Visual outcomes of surgical intervention for pseudotumour cerebri: optic nerve sheath fenestration versus cerebrospinal fluid diversion

Abstract

Objective: To compare visual outcomes in pseudotumour cerebri (PTC) patients who underwent either optic nerve sheath fenestration (ONSF) or cerebrospinal fluid (CSF) diversion (shunt) for treatment of visual loss from papilloedema.

Methods: Comparative case series of thirty-three patients (33 eyes) who underwent either ONSF (14 patients) or CSF shunt (19 patients) for papilloedema and vision loss. Preoperative and final postoperative visual acuity and mean deviation (MD) on automated perimetry were assessed in addition to papilloedema severity and resolution. Mann-Whitney U test was employed to evaluate differences in final visual outcomes.

Results: Postoperative visual acuity did not differ between ONSF (76.4 ETDRS equivalent letters) and shunt (76.4 letters), although there was a trend toward worse preoperative acuity in the ONSF cohort. Final MD was significantly better after shunt (-9.23 dB) compared to ONSF (-17.29 dB), U=52.0, p=0.036. Preoperative papilloedema was qualitatively worse in the ONSF group.

Conclusions: Visual acuity and MD improved after ONSF and shunt procedures in patients with severe vision loss from PTC and papilloedema. Improvement of MD in both groups was of the same magnitude (6 dB), but because the two groups were not entirely comparable, prospective comparison of the two procedures is required to establish the relative efficacy of each procedure.

Keywords: Field of vision; Optic Nerve; Treatment Surgery.