The changes of corneal thickness after LASIK Surgery

Objective To analysis the changes of corneal thickness after LASIK. Methods The central corneal thickness of 641 patients (1210) eyes) of myopia was measured with PACHY METER (SP-3000) pachymeter before and 13 month after LASIK.They were divided into four groups according to the degree of myopia.The central corneal thickness of the four groups was measured and analysed. Results The central corneal thickness of patients with refaction greater than -6.00 DS decrease 1.31 μm when the refraction increase 1.00 DS. The difference is very prominent between the actual corneal thickness of 1 and 3 month post-operation and predicted ablated corneal thickness.The difference is negative correlation with the percentage of residual refraction within ±0.50 DS and ±1.00 DS (r=-0.1 and r=-0.3,P0.01). Conclusion The corneal thickness of myopia with high degree and supra high degree become thinner with the increase of refraction.The actual corneal thickness 1 and 3 month after LASIK is larger than predicted corneal thickness. The difference of actual centeral thickness with predicted one is direct proportion to the residual refraction of post-operation.