Effect of orthokeratology in patients with myopic regression after refractive surgery

• Despite advances in excimer laser technology, many refractive surgery patients still experience myopic regression.
• Ortho-K lenses may be an effective solution for patients with myopic regression following keratorefractive surgery.
• Estimated K value can be used as reference value in ortho-K prescription.

PurposeTo evaluate the clinical effect of orthokeratology (ortho-K) lenses and to introduce the fitting steps of ortho-K lens for myopic regression after keratorefractive surgery.MethodsTwenty-one eyes from 12 patients with myopic regression after keratorefractive surgery were fitted with ortho-K lenses and followed up for 12.11 ± 3.68 months. The mean K value of the peripheral cornea was used to speculate preoperative central corneal K value, estimated K. After dispensing the lenses according to estimated K, biomicroscopic examination including fluorescein staining and over-refraction were performed to determine the final K and final lens power.ResultsLogMAR uncorrected visual acuity was 0.48 ± 0.39 before and 0.00 ± 0.00 after wearing ortho-K lenses (p < 0.001). Pre-fitted refractive error was −1.87 ± 1.05 diopters (D) in myopia, 0.54 ± 0.42 D in astigmatism, and spherical equivalent of −2.14 ± 1.01 D. At the final visit myopia level and spherical equivalent significantly decreased to −0.73 ± 0.84 D (p < 0.001) and −1.01 ± 0.87 D (p < 0.001), respectively. Estimated K was 8.07 ± 0.36 mm, and final K used for ortho-K prescription was 8.19 ± 0.30 mm. Final K significantly correlated with K value of pre-fitted peripheral cornea (r = 0.737, p < 0.001) and estimated K (r = 0.721, p < 0.001), respectively. There was no correlation between pre-fitted degree of myopia and the Final lens power (r = 0.429, p = 0.053).ConclusionsOrtho-K lenses may be an effective solution for patients with myopic regression following keratorefractive surgery. Estimated K value can be used as reference value in ortho-K prescription.