RESUMEN
?AlM:To compare the effect of iris location guided sub-bowman keratomileusis ( SBK ) and iris location guided thin - flap laser in situ keratomileusis ( LASlK ) for extremely high myopia treatment. ?METHODS:lris location guided SBK was performed in 64 eyes of 32 patients with extremely high myopia and 42 eyes of 84 patients were received iris location guided thin-flap LASlK. All the patients’ spherical refraction was-9. 00D ~ - 11. 00D and the age was 22 ~ 35 years. Uncorrected visual acuity ( UCVA) , refraction, split-lamp examination, topography examination, central corneal stroma thickness, thickness of central corneal flap, thickness of peripheral corneal flap and complication was examined in these patients and follow-up was 6mo. ?RESULTS:At 6mo after surgery, 93. 8% of the patients received iris location guided SBK and 92. 9% received iris location guided thin-flap LASlK achieved a UCVA better than 20/20. There was no significant difference between two groups. Refraction between ±0. 5D was 89. 1% of SBK group and 84. 5% of LASlK group. There was no significant difference. Corneal rear surface height of SBK was 0. 046±0. 012μm and LASlK was 0. 056±0. 015μm. Thickness of corneal stroma after surgery was 328. 6±14. 7μm in SBK group, while it was 301. 2±21. 6μm in LASlK group and there was significant difference ( t =3. 127, P=0. 001). BUT was 11. 38±4. 02s and 17. 81±4. 89s in SBK and LASlK group respectively, with no statistical difference. There was no serious complication in two groups.?CONCLUTlON:Both iris location guided SBK and thin-flap LASlK are effective for extremely high myopia, but SBK is safer and more predictive than thin-flap LASlK.