【作者】 张琪；

【导师】 姚克；

【作者基本信息】 浙江大学 ， 眼科学， 2007， 硕士

【摘要】 目的探讨后发性白内障(posterior capsular opacification,PCO)对视功能的影响,比较不同程度不同类型的PCO引起的最佳矫正视力(best correct distant visualacuity,BCDVA)、对比敏感度(contrast sensitivity function,CS)、眩光敏感度(glare sensitivity,GS)的改变。寻求临床量化PCO准确实用的诊断标准,探讨Nd:YAG激光晶状体囊膜切开术的手术时机。方法老年性白内障行超声乳化白内障吸除合并人工晶体植入术后患者151例(190眼),40眼无PCO,150眼有各种程度PCO,其中Nd:YAG激光囊膜切开术治疗的患者58例(67眼)。所有患者检查裂隙灯、眼底、眼压、BCDVA、CS、GS;PCO的150眼散瞳至瞳孔直径达6mm以上拍摄晶状体后囊膜裂隙灯直接照明和后部发射照明数码照片。Nd:YAG激光囊膜切开术治疗的67眼,于治疗后一周复查裂隙灯、眼底、眼压、BCDVA、CS、GS。标准对数视力表检查BCDVA,为便于统计结果转换成LOGMAR记录。CGT-1000(contrast glare tester,CGT-1000 Takagi Seiko,日本)检查对比敏感度阈值、眩光敏感度阈值,阈值取倒数即为CS、GS,统计时取LOG计算。TOPCON SL-8Z裂隙灯连接的SONY DXC-990D 3CCD彩色数码照相机和IMAGEnet 2000软件观察、拍摄、选择、存储晶体后囊膜直接照明和后部反射照明照片。根据裂隙灯、眼底检查按Odrich法对PCO主观分级,并使用EPCO软件(Evaluation of Posterior Capsule Opacification,EPCO;海德堡大学德国)分析后部反射照明数码照片,半客观量化PCO程度。选择23眼,有两张不同角度拍摄的高度清晰的后部反射照明数码照片,由OSCA软件(objective system capsuleanalysis,OSCA;爱丁堡大学英国)分析,完全客观的量化PCO程度。ZEISS VISULAS YAGⅡ激光机行Nd:YAG激光囊膜切开术,随机选择3mm或4mm切开直径。1后囊膜混浊测量方法比较:比较主观临床分级、半客观EPCO值、完全客观OSCA值与BCDVA、CS、GS的关系,并比较EPCO值在不同检查者间的差异。2后囊膜混浊与BCDVA、CS及GS下降的关系:分别比较不同程度不同类型的PCO对BCDVA、CS及GS的影响。3 Nd:YAG激光治疗前后视功能的改变:不同程度PCO在Nd:YAG激光治疗前后BCDVA、CS、GS的改变,并比较3mm和4mm不同切开直径患者治疗后的BCDVA、CS及GS。结果1后囊膜混浊测量方法比较:1.1 23眼PCO EPCO值、OSCA值和临床分级比较,EPCO与OSCA相关性佳(r=0.508,P＜0.05),EPCO与临床分级、log MAR相关性(r=0.711、r=0.669,P＜0.01)高于OSCA(r=0.415、r=0.512,P＜0.05)。LOGCS、LOGGS(除高频区0.7°视角)与EPCO值的相关性最明显(P＜0.01),高于临床分级、OSCA值(P＜0.05)。1.2 30张后部反射照明数码照片,轻、中、重各10张,3位检查者之间的PCO面积相关性明显(r分别为0.864、0.878、0.832,P＜.001);检查者之间EPCO值的相关性更加明显(r分别为0.977、0.977、0.965,P＜.001)。2后囊膜混浊与BCDVA、CS及GS下降的关系:无PCO的40眼作为对照组,不同程度PCO的150眼按Odrich法分1级:轻度62眼,2级:中度66眼,3级:重度22眼。2.1轻度PCO按形态分云雾状(6眼)、纤维状(21眼)、薄层状(35眼),只有薄层状PCO组视力下降,术后发生时间较迟(P＜0.01)。云雾状、薄层状组在高频区CS,纤维状组在中频区GS下降,差异明显(P＜0.05)。2.2中度PCO按形态分纤维状(6眼)、厚层状(27眼)、珍珠状(26眼),各组间CS、GS有明显差异。珍珠状组各频区CS、GS均低于纤维状组,差异明显(P＜0.05);厚层状界于两组间,与珍珠状组无明显差异。2.3不同类型PCO的EPCO值与CS、GS关系:珍珠状PCO对CS、GS曲线影响最大,EPCO值与CS、GS呈明显负相关,中频区(2.5°视角)最明显,对GS的影响更大于CS(r=-0.676、-0.632,p＜0.01)。回归方程为loggs2.5°=2.04—0.60 epco、loges2.5°=1.94—0.48epco层状EPCO值与CS、GS(除高频区)也呈明显负相关,低中频(4.0°视角)相关性最大(r分别为-0.453、-0.473,p＜0.01)。纤维状、云雾状PCO的EPCO值与各频区CS、GS无明显相关性。3 Nd:YAG激光治疗前后视功能的改变:Nd:YAG激光晶体囊膜切开术治疗PCO 58例(67H艮)3.1按EPCO值分四组EPCO＜1、1≤EPCO＜2、2≤EPCO＜3、EPCO≥3。各组间后囊膜切开前EPCO、LOGMAR、各频区CS、GS(除0.7°视角)有显著差别(p＜0.01),切开后无差别。各组内后囊膜切开前、后比较,EPCO＜1组后囊膜切开前、后无差别,其他三组LOGMAR均降低(p＜0.01),1≤EPCO＜2组除高频区(p＜0.05)、2≤EPCO＜3组全频区、EPCO≥3组除高频区(p＜0.01)CS、GS都提高,差异明显。3.2 Nd:YAG激光囊膜切开随机分3mm、4mm切开直径两组,分别为24眼、43眼,后囊膜切开后的LOGMAR、CS、GS无差异;与对照组比较LOGMAR无差异,中低频区CS(p＜0.05)、各频区GS(除0.7°视角)降低(p＜0.01)。结论1 EPCO是准确实用的PCO评估方法与完全客观的OSCA相关性明显,比后者与临床分级、视功能的相关性更高;而且EPCO评估方法简便,检查者之间的个体差异轻微,可重复性佳。2 CS、GS比视力更早更敏感的反映视功能。轻度的PCO只有薄层状视力下降,云雾状、纤维状视力正常,但CS、GS已有下降。珍珠状PCO对CS、GS的影响最大,中频区最明显;其次为层状,低、中频区明显;纤维状、云雾状影响较小。3 EPCO值可作为Nd:YAG激光晶体囊膜切开术的时机选择的指标,轻度PCO如EPCO＜1不宜治疗,EPCO≥1进行治疗能取得较好作用。选择3mm或4mm后囊膜切开直径对视功能的改善无明显差异。但后囊膜周边的混浊对视功能存在影响,尤其是引起GS降低。更多还原

