Iridian and Chorioretinal Coloboma: A Case Report

Abstract

Aims: To report an unusual bilateral presentation combining anterior and posterior segment colobomas with marked asymmetry in visual outcome, highlighting the importance of detailed clinical and imaging assessment particularly when there is significant asymmetry in anatomical involvement and visual outcome. Presentation of Case: A 17-year-old female with no significant medical or familial history presented with decreased visual acuity in her right eye. Visual acuity was limited to counting fingers in the right eye and 20/20 in the left. Slit-lamp examination revealed an iris coloboma in the left eye. Fundus examination showed a large chorioretinal coloboma involving the optic disc and inferior retina in the right eye. A smaller, inferotemporal chorioretinal coloboma was also observed in the left eye, sparing the macula. Neurological and systemic evaluations were unremarkable. Discussion: This case illustrates the heterogeneity of colobomatous malformations in terms of anatomical presentation and visual prognosis. The presence of extensive posterior segment involvement in the right eye was associated with severe visual loss, while the functionally preserved left eye showed limited involvement. Multimodal imaging plays a key role in defining the extent of the lesions and ruling out associated anomalies or syndromic forms. The distribution of the lesions along the embryonic fissure supports their classification as typical colobomas. Conclusion: Colobomas can present with bilateral but asymmetrical involvement of ocular structures. Early diagnosis, comprehensive imaging, and long-term monitoring are essential to anticipate complications and guide visual rehabilitation. This case highlights the importance of individualized assessment in the management of congenital ocular malformations.