Purpose

Optic nerve gliomas are benign tumors categorized as pilocytic astrocytomas and represent a significant portion of primary optic nerve tumors. They comprise around half of all primary optic nerve tumor cases and 1.5% to 4% of all orbital tumors. They are most common in Children representing about 90% but can occur in Adults representing 10%. Optic nerve gliomas develop anywhere between the optic nerve head next to the retina and the optic chiasm, where the left and right optic nerve partially cross. Only 25% of optic nerve gliomas are confined to the optic nerve itself, while in 40-75% of cases optic gliomas involve chiasm, hypothalamus and other structures. They are extremely aggressive causing a rapid deterioration of vision and death mostly within months. Though low-grade optic gliomas of adulthood were reported in some cases, most of them were aggressive featuring diffused infiltration inseparable from the optic nerve, fast tumor growth requiring radiotherapy or chemotherapy.

Case Report

A 34-year-old Man noticed double vision and protruding of the left eye for 3months.Ocular examination revealed Proptosis of the left eye. Visual acuities were 20/20 in both eyes. Intraocular pressures were normal. Patient had no known medical condition. Thyroid functional test and head Ct scan was conducted. TFT was normal but head CT scan unveiled a 2.8 x 2.6cm avidly enhancing intraconal lesion involving the left optic nerve causing left eye Proptosis suggestive of left optic nerve glioma.

Conclusion

Although optic nerve gliomas are generally accepted benign tumors in children, these lesions are rare and almost all malignant in adults predicting an extremely poor prognosis. Early diagnosis is mandatory and management should involve an integrated approach of neurosurgeons, plastic surgeons, ophthalmologist and radiologist.     

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