Asymmetric Optic Nerve with Small Disc and Large Cup: A Rare and Challenging Case of Unilateral Optic Nerve Hypoplasia

Authors: Aung KH* and Aye MTH

DOI: 10.23880/oajo-16000344

Volume 10, Issue 2

Abstract

Optic nerve hypoplasia (ONH) is a congenital anomaly characterized by a structurally small optic nerve head with reduced retinal ganglion cell axons. It is commonly recognized in childhood often associated with visual dysfunction or systemic abnormalities. However, rare cases may present in adulthood with normal visual acuity and atypical optic disc morphology that may create diagnostic uncertainty. We report a 26-year-old lady with a small optic disc and larger cup-to-disc ratio in one eye, mimicking Normal tension glaucoma (NTG). Despite normal intraocular pressure, visual field testing and optical coherence tomography revealed defects suggesting optic neuropathy. Neuroimaging confirmed focal hypoplasia of the retrobulbar optic nerve. This case highlights the diagnostic complexity of optic nerve hypoplasia and the importance of integrated evaluation to differentiate congenital anomalies from glaucoma.

Keywords: Optic Nerve Hypoplasia; Normal Tension Glaucoma; Asymmetric Optic Disc; Glaucomatous Optic Neuropathy; Retinal Nerve Fiber Layer Thinning

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