The “Keyhole” Pupil: Clinical Significance of Ocular Coloboma

Published:September 13, 2021DOI:
      A 13-year-old girl was referred to our clinic for evaluation of a “keyhole” abnormality of her left eye. The patient's medical and ocular history was unremarkable. Ocular examination revealed a best-corrected visual acuity of 20/20 in the right eye and 20/200 in the left eye. The ocular examination of the right eye was unremarkable. The left eye revealed an inferonasal defect of the iris (Figure 1). Intraocular pressure was 13 mm Hg in both eyes. Funduscopic examination in the left eye revealed a white, scarred area in the inferior quadrant with pigment deposition scattered through the lesion and its borders with the normal retina (Figure 2). No signs of retinal detachment were evident. The optic nerve of the left eye showed inferior nerve fiber thinning with irregular borders, excavation, and anomalous configuration (Figure 3).
      Figure thumbnail gr1
      Figure 1The characteristic “keyhole” pupil of the patient's left eye, suggestive of an ocular coloboma.
      Figure thumbnail gr2
      Figure 2Fundus photo of the left eye demonstrating a chorioretinal coloboma.
      Figure thumbnail gr3
      Figure 3Optic nerve photo of the left eye demonstrating the area of excavation of the optic nerve (black circle).

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