revealed left center scotoma, and choroidal folds were present on the left optic nerve disc's temporal side. Contrast-enhanced magnetic resonance imaging (MRI) revealed an approximately 3.5 mm space-occupying lesion in the left optic nerve sheath near the optic chiasm causing CSF congestion inside the left optic nerve sheath. Optic nerve sheath meningioma was suspected, and the patient received consultation at our hospital's neurosurgery department. As surgery was not suitable, the condition's progression was observed. Approximately one year later, his visual acuity decreased to less than 20/200 OS, and left CFF fell to an unmeasurable level. Following his first visit to our hospital's ophthalmoplasty reconstructive surgery department, left optic nerve sheath fenestration was performed for optic nerve sheath decompression. Under general anesthesia, a 2 mm window was created using a superomedial lid crease incision on the left optic nerve sheath to drain the CSF. Immediately after the surgery, visual acuity improved to 20/80 OS, CFF improved to 15 Hz, and left choroidal folds returned to normal. The optic nerve disc's mean blur rate, as measured by laser speckle flowgraphy which measures blood flow of the optic disc, also improved from 10 to 22.5.
Conclusions: Optic neuropathy can result from increased CSF pressure in the optic nerve sheath due to optic nerve sheath meningioma. Optic nerve sheath fenestration is an effective option in such cases.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 125: 596-603, 2021.

Key words
Optic nerve sheath meningioma, Cerebrospinal fluid congestion, Optic neuropathy, Optic nerve sheath fenestration
Reprint requests to
Yasushi Fujita, M. D. Department of Ophthalmology, Osaka Medical and Pharmaceutical University. 2-7 Daigaku-machi, Takatsuki-shi, 569-0801, Japan