双通道视觉分析系统评估配戴角膜塑形镜前后的视觉质量和眼内散射

Assessment of optical quality and intraocular scattering before and after orthokeratology with a double-pass optical quality analysis system

目的使用双通道视觉质量分析仪器OQAS-Ⅱ对8~16岁近视患者配戴角膜塑形镜前后的视觉质量和眼内散射变化进行评估。方法收集2013年4月至10月在天津医科大学眼科医院验配角膜塑形镜患者中随机选取8~16(12.03±2.56)岁32例患者,屈光度为-1.00^-5.75(-3.77±1.78)DS,散光度数为0^-1.50(-0.45±0.57)DC。患者在配戴塑形镜前、配戴后7 d、1个月、3个月分别接受OQAS检查,包括调制传递函数(modulation transfer function,MTF)截止频率、客观散射系数(objective scatter index,OSI)、不同对比度下OQAS值(OV100%、OV20%、OV9%、OV平均)。OQAS检查视觉质量时统一使用4 mm瞳孔直径。结果 MTF截止频率配戴前为30.13±11.45,配戴后7 d为23.33±6.58,1个月为22.52±7.11;OV100%配戴前1.01±0.29,配戴后7 d为0.81±0.21、1个月0.85±0.18;OV20%配戴前1.06±0.33,配戴后7 d为0.87±0.22、1个月0.89±0.20;OV9%配戴前1.14±0.37,配戴后7 d 0.88±0.23、1个月0.92±0.22;OV平均配戴前1.07±0.32,配戴后7 d为0.85±0.21、1个月0.89±0.21;OSI配戴前0.84±0.85,配戴后7 d 1.25±0.75、1个月1.26±0.90,均有升高(P<0.01)。配戴角膜塑形镜后3个月和配戴前各数据比较差异均无统计学意义(配戴后3个月时MTF截止频率30.59±5.23、OV100%0.98±0.24、OV20%1.04±0.27、OV9%1.10±0.32、OV平均1.04±0.27、OSI 0.71±0.36,均为P>0.05)。配戴前后MTF截止频率与眼轴长度均无显著相关性(均为P>0.05)。结论患者配戴角膜塑形镜后初期视觉质量下降,表现为MTF截止频率和各对比度下OQAS值下降,OSI升高。配戴塑形镜后3个月视觉质量逐渐恢复到配戴前水平。

Objective To objectively assess changes in optical quality and in- traocular scattering in myopic patients aged 8 years to 16 years after orthokeratology with a double-pass instrttment （optical quality analysis system, OQAS Ⅱ）. Methods A prospective study. 32 myopic patients （57 eyes） with spherical equivalent ranged from -1.00DSto -5.75 DS （ -3.77±1.78）DS and astigmatism ranged from0 DC to - 1.50 DC （ - 0.45 ± 0.57 ） DC in our hospital from April 2013 to October 2013 under- went orthokeratology treatment. The patients were analyzed before orthokeratology and 7 days, 1 month and 3 months after orthokeratology, the values of MTF cutoff frequen- cy, objective scattering index （OSI）, and OQAS values under different contrast （OV100% ,OV20% , OV9% , OVaverage） were assessed by OQAS II for a 4 nun pupil. Results The MTF cutoff frequency before orthokeratology and 7 days, 1 month after orthokeratology were 30. 13 ± 11.45,23.33 ± 6.58,22.52 ± 7. 1 1, respectively; OV100% before orthokeratology and 7 days, 1 month after orthokeratology were 1.01 ± 0. 29, 0.81±0. 21,0. 85 ± 0. 18, respectively; OV20% before orthokeratology and 7 days, 1 month after orthokeratology were 1.06 ± 0.33,0.87 ± 0.22,0.89 ± 0.20, respectively; OV9% before orthokeratology and 7 days, 1 month after orthokeratology were 1. 14 ± 0. 37,0. 88 ± 0. 23,0. 92 ± 0.22, respectively; OVaverage before orthokeratology and 7 days, 1 month after orthokeratology were 1.07 ± 0.32,0.85 ± 0. 21,0. 89 ± 0.21, respec- tively; OSI before orthokeratology and 7 days, 1 month after orthokeratology were 0.84± 0.85,1.25 ± 0.75,1.26 ± 0.90, respectively, There were significant differences compared to the pre-treatment （ all P 〈 0.01 ）. The MTF cutoff frequency, OVI00% , OV20% , OV9% , OVaverae, OSI at 3 months after orthokeratolo were 30.59 ± 5.23.0. 98 ± 0.24,1.04 ± 0.27,1. 10± 0.32,1.04 ± 0.27,0. 71 ± 0. 35, respectively, there was no statistical difference compared to the pre-treatment （ all P 〉 0.05 ）. There was no significant correlation between MTF cutoff frequency and axial length （ all P 〉 0.05 ）. Conclusion The optical quality decreases in orthokeratology patients at early period of treatment, MTF cutoff frequency and OQAS values under different contrast decrease, and OSI increase. The optical quality at 3 months after orthok- eratology return to the level after orthokeratology.