Optic Nerve Glioma - A Rare Case Study

Udbuddha Dutta, Susrut Eye Foundation & Research Centre, and R.G. Kar Medical College and Hospital, Kolkata,India

Abstract:
An optic nerve glioma is a slow growing tumour which typically affects children. Malignant gliomas are rare and almost always occur in adult males with a very poor prognosis. It is a brain tumour that arises in or around the optic nerve, which connects the eye to the brain .We describe a case of a 5 year old boy with painless progressive enlargement of the left eye since the past 1 year . He also complained of a loss of vision in the left eye. The father had a history of Neurofibromatosis type 1. The child was clinically evaluated and required investigations were carried out. This was consistent with the diagnosis of optic nerve glioma. Early diagnosis is the key factor and an integrated approach should involve neurosurgeons, plastic surgeons, ophthalmologists and radiologists.

Picture Courtesy: Google

Introduction:

Optic nerve glioma (also known as optic pathway glioma)is the most common primary neoplasm of the optic nerve.Along with reducing visual acuity in the affected eye, thetumor sometimes produces additional symptoms as itgrows. A low-grade form of this neoplasm, benign opticglioma, occurs most often in pediatric patients. Anotherform, aggressive glioma, is most common in adults; it isfrequently fatal, even with treatment.1,2,3Many children with optic nerve glioma are also known tohave neurofibromatosis type 1 (NF-1) or, in some cases,hybrid phakomatosis.4

Case Report:

We describe a case of a 5 year old boy with painlessprogressive enlargement of the left eye since the past 1 year.He also complained of a loss of vision in the left eye. Thefather had a history of Neurofibromatosis type 1. Presentingvisual acuity was absence of light perception in the left eyeand the proptosis was measured of 25mm which was inthe downward and outward direction. A relative afferentpupillary defect was noticed in the left eye and extraocularmovements were restricted superiorly and medially.Funduscopy of the left eye revealed a pale disc, blurring ofthe disc margins and presence of optociliary shunt vessels.CT scan of the left eye showed a fusiform optic nerveswelling. MRI showed a fairly large fusiform swelling in leftoptic nerve, pressure effect on ocular bulb with proptosis, noextension of the lesion in optic canal.The patient was posted for lateral orbitotomy. Biopsy wastaken from the same. It revealed low grade spindle shapedpilocytic (hair like) astrocytes & glial filaments, with thepresence of numerous Rosenthal’s fibers.