Investigational Eye Antiseptic Shows Promise in Enhancing Patient Comfort | ASRS 2025

Patients undergoing intravitreal injections to treat age-related macular degeneration who were given an investigational antiseptic experienced less pain and had fewer adverse events than patients given povidone-iodine, according to data presented at the American Society of Retina Specialists (ASRS) annual meeting being held in Long Beach, California.

Povidone-iodine is an antiseptic used during ophthalmic procedures, including intravitreal injections of medications used to treat age-related macular degeneration, to prevent infections. It is nontoxic but can result in pain and adverse corneal events.

Karen M. Wai, M.D.

“As any retina specialist in this room knows, 5% povidone-iodine causes at least a mild level of ocular pain and toxicity for most patients, but a subset of patients actually have severe and debilitating ocular pain. However, the lack of equity-approved alternatives leads to near-exclusive use, despite toxicity,” Karen M. Wai, M.D., clinical assistant professor of Ophthalmology at Stanford Medicine, said during the late-breaking presentation.

Researchers at Stanford wanted to test the safety and efficacy of IRX-101, a novel ocular antiseptic, in reducing post-intravitreal injection pain and corneal epitheliopathy compared with 5% povidone-iodine. Developed by iRenix Medical, a small private company in Palo Alto, California, IRX-101 is a novel, minimally toxic ocular antiseptic agent. Wai said IRX-101 consists of stable aqueous chlorine dioxide and is a broad antimicrobial agent.

“In preclinical studies, IRX-101 achieved complete kill of Staphylococcus epidermidis and Staph aureus in 15 to 30 seconds, whereas povidone iodine fails to reach these levels with even two minutes of exposure,” Wai said. Staph epidermidis and Staph aureus are two Gram-positive bacteria that can lead to serious infections of the eye.

Thirty-three patients were included in cohort 1, which was the phase 1b portion of the study. Following two minutes of exposure, IRX-101 was well-tolerated; adverse events were primarily mild with no severe adverse events and no serious adverse events.

In the phase 2b portion, cohort 2, of the RELIEF trial, Wai and her colleagues recruited patients undergoing intravitreal anti-vascular endothelial growth factor (VEGF) treatment, which reduces blood vessel leakage and growth. In this portion of the study, 155 patients were randomized (2:1) to receive IRX-101 or 5% povidone-iodine.

Researchers assessed patient pain scores and post-injection corneal fluorescein staining, a test to examine the surface of the cornea.

They found that both pain and corneal fluorescein staining scores were significantly lower with IRX-101 than with povidone-iodine. One hour after the injection, participants who received IRX-101 were more likely than those who received povidone-iodine to report that they were “happier than a previous injection.”

Additionally, a subset of patients who were identified as sensitive to povidone-iodine was also found to have lower pain and corneal fluorescein staining scores. Another subset analysis looked at patients who had received chlorhexidine as an antiseptic during a previous injection.

“Forty patients in this study were previously treated with chlorhexidine, and of these 40 patients, 27 were actually randomized to receive IRX-101. Of all 27 of these patients, not a single one prefers a chlorhexidine injection,” Wai said. She also pointed that

In response to a question about the potential of this product to add to costs, Wai said the company is committed to having the cost be accessible and available to patients to improve the patient experience with injections.