Ophthalmological manifestations in type 2 neurofibromatosis

Abstract

Purpose: Type 2 neurofibromatosis (NF2) is a rare and serious genetic disease characterized by the development of multiple nervous tumors. Ophthalmologic manifestations are frequent and can sometimes suggest the diagnosis of NF2 before the genetic results. The aim of this prospective series of cases is to evaluate the type and prevalence of ophthalmological manifestations in NF2.

Methods: Patients with genetically confirmed NF2 seen in the Ophthalmology department from a single tertiary center, in collaboration with the NF2 international reference center between November 2013 and November 2014 were prospectively included. For each patient, the best corrected visual acuity (BCVA), oculomotricity examination, slit lamp examination, fundus examination and macular SD-OCT were performed.

Results: 47 patients (30W/17M) were included in the study. Mean age was 34.3 years old (range: 14-70). 45% of patients had a significantly decreased visual acuity (VA) on at least on eye (0.5 logMar), with an average VA of 0.31 logMar. 40% of patients had a significant cataract, 26% of patients presented an exposure keratitis due to facial nerve paresis and 21% of patients had an optic disc atrophy. In 43% of patients, an oculomotor disorder was observed. An epiretinal membrane (ERM) was diagnosed on SD-OCT in 64% of patients.

Conclusions: Visual impairment in type 2 neurofibromatosis is frequent and mostly related to optic nerve atrophy or exposure keratitis. Cataract and ERM were non-symptomatic in most patients, but these latter can guide the diagnosis if the suspicion is high. We report the largest prospective series of ocular manifestations in NF2. The impairment of the visual function is multi-factorial and all the more disabling as it occurs in patients whose sensory perception is often already impaired by a lesion of the 8th cranial nerve.