后房型人工晶体倾斜和偏心的活体测量及研究

Measurement and research of posterior chamber intraocular lens tilt and decentration in vivo

目的观察后房型人工晶体在活体眼内的位置情况，倾斜、偏心对术后视力的影响。方法采用通过第３、第４浦肯野影像测量人工晶体倾斜及眼前节照片测量人工晶体偏心的方法，对６４只白内障囊外摘除及人工晶体植入术后的活体眼进行测量。结果平均倾斜（６．９５±２．４６）°；平均偏心（０．６６±０．２８）ｍｍ。对称性固定袋袋组与不对称性固定袋沟组比较，倾斜和偏心差异均有非常显著性（Ｐ＜０．００１）。其中袋袋固定方式中，无放射状撕裂平均偏心最低０．３２ｍｍ。倾斜＞９．６５°同时偏心＞１．０２ｍｍ时，眩光、单眼复视等症状明显。结论人工晶体于无前囊放射状撕裂的囊袋中最稳定，保持中心位置最持久。倾斜、偏心不同程度地影响术后视力质量。

Objective To observe the situation of implanted lenses in vivid eyes and postoperative visual acuity affected by the lens tilt and decentration. Methods 64 eyes underwent extracapsular cataract extraction with posterior chamber lens implantation. Postoperatively, the lens tilt was measured by means of the 3 rd and 4 th Purkinje images, and the decentration of lenses was measured on the anterior segment photographs taken with a fundus camera. Results The mean tilt was (6.95±2.46)°, and the mean decentration, (0.66±0.28) mm. There were a significant differences in the tilt and decentration between the symmetrical bag/bag and asymmetrical bag/sulcus group ( P <0.001). Bag/bag group without tear had less average decentration 0.32 mm. When tilt was more than 9.65 degrees and decentration was more than 1.02 mm, the symptom such as glare or monocular diplopia was obvious. Conclusions These results indicate that in the bag without tear, the lenses have a perfect stability and consistent centration, and the tilt and decentration of the implanted lens affect postoperative visual quality in varying degrees.