Abstract:

Objective To observe the changes of corneal parameters after stopping wearing orthokeratology. Design Retrospective case series. Participants 49 eyes of 26 patients with myopia who had received orthokeratology in Beijing Xinli Eye Clinic from October 2010 to March 2013 and planned to stop wearing orthokeratology in order to change new lens. Methods Corneal curvature, corneal astigmatism and corneal thickness were measured with Pentacam. The changes of corneal parameters were observed in the following time points: before wearing, twelve months after wearing, 3~4 weeks after stopping wearing. Main Outcome Measures Flat corneal curvature, steep corneal curvature, corneal astigmatism, corneal thickness. Results Before wearing, twelve months after wearing, 3~4 weeks after stopping wearing, flat corneal curvature was (42.32±1.87)D, (40.18±1.83)D, (41.97±1.86)D, respectively. Steep corneal curvature was (43.46±1.76)D, (41.46±1.74)D, (43.30±1.90)D, respectively. There was no significant difference before wearing and 3~4 weeks after stopping wearing(P=0.534, 0.777). The corneal astigmatism had no statistical difference between different time points. There was slightly reduction in corneal thickness twelve months after wearing, and corneal thickness gradually recovered 3~4 weeks after stopping wearing. The corneal thickness was (546.23±24.33) μm, (537.18±27.89) μm, (541.23±22.25) μm at the three different time points respectively. But the corneal thickness had no statistical difference among different time points. After the shaping effect was stable, correcting each -1.00 D myopia diopter the K value decreased (0.52±0.18) D and the corneal thickness reduced for (2.35±2.23) μm. After stopping wearing for 3~4 weeks, the recovery of K value was (86±15)% and the recovery of corneal thickness was (68±45)%. Conclusion Stopping wearing orthokeratology for 3~4 weeks, corneal parameters returned to near the level before wearing. (Ophthalmol CHN, 2016, 25: 306-309)

Key words: myopia, orthokeratology, corneal curvature, corneal astigmatism, corneal thickness