Topographic changes simulating keratoconus in patients with irregular inferior epithelial thickening documented by anterior segment optical coherence tomography

Abstract

Purpose: To present six patients with keratoconus-like topographic changes due to inferior inhomogenous epithelial thickening, demonstrated by AS-OCT epithelium map. Patients and methods: We present twelve eyes of six patients evaluated in the refractive surgery consultation with Pentacam® HR Scheimpflug rotating camera system, presenting topographical irregularities suggestive of keratoconus. Slit-lamp examination, best-corrected visual acuity, Scheimpflug tomography and anterior segment optical coherence tomography epithelium map (Optovue® ) were conducted and analyzed. Results: The mean age was 42 years and the female:male ratio was 2:1. Mean Kmax was 45 ±2 D. The mean corneal thickness at apex was 560±33 μm and the mean thickness at the thinnest location was 555±34 μm. All patients had an abnormal index of height decentration (IHD) in at least one eye. In all cases, anterior segment OCT demonstrated relative epithelial thickening over the steep area measured by tomography. The mean thickness of the inferior epithelium over the suspicious area was 60±2 μm, whereas the mean thickness of the superior epithelium was 56±2 μm. Conclusion: Epithelial irregularity, as measured by anterior segment OCT, should be considered as a possible contributing factor in the appearance of suspicious keratoconus-like topographies.