This article is more than 5 years old. Information may no longer be current.
SBK shows safety and efficacy comparable to thick-flap LASIK
J Cataract Refract Surg. 2008;34(12):2073-2078.
Click Here to Manage Email Alerts
Sub-Bowman's keratomileusis proved similarly safe and effective compared to thick-flap LASIK.
Investigators conducted a retrospective study to compare visual outcomes in patients with moderate or high myopia who underwent sub-Bowman's keratomileusis (SBK) or thick-flap LASIK. They also performed a case-control-matched analysis to assess the impact of flap thickness on refractive and visual results.
Results of the first study showed no significant differences in postoperative uncorrected visual acuity, best corrected visual acuity or changes in BCVA between the SBK and LASIK groups. Also, no eyes in either group lost two or more lines of BCVA; 27.3% of SBK eyes lost one line of BCVA, and 8.1% of LASIK eyes lost one line.
Data from the second study showed no significant difference in intended vs. achieved refractive error between the two groups. The results showed that corneal flap thickness does not affect refractive outcomes in patients with sufficient residual stromal bed thickness.
I think it’s a very important paper because there has been some discussion as people have been going to thinner flaps whether there was any more risk with thin flaps, such as the flaps tearing when they were lifted or wrinkling more because they were thinner. It shows that if you compare the safety of doing surgery with a thicker flap, around 140 µm, which was the standard for years, to the new trend for SBK and thinner-flap LASIK, that the results were very comparable.
The reason that’s important is we’re learning from other studies, including some that we’ve done, that if you do a thinner flap, it cuts fewer fibers and fewer nerves, patients have quicker recovery, and especially because it cuts fewer nerves there appears to be less dry eye. So this paper is an important one because it confirms a trend that’s already happening and adds new information that it’s OK to do a thinner flap and you can expect good results. Occasionally you have to have a reality check and just say, “Are we heading in the right direction.” I think this paper adds information to that.
– Daniel S. Durrie, MD
OSN Refractive Surgery Section Editor