Abstract:AIM:To assess efficacy, stability, and change in cylindrical degree and axis after real-time iris recognition combined with wavefront guided laser in situkeratomileusis (LASIK) for the correction of moderate or high myopic astigmatism.METHODS:In this prospective contrast study, 115 patients (211 eyes) with moderate or high myopic astigmatism were randomly divided into two groups:the experimental group (57 cases, 104 eyes) received real-time iris recognition combined with wavefront guided LASIK, and the control group (58 cases, 107 eyes) received conventional wavefront guided LASIK. The naked visual acuity, best-corrected visual acuity(BCVA), the degree and axis of astigmatism, wavefront aberration were compared between two groups at postoperative 1 month, 3 months and 6 months.RESULTS:In experimental group, static iris recognition detected that eye cyclotorsional misalignment was 2.61°±2.08°, dynamic iris recognition detected that the intraoperative cyclotorsional misalignment range was 0°-5°. Six months after operation, the naked vision of 96 eyes(92.3%) in experimental group and 78 eyes (72.9%) surpassed the preoperative BCVA of each group(P＜0.01); the degree of astigmatism in experimental group(-0.28±0.26D) was significantly lower than that in the control group (-0.44±0.35D) (P＜0.05). In experimental group, 49 eyes became non-astigmatism 6 months after operation and in control group 31 eyes. At 6mm pupil size, there was significant different in third order coma aberration between experimental group and control group(P＜0.01).CONCLUSION:Real-time iris recognition can compensate deviation from eye cyclotorsion and pupil centroid shift, more precise treatment for the degree and axis of astigmatism, and increase visual quality in LASIK.
