Drug device safe, tolerated for post-cataract pain

By Lynda Charters; Reviewed by John Berdahl, MD

Use of a dexamethasone insert 0.4 mg (Dextenza, Ocular Therapeutix) to treat pain after cataract surgery was found to be both safe and well tolerated, with incidence rates of adverse events similar to those that developed in the placebo group.

The drug was evaluated in two multicenter phase III clinical trials of postoperative pain and inflammation, and the data from the trials were pooled to reach this conclusion.

One of the investigators, John Berdahl, MD, in private practice at Vance Thompson Vision, Sioux Falls, SD, explained that sustained-release intracanalicular drug inserts have been developed to deliver ophthalmic medications to the ocular surface. This technology facilitates one-time administration of a corticosteroid postoperatively that delivers a tapered, extended-release dose of dexamethasone over a period of about 4 weeks.

However, concerns have been expressed about the use of a corticosteroid during the perioperative period, with a special concern being spiking of IOP.

Additional concerns associated with this type of device include material retention in the eye and the potential for development of canaliculitis.

Diving deeper

Dr. Berdahl and colleagues pooled the data from the phase III clinical trials in which the dexamethasone insert was evaluated to determine the effect of implantation of the device on pain and inflammation after cataract surgery. The results of these trials had been presented previously.

Patients were included who had a visually relevant cataract and were scheduled to undergo clear corneal cataract surgery with phacoemulsification and implantation of a posterior IOL and a potential postoperative pinhole-corrected Snellen visual acuity of 20/200 or better in both eyes.

Study patients were evaluated during visits that occurred over 90 and 120 days.

The primary study endpoints were the absence of pain at day 8 postoperatively and the absence of anterior chamber cells at day 14 postoperatively.

Safety evaluations included the recording of adverse events, slit-lamp biomicroscopy, IOP and visual acuity measurement, and a dilated fundus examination. IOP spikes of 10 mm Hg or higher and canaliculitis were considered treatment-emergent adverse events.

A total of 322 patients received the dexamethasone insert on the day of surgery, and 172 adverse events were reported by these patients; in the placebo vehicle group, 106 adverse events were reported.

Dr. Berdahl noted that the proportion of subjects with at least one adverse event was similar in the two treatment groups; more subjects in the placebo group reported at least one ocular adverse event in the study eye compared to the patients treated with the dexamethasone insert. No serious adverse events in either study group were related to the treatment.

The most frequent ocular adverse events in the dexamethasone insert and placebo groups, respectively, were anterior chamber inflammation, characterized as anterior chamber inflammation (5.9% and 7.3%), iritis (4.0% and 9.1%), or iri docyclitis (0% and 0%); increased IOP (5.6% and 4.3%); corneal edema (1.6% and 5.5%); and ocular inflammation (0% and 3.0%).

The insert could be visualized in 100% and 90% of subjects on days 14 and 30 postoperatively, respectively. One subject in the placebo group and no patients in the dexamethasone insert group withdrew from the study as the result of an adverse event. 

John Berdahl, MD

e: johnberdahl@gmail.com

This article was adapted from a presentation at the 2017 meeting of the American Academy of Ophthalmology. Dr. Berdahl is a consultant to Ocular Therapeutix and an investigator in this study. Ocular Therapeutix sponsored this study.