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目的：探讨准分子激光角膜切削术（ｐｈｏｔｏｒｅｆｒａｃｔｉｖｅｋｅｒａｔｅｃｔｏｍｙ，ＰＲＫ）后肌性视疲劳与切削偏心的关系。方法：对８例１６只眼近视性屈光不正行ＰＲＫ后随访６～１４个月，视力均在０．８以上且主观接受棱镜矫正的肌性视疲劳者，根据术后与术前的角膜地形图及其相减图的数据，按Ｈｏｌａｄａｙ法计算角膜实矫屈光度Ｄ，检测偏离瞳孔中心的切削偏心量ｈ（以ｍｍ为单位）及方向。用公式（棱镜度）δ≈Ｄｈ计算切削偏心所致棱镜效应值并与主观接受矫正的棱镜相比较。结果：主观接受与按公式计算的棱镜度相近，两者差值平均为０．１０△±０．２５△，主观接受的棱镜基底朝向均与偏心方向一致。结论：切削偏心为ＰＲＫ后肌性视疲劳的主要原因，偏心所致棱镜效应可用δ≈Ｄｈ估算；应重视ＰＲＫ后肌性视疲劳的诊断、治疗和预防。
Objective: To investigate the relationship between muscle visual fatigue and cutting eccentricity after photorefractive keratectomy (PRK). Methods: Eight patients with myopic ametropia of 16 eyes of 6 eyes were followed up for 6 to 14 months with visual acuity of 0.8 or more, and subjectively received prism correction of myopia. According to the postoperative and preoperative corneal Topographic maps and their subtraction maps were calculated using Holaday’s method to calculate corneal real dioptre D, and to measure the amount of cutting eccentricity h (in mm) and the direction from the center of the pupil. The prism effect due to cutting eccentricity is calculated by the formula (prism degree) δ≈Dh and compared with the prism that subjectively accepts the correction. Results: The subjective acceptance is similar to the prism calculated by the formula, the average difference between them is 0.10 △ ± 0.25 △. The subjective acceptance of the prism base is in the same direction as the eccentricity. Conclusions: The eccentricity of cutting is the main cause of muscular visual fatigue after PRK. The prism effect caused by eccentricity can be estimated by δ≈Dh. The diagnosis, treatment and prevention of muscular fatigue should be emphasized after PRK.