Unilateral Optic Nerve Sheath Fenestration in Idiopathic Intracranial Hypertension: A 6-Month Follow-Up Study on Visual Outcome and Prognostic Markers

Abstract

Loss of vision is a feared consequence of idiopathic intracranial hypertension (IIH). Optic nerve sheath fenestration (ONSF) may be an effective surgical approach to protect visual function in medically refractory IIH. In this study, we evaluate the impact of unilateral superomedial transconjunctival ONSF on bilateral visual outcome using a comprehensive follow-up program. A retrospective chart review of IIH patients who underwent unilateral ONSF between January 2016 and March 2021 was conducted. Patients fulfilling the revised Friedman criteria for IIH and who had exclusively received ONSF as a surgical treatment were included. Main outcomes were visual acuity (VA); perimetric mean deviation (PMD); papilledema grade; and optic nerve head elevation (maxONHE) 1 week, 2 weeks, and 1, 3, and 6 months after surgery. VA (p < 0.05), PMD (p < 0.05), papilledema grade (p < 0.01), and maxOHNE (p < 0.001) were improved after 6 months on both the operated and non-operated eye. Prolonged surgical delay impedes PMD improvement (r = −0.78, p < 0.01), and an increasing opening pressure initiates a greater ganglion cell loss (r = −0.79, p < 0.01). In this small case series, we demonstrate that unilateral superonasal transconjunctival ONSF is a safe procedure with an effect on both eyes. Optic nerve head elevation and PMD are feasible biomarkers for assessing early treatment efficacy after ONSF.

Cerebral Venous Outflow Implications in Idiopathic Intracranial Hypertension—From Physiopathology to Treatment

“…The reduction of the papilledema and the stability of the visual field in the contralateral (not operated) eye suggest that bilateral ONSF may not always be necessary in patients with bilateral visual loss and papilledema due to IIH, and probably that the cerebrospinal fluid that filters through the dural opening fistula into the orbit produces a subsequent decrease of subarachnoid CSF pressure, and this could explain the therapeutic effect. Unilateral superomedial transconjunctival ONSF was the single treatment method in another small retrospective case series of patients with IIH [ 81 ]. Visual acuity, perimetric mean deviation, papilledema grade, and optic nerve head elevation were significantly improved after 6 months in both the operated and non-operated eye.…”

Evolving Evidence in Idiopathic Intracranial Hypertension

“…A number of groups tackled this topic and provided their insights into the various surgical techniques deployed currently for IIH. These included neurosurgical shunting [2,6], optic nerve sheath fenestration [2,17], and venous sinus stenting [2,18]. The most common surgery for sight threatening IIH both in the United Kingdom [2] and USA [19] is neurosurgical shunting and Sunderland et al provided a detailed dialogue of the choices for devices and a stepwise approach for successful cerebrospinal fluid diversion [6].…”

“…Despite this good news, when comparing the surgical disciplines the 30 day readmission rate was highest for shunting as compared to bariatric surgery, stenting and optic nerve sheath fenestration in IIH [2]. Hagen et al evaluated the impact of unilateral superomedial transconjunctival optic nerve sheath fenestration [17]. In this retrospective consecutive medically refractory cohort, they noted that higher lumbar puncture opening pressure was predictive of retinal ganglion cell loss.…”

“…In this retrospective consecutive medically refractory cohort, they noted that higher lumbar puncture opening pressure was predictive of retinal ganglion cell loss. They also were able to determine that surgical delay impacted upon the visual field global outcome of mean deviation [17]. This is important knowledge for clinicians who may have to enlist the help of an expert surgeon, who may not yet understand the priority for surgery when dealing with sight threatening disease in IIH.…”

Erratum: Hagen et al. Unilateral Optic Nerve Sheath Fenestration in Idiopathic Intracranial Hypertension: A 6-Month Follow-Up Study on Visual Outcome and Prognostic Markers. Life 2021, 11, 778

“…It has come to our attention that there has been an error in the previous work [ 1 ]. Due to an error during copy editing, some of the “Snellen equivalent” data in the Table 2 are incorrect in the published paper.…”