Abstract:AIM: To evaluate the stabilization of long-term optical quality after laser in situ keratomileusis(LASIK)for myopia by Optical Quality Analysis System.
METHODS: Totally 70 eyes from 35 student volunteers after LASIK and 140 eyes from 70 normal student volunteers were recruited from the Fourth Military Medical University. The volunteers after LASIK were divided into recent observation group(2～4a after LASIK)and long-term observation group(5～10a after LASIK). The normal volunteers were divided into recent control group and long-term control group,to analysis the influence of confounding factors such as age and eyes-using habit on the optical quality. The observation groups and the control groups were compared respectively. The objective scattering index(OSI), modulation transfer function cutoff frequency(MTF cutoff), Strehl ratio(SR),OQAS value in 100% contrast(OV100%), OQAS value in 20% contrast(OV20%), OQAS value in 9% contrast(OV9%)were analyzed.
RESULTS: The OSI of observation group improved significantly but the MTF cutoff, SR, OV100%, OV20% and OV9% decreased significantly in several years after LASIK(P<0.05). The optical quality is generally stable after LASIK. The OSI had a tendency to reduce and the MTF cutoff, SR, OV100%, OV20% and OV9% had a tendency to improve, but showed no significant difference.
CONCLUSION: LASIK, one of the most frequent operation methods for myopia correction, can reduce the optical quality in a certain extent. The optical quality has a tendency to recover in several years after LASIK, but not completely. OQAS is a feasible method in assessing the long-term optical quality after LASIK.
