Study finds optic nerve sheath decompression effective for improving, stabilizing patients with IIH, CVT

Optic nerve sheath decompression can improve or maintain vision among patients with idiopathic intracranial hypertension and cerebral venous thrombosis, a study by researchers in India suggests.

"Early surgical intervention is associated with better visual outcome," the authors said. "However, the study cannot make specific recommendations at this time of the ideal stage at which to intervene and [which of the most sensitive parameters of early decompensation] could be used as guidelines to decompress."

Suneetha Nithyanandam, MS, and colleagues at St. Johns Medical College Hospital in Bangalore evaluated visual and functional outcomes after performing optic nerve sheath decompression on 41 eyes of 21 patients with visual loss due to idiopathic intracranial hypertension (IIH) and cerebral venous thrombosis (CVT). The decompression procedure was performed using a medial transconjunctival approach through a 270° peritomy.

Seven eyes of four patients with absent light perception at baseline were evaluated separately. IIH was secondary to CVT in all four of these patients, the authors noted.

At 3 months postop, best corrected visual acuity and visual field had stabilized or improved in 32 of 34 eyes (94%), with only two eyes of one patient showing postoperative worsening.

A statistically significant reduction in echographic optic nerve sheath diameter was observed in all patients at 3 months postop (P < .001), with further reductions at 6 months (P = .023).

"The outcome in the IIH and CVT groups was comparable," the authors said.

Of the seven eyes with absent light perception, four eyes showed marginal improvement in visual acuity and four eyes had transient benign complications, according to the study, published in the March/April issue of Indian Journal of Ophthalmology.