白内障术后不同人工晶状体对比敏感度的研究

目的：研究白内障术后非球面晶状体、单焦晶状体和多焦晶状体功能视力的比较。方法：白内障超声乳化联合人工晶状体（IOL）植入术后患者90例90只眼,随机分为三组,其中非球面晶状体组30例30只眼,单焦晶状体组30例30只眼,多焦晶状体组30例30只眼。与上述三组年龄匹配的门诊患者30例30只眼为对照组。所有患者年龄为50-80岁,矫正视力均≥0.8,且除了白内障之外,无任何影响对比敏感度（CS）的眼疾,亦无其他可能影响CS的全身性疾病。对照组及白内障患者于术后30 d,分别用CSV-1000E对比敏感度测试仪（由VECTORVISION公司提供）进行对CS测定。结果：白内障术后患者的CS大致恢复至正常范围,但较正常组降低。非球面晶状体组在6、12和18周/度（cpd）时,与其他组比较显著提高患者CS（P〈0.05）,且多焦晶状体组明显低于单焦晶状体组（P〈0.01）。结论：非球面晶状体通过其独特的Z-SHARP光学技术抵消了球面像差,从而有效地提高了CS。

Study of contrast sensitivity of different intraocular lens after cataract surgery

Objective:Contrast sensitivity(CS) is a new technique which measures the discrimination capacity of the human eye to an object under low contrast conditions.It is more acute and more complete in reflecting visual function than the Snellen chart which is used to test the discrimination under high contrast conditions.Our purpose is to compare the effect of an aspheric intraocular lens(IOL) with those of conventional monofocal silicone and acrylic IOL and multifocal IOL on functional visual performance. Methods:To 90 eyes after phaco emulsification with IOL implantation,30 eyes of age-matched patients were selected as control,all patients were 50-80 years old,with no disorders,other than cataract,known to affect CS.Corrected visions were all over 0.8.The CS was measured 30 days after surgery.Results:After surgery the patients' CS returned to the normal level,but which was lower than that of the control's.The aspheric IOL provided statistically significant better contrast sensitivity at 6,12 and 18 cycles per degree. Conclusion:The use of a modified prolate IOL in cataract surgery has the potential to improve CS,which is designed to partially compensate the average spherical aberration of the cornea.