早期皮质性白内障不同对比度下视力的临床观察

Early clinical evaluation of contrast visual acuity in patients with age-related cataract

目的：分析早期皮质型白内障患者在不同对比度下视力（CVA）的改变，了解测量CVA在评价早期白内障患者视功能中的作用。方法病例对照研究。入选标准：选取早期皮质性白内障患者52例（104只眼），正常对照组52例（104只眼），共入选104例。性别年龄不限，屈光状态检查球镜度数-3.00～3.00 D，柱镜度数为-1.50～1.50 D，单眼最佳矫正视力≥0.8，将其按照性别相同、年龄相仿（≤5岁）及最佳矫正远视力相近（ETDRS视力表相差≤1行）的原则配对分组，共计52对。对受试者先行眼部及屈光检查，随后在暗室内使用多功能视力测试仪检测对比度（MFVA）为100％、25％、10％、5％CVA。采用配对t检验及F检验分别对检测数据进行分析。结果白内障患者组在对比度为100％、25％、10％、5％下的右眼CVA分别为0.99±0.26、0.59±0.23、0.38±0.19、0.23±0.12，左眼CVA分别为0.98±0.28、0.59±0.18、0.38±0.14、0.23±0.10，双眼CVA分别为1.15±0.26、0.73±0.20、0.49±0.16、0.30±0.10，均较健康对照组显著下降（右眼t=-6.49，-7.25，-7.57，-5.45；左眼t=-5.78，-7.51，-6.41，-7.16；双眼t=-4.33，-7.60，-7.53，-9.75；P均〈0.01）。不同晶状体皮质的混浊程度均会造成在对比度为100％、25％、10％、5％下的CVA显著下降（I级：F=50.18，P〈0.01；Ⅱ级：F=23.08，P〈0.01；Ⅲ级：F=20.17，P〈0.01）不同晶状体皮质的混浊程度均会造成在对比度为100％、25％、10％、5％下的CVA较健康对照组显著下降（I级：t=-6.49，-7.25，-7.57，-5.45，P均〈0.05；Ⅱ级：t＝-5.78，-7.51，-6.41，-7.16，P均〈0.01；Ⅲ级：t=-4.33，-7.60，-7.53，-9.75，P均〈0.01）。结论对于早期白内障患者，对比度为100％、25％、10％、5％CVA的测量较最佳矫正视力能更全面、更灵敏的评价视功能。（中华眼科杂志，2015，51：510-514）

Objective To evaluate the changes of the contrast visual acuity （CVA） in early age-related cataract patients. Methods Case-controlled study. One hundred and four eyes of 52 age-related cataract patients, with the best corrected visual acuity equal to or more than 0.8, equivalent spherical diopters of-3.00 to 3.00 DS and astigmatic diopters of-1.50 to 1.50 DC, were selected as the cataract group. Another 104 eyes of 52 normal adults, with the best corrected visual acuity equal to or more than 0.8, equivalent spherical diopters of-3.00 to 3.00 DS and astigmatic diopters of-1.50 to 1.50 DC, were selected as the control group. They were paired according to sex, the similar age and the best corrected visual acuity. After eye and refractive examinations, all examinees received the CVA measurements in different contrast levels between the optotypes and background （100%, 25%, 10% and 5%） in the dark room by the multifunction visual acuity chart. SPSS 18.0 software package was used for paired t test. Results In the cataract group, CVA decreased more significantly than the control group. OD：0.99±0.26, 0.59±0.23, 0.38± 0.19, 0.23±0.12. OS：0.98±0.28, 0.59±0.18, 0.38±0.14, 0.23±0.10. OU：1.15±0.26, 0.73±0.20, 0.49±0.16, 0.30 ± 0.10（OD： t=-6.49,-7.25,-7.57,-5.45. OS： t=-5.78,-7.51,-6.41,-7.16. OU： t=-4.33,-7.60,-7.53,-9.75, P〈0.01）. There was a significant decrease in different degrees of cortical cataract（F100%=50.18, P=0.000. F25%=23.08, P=0.000. F10%=20.17, P=0.000. F5%=13.42, P=0.000）. There was a significant decrease in different degrees of cortical cataract compared with the control group（C1：t=-6.49,-7.25,-7.57,-5.45,P〈0.05. C2：t=-5.78,-7.51,-6.41,-7.16,P〈0.01. C3：t=-4.33,-7.60,-7.53,-9.75,P〈0.01）. Conclusion CVA was more reliable than the best corrected visual acuity in evaluating vision function in patients with early age-related cataract.