Comparison of microkeratome assisted sub-Bowman keratomileusis with photorefractive keratectomy.
OBJECTIVE
To compare the outcomes of photorefractive keratectomy (PRK) and thin-flap Laser-Assisted in Situ Keratomileusis/sub-Bowman keratomileusis (SBK) with intended flap thicknesses of 100 μm using the One Use-Plus SBK microkeratome.


METHODS
Ninety-eight eyes of 52 subjects with myopic manifest refraction spherical equivalent (MRSE) of up to -5 diopters (D), a stable refraction for 1 year and a corrected distance visual acuity (CDVA) of at least 20/20 in each eye which had undergone SBK or PRK were reviewed retrospectively. Primary outcome measures were MRSE, uncorrected distance visual acuity (UDVA), CDVA, pachymetry and higher order aberrations (HOA). All patients were seen at 1 and 3 days, 1 week, and 1, 3, and 6 months after surgery.


RESULTS
Both MRSE and UDVA showed a statistically significant improvement at postoperative 1, 3 and 6 months from baseline in both SBK and PRK groups. At postoperative 6 months, 100% of eyes were within ±0.50 D of attempted correction in both groups. However, SBK group demonstrated better outcomes with 81% of eyes within ±0.13 D, compared to 70% eyes in the PRK group. Both SBK and PRK group demonstrated similar refractive astigmatism accuracy at postoperative 6 months, with 88% of eyes having cylindrical error ⩽0.25 D. None of eyes lost any lines of CDVA in the PRK, and 2% eyes lost one line of CDVA in SBK group at postoperative 6 months.


CONCLUSIONS
The visual and refractive outcomes after both PRK and microkeratome assisted SBK are comparable, albeit with a higher complication rate in the SBK group.
Taif University, PO Box 795, Taif 21944, Saudi Arabia.
Talal A
TA
Althomali
Microkeratome assisted thin-flap LASIK; SBK; Sub-Bowman keratomileusis; Thin-flap LASIK