双通道视觉质量分析系统评价弱视儿童的视觉质量

目的　应用双通道视觉质量分析系统（ｏｐｔｉｃａｌｑｕａｌｉｔｙａｎａｌｙｓｉｓｓｙｓｔｅｍ，ＯＱＡＳⅡ）比较弱视儿童与正常儿童视觉质量和散射的差异，为临床应用提供一定的参考依据。方法　在广西视光中心弱视门诊就诊患儿中随机选取弱视儿童２８例（５３眼）和正常儿童２８例（４７眼）作为弱视组和正常对照组，所有入选儿童行客观视觉质量分析系统（ＯＱＡＳⅡ，Ｖｉｓｉｏｍｅｔｒｉｃｓ公司）检测、散瞳检影验光和标准对数视力表评估。比较两组屈光度、视力、ＭＴＦ截止空间频率（ＭＴＦｃｕｔｏｆｆ）、斯特列尔比值（ｓｔｒｅｈｌｒａｔｉｏ，ＳＲ）、客观散射指数（ｏｂｊｅｃｔｉｖｅｓｃａｔｔｅｒｉｎｇｉｎｄｅｘ，ＯＳＩ）值及对比度为１００％、２０％、９％时的ＯＶ值（ＯＱＡＳｖａｌｕｅ，ＯＶ１００％、ＯＶ２０％和ＯＶ９％）。结果　弱视组矫正视力和等效球镜分别为０．２６±０．１７ｌｏｇＭＡＲ和（２．９１±３．２５）Ｄ，弱视组ＭＴＦｃｕｔｏｆｆ、ＳＲ、ＯＳＩ、ＯＶ１００％、ＯＶ２０％和ＯＶ９％分别为（３０．９１±１５．２４）ｃ?ｄ－１、０．２０±０．１１、１．１５±１．４２、（１．０３±０. ５１）ｃ?ｄ－１、（０．７８±０．４５）ｃ?ｄ－１、（０．５２±０．３８）ｃ?ｄ－１；正常对照组ＭＴＦｃｕｔｏｆｆ、ＳＲ、ＯＳＩ、ＯＶ１００％、ＯＶ２０％和ＯＶ９％分别为（３７. ４９±９．８１）ｃ?ｄ－１、０．２３±０. ０７、０. ７４±１．３９、（１．２５±０．３３）ｃ?ｄ－１、（０．９４±０．３０）ｃ?ｄ－１、（０．６１±０．２１）ｃ? ｄ－１。两组儿童ＭＴＦｃｕｔｏｆｆ、ＯＶ１００％和ＯＶ２０％比较，差异均有统计学意义（均为Ｐ＜０．０５）。弱视儿童的球镜和柱镜度数与ＭＴＦｃｕｔｏｆｆ、ＳＲ、ＯＳＩ、ＯＶ１００％、ＯＶ２０％和ＯＶ９％均存在统计学意义的相关性（均为Ｐ＜０．０５）。结论　弱视儿童的视觉质量较正常儿童差，且主要表现在中高频对比度部分下降，散射不是导致弱视儿童视觉质量下降的因素。

Evaluation of visual quality in amblyopic children using double-pass optical quality analysis system

Objective To evaluate the visual quality of the amblyopic children and normal children using double-pass optical quality analysis system ( OQAS II ) , and offer the reference data for clinical application. Methods Fifty-three eyes from 28 amblyopic children and 47 eyes from 28 normal children were randomly selected from the Visual Science and Optometry Center of Guangxi. The visual quality , refraction and visual acuity were measured using OoASII ( Visiometrics Inc, Spain) , retinoscopy optometry with cycloplegia and logarithmic visual acuity chart. The visual acuity, refraction.MTF cutoff. Strehl ratio ( SR) , objective scattering index ( OSI) and OQAS value with the contrast at 100% ,20% and g% ( OVIOO% . OV20% and OVg% ) of children were analyzed. Results BCVA and spherical equivalent of amblyopic children were 0. 26 + 0. 17 logMAR and ( 2. 91 + 3. 25 ) D, respectively. The MTF cutoff, SR. OSI. OVIOO% . OV20% and OVg% were ( 30. 91 + 15. 24) c . d’1 ,0. 20 +0. 11 .1. 15 + 1. 42 . ( 1. 03 + 0. 51) c . d-l . ( 0. 78 + 0. 45 ) c . d-l and (0. 52 + 0. 38) c . d-l in amblyopic children and ( 37. 49 +9. 8l)c . d-l ,0. 23 +0. 07 .0. 74 + 1. 39 . ( 1. 25 +0. 33)c . d’1 , ( 0. 94 +0. 30)c . d -l and ( 0. 61 + 0. 21 ) c . d - I in normal children. Statistical significant difference in the MTF cutoff , OVIOO% and OV20% between two groups were observed ( all P < 0. 05 ) . The sphere and cylinder were statistical significantly correlated with MTF cutoff. SR. OSI.OVIOO% , OV20% and OVg% in amblyopic children ( all P < 0. 05 ) . Conclusion Visual quality of amblyopic children is lower than that of normal children, especially in the OQAS value at the high and moderate contrast frequency. Scattering is not the cause of reduced visual quality in amblyopic children.