Clinical outcomes and safety of intra-capsular bag soft-shell technique during phacoemulsification for hard nuclear cataract

Background

Phacoemulsification for hard nuclear cataract is easy to cause corneal edema and posterior capsular rupture.Researches determined that soft-shell technique phacoemulsification can effectively reduce corneal edema, but the risk of posterior capsular rupture during the surgery is still existed.Whether intra-capsular bag soft-shell technique can protect the posterior capsular of lens from rupture is still unclear.

Objective

This study was to observe the effect of intra-capsular bag soft-shell technique phacoemulsification on hard nuclear cataract.

Methods

A prospective cohort study was designed.One hundred and sixty-eight eyes of 160 patients with age-related cataract and Ⅳ-Ⅴ grade of nucleus were enrolled in Affiliated Second Hospital of Zhengzhou University from November 2013 to May 2015 under the approval of Ethic Commission and informed consent of the patients.The eyes were randomized into the intra-capsular soft-shell technique group and conventional soft-shell technique group with the matched age, gender and nuclear hardness in a manner of randomized block design.A 3.0 mm incision of cataract phacoemulsification with soft-shell technique in capsular bag was performed on 80 eyes of 78 patients in the intra-capsular soft-shell technique group, and conventional soft-shell technique phacoemulsification was performed on 88 eyes of 82 patients in the conventional soft-shell technique group.Intraoperative records including the cumulative dissipated energy, effective phacoemulsification time and posterior capsular changes were recorded during the surgery.Postoperative follow-up indexes included corneal edema, endothelial cell density, BCVA and intraocular pressure changes.

Results

The mean cumulative dissipated energy and operation duration were (20.13±8.34)% and (14.28±2.17) minutes in the intra-capsular soft-shell technique group, and those in the conventional soft-shell technique group were (19.67±5.24)% and (15.36±3.49) minutes, showing significant differences between them (t=0.216, P=0.376; t=0.403, P=0.518). Posterior capsular rupture occurred in 1 eye in the intra-capsular soft-shell technique group and 7 eyes in the conventional soft-shell technique group.The percentages of eyes with BCVA≥0.5 were 78%, 83% and 92% in postoperative 1 day, 1 week and 1 month in the intra-capsular soft-shell technique group, and those in the conventional soft-shell technique group were 56%, 71% and 89%, with a significant increase in postoperative 1 day, 1 week in the intra-capsular soft-shell technique group (χ²=5.130, P=0.027; χ²=4.361, P=0.032). The corneal endothelial cell loss rates were 6.97% and 7.19% in the intra-capsular soft-shell technique group and conventional soft-shell technique group respectively in postoperative 3 months, with no significant difference between them (P>0.05). The intraocular pressure was (20.16±4.23)mmHg (1 mmHg=0.133 kPa) in postoperative 1 day in the intra-capsular soft-shell technique group, which was significantly higher than (17.38±5.21)mmHg in the conventional soft-shell technique group (t=1.241, P=0.037).

Conclusions

Intra-capsular bag soft-shell technique phacoemulsification for hard nuclear cataract can decrease the intraoperative and postoperative complications and quicken the visual recovery after surgery.

Cataract/surgery; Cataract, hard nuclear; Phacoemulsification; Soft-shell technique in capsular bag; Treatment outcomes; Safety