Investigators prospectively compared the effects of bromfenac and indomethacin on intraoperative pupil size during cataract surgery.
This randomized, controlled single-center study included 53 patients who were prescribed topical bromfenac 0.09% (once daily) or indomethacin 0.1% (4 times daily) during the preoperative period. Patients were divided into 4 groups: 12 patients underwent femtosecond laser–assisted cataract surgery (FLACS) with bromfenac, 12 patients underwent FLACS with indomethacin, 12 patients underwent corneal paracentesis with bromfenac, and 17 patients underwent corneal paracentesis with indomethacin.
Pupil diameter was measured at 5 time points, and cytokine levels (IL-1B, IL-2, IL-4, IL-5, IL-6, IL-8, IL-8, IL-10, IL-12p70, IFN-gamma, TNF-alpha, and TNF-beta) were obtained from aqueous humor samples prior to starting the phacoemulsification portion of the surgery.
This study found that IL-6 appears to be a prominent cytokine that can be viewed as a biomarker for cytokine imbalance caused by surgical intervention. This was supported by the fact that patients who received bromfenac were able to better maintain intraoperative mydriasis and had lower expression of IL-6. This suggests bromfenac may be a better inhibitor of pro-inflammatory cytokines. This was observed in both the FLACS groups and the paracentesis-only groups.
One limitation of this study was that the aqueous samples were obtained at different time points during the surgery as it was necessary to inject viscoelastic and perform a capsulotomy in the paracentesis-only groups, whereas the samples from the FLACS group was obtained immediately after paracentesis. Another limitation, which was mentioned by the authors, could have been due to how the samples were stored prior to analysis. The most significant limitation is the fact that every person reacts differently to surgical trauma, and this unknown cascade of inflammatory factors in each individual could confound the results, especially considering the small sample size.
Adequate pupil dilation is important for good surgical results, especially since the arrival of FLACS. Knowing which inflammatory cytokines can affect pupil size is important as we develop better anti-inflammatory and mydriatic agents. As we know, NSAIDs are known inhibitors of pro-inflammatory cytokines, yet indomethacin is not as commonly used as other NSAIDs such as bromfenac in cataract surgery. The findings here show that bromfenac may be superior, but the greatest benefit is the knowledge of which cytokines that are important for mydriasis, which could be useful in directing future research.