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Last Month’s Blink

Bilateral Segmental Optic Disc Hypoplasia

Written and photographed by: Anamika Dwivedi, MS, Shyam Shah Medical College, Rewa, Madhya Pradesh, India.

A 19-year-old nursing student complained of occasional mild headache, which she thought might be related to refractive error. She had no significant medical or ocular history.

On examination, her uncorrected visual acuity was 20/20 in both eyes. Intraocular pressure was 12 mm Hg in both eyes, and the pupillary reactions and anterior segments were normal.

The optic discs of both eyes were smaller than normal, with cup-disc ratios of 0.5, and the cups were shifted nasally. Both optic discs showed ab­normal thinning of nasal neuroretinal rim, with a large sectoral nerve fiber layer defect in nasal half of retina; this was more prominent on red free photography (Figs. 1A, 1B). OCTs revealed disc areas of 1.43 mm² in the right eye and 1.49 mm² in the left. OCT also showed retinal nerve fiber layer thinning (Figs. 2A, 2B). Perimetry showed a temporal hemianopia in the right eye and infero­temporal field defect in the left (Figs. 3A, 3B).

The patient was diagnosed with segmental optic disc hypoplasia. Magnetic resonance imag­ing of the brain, done to rule out any associated structural anomaly, was found to be normal.

Despite her optic disc hypoplasia, the patient had no visual symptoms.

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