Epithelial Hyperplasia as a Cause of Irregular Astigmatism: Successful Treatment by Mechanical Removal of the Epithelium Only

Abstract

Abstract Background The corneal epithelium remodeling in response to changes in the anterior corneal surface (keratoconus, corneal refractive surgery) is well-documented in the literature. However, several conditions may induce a different behavior of the epithelium, in which focal areas of epithelial thickening induce irregular astigmatism. This case report presents a very unusual case of irregular astigmatism induced by an epithelial hyperplasia of unknown etiology, which was treated by mechanical removal of only the epithelium. Case presentation A 29-year-old woman underwent implantable collamer lens implantation to correct myopia. The patient provided written informed consent. The procedure was uneventful in both eyes. Twenty months later, she complained of decreased visual acuity in the left eye (LE) (uncorrected distance visual acuity (UCDVA) was 20/30; corrected distance visual acuity was 20/20 with + 1.00 -2.25 x 170). Corneal topography revealed a nasal steepening in the LE. Although the corneal thickness map was normal, epithelial thickness mapping revealed a localized nasal area of epithelial hyperplasia in the LE, that matched with the area of steepest curvature. Slit lamp examination showed a total clear cornea with no signs of abnormality. Medical history was unremarkable and a case of epithelial hyperplasia without active inflammation of unknown etiology was considered. The decision was made to perform a mechanical removal of the corneal epithelium after application of diluted alcohol. One month after the procedure, the topography of the epithelized cornea showed a regular bow tie pattern and UCDVA improved to 20/20. No recurrence of the epithelial hyperplasia was detected after eight months. Conclusions Focal epithelial hyperplasia may induce irregular astigmatism. Epithelial thickness mapping is a very helpful technology to assess cases with irregular topography. De-epithelization as an isolated procedure may be useful to manage these cases successfully. Further investigations are required to understand the mechanism that may trigger the spontaneous development of a focal epithelial hyperplasia.