Wavefront-guided Sub-Bowman's Keratomileusis For The Correction Of Refractive Errors

Objective:To explore the safety and efficacy of wavefront-guided sub-Bowman's keratomileusis(WASCA-SBK) in the treatment of refractive errors.Methods:A self-control study of 10 patients (20 eyes) with refractive errors undergoing WASCA-SBK with the MEL 80 excimer laser system was performed. Uncorrected vision acuity (UCVA), best-spectacle corrected visual acuity (BSCVA), manifest refraction, higher order aberration (HOAs). contrast sensitivity were measured and recorded preoperatively and at two weeks, one month and three months postoperatively for each eye. Statistical analysis was performed using SPSS 17.0 for windows, a p value<0.05 was considered significant.Results:10 patients (20 eyes) joined the follow-up and nobody was lost. UCVA in post-operation had a significant increase when compared to that in pre-operation (p <0.05). At 2 weeks,1 month and 3 months postoperatively. the percentage of UCVA better than 0.8 was 100%, and the percentage of UCVA better than 1.0 was 95%,100%. 90%. BSCVAs of all eyes postoperatively were 1.0, the same as those preoperatively. There was a significant decrease in spherical equivalent between pre-operation and post-operation (p<0.05). The percentage of spherical equivalent (SE) between±0.5D was 95%(19/20)5100%(20/20),95%(19/20). Spherical equivalents of all eyes were between±1.0D. The RMS of total high order aberration and spherical aberration in the post-operation were significantly higher than those in pre-operation, while there was no significant difference in coma aberration. At 2 weeks, postoperative contrast sensitivity without glare was significant lower than that of pre-operation at 4.2cpd. At 3 months, there was no significant difference in contrast sensitivity with or without glare between pre-operation and post-operation.Conclusion:Wavefront-guided sub-bowman's keratomileusis (WASCA-SBK) was safe, effective, predictable and stable for the treatment of refractive errors. Although the higher order aberrations postoperatively were more than preoperatively, there wasn't a sharp decline in contrast sensitivity. WASCA-SBK achieves good visual quality'.