The Comparative Study Of Clinical Data And Pathology Of Posterior Capsule Opacification Between Er:YAG Laser Emulsification And Phacoemulsification For Cataract Surgery

Objective:To compare the clinical data and pathology of posterior capsule opacification between Er:YAG laser emulsification and phacoemulsification for cataract surgery, and to evaluate the safety and efficiency of Er:YAG laser emulsification to prevent of posterior capsule opacification after cataract surgery.Methods:This randomized prospective clinical study included 167 consecutive cataractous eyes from 2000.10 ~ 2001.12 in changzheng hospistal: 85 eyes underwent conventional phacoemulsification (group A) , and 82 eyes underwent surgery with the Er:YAG laser (group B) . The two groups were further classified by cataract density. Patients groups were examined 6 months postoperatively to evaluate surgical time, intraocular pressure(IOP), pachymetry, endothelial cell loss, posterior capsule opacification and visual acuity. Thirty New Zealand rabbits (30 eyes) were randomly divided into two groups: (group A), Er:YAG laser emulsification (group B). All eyes were examined by slit-lamp microscopy, light and electron microscopy were taken 12 weeks after surgery.Results:With phacoemulsification, there were no significant changes in IOP compared with the preoperative measurements. Laser emulsification of 4+ cataracts resulted in IOP increases of 10.5 %, and compared with â…  , â…¡ and â…¢ cataracts, there were significant difference(p<0.01). Slight endothelial cell losses occurred in all cases. In group A, the results were similar, but with laser, the results were significantly decrease of 8.2 % with IV cataracts. In group A, the visual acuities were similar with all types of cataract; in group B, similar values were seen with â… , â…¡ and â…¢ cataracts, but with IVcataracts, the average visual activity was much poorer compared treated with group A (p<0.01). The rates of posterior capsule opacification at post-operative 1 year and 3 year in laser emulsification surgery group were 9.8% and 14.7%, respectively; and those in phaco group were 45.9% and 49.4%. The differences were significant.(p<0.01). In the 3th day after the operation, aqueous flare in group A was more sevious than in group B. The difference was significant (x~2=8.084, p=0.032). In our animal experiment, the rate of posterior capsule opacification at post-operative 12 weeks of Er:YAG laser emulsification group is much lower thanphacoemulsification group ( *2=10.461,/7=0.001). Light and electron microscopy did not revealed any active cell proliferation in the posterior capsules in Er:YAG laser emulsification group.Conclusion:Er:YAG laser emulsification was as effective and reliable as phacoemulsification in removing cataracts and can effectively inhibit the occurrence of posterior capsule opacification.