Keratoconus Following Bilateral Corneal Transplants: An Unusual Case Report and Literature Review

Authors

Asher Neren, MD; Julie Linden Soto MD, Robert Nick Hogan MD, Dwight Cavanagh MD, PhD

Keywords

atopy, cornea, penetrating keratoplasty, vernal keratoconjunctivitis, keratoconus

Abstract

Purpose:  To report a rare case of clinical keratoconus (KC) in bilateral penetrating grafts confirmed by electron microscopy at the time of repeat penetrating keratoplasty (PK).

Methods:  A case review of a female patient with bilateral severe vernal keratoconjunctivitis (VKC) who underwent bilateral corneal transplants in 1983 at age 12 for indolent vernal ulcers that progressed to descemetoceles and perforated. She subsequently underwent repeat PK’s in both eyes (right eye (OD):2010; left eye (OS):1987) and twenty-seven years later, had developed KC in both transplants.  The patient underwent topography and anterior segment ocular coherence tomography (OCT), and the corneal button from her repeat PK OD was sent for electron microscopic (EM) evaluation. A comprehensive literature review was performed evaluating the occurrence of KC in both lamellar and penetrating corneal transplants.

Results:  EM and histopathologic findings from the corneal button from the repeat PK OD revealed central loss of bowman’s layer, peripheral thinning of the corneal stroma, thickening of the epithelium at the site of stromal thinning, and several fragments of descemet’s membrane embedded in the posterior corneal stroma, all consistent with KC. Topography and anterior segment OCT of both repeat PK’s and her own corneal tissue revealed similar changes consistent with KC.

Conclusions:  Late development of KC in corneal transplants occurs with increasing frequency over time and is more prominent in older corneal donors. Although the exact cause(s) of KC seen in this patient’s own cornea and bilateral grafts is unknown, the risk appears to be associated with her possible genomic predisposition and her history of severe atopy and VKC.  Younger atopic patients undergoing PK should therefore be cautioned that late development of KC may occur.