Neurofibromatosis
Neurofibromatosis (NF), the most common phakomatosis, has 2 recognizable forms. Neurofibromatosis 1 (NF1), also known as von Recklinghausen disease or peripheral neurofibromatosis, is the most common type, with a prevalence of 1 in 3000–5000 persons. NF1 is localized to band 11 of the long arm of chromosome 17 and is inherited in an autosomal dominant pattern in approximately 50% of cases; the other 50% of cases are sporadic. In individuals with NF1, the neurofibromin gene is abnormal, and loss of tumor suppressor function leads to proliferation of neural tumors. The presence of ectropion uveae is a common ocular finding in this disease; its presence in a neonate warrants a workup for NF1. Other ocular findings associated with NF1 include Lisch nodules, choroidal lesions, optic nerve gliomas, eyelid neurofibromas, and glaucoma. Coexisting ptosis and glaucoma in a child should also prompt a workup for NF1; the ptosis may be due to an eyelid neurofibroma. Although the incidence of glaucoma in individuals with NF1 is low overall, the presence of an eyelid neurofibroma is strongly associated with glaucoma on the ipsilateral side. Systemic melanocytic lesions include cutaneous café-au-lait spots, cutaneous neurofibromas, and axillary or inguinal freckling. If glaucoma is present at birth it is thought to result from abnormal formation of angle structures. If it develops later in life, the mechanism is thought to be either infiltration of the angle with neurofibromatous tissue or angle closure caused by thickening of the ciliary body and choroid. Surgical treatment is often necessary, but success rates of surgical treatment in cases of NF1-associated glaucoma are lower than success rates for cases of PCG.
Neurofibromatosis 2 (also called central neurofibromatosis) is characterized by the presence of bilateral acoustic neuromas and is not associated with glaucoma.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.