ABSTRACT.Purpose: Ophthalmic features of neurofibromatosis 2 (NF2) include juvenile cataract, retinal hamartomas and tumours of the cranial nerves. We hypothesize that these tumours lead to strabismological and neuro-ophthalmological symptoms, including palsies of cranial nerves III, IV and VI, nystagmus and gaze palsies. Methods: We carried out a retrospective review of 73 patients with known genotype. They underwent ophthalmic, neuro-ophthalmological and strabismological examination. Statistical analysis was performed by calculating odds ratios and their 95% confidence intervals. Results: Mean best corrected visual acuity was 0.85. Strabismus was found in 38 of 73 patients (52%). A deviation based on a cranial nerve palsy was found in 16 patients (22%) and three had supranuclear palsies. Eleven of 73 patients had a nystagmus, mostly caused by peripheral-vestibular disturbance. Binocular single vision was normal in 41 (58%), subnormal in six (8%) and not present in 24 (34%) patients. The average refractive error was ) 0.57 D. Myopia of ‡ 0.5 D was present in 47 (33%) eyes and hyperopia of ‡ 2.0 D was measured in 11 (8%) eyes. In the subgroup analysis of NF2 mutation types, the relative risk for cranial nerve palsies and negative stereopsis was statistically significantly increased for the nonsense mutation group. The mosaicism group had a statistically significant decreased relative risk for concomitant squint, as did patients with unfound mutations for strabismus and poor stereopsis. Conclusions: The present study is, to our knowledge, the first to examine a larger collection of NF2 patients for strabismological and neuro-ophthalmological lesions. Compared with the normal population, our sample showed a higher amount of strabismus, refractive errors and an increased incidence of vestibular nystagmus.

Compliance with amblyopia treatment and long-term visual acuity in the cases presented here are even more favorable than described in the literature. As the amount of crowding is small, we conclude that there is little relative (additional) amblyopia and that the functional outcome is limited only by the degree of ocular malformation. Surgical treatment in comparable cases is encouraged.