BOSTON — The investigational compound OMS302 (Omeros Corp.) is safe and effective in preventing miosis and maintaining mydriasis during surgery for intraocular lens replacement, 2 new phase 3 studies show. It also controls acute postoperative pain.
Preventing pupillary constriction during lens replacement surgery can help prevent trauma and inflammation. Because there is no product currently approved by the US Food and Drug Administration (FDA) for this indication, doctors in the United States commonly resort to compounding epinephrine and working with off-label combinations.
OMS302 is a safer FDA-approved alternative, said lead author Thomas Walters, MD, an ophthalmologist from Texan Eye in Austin.
OMS302 contains low concentrations of the alpha-1-adrenergic receptor agonist phenylephrine HCL (483 µmol/L) and the nonsteroidal anti-inflammatory drug (NSAID) ketorolac (89 µmol/L). This combination is added to a standard irrigating solution that is used continuously during intraocular lens replacement surgery.
"This would be the first product of its kind, filling a niche with an effective and safe alternative to having a nurse mix and match an extremely accurate dilution that is not FDA-approved in the operating room," he told Medscape Medical News.
Dr. Walters presented combined results from the 2 double-masked phase 3 trials here at the American Society of Cataract and Refractive Surgery 2014 Symposium.
In the intent-to-treat analyses, all patients received standardized preoperative topical mydriatics and anesthetics (lidocaine or tetracaine) during surgery. In addition, 403 were randomized to receive OMS302 and 405 were randomized to receive placebo.
Intraoperative pupil diameter, measured every minute during the surgery, was well maintained in the OMS302 group, whereas steady pupil constriction was seen in the placebo group (P < .0001).
Fewer patients in the OMS302 group than in the placebo group had a pupil diameter smaller than 6 mm during surgery (10% vs 42%; P < .0001), and fewer patients in the OMS302 group had pupil constriction of more than 2.5 mm during surgery (2% vs 27%; P < .0001).
Overall pain, assessed every 2 hours for 12 hours after surgery, was less in the OMS302 group than in the placebo group (P < .0001).
Table. Pain Measured After Surgery
|Pain||OMS302 Group, n (%)||Placebo Group, n (%)||P Value|
|None||104 (26)||69 (17)||.0027|
|Moderate to severe||29 (7)||57 (14)||.0014|
Adverse events were assessed for 14 days after surgery. Eye pain was less common in the OMS302 group than in the placebo (30% vs 40%), as was headache (6% vs 9%), but eye inflammation and anterior chamber inflammation were similar in the 2 groups.
Although the NSAID ketorolac is available for topical and systemic treatment, OMS302, if approved, would be the first intraocular injection, Dr. Walters reported.
"Pain medication is commonly used pre- or postoperatively, but everything that goes into the eye preoperatively gets washed out in the irrigating process," he explained. "With this combination product, there is constant irrigation during the surgery itself, so the eye is continuously bathed in the product, allowing for improved postoperative pain control."
Session moderator Paul Arnold, MD, from Eye Surgeon Associates in Bettendorf, Iowa, said he agrees that this product could fill an important need for ocular surgery.
"I was impressed by the findings presented," he told Medscape Medical News.
"It would certainly be preferable to have a drug that is uniform and meets FDA production standards, rather than relying on a hospital pharmacy or compounding pharmacy," he explained.
Dr. Arnold suggested that strengthening the concentration could make it even more effective. "If I were in charge of formulating this drug, I would try to get higher concentrations of both medications," he said.
"Once proven safe and effective, I would recommend using it in all cataract cases."
Dr. Walters reports receiving travel reimbursement and research support from Omeros Corp. His coauthors are all paid consultants for Omeros Corp. Dr. Arnold has disclosed no relevant financial relationships.
American Society of Cataract and Refractive Surgery (ASCRS) 2014 Symposium. Presented April 27, 2014.
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Cite this: Combination Drug Shown to Prevent Miosis in Ocular Surgery - Medscape - May 07, 2014.