Abstract: 【Abstract】 Objective To investigate the short term influence of orthokeratology on corneal biomechanical properties. Design Prospective case series. Participants 30 eyes of 15 subjects with -1.50~-6.00 D myopia. Methods All subjects wore overnight orthokeratology for 1 night. Corneal resistance factor (CRF) and corneal hysteresis (CH) were measured with ocular response analyzer and corneal thickness and corneal curvature were measured with Pentacam analysis system at pre-wearing, just after contact lens removal and 4 hours after lens removal. Main Outcome Measures Mean spherical equivalent(SE), keratometric curvature, central corneal thickness (CCT), CH, CRF. Results Mean SE decreased from -3.72±1.82 D (baseline) to -2.12±1.93 D (immediately after one night wearing) and recovered to -2.59±1.98D (4 hours after removed). Keratometric curvature were significantly reduced from 41.95±1.12 D (baseline) to 41.22±1.34 D  (immediately after one night wearing) and recovered to 41.44±40.10 D (4 hours after removed). One night post-wearing, the mean CCT of all subjects were significantly increased from 535.9±34.5 μm to 553.3±36.6 μm（P=0.000 ）and recovered to 535.0±40.3 μm 4 hours after lens removal. CRF increased from 10.0 ±1.4 mm Hg to 10.7±1.5 mm Hg in the effect phase（P=0.037）and decreased to 9.6±1.2 mm Hg in 4 hours after lens removal. There was no difference of CRF between pre- wearing and 4 hours after lens removal（P=0.148）. There was no significant change in CH throughout the study（P=0.163）. Conclusion Corneal biomechanics changed with corneal shape after short-term orthokeratology. The corneal biomechanical measurements can be used as a method observing corneal micro-structural changes after orthokeratology. (Ophthalmol CHN, 2012, 21: 381-383)

Key words: myopia, orthokeratology, corneal biomechanical properties, corneal thickness