EyeWorld Asia-Pacific September 2015 Issue

23 September 2015 EWAP FEATURE Plugging up cataract compliance issues by Maxine Lipner EyeWorld Senior Contributing Writer Dexamethasone- dispensing device makes inroads I magine not having to worry about cataract patients taking their medications to control pain and inflammation postoperatively. A new tear duct implant has been developed to automatically dispense dexamethasone, according to Thomas R. Walters, MD, in private practice at Texan Eye, Austin, Texas. This device, called the OTX-DP (Ocular Therapeutix, Bedford, Mass.), provides up to a month of sustained reduction of inflammation and pain following cataract surgery, he reported. Development of this first-of- its-kind device was spurred by compliance factors that can be an issue in some cases, particularly for the elderly, Dr. Walters noted. “To get reliable dosing, it is nice to take that out of the patients’ hands and present a delivery system that can be trusted to deliver the exact steroid dose over the time period that we need for cataract surgery,” he said, adding that this gives predictable, reliable dosing of the dexamethasone used for reducing the postoperative pain and inflammation associated with cataract surgery. Eyeing the plug The device is easy to implant. “It’s placed through the lower punctum into the ampulla of the distal canaliculus of the lower or upper tear drainage system,” Dr. Walters said. “It’s just like inserting any other punctum plug, with which all ophthalmologists have experience.” It glides in and once it is in the ampulla of the distal canaliculus, it expands and stays lodged in place, eluting the dexamethasone over the prescribed period, he explained. Dr. Walters views the OTX- DP as an improvement over the use of traditional drops. “With this product, the dexamethasone slowly elutes from the plug and provides a constant dosing,” he said. “With traditional drops, you get a dose and then you get a spiked dose response curve, which then diminishes after the drop is delivered.” The OTX-DP dosing is more precise, and it takes the patient’s compliance with self-dosing out of the equation, Dr. Walters said. Studying outcomes Recent study results have been promising. In the study, 59 patients were randomized to either receive dexamethasone delivered through the OTX-DP or a placebo plug as the sole postoperative anti-inflammatory after cataract surgery, Dr. Walters explained. For those receiving the dexamethasone-eluting punctum plug, inflammation was readily curtailed. “Results of the plug (with dexamethasone) were statistically significant for absence of postoperative pain compared to placebo at all time points,” Dr. Walters said. “The dexamethasone plug also showed statistical superiority over placebo for absence of cells in the anterior chamber at day 14.” What’s more, the plug eluting the dexamethasone showed statistical superiority over the placebo plug with regard to the need for adding rescue medications for breakthrough inflammation postoperatively, he said. Dr. Walters was a bit surprised by the results. “I didn’t think that a single agent such as an external delivery device would be able to deliver a consistent ability to control inflammation,” he said. “Also, the patients were very comfortable with the device and liked the fact that they didn’t have to self-deliver an eye drop to the eye.” When it came to pain management, the dexamethasone plug was statistically superior, he noted. There were no adverse events reported with use of the device. Once its usefulness is served, the plug itself ultimately dissolves. “The implant turns into a gel and then over a 30- to 60-day period turns into a liquid and is flushed out by the natural tear pump mechanism that pumps through the tear drainage system,” Dr. Walters explained. “The plug just washes away in the natural tear flow through the nasal lacrimal system.” While this phase 2 FDA study of the punctum plug only involved dexamethasone, the device could also be useful for other agents, Dr. Walters said. “There are plans in development for pharmaceuticals associated with other conditions, including delivery of prostaglandins for glaucoma and other pharmaceuticals associated with glaucoma care or anti- inflammatory care like nonsteroidal anti-inflammatories,” he said. Next up is to obtain FDA approval for the punctum plug and start getting clinical experiences with this over a broad spectrum of applications so that it’s not just limited to cataract surgery, Dr. Walters said. In addition, he hopes to have the plug available for acute use of anti-inflammatory indications such as seasonal allergies or iritis. Overall, he views the punctum plug as making new inroads in cataract management. “I think this is a game changer for the delivery of postoperative anti-inflammatory medication to the eye,” he said. “It takes patients’ compliance to drop therapy out of the equation.” EWAP Editors’ note: Dr. Walters has financial interests with Ocular Therapeutix. Contact information Walters : Tom@nobhill.me The OTX-DP automatically dispenses dexamethasone. Source: Thomas R. Walters, MD