方法：超高度近视患者行虹膜定位引导的SBK治疗的患者32例64眼，行虹膜定位引导的超薄瓣LASIK治疗的患者42例84眼，年龄22～35岁，术前等效球镜屈光度-9.00～-11.00D，随访6mo观察两术式的治疗效果。观察指标包括裸眼视力(UCVA)、屈光状态、裂隙灯检查、残余角膜基质床厚度、角膜地形图、角膜厚度、角膜瓣厚度并发症。

结果：术后随访6mo，UCVA≥1.0者SBK组为93.8%，超薄瓣LASIK组为92.9%，两术式相比较差异无统计学意义； 残余屈光度在±0.50D以内者SBK组为89.1%，超薄瓣LASIK组为84.5%，两术式相比较差异无统计学意义； SBK组角膜后表面Diff值为0.046±0.012μm，超薄瓣LASIK组为0.056±0.015μm，两术式相比较差异无统计学意义； 术后SBK组角膜中央残余基质厚度为328.6±14.7μm，超薄瓣LASIK组为301.2±21.6μm，两组相比较差异有显著性(t=3.127，P=0.001)； SBK组、超薄瓣LASIK组患者泪膜破裂时间(BUT)分别为11.38±4.02s和17.81±4.89s，两组相比较差异无统计学意义。术后两组患者均无严重并发症。

结论：虹膜定位引导的SBK和超薄瓣LASIK治疗超高度近视具有良好的效果，与LASIK相比SBK制作角膜瓣的预测性更好，可以降低医源性圆锥角膜发生的概率； 术后干眼症状轻、恢复更快，对于超高度近视患者来说是一种经济有效的手术治疗方式。

METHODS:Iris 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 LASIK. 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 LASIK 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 LASIK group. There was no significant difference. Corneal rear surface height of SBK was 0.046±0.012μm and LASIK 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 LASIK 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 LASIK group respectively, with no statistical difference. There was no serious complication in two groups.

CONCLUTION: Both iris location guided SBK and thin-flap LASIK are effective for extremely high myopia, but SBK is safer and more predictive than thin-flap LASIK.