AIM:To investigate the changes and effects of orthokeratology on corneal morphology.

METHODS: Totally 90 patients were treated with orthokeratology from January 2015 to December 2016. They were divided into observation group(overnight wearing)and control group(daytime wearing), 45 cases(90 eyes)in each. The central corneal thickness, corneal curvature,spherical equivalent(SE), uncorrected visual acuity(UCVA)of both groups were compared before and after wearing orthokeratology lens for 1wk, 1, 3, and 6mo.

RESULTS: The central corneal thickness of two groups before wearing glasses was significantly higher than that of the cornea after wearing glasses 1wk, 1, 3 and 6mo(all P<0.05); the central corneal thickness of the observation group at 1, 3 and 6mo after wearing glasses was significantly lower than that of the control group(P<0.05). The corneal curvature values of the two groups before wearing glasses were significantly higher than that of the cornea after wearing for 1wk, 1, 3 and 6mo(all P<0.05). The corneal curvature of observation group at 6mo was significantly lower than that of the control group(40.0±0.5D vs 41.3±0.9D, P<0.05). The staining rate of corneal epithelium was observed at 3mo after wearing glasses. The positive rate of epithelial staining was 49%(44/90)in the observation group and 29%(26/90)in the comparison group; the grade 0, grade 1 accounted for the majority of the two groups. With the orthokeratology lens wearing longer, the SE level of two groups showed a downward trend. The spherical equivalent of observation group at 6mo was significantly lower than that of the control group(-0.42±0.20D vs -0.52±0.19D, P<0.05). The UCVA value of two groups after wearing glasses significantly increased than that before wearing glasses(all P<0.05).

CONCLUSION: Wearing orthokeratology lens can reduce myopia degree. Wearing it overnight has the better outcome than wearing in the daytime.