【Abstract】 PURPOSE:To investigate the correlation between visual acuity,contrast sensitivity,glare sensitivity,and the degree of posterior capsule opacification(PCO)in different morphology.Ascertain accurate and practical quantification system of PCO assessment and to be able to predict outcomes following Nd:YAG laser capsulotomy.METHODS:One hundred and ninety pseudophakic eyes of 151 patients were recruited in this study,40 eyes without PCO as control,150 eyes with PCO of varying intensity and morphologic.The eyes were examined with a slit-lamp and direct ophthalmoscope. Intraocular pressure,visual acuity,contrast sensitivity and glare sensitivity were measured,Reflected-light and retroillumination digital images of the PCO was acquired after mydriasis.Sixty-seven eyes of 58 patients were re-examined 1 week after Nd:YAG laser capsulotomy.As main outcome measures,best corrected distant visual acuity was examined using logarithmic charts and and converted to a logarithm of minimal angle of resolution(log MAR)scale.Contrast thresholds with or without glare were measured using contrast glare tester(CGT-1000;Takagi Seiko,Japan).Contrast sensitivity as well as glare sensitivity was calculated as inverse value of the contrast threshold.Reflected-light and retroillumination digital images of the PCO were taken using a SONY DXC-990D 3CCD colour digital camera system based on TOPCON SL-8Z slit-lamp and saving into IMAGEnet 2000 softwarePCO was grade according Odrich’s method based on slit-lamp and direct ophthalmoscopic evaluation,density value was measured using Evaluation of Posterior Capsule Opacification(EPCO,M.R.Tetz,Ch.Nimsgern,Humboldt-niversity, Germany)and 23 eyes using Objective System Capsule Analysis(OSCA,T.M.Aslam Edinburgh-University,UK)with retroillumination digital images.After full mydriasis,67 eyes underwent Nd:YAG laser posterior capsulotomy with a Q-switched ZEISS VISULAS YAGⅡlaser.An approximately 3-mm or 4-mm diameter area of the central posterior capsule was then cleared by emitting laser energy on the capsule.1.Comparison of 3 methods for analysis of posterior capsule opacification:To compare the results of PCO severity and correlation between the measurement of PCO severity and visual function testing in 23 eyes.2.The effect of Posterior Capsule Opacification on visual function:Compare the correlation between visual acuity,contrast sensitivity,glare sensitivity,and the degree of posterior capsule opacification(PCO)in different morphologic.3.The improvement in visual function after Nd:YAG laser posterior capsulotomy:Compare the improvement in visual function before and after Nd:YAG laser posterior capsulotomy in different extents and the influence of two different diameter of posterior capsulotomy:RESULTS:1 Comparison of 3 methods for analysis of posterior capsule opacification:1.1 To compare the EPCO scores,OSCA scores and clinical PCO severity,EPCO scores and OSCA score showed a significant correlation(r=0.508,P＜0.05),and EPCO scores showed a better correlation with clinical PCO severity and IogMAR (r=0.711、r=0.669,P＜0.01)than OSCA score(r=0.415、r=0.512,P＜0.05),also logCS、logGS showed a best orrelation with EPCO scores.1.2 Correlation between the EPCO area and total scores measured by 3 independent observers using a library of 30 retroillumination images ranging from clear posterior capsules to very severe PCO.Correlations between EPCO area of 3 clinicians are significant(r=0.864,0.878,0.832 P＜.001),between EPCO scores are more significant (r=0.977,0.977,0.965 P＜.001). 2 The effect of Posterior Capsule Opacification on visual function:2.1 Mild PCO is classified into 3 morphologys as clouding(or trace)6 eyes,fibrosis 21 eyes,thin layer 35 eyes.The visual acuity impaired in patients with thin layer and preserved in the others,but it is impaired in high frequency contrast sensitivity of clouding and intermediate frequency glare sensitivity of fibrosis.2.2 Moderate PCO is classified into 3 morphologys as fibrosis 6 eyes,thick layer 27 eyes,pearl 26 eyes.No difference on visual acuity each other,but it is significant different on contrast sensitivity and glare sensitivity.Patients with pearl-type PCO had lower contrast sensitivity and glare sensitivity than those with fibrosis-type PCO, thick layer was in the middle of the two types and approach to pearl-type.2.3 A strong correlation existed between the EPCO scores and visual function with pearl-type PCO,logcs2.5°= 1.94—0.48epco(r:0.-632、p＜0.01)loggs2.5°= 2.04—0.60 epco(r:-0.676、p＜0.01),a weak and significant correlation with layer-type PCO,no significant correlation with clouding and fibrosis types.3 The improvement in visual function after Nd:YAG laser posterior capsulotomy3.1 Classified 67 eyes underwent Nd:YAG laser posterior capsulotomy into 4 groups according EPCO scores,EPCO＜1,1≤EPCO＜2,2＜EPCO＜3,EPCO≥3.There is no difference on visual function between groups after Nd:YAG laser posterior capsulotomy.No improvement on visual function after capsulotomy in group EPCO＜1,but significant improvement in the other 3groups.3.2 Nd:YAG laser posterior capsulotomy in different diameter of capsulotomy 3-mm 24 eyes and 4-mm 43 eyes,no difference on visual function between groups after capsulotomy,but compared to no PCO patients,it was impaired at low to intermediate frequencies contrast sensitivity and all spatial frequencies glare sensitivity.CONCLUSION:1 EPCO is a accurate and practical quantification system of PCO assessment,it is good correlation with completely objective OSCA,and showed a better correlation with clinical PCO severity and visual function.It was successfully used to calculate the severity of PCO.And the assessment is simple,the individual difference of the Examiner is slight and reproductive well.2 Contrast sensitivity and glare sensitivity has a strong association with PCO than does visual acuity and therefor should be considered to reflect most accurately the degree of PCO.The effect of PCO on visual function is different in varing morphology.Pearl -type PCO impaired visual function severely,clouding and fibrosis types PCO effect slight,thick layer-type PCO approach to pearl-type.3 The EPCO will be able to predict outcomes following Nd:YAG laser capsulotomy.If EPCO＜1,the patient is not proper to be treatment,and EPCO≥1 the patient underwent capsulotomy can improve visual function significant.No significant difference in 3mm or 4mm diameter capsulotomy on visual function.But the opacification at periphery of posterior capsule considered impaired contrast sensitivity and glare sensitivity particularly.更多还原