Reduction in surgical time and iris manipulation using continuous intracameral irrigation of phenylephrine and ketorolac to prevent miosis in FLACS

In their study of the effect of replacing intracameral irrigation of phenylephrine with intracameral irrigation of ketorolac and phenylephrine during femtosecond laser–assisted cataract surgery (FLACS), Walter et al.1 retrospectively assessed the rate of phacoemulsification surgery requiring pupil expansion devices. They also reported the time recorded for surgery after introducing phenylephrine 1.0%–ketorolac 0.3% (Omidria) into their routine cataract surgery technique. Because of the retrospective cohort design of the study, several key measurements were not performed throughout the trial and potential sources of bias were introduced. Before incorporating the addition of ketorolac into the irrigating fluid during routine surgery, it would be preferable to perform a randomized controlled trial (RCT) to further remove the bias associated with cohort studies. We reject the authors’ suggestion that there is sufficient clinical evidence of benefit to render an RCT on this issue unethical. As mentioned, several measurements were missed, and these would have increased the validity of the authors’ conclusions. The main variable that was not recorded was the intraoperative pupil diameter, which should have been measured at the start of surgery at various timepoints throughout the case. The authors state that reduced surgical time is a main benefit of Omidria; however, they do not explore whether more cases could be scheduled within the time gained. Furthermore, we suggest that for most routine cataract surgeries in which the pupil diameter is moderate to very large, the pupil diameter itself should not modify the surgical time and that a substantial reduction in pupil size would have to occur before the surgical technique is affected. Thus, we cannot quite understand why there was a 14.0% reduction in surgical time with the use of Omidria. In addition, the authors do not mention the cost incurred from using the altered irrigation solution and no cost-benefit analysis was performed. Due to this product not being available in the United Kingdom, we lack clinical experience with its use; however, our understanding is that Omidria has “pass-through” status in the United States. This means the surgeon receives a separate reimbursement from the surgical procedure at the average selling price plus 6.0%.A Therefore, rather than incurring additional cost from using this product, surgeons are in a position to increase their profits. Also, the financial declarations from the paper’s authors relating to the manufacturer of Omidria (Omeros Corp.) are not ideal for a study of this nature. In this series, the addition of a nonsteroidal antiinflammatory drug (NSAID) into the irrigating fluid was in conjunction with a 2-day preoperative course of topical bromfenac. We note an absence of a proposed rationale for the benefit of dual routes of NSAID delivery. We would be interested to know the authors’ thoughts on why this provides an additional benefit. The introduction of a new drug into surgery comes with associated risks. It is of the utmost importance to patient safety to highlight any adverse events of a new therapy or route of delivery, none of which were mentioned in the study. We would caution against introducing additional intracameral drugs when they are not required. In particular, we would welcome a study of the endothelial cell counts after cataract surgery with and without Omidria. There is little mention of other preoperative medications, for example the preoperative mydriatic therapy used, which is of particular importance for a study of intraoperative pupil size. We would like to use this opportunity to recommend our mydriatic regimen for FLACS, which we presented in a prospective randomized controlled study.3 After the introduction of the femtosecond laser to our unit, we saw several cases of post-laser miosis during the surgical learning curve. This was often refractory to preoperative pharmacologic agents, such as intracameral phenylephrine, thus requiring the use of mechanical pupil stabilization. Based on personal correspondence and available evidence in the literature, we adopted the following regimen: (1) preoperative mydriasis using a tropicamide 0.28 mg–phenylephrine 5.4 mg (Mydriasert) ophthalmic insert, (2) 2 drops of topical preoperative diclofenac sodium 0.1% w/v given at least 15 minutes apart,2 and (3) 1 drop of tropical phenylephrine 10.0% after laser delivery. With this regimen, there was only 1 documented case of post-laser miosis requiring the use of a Malyugin ring (0.5%) and 1 additional recorded case of intraoperative floppy-iris syndrome (0.5%) in the FLACS group in our RCT of 200 eyes of 200 patients.3 In summary, we propose that with the correct preoperative mydriatic regimen, FLACS–associated miosis can be avoided. We struggle to reach the same conclusions based on the data presented by Walter et al.1 We would therefore recommend our above protocol to readers performing FLACS in the absence of more robust clinical evidence supporting the additional inclusion of an intracameral NSAID in the irrigating fluid.