Visual loss in orbitofacial neurofibromatosis type 1

On occasion, neurofibromas in neurofibromatosis type 1 may be present on the lid, brow, or face of an infant or child, a circumstance commonly referred to as "orbitofacial neurofibromatosis" (OFNF). The present study evaluates the causes and extent of visual loss in a group of patients with OFNF.

Case series.

Fifty-five patients with OFNF.

Retrospective medical record review and reexamination of selected patients from one institution.

Visual acuity and identification of underlying cause of reduced vision.

Fifty patients with unilateral OFNF (23 male, 27 female, aged 4-48 years at last visit) and 5 patients with bilateral OFNF (2 male, 3 female, aged 15-43 years) had adequate information available to assess afferent visual functioning. Nine patients (4 male, 5 female, aged 4-28 years) had optic pathway glioma (OPG) in addition to OFNF. Patients were followed as long as 27 years (mean 8.4 years). Thirty-nine patients (71% of total) had visual acuity of ≤20/60 on the side of OFNF involvement (or the side of worse OFNF involvement in patients with bilateral disease). One or more causes of amblyopia were present in 29 of these patients, 19 patients had organic disease of the eye (e.g., glaucoma or retinal detachment) or the afferent system (e.g., OPG), and 12 patients had correctable refractive errors.

Visual loss in this OFNF cohort was common, typically profound, and usually multifactorial. Some causes of visual loss (including congenital glaucoma with buphthalmos and retinal detachment, disconjugate gaze due in part to distorted skull development causing strabismic amblyopia, and OPG) were difficult to treat adequately and tended to cause progressive, profound visual loss. Therefore, careful observation should be made during the period of visual immaturity for possible causes of amblyopia that might be treatable, such as refractive changes, occlusion of the visual axis, or congenital glaucoma. As affected individuals get older, physicians must be vigilant for the progression of optic nerve disease due to glaucoma or OPG and to the possibility that vision might be improved by refraction.