| Purpose:To compare the clinical outcomes of Sub-Bowman Keratomileusis performed by One-Use-Plus disposable microkeratome (OUP-SBK) and conventional laser in situ keratomileusis (LASIK) in treating myopia.Methods:84 eyes of 43 patients were randomly divided into SBK group and LASIK group.48 eyes that underwent SBK had mean spherical equivalent (SE) refraction of-6.48±2.74D (ranging from-2.75 to-14.00D), and that of 36 eyes that underwent LASIK was-7.36±1.79D (ranging from-3.50～-10.75D). Visual and refractive results, SE, higher order aberrations (HOA). contrast sensitivity (CS) were recorded 1 month and 3 month postoperatively. Effectiveness, predictability, stability and visual quality were compared between the two groups.Results:3 month postoperatively, mean uncorrected visual acuity (UCVA) was 0.98±0.19 (Snellen Chart) in SBK group and 1.01±0.20 in LASIK group, and the percentage of UCVA equal to and above 1.0 was 62.5%and 14.6%in SBK group. 44.4%and 25.0%in LASIK group; Mean best corrected visual acuity (BSCVA) was 1.07±0.12 in SBK group and 1.08±0.17 in LASIK group, and the percentage of BSCVA equal to and above 1.0 was 70.8%and 29.2%in SBK group,58.4%和33.3%in LASIK group; SE ranged from-0.5D to 0.5D and-1.0D to 1.0D in SBK group accounted for 77.08%and 87.50%, while in LASIK group, it accounted for 75.00%and 94.44%. There were no significant differences between the related datas above of the two groups(P>0.05). The amounts which SE changed from 1 month to 3 month postoperatively were similar in both groups (p>0.05). Postoperative HOA, coma and spherical aberrations of both groups were obviously higher than those preoperatively (P<0.05); Moreover, postoperative spherical aberrations of SBK group (0.28±0.15um) were significantly lower than those of LASIK group (0.77±0.36um) (P＜0.05), while the variations of other parameters were similar in both groups (P>0.05). Postoperative glare contrast sensitivity (CS) had an obvious decrease at all spatial frequencies in SBK group, while there was only decrease at low spatial frequencies compared with preoperative datas in LASIK group.3 month postoperatively, non-glare CS of SBK group was lower at 1.0 and 1.7cpd, which were low spatial frequencies, than that of LASIK group, and glare CS was lower at 1.0,1.7,2.6,4.2 cpd compared with LASIK group.Conclusion:OUP-SBK shows similar effectiveness, predictability and stability to LASIK in treating myopia, as well as equally inducing higher order aberrations; however, in this study, OUP-SBK shows lower glare CS mainly at medium spatical frequency, which may indicate that its visual quality in the dark is worse than LASIK short-term postoperatively. It is worth mentioning that the importance of performing OUP-SBK is to extend the range of power correction of conventional LASIK and enable patients who have high myopia with thin central cornea to accept LASIK surgery. |
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