AIM: To assess the effect of intraocular lens' material and posterior surface curvature on capsular bend speed.

METHODS: A non-randomized clinical trial. According to the implanted intraocular lens(IOL), senile cataract patients were divided into three groups, 15 eyes in Proming^®A1-UV group, 15 eyes in Akreos^® AO group and 15 eyes in AcrySof^® IQ group. The adhesion degree between capsule and IOL optic edge in eyes was measured by slit lamp at 1d, 1wk, 2wk and 4wk after cataract surgery.

RESULTS: At postoperative 1d, the Capsular Bend Indexs(CBIs)of A1-UV group, AO group, IQ group were 3.34±0.22, 3.00±0.19, 3.45±0.42, respectively and the differences were statistically significant(χ²=16.55, P<0.05). Pairwise comparison results showed that the difference between A1-UV group and AO group was statistically significant(χ²=12.02, P<0.05). The difference between A1-UV group and IQ group was no statistically significant(χ²=0.01, P>0.05). The difference between AO group and IQ group was statistically significant(χ²=12.79, P<0.05). At postoperative 1wk, the CBIs of A1-UV group, AO group, IQ group were 4.01±0.04, 3.08±0.26, 3.50±0.44, respectively and the differences were statistically significant(χ²=29.07, P<0.05). Pairwise comparison results showed that the difference between A1-UV group and AO group was statistically significant(χ²=28.64, P<0.05). The difference between A1-UV group and IQ group was statistically significant(χ²=10.53, P<0.05). The difference between AO group and IQ group was no statistically significant(χ²=4.44, P>0.05). At postoperative 2wk, the CBIs of A1-UV group, AO group, IQ group were 4.04±0.08, 3.15±0.32, 3.53±0.47, respectively and the differences were statistically significant(χ²=27.49, P<0.05). Pairwise comparison results showed that the difference between A1-UV group and AO group was statistically significant(χ²=26.69,P<0.05). The difference between A1-UV group and IQ group was statistically significant(χ²=11.28, P<0.05). The difference between AO group and IQ group was no statistically significant(χ²=3.27, P >0.05). At postoperative 4wk, the CBIs of A1-UV group, AO group, IQ group were 4.04±0.08, 3.16±0.36, 3.65±0.46, respectively and the differences were statistically significant(χ²=25.14, P<0.05). Pairwise comparison results showed that the difference between A1-UV group and AO group was statistically significant(χ²=25.15, P<0.05). The difference between A1-UV group and IQ group was statistically significant(χ²=7.11, P<0.05). The difference between AO group and IQ group was no statistically significant(χ²=5.52, P>0.05).

CONCLUSION: Capsular bend speed can be influenced by the combined action of IOL's material and posterior surface curvature. IOL's material significantly influences capsular bend speed at postoperative 1d. Hydrophobic acrylic IOL speeds up the capsular bend. At postoperative 1-4wk, the main factor influencing the capsular bend speed is mechanical structure, with a weakening influence of material. IOL with high convex posterior surface can form capsule bend rapidly, expedite the procedure of the capsular adhesion toward the optic edge, and reduce the time of migration and proliferation of lens epithelial cells to the posterior capsule, which has important clinical application value.