Effects Of Different Energy Levels On The Generation Of Oxidative Stress In Femtosecond Laser-Assisted Cataract Surgery

Phase I: A total of 60 porcine eyes were used. The eyes were randomized into 2 groups that underwent femtosecond assisted (FSL) capsulotomy and/or lens fragmentation (50 eyes) and a control group without laser treatment (10 eyes). The capsulotomy energy was either 90 % or 150%, and the lens fragmentation energy was either 90% or 100% or 150% (n=5 for each). Phase II: 28 patients were randomized to receive conventional phacoemulsification or FLACS (n=14 eyes for each). Another matched cohort of 43 eyes received FLACS with preoperative topical ketorolac tromethamine (FLACS-NSAID group; 90 % or  150% capsulotomy energy). Aqueous oxidative stress was evaluated by measuring malondialdehyde (MDA) and superoxide dismutase (SOD) using ELISA.

In porcine experiments, an increase in fragmentation energy resulted in increased MDA and SOD production, while an increase in capsulotomy energy did not significantly change the oxidative stress production. In the clinical cohort, the difference in the aqueous MDA levels between all FLACS groups and the control group was statistically significant. After phacoemulsification, the MDA levels insignificantly increased in the conventional, FLACS and FLACS-NSAID groups, in comparison with the levels before phacoemulsification. An increase in capsulotomy energy did not increase the MDA level. The preoperative NSAID treatment did not suppress the MDA increase resulting from laser pretreatment.

Increased lens fragmentation energy resulted in increased aqueous oxidative stress in FLACS, and this oxidative stress reaction was not suppressed by preoperative NSAID treatment.