Abstract: Objective To investigate the effects of orthokeratology on refractive system and intraocular pressure in teenagers.Methods 200 eyes (100 teenagers) were enrolled. Uncorrected visual acuity, diopter, corneal curvature, equivalent refractive,thickness of central cornea, tear break-up time and intraocular pressure were examined 5 times (before glasses-fitting; 1 weeks, one month, two month and six month after glasses-fitting). Results The uncorrected visual acuity, diopter, corneal curvature, equivalent quivalent refractive intraocular pressure were significantly decreased in 1 week and began to stabilize 1 month later. There were no significant differences between tear break-up time and central corneal thickness, or axial length. Though 98% patients presented with mild corneal staining and 10.5% with conjunctivitis, symptoms disappeared after proper treatment. Conclusion Orthokeratology can reduce the degree of myopia to improve visual acuity by changing corneal curvature. After proper treatment, there is no serious complication and no irreversible damage.

Key words: Quivalent refractive, Corneal curvature, Axial length, Complication, Intraocular pressure