Morning Glory Disc Anomaly in Neurofibromatosis Type 2 FREE

Neurofibromatosis type 2 (NF 2) is an autosomal dominant disorder characterized by a propensity for the development of vestibular schwannomas and other tumors of neural coverings (meningiomas, ependymomas) within the central nervous system. Ophthalmological findings in NF 2 include juvenile lens opacities,¹ epiretinal membranes,² combined pigment epithelial and retinal hamartomas,³ and disc gliomas.⁴ We describe 2 patients with NF 2 who had morning glory disc anomalies.

An 11-year-old boy with a history of strabismus and poor vision in the right eye since birth, was examined and was found to have a dysplastic optic disc in the right eye. Computed tomographic scanning showed multiple intracranial tumors including bilateral vestibular schwannomas and a large meningioma occupying the suprasellar cistern and extending along the sphenoid wing into the right orbit. Ophthalmological examination showed no abnormalities in the left eye. The right eye was enophthalmic and had no light perception, no direct pupillary response to light, and severely decreased range of ductions in all directions. Slitlamp biomicroscopy disclosed a posterior subcapsular lens opacity in the right eye. Retinal examination revealed a depigmented, dysplastic lesion involving the peripapillary and macular region. (Figure 1, left). The margins of the optic disc were difficult to identify. A white tuft of glial tissue obscured the central portion of the disc. A red mass, presumably a vascular hamartoma, was situated at the superior temporal region of the disc. The nasal retinal vessels were anomalous, increased in number, and ran an abnormally straight course over the peripapillary retina. The temporal retinal vessels had a normal configuration. Ultrasonography showed a flattened contour of the peripapillary retina and mild elevation of the disc, with no excavation or calcification.

A 2-year-old boy with exotropia was noted to have a macular scar in the right eye and a morning glory disc anomaly in the left eye. Reexamination at 6 years of age disclosed 2 inferior retinal holes in the left eye that were successfully treated with cryotherapy. At 13 years of age his corrected visual acuity was 20/200 OD and 20/25 OS. Retinal examination in the right eye disclosed that the macular scar represented a combined pigment epithelial and retinal hamartoma. In the left eye, a partly pigmented, nonexcavated ring of yellow-white subretinal tissue surrounded an elevated optic disc (Figure 1, right). A large, white, glial tuft covered the central portion of the disc. The superior retinal vessels appeared increased in number and ran an abnormally straight course over the peripapillary retina. The inferior retinal vessels appeared to originate from the periphery of the disc but were otherwise normal in size and configuration. Two small peripapillary arteriovenous communications at the 4-o'clock position and at the 7-o'clock position were present, along with a third that crossed the horizontal raphe temporal to the macula.

At age 17 years, a computed tomographic scan disclosed bilateral acoustic neuromas. Magnetic resonance imaging showed bilateral oculomotor schwannomas, multiple spinal tumors, and no enlargement of the retrobulbar optic nerves. At age 20 years, he developed a rhegmatogenous retinal detachment in the left eye which was surgically repaired.

The morning glory disc anomaly is a congenital, funnel-shaped excavation of the posterior fundus that surrounds and incorporates an enlarged, dysplastic optic disc. A wide annulus of chorioretinal pigmentary disturbance surrounds the disc and forms the wall of the excavation. A white central glial tuft overlies the disc. The retinal vessels arise from the periphery of the disc and run an abnormally straight course over the peripapillary retina.⁵

The morning glory disc anomaly is rarely associated with genetic disorders. Both patients described in this case report had NF 2 with morning glory disc anomalies that shared the following atypical features: (1) no excavation of the peripapillary fundus; (2) minimal enlargement of the optic disc; (3) an unusually large depigmented ring of dysplastic tissue surrounding the disc; and (4) some preservation of the normal retinal vasculature. These atypical findings indicate that the pathogenesis of the morning glory appearance in NF 2 may be different than in other individuals with the isolated anomaly.

Case 2 had been previously reported in this ARCHIVES for the association of multiple retinal arteriovenous communications with a morning glory disc anomaly, when significance of the contralateral fundus lesion—a combined pigment epithelial and retinal hamartoma in a patient with NF 2 —was unrecognized.⁵ The finding of a morning glory disc anomaly in a patient with hearing loss, juvenile cataracts, or an unexplained retinal lesion should prompt craniospinal neuroimaging to look for occult tumors.

Corresponding author: Klara Landau, MD, UniversitätsSpital Zürich, Augenklinik, Frauenklinikstr 24, CH-8091 Zürich, Switzerland (e-mail: Landau@opht.unizh.ch).