青少年近视患者夜戴角膜塑形镜后的视觉质量评估

Evaluation of visual quality after overnight orthokeratology

背景角膜塑形镜配戴可暂时改变眼的近视度数，但其对配戴者视觉质量的影响值得关注。目的观察青少年近视患者使用夜戴型角膜塑形镜后视觉质量的改变。方法采用描述性系列病例观察研究设计。每个受试者纳入研究前均签署知情同意书。收集2010年1月1日至12月30目的近视患者76例150眼，年龄（14．90-＋1．24）岁；平均等效球镜度（SE）为（-2．79＋0．82）D。所有患者均在四川大学华西医院眼科配戴夜用型角膜塑形镜，每日戴镜至少8h，分别于配戴前及配戴后第1周、第3个月时接受主觉验光、裸眼视力（UCVA）、对比敏感度、角膜地形图、像差检查，并由同一验配医师询问患者配戴前后的视觉质量及相关症状。视觉质量的评价标准参照美国国家眼科研究院屈光不正生活质量量表（NEI—RQL42），采用SPSS13．0统计学软件对相关数据进行重复测试单因素方差分析。结果配戴角膜塑形镜1周、3个月后sE分别为（-0．33±1．02）D和（-0．26±0．60）D，较配戴前的（-2．79±0．82）D显著下降，差异均有统计学意义（P〈0．01），而配戴后1周和3个月问sE差异无统计学意义（P=0．161）。配戴角膜塑形镜后1周和3个月各空间频率下对比敏感度均低于配戴前，差异均有统计学意义（1周：3cpd时P=0．001，6cpd时P=0．001，12cpd时P〈0．05，18cpd时P〈0．05；3个月：3cpd时P=0．001，6cpd时P=0．001，12cpd时P〈0．05，18cpd时P〈0．05），而配戴后1周和3个月之间患眼对比敏感度的差异均无统计学意义（P〉0．05）。配戴角膜塑形镜1周、3个月后角膜平坦K值、陡峭K值、e值均较配戴前明显降低，差异均有统计学意义（均P=0．000），而角膜表面非对称指数（SAI）、角膜表面规则指数（SRI）较配戴镜前均明显增加，差异均有统计学意义（均P=0．001）。配戴角膜塑形镜前后的像差研究显示，总高阶像差、3阶像差和4阶像差在戴镜后1周和3个月均明显增加，与戴镜前比较差异有统计学意义（P〈0．05），戴镜后1周和3个月间差异均无统计学意义（P〉0．05），总像差及2阶像差在戴镜1周后与3个月均显示降低，与戴镜前比较差异均有统计学意义（P〈0．05），但戴镜后1周和3个月间差异均无统计学意义（P〉0．05）。配戴角膜塑形镜前后5项视觉质量项目（从明处到暗处适应容易程度、夜间骑车容易程度、夜间是否常看到灯光晕环光圈、视力波动出现的频率、眩光程度）评分的差异均有统计学意义（P〈0．05），而视力波动出现的频率在配戴后1个月和3个月间差异均有统计学意义（P〈0．05）。结论配戴夜戴型角膜塑形镜戴后1周可使近视度数降低，配戴3个月近视度数趋于稳定。配戴角膜塑形镜可使角膜形状趋向不规则，对比敏感度下降，3阶像差和4阶像差增加。主观视觉质量较框架眼镜矫正时降低，尤其是夜间视觉质量。

Background Orthokeratology has been proved to temporarily alter the equivalent sphere,but its effects on visual quality deserve attention. Objective The present study was to investigate the visual quality after overnight orthokeratology in pre-adoleseent myopes. Methods Written informed consent was obtained form eaeh subject prior to entering into this series. A descriptive study design was used. One hundred and fifty eyes of 76 teenagers aged （14.90±1.24）years with low and moderate myopia （-2. 79±0.82）D were included in the study. Fitted with Ortho-K contact lens, the lens was wore every night for over 8 hours. Subjective refraction, uncorrected visual acuity （UCVA） , contrast sensitivity function, corneal-topography, and aberrometry were examined before, 1 week and 3 months after the initiation of orthokeratology. Visual quality was generally evaluated by comparing before wearing,1 week and 3 months after wearing using the National Eye Institute refractive error quality of life instrument （NEI-RQL42TM）. All the procedures were performed by the same clinician. Results Spherical equivalent refractions were （ -0. 33± 1.02 ） D and （ - 0.26 ± 0. 60 ） D 1 week and 3 months after orthokeratology, showing significant decline in comparison with （ -2.79-±0.82 ） D of before orthokeratology （ P = 0. 001,0. 001 ）. However, no considerable difference was seen between 1 week and 3 months after orthokeratology （P= 0. 161 ）. Contrast sensitivity function was significantly different in all spatial frequencies before wearing, 1 week and 3 months after wearing, and those of 1 week and 3 months after wearing were significantly lower than those of before wearing （ 1 week ：3 cpd P = 0. 001,6 cpd P=0. 001,12 cpd P〈0.05,18 cpd P〈0.05;3 months：3 cpd P=0. 001,6 cpd P=0. 001,12 cpd P〈 O. 05,18 cpd P〈0. 05）. There was no significant change in contrast sensitivity function between 1 week and 3 months of orthokeratology （P〉0.05）. Flat K, steep K and corneal eccentricity （e） were significantly reduced （P = 0. 000 ）, and surface asymmetry index （SAI） and surface regularity index （SRI） were significantly improved after orthokeratology in comparison with before orthokeratology （ both P = 0. 001 ）. Root mean square （RMS） of total higher-order,third-order and fourth-order aberrations were significantly increased （P〈0.05）, but RMS of whole aberration and second-order aberrations significantly decreased after orthokeratology （P〈 0.05 ）. There were no significant changes in the fifth-order,sixth-order and seventh-order aberration among pre-wear, 1 week and 3 months after orthokeratology. Scales of dark to bright,nocturnal driving,glare,visual fluctuate and halo were lower than those before orthokeratology （P〈0.05）. The scales of visual fluctuate between 1 month and 3 months after orthokeratology had significant differences （P 〈0. 01 ）, while the rest of the scales had no significant differences （P〉O. 05）. Conclusions Orthokeratology can reduce myopic diopter 1 week after orthokeratology. The overnight wearing of fitted orthokeratology can decrease contrast sensitivity and increase corneal surface irregularity and RMS of third-order and fourth-order. Compared with spectacles,orthokcratology reduces subjective visual quality,especially nocturnal quality.