Posterior Amorphous Corneal Dystrophy Associated With Keratoglobus: A Case Report

Purpose: Posterior amorphous corneal dystrophy (PACD) is a rare disorder characterized by sheet-like opacification of the posterior corneal stroma, corneal thinning, and decreased corneal curvature. It is not known to be associated with progressive corneal ectasia. In this report, we examine the course of a patient with PACD who developed bilateral keratoglobus-type corneal ectasia. Methods: The clinical history of a single patient is reviewed from birth through age 15. Visual acuity, refraction, ultrasound pachymetry, anterior segment optical coherence tomography, corneal topography, and corneal tomography are presented. Results: The patient was noted to have bilateral cloudy corneas at birth. Congenital infection, metabolic disease, and glaucoma were ruled out. Anterior segment optical coherence tomography demonstrated posterior stromal opacification typical of PACD. Over time, the patient progressed from best uncorrected visual acuity of 20/20-2 OD and 20/25-3 OS to PROSE lens-corrected visual acuity of 20/30-3 OD and 20/30-3 OS. Central corneal thinness progressed from 491 to 408 mm in the right eye and from 505 to 389 mm in the left eye. Steepening in corneal axial/sagittal curvature developed in both eyes beginning inferiorly then involving the corneas diffusely. Conclusions: In this case report, we illustrate progressive corneal ectasia in a patient with PACD. Although both conditions may represent changes in the structure and integrity of corneal collagen, whether an association exists between the 2 conditions is unknown.