不同类型和部位后发性白内障对视功能的影响

The effect of location and type of posterior capsule opacification on visual function

目的应用计算机图像分析软件评价后发性白内障(posterior capsule opacification,PCO)的形态,以探讨不同类型、部位PCO对最佳矫正视力(best corrected visual acuity,BCVA)、对比敏感度(contrast sensitivity,CS)和眩光敏感度(glare sensitivity,GS)的影响。方法收集拟行激光后囊切开术的PCO患者61例(67眼),充分散瞳,行详细眼科检查后,应用裂隙灯照相获取PCO后照法照片,使用PCO计算机分析软件(POCOman软件)对其进行形态学分析。同时分别测量所有患者激光后囊切开术术前及术后1周BCVA、CS、GS。分析不同类型、不同部位PCO对BCVA、CS、GS的影响。结果珍珠型PCO的BCVA、各频段CS和GS均低于纤维型PCO,且两者之间的差异有统计学意义(P<0.05)。其中,4.0mm珍珠型PCO在低、中频段CS和中频段GS均低于中央2.0mm珍珠型PCO,差异有统计学意义(P<0.05);中央2.0mm纤维型PCO在中、高频段CS和低、中频段GS均低于中央4.0mm纤维型PCO,差异有统计学意义(P<0.05)。中央2.0mm珍珠型PCO对BCVA的影响最为显著;中央4.0mm珍珠型PCO对CS和GS的影响最为显著。结论珍珠型PCO对BCVA、各频段CS和GS的影响大于纤维型PCO。珍珠型PCO在中央4.0mm区对视功能的影响大于中央2.0mm区;纤维型PCO在中央2.0mm区对视功能的影响大于中央4.0mm区。

Objective To use computer-aided picture analysis methods （POCOman software） to evaluate posterinr capsule opacification （PCO）, and to investigate the correlation between the changes in best corrected visual acuity （BCVA）, contrast sensitivity （CS）, and glare sensitivity （GS） and the difference in the morphology characteristics of PCO. Methods After pupil dilation, 67 slan- dardized digital retrnilhnnination images nf eyes （61 cases） with PCO were selected using a slit-lamp photographic system （digital camera with computer）. The images were analyzed with POCOman software hy masked examiners. Measurements of best corrected visual acuity, contrast sensitivity and glare sensitivity we,re obtained before and 1 week after Nd：YAG laser capsulotomy. The correlations between BCVA, CS, GS anti different morphologic characteristies nf PCO were analyzed. Results BCVA, CS and GS at all spatial frequencies in the pearl-type PCO were lower than those in the fibrosis-type PCO and they were significantly different （P〈 0.05）. CS al low and medium spatial frequeneies and GS at medium spatial frequencies in the eentral 4.0 mm of the pearl-type PCO were lower Ihan that of the central 2.0 mm of the same area and they were signifieantly different （P〈0.05）. CS at mediunl and high spatial frequencies and GS at low and medium spatial frequencies in tile central 2.0 mm of the fibrosis-type PCO were lower than that of the central 4.0 mm in the same area and they were significantly different （P〈0.05）. The effeet on BCVA was primarily correlated to the pearl-type PCO in the central 2.0 ram; the effects on CS and GS were primarily correlated to the pearl-type PCO in the central 4.0 ram. Conclusion The effects on BCVA, CS and GS at all spatial frequencies in the pearl-type PCO were greater than that of the fibrosis-type PCO. The pearl-type PCO in the central 4.0 mm had a greater effect on yisual tuuetion than that of the central 2.0 mm. The fibrosis-type PCO in the central 2.0 mm had a greater effect on visual function than that of the central 4.0 mm.