Effects of ethylenediaminetetraacetic acid chelation for calcific band keratopathy on corneal topography assessed by fourier harmonic analysis.

Abstract

Purpose: Chemical chelation with ethylenediaminetetraacetic acid (EDTA) is an established treatment for calcific band keratopathy (CBK), whereas removal of calcium deposits from the subepithelial layer of the cornea may cause corneal irregularity. Using Fourier harmonic analysis, we analyzed the corneal topography in eyes with CBK treated by EDTA chelation.

Study design: Retrospective, single-center study.

Methods: This study included 42 eyes of 26 patients who underwent chemical chelation using EDTA for CBK at the Kyorin University Hospital. Clinical data included age, sex, refraction, visual acuity, operation records, and corneal topography. Corneal topography was evaluated by a TMS-5 Corneal Topographer, and 3.0- and 6.0-mm-diameter Fourier series harmonic analyses were performed. Refraction, visual acuity, and parameters of corneal topography were compared before surgery and at 1 and 4 weeks postoperatively.

Results: Visual acuity and refraction (spherical equivalent and astigmatism) did not significantly change at 4 weeks postoperatively. Fourier harmonic analysis revealed that there were no time serial changes in the spherical component and regular astigmatism in both 3.0- and 6.0-mm analyses. Asymmetry astigmatism, and high-order irregularity significantly increased at 1 week postoperatively but decreased at 4 weeks postoperatively, with no statistical differences compared with preoperative data.

Conclusion: The effects of EDTA treatment on the corneal shape and refraction are minimal, which is beneficial for maintaining visual function in patients with CBK.