Fluorophotometry to Evaluate the Corneal Epithelium in Eyes Undergoing Contact Lens Corneal Reshaping to Correct Myopia

Abstract

To determine whether use of Corneal Refractive Therapy (CRT, Paragon Vision Sciences) lenses have an adverse effect on the health of corneal epithelium by monitoring epithelial permeability by fluorophotometry. Eight patients with healthy eyes and whose refractive error was between -0.50 and -4.00 diopters (D) sphere and up to -1.75 D of astigmatism were enrolled. On the day of the fitting, two baseline fluorometric scans of the right eye were taken using the Ocumetrics Fluorotron Master. After 15 minutes, another two scans were taken of the right eye. The same fluorophotometry technique was repeated on day 1, 1 week, 1 month, and 3 months after the patient began overnight wear of the lenses. Patients' baseline corneal fluorescein levels and peak corneal fluorescence values after rinsing were compared to initial pre-fitting values to determine changes in corneal epithelial permeability. After patients used orthokeratology, uncorrected visual acuity was 20/20 or better in 9/16 eyes and 100% had achieved 20/40 or better by day 7. No adverse events were seen in patients utilizing orthokeratology, and eye examinations for these patients continued to be within normal limits. After nightly use of orthokeratology for 1 month, baseline fluorescence of the cornea (15.64 +/- 2.29 ng/mL vs 17.31 +/-5.43 ng/mL, P = .80) remained stable, and the post-15 minute scan peak corneal fluorescence values did not show significant changes from the pre-fitting (51.46 +/- 17.28 ng/mL) after use of orthokeratology (63.80 +/- 41.25 ng/mL) (P = .78). Reshaping of the cornea through the use of orthokeratology does not have adverse effects on corneal epithelium as evaluated by changes in corneal epithelial permeability.