Changes in aqueous oxidative stress, prostaglandins, and cytokines: Comparisons of low-energy femtosecond laser-assisted cataract surgery versus conventional phacoemulsification

Abstract

Purpose: To compare the aqueous oxidative stress, prostaglandin E₂ (PGE₂), and cytokine levels after low-energy femtosecond laser-assisted cataract surgery versus conventional phacoemulsification, and to evaluate the effect of a nonsteroidal antiinflammatory drug (NSAID) on the aqueous profiles.

Setting: Singapore National Eye Center, Singapore.

Design: Randomized controlled trial.

Methods: Thirty-five patients were randomized to receive conventional phacoemulsification in one eye and femtosecond laser-assisted cataract surgery in the fellow eye. Another matched prospective cohort of 35 patients was included to receive femtosecond laser-assisted cataract surgery with a preoperative NSAID. Aqueous humor was collected after the laser was used or at the beginning of surgery (conventional phacoemulsification), and at the end of phacoemulsification. The levels of aqueous malondialdehyde (MDA), PGE₂, and cytokines, chemokines, and growth factors were analyzed. The postoperative aqueous flare levels were evaluated.

Results: Compared with the conventional group, the femtosecond-assisted group had a significantly higher PGE₂ (P = .01) and interleukin-1 receptor antagonist levels (P = 0.04). The preoperative NSAID significantly reduced the PGE₂ surge (P = .002) and the mean reduction in pupil diameter (P = .02). The MDA concentrations before phacoemulsification were 0.24 μmol/L ± 0.18 (SD), 0.51 ± 0.41 μmol/L and 0.59 ± 0.52 μmol/L for the conventional, femtosecond-assisted, and femtosecond-assisted NSAID groups, respectively (P = .42). After phacoemulsification, the PGE₂ and MDA levels increased in all groups. The MDA induction was significantly correlated with the phacoemulsification time (P = .002). The postoperative flare was insignificantly higher in the femtosecond-assisted group than the conventional group.

Conclusions: Compared with conventional phacoemulsification, the femtosecond laser-assisted cataract surgery performed with the Femto LDV Z8 laser platform induced a significantly higher PGE₂ level. The MDA and postoperative aqueous flare level were insignificantly higher. The preoperative NSAID reduced the PGE₂ surge and occurrence of intraoperative miosis. The oxidative stress induced during phacoemulsification was strongly correlated with phacoemulsification time.