多光区准分子激光角膜切削术治疗高度近视眼

Results of multizone excimer laser photorefractive keratectomy for high myopia

目的研究多光区准分子激光角膜切削术（multizonephotorefractivekeratectomy,PRK－MZ）治疗高度近视眼的疗效。方法229眼高度近视（－6．25～－9．00D）经PRK－MZ治疗后随访1a，观察视力、屈光稳定性和角膜Haze，用角膜地形图对PRK－MZ术后角膜形态及平均角膜屈光力（ACP）进行研究。结果PRK-MZ治疗1a后．197（86.03％）眼裸眼视力≥0．8，37（16．16％）眼屈光回退≥－1．00D，角膜Haze0．5～1级者5眼（2．18％），ACP值在PRK－MZ治疗后1mo、6mo及1a时较术前显著下降（P＜0.01），术后1a时ACP值较术后1mo和6mo时增加（P＜0．05）；角膜表面规则指数（SAI）在PRK-MZ术后无明显变化．角膜表面不规则指数（IAI）亦无变化。结论PRK-MZ治疗－6．25～－9．00D范围的高度近视仍有较好疗效，不影响角膜表面形态，但屈光稳定性降低，角膜Haze在随访1a中逐渐减退或消失。

Objective To evaluate the efficacy. safety and stability of multizone photorefractive keratectomy (PRK-MZ ) for high myopia.Methods The 229 eyes (147 patients ) of high myopia (range:- 6. 25～-9. 00D) were treated by PRK-MZ with a Kenacor 116 excimer laser and followed up for 12months.Results One year after the therapy uncorrected visual acuity of 0. 8 or better was attained in 179 of 229 eyes (86. 03% ). And 16. 16% (37 of 229) of the eyes had a my opia of-1. 00 diopter spherical equivalent or more. At the 12th month. only 2. 18% (5 of 229 ) of the eyes with corneal 'Haze' of 0. 5～1 scale. After PRK-MZ, average corneal power (ACP) was significantly lower than pre-operation (P< 0.01).But at 12 months. ACP was increased slightly again. Surface regular corneal indexes (SRI ) and surface corneal asymmetry indexes (SAI)had on change and their stability kept on for 6 months after PRK-MZ. Irregular astigmatism indexes (IAI) also had no change and kept it's stability after PRK-MZ as the long time followed up.Conclusions PRK-MZ is good for high myopia. but it is less reliable for mild and moderate myopia. Surface corneal shapes had no change. corneal ' Haze' was decreased or disappeared after PRK-MZ during the timefollowed-up.