Purpose
To evaluate mechanical properties changes in the rabbit posterior lens capsule over the postoperative course of cataract surgery.
Methods
Phacoemulsification was performed for 9-week-old Japanese white rabbits. A capsule tension ring (CTR) and an intraocular lens (IOL: YA-60BB, HOYA) were implanted in the eye (n=3). The lens capsule was extracted in the 4-week postoperative and was fixed by fixture that was placed in normal saline at room temperature. The tensile tester (MINI44, INSTRON) with a rod was used to pierce for measuring the posterior capsule load and displacement to breaking point under the following condition; Gauge Length (1.5 mm), Speed (10 mm/min). The integral load from 1.5 mm to the breaking point in displacement was defined as total deformation energy. For comparison, five capsules, which were extracted immediately after CTR-insertion surgery, were used.
Results
The results of the piercing-load measurement are shown for the control group (Fig. 1) and the 4-week postoperative group (Fig.2). For total deformation energy, the control group scored 0.038 Nmm, whereas the 4-week postoperative group scored 0.066 Nmm, significantly higher than the control group (P=0.025).
Conclusions
The lens capsule needs more energy for deformation over the postoperative course of cataract surgery.