AIM: To compare the accuracy of different refraction measurements after laser in stiu keratomileusis(LASIK)for myopia and astigmatism.

METHODS: Totally 48 cases 96 eyes with myopia were measured before and one month after LASIK, with auto refractor(TOPCOON)objectively, girdle-shaped scissors-shadow scope and subjectively trial lens. The data obtained were statistically analyzed.

RESULTS: Both spherical power and astigmatism results of three measurements had no statistical difference preoperatively(F=4.32, P=0.69; F=0.57, P=0.57). Postoperatively, refraction test with girdle-shaped scissors-shadow scope and trial lens had no statistical difference(P=0.68; P=0.15). But refraction with auto refractor had statistical difference with the tests with the first two methods(P=0.00).

CONCLUSION: Preoperatively, the objective refraction with an auto refractor is approximate to the retinoscopy optometry and the subjective refraction. The postoperative objective refraction with an auto refractor is less accurate than that preoperatively. It is not sufficient to determine the accurate value of the ametropia. Cycloplegic dioptoscopy can get a relative accurate diopter values after LASIK.