Article

Topical antibiotic for bacterial conjunctivitis hastens recovery

A phase III clinical trial showed that a new ocular solution of azithromycin 1%, formulated with a patented delivery vehicle, significantly shortened the time to clinical resolution and bacterial eradication of infectious bacterial conjunctivitis when used as primary therapy for 5 days.

Key Points

Bacterial conjunctivitis is primarily caused by Haemophilus influenzae, Staphylococcus aureus, and Streptococcus pneumoniae. Even though the natural course of bacterial conjunctivitis is short-from 8 to 10 days-antibiotics frequently are prescribed to hasten the patient's recovery, reduce the risk of spreading the infection to other individuals and the chance of sequelae, and prevent the possibility of recurrence of the infection, he reported.

Dr. Abelson is an associate clinical professor of ophthalmology at Harvard Medical School and a senior clinical scientist at Schepens Eye Research Institute, Boston.

Azithromycin is a broad-spectrum drug that is active against gram-positive, gram-negative, and atypical bacteria. This new ocular solution of 1% azithromycin (Aza-Site, InSite Vision) is delivered with a novel ocular delivery system (DuraSite, InSite Vision) and "stays in contact with the conjunctiva and delivers active drug to the ocular surface over a period of several hours," he said. "These attributes support a simplified and short therapeutic regimen that delivers high bactericidal concentrations of azithromycin to the site of the infection."

The azithromycin 1% solution was evaluated for safety and efficacy in the treatment of bacterial conjunctivitis during a multicenter, double-masked clinical study with a control group, which was conducted at 69 centers in the United States, Mexico, Guatemala, and the Dominican Republic. The study duration was 6 days, with three visits. The drug was administered twice daily on days 1 and 2 and once daily on days 3 through 5.

The investigators recorded the clinical signs and obtained specimens for bacterial culture at baseline and at two follow-up visits. Patients were included if they were aged 1 year or more.

Other inclusion criteria included a clinical diagnosis of bacterial conjunctivitis with symptoms of less than 3 days duration and a best-corrected visual acuity of 20/100 or better. Bacterial conjunctivitis was confirmed by laboratory testing.

Patients were excluded if they had debilitating disease, previous or concomitant use of any antibiotic or topical ophthalmic solution, suspected viral or allergic conjunctivitis, or a positive pregnancy test. The clinical study was designed and conducted in concert with Ophthalmic Research Associates, North Andover, MA.

Study endpoint

The primary study endpoint was clinical resolution of the bacterial conjunctivitis at the third visit. Clinical resolution was defined as the absence of all clinical signs such as conjunctival discharge and bulbar and palpebral conjunctival injection.

A total of 279 patients were evaluated for efficacy. The mean age was 28.4 years (range, 1 to 96 years). The results indicated that, at the third visit on day 6, 63.1% of the subjects randomly assigned to receive azithromycin had clinical resolution compared with only 49.7% of the participants randomly assigned to receive the vehicle (p = 0.030). The rate of bacterial eradication in the study population at the third visit was 88.5% in those who received azithromycin and 66.4% in those who received the vehicle (p < 0.001), according to Dr. Abelson.

"Azithromycin 1% ophthalmic solution in [the novel ocular delivery system] successfully eradicated pathogens that were resistant to azithromycin and other antibiotics used in commercial eye drops," he said. "Regarding both clinical cure and bacterial eradication, [this topical agent] offers physicians an additional ocular antibiotic choice that competes very favorably with current eye drop treatments."

Newsletter

Don’t miss out—get Ophthalmology Times updates on the latest clinical advancements and expert interviews, straight to your inbox.

Related Videos
(Image credit: Ophthalmology Times)  ASCRS 2025: Joaquin De Rojas, MD, leverages machine learning model to predict arcuate outcomes
(Image credit: Ophthalmology Times) ASCRS 2025: AnnMarie Hipsley, DPT, PhD, presents VESA for biomechanical simulation of presbyopia progression
Shehzad Batliwala, DO, aka Dr. Shehz, discussed humanitarian ophthalmology and performing refractive surgery in low-resource, high-risk areas at the ASCRS Foundation Symposium.
(Image credit: Ophthalmology Times) ASCRS 2025: Advancing vitreous care with Inder Paul Singh, MD
(Image credit: Ophthalmology Times) The Residency Report: Study provides new insights into USH2A target end points
Lisa Nijm, MD, says preoperative osmolarity testing can manage patient expectations and improve surgical results at the 2025 ASCRS annual meeting
At the 2025 ASCRS Annual Meeting, Weijie Violet Lin, MD, ABO, shares highlights from a 5-year review of cross-linking complications
Maanasa Indaram, MD, is the medical director of the pediatric ophthalmology and adult strabismus division at University of California San Francisco, and spoke about corneal crosslinking (CXL) at the 2025 ASCRS annual meeting
(Image credit: Ophthalmology Times) ASCRS 2025: Taylor Strange, DO, assesses early visual outcomes with femto-created arcuate incisions