配戴角膜矫形镜对角膜形态和单色光波阵面像差的影响

Effects after orthokeratology on corneal topography and monochromic wavefront aberration

目的探讨角膜矫形镜对角膜形态和单色光波阵面像差的影响,评价角膜形态的改变对眼球光学性能的影响。方法 选择近视眼志愿者25例(50只眼),屈光不正等效球镜度数为-1.75--4.75D,受检眼均在配戴前进行裂隙灯显微镜检查、最佳矫正视力的检查、角膜地形图检查和单色光波阵面像差测量。受检者夜戴镜片至少7 h,配戴后1 d、1、2、4、8、12周晨起戴镜片检查,详细记录配戴者戴镜的天数和夜戴的时间。分别进行裂隙灯显微镜检查、最佳矫正视力检查、角膜地形图检查,12周后随访检查再次作单色光波阵面像差的测量。结果受检者戴镜前的矫正视力为-0.0628±0.0286(LogMAR),而戴角膜矫形镜12周后的矫正视力为-0.0120±0.0318,两者比较差异有显著意义(F=17.821,P<0.001);戴镜前单色光波阵面像差Zernike函数值的均方根RMS(Root-Mean-Square)为(0.5766±0.4771)μm,而戴镜90 d后单色光波阵面像差Zernike函数值的均方根RMS值为(1.3731±0.8039)μm,两者比较差异有显著意义(F=36.513,P<0.001),与各级像差相关的Zernike函数值的RMS值均增加;角膜地形前表面偏心率下降,但后表面偏心率增加。结论降低近视度数的角膜矫形镜可引起患者视觉质量的下降。

Objective To assess the corneal topography and monochromatic wavefront aberration among subjects using orthokeratology. Changes of ocular optical quality and related visual functions induced by corneal topography were studied. Methods Twenty-five young myopic subjects (50 eyes) were recruited with myopia from - 1. 75 - -4. 75 D. Orthokeratology lens were fitted at the initial visit with overnight wear program. Subjective refraction, corrective visual acuity, corneal topography and slit lamp examination were performed before and 1 day, 1 week, 2 weeks, 4 weeks, 8 weeks and 12 weeks after the fitting of orthokeratology lens. The monochromic wavefront aberration was measured in initial visit and after 12 weeks. Result The best corrected visual acuity was reduced significantly from ( - 0. 0628 ± 0. 0286 ) LogMAR (before orthokeratology) to - 0. 0120 ± 0. 0318 ( 12 weeks after orthokeratology) ( F = 17. 821, P < 0. 001) . Root-mean-square ( RMS) of wavefront aberration increased significandy from (0. 5766 ?. 4771) μm (before orthokeratology) to (1.3731±0.8039) μm (12 weeks after orthokeratology) (F = 36. 513, P <0. 001) . RMS of Zernike function of each order was increased as well. The rate of eccentric in posterior surface of corneal increased significandy after the using of orthokeratology lens. Conclusions Orthokeratology is one of the effective methods for reducing myopia temporarily. However, the best corrected visual acuity is decreased after using of orthokeratology. The increase of aberration induced by orthokeratology can be the cause of reduction of ocular optical quality. ( Chin J Ophthalmol, 2004,40:471 -473)