Overnight Orthokeratology: Refractive and Corneal Recovery After Discontinuation of Reverse-Geometry Lenses

Purpose. To determine the refractive and corneal topographic recovery after the use of reverse-geometry contact lenses for overnight orthokeratology. Methods. Both eyes of 15 subjects were fitted with reverse-geometry contact lenses that were worn by the subjects for 1 month. Uncorrected visual acuity, refractive correction (sphere and spherical equivalent), corneal curvature, and corneal thickness were measured during this time and for 2 weeks after discontinuation of lens wear. Results. Ten subjects completed the investigation. Uncorrected visual acuity, refractive correction, and corneal curvature had changed significantly (P= 0.01) after 1 month of lens wear. By the end of 1 month, central corneal thickness was significantly thinner than the baseline value (P= 0.01), but it recovered fully after one night of no lens wear. Recovery of corneal curvature was complete 1 week after lens wear was discontinued. Refractive correction and binocular uncorrected visual acuity recovered fully after 2 weeks. Monocular uncorrected visual acuity remained significantly (P= 0.01) different from baseline acuity 2 weeks after lens discontinuation. Conclusions. Full effect of overnight orthokeratology in low myopes is achieved within 1 week of initiating use of reverse-geometry lenses. Recovery after short-term use of reverse-geometry lenses is rapid for corneal thickness and corneal curvature. Refractive correction and binocular uncorrected visual acuity recovered fully after 2 weeks. Monocular uncorrected visual acuity was the slowest to recover and had not achieved full recovery after 2 weeks.