Varied Presentations of Posterior Keratoconus: A Clinical Case Series.

Purpose: To describe the varied presentations of posterior keratoconus.

Methods: This is a 3-year institute-based retrospective study report from June 2015 to June 2018 that describes 13 eyes of 12 patients with varied presentations of posterior keratoconus, evaluating tomographic changes using Scheimpflug corneal tomography and anterior segment optical coherence tomography. Slit-lamp examination revealed circumscribed nebular corneal opacity with posterior corneal depression.

Results: Eleven patients had unilateral and one had a bilateral presentation. Five patients presented in the first and second decade with a nebular opacity and circumscribed excavation of the posterior cornea. One patient was a 12-year-old girl who presented with systemic manifestations. Seven others were middle-aged adults with superior, central, or peripheral excavation. Two patients had microcornea.

Conclusions: This is the largest case series on posterior keratoconus, depicting its varied features. Diagnosis of this uncommon condition requires a high index of suspicion, meticulous slit-lamp examination, and systemic evaluation to rule out other associated anomalies. We report a patient of unilateral posterior keratoconus with systemic associations, second such case in the literature.