Combination therapy targets pupil maintenance, pain

Take-home: The combination of phenylephrine and ketorolac helped maintain pupil diameter and lowered postoperative pain compared with placebo in patients having cataract surgery in two pooled phase III studies.

AUSTIN, TEXAS-Patients who received the combination medication phenylephrine/ketorolac (Omidria, Omeros Corp.) during cataract surgery were better able to maintain their pupil diameter during surgery compared with placebo, according to Thomas Walters, MD.

The investigation looked at the pooled results from 2 phase III randomized, double-masked, placebo-controlled studies including 808 subjects-403 received phenylephrine/ketorolac and 405 received placebo. The study objectives were to measure maintenance of pupil diameter during cataract surgery or refractive lens exchange and postoperative ocular pain during the first 10 to 12 hours after surgery.

The medication was administered in standard irrigation solution during the procedure, and all subjects in both areas received standard preoperative mydriatic and anesthetic agents.

Procedure times were categorized as 10 minutes or less, longer than 10 minutes, longer than 12 minutes, longer than 15 minutes, and longer than 20 minutes. Researchers used the mean area under the curve analysis to measure intraoperative change from baseline in pupil diameter (See results in Figure 1) and postoperative subject-reported ocular pain as measured by a Visual Analog Scale (See results in Figure 2, next page).

Figure 1. Researchers used the mean area under the curve analysis to measure intraoperative change from baseline in pupil diameter.

All procedures were recorded, and changes in pupil diameter were measured at 1-minute intervals from time of incision to wound closure (end of surgery). A single masked central reader made the measurements.

Better pupil maintenance

Better pupil maintenance

Demographics and cataract characteristics were similar between the group receiving phenylephrine/ketorolac and the placebo group. The group receiving phenylephrine/ketorolac had better pupil maintenance at all time points, and there was less postoperative pain, said Dr. Walters, who is in private practice at Austin, TX.

Figure 2. Researchers used the mean area under the curve analysis to measure postoperative subject-reported ocular pain as measured by a Visual Analog Scale.

As for postoperative ocular pain, “it increased in the placebo group with increasing surgical duration, but was numerically similar in the phenylephrine/ketorolac group,” Dr. Walters added.

Adverse events were reported in 60% and 66.9% of the phenylephrine/ketorolac and placebo groups, respectively. The most common adverse events in the treatment group were eye pain and eye inflammation. Eye pain was more common in the placebo group.

The addition of phenylephrine/ketorolac to the cataract surgeon’s armamentarium is important because of the risks associated with pupil constriction, Dr. Walters said.

“You can get iris touch with the phaco probe, which induces miosis and inflammation,” Dr. Walters explained. “When you have reduced visibility of the lens, it makes the procedure more difficult for the surgeon and potentially more complicated for the patient with iris trauma and post-op inflammation.”

Concerns about pupil constriction are especially prevalent in older patients and those with floppy iris syndrome or diabetes.

“All are prone to post-op inflammation,” Dr. Walters said. “It makes the procedure more difficult if the pupil constricts. This medication aids with ease of the procedure and quicker visual recovery.”

Thomas Walters, MD.

e: tom@nobhill.me

This article was developed based on Dr. Walters’ presentation at the 2016 American Society of Cataract and Refractive Surgery annual meeting. Dr. Walters is a consultant for the Omeros Corp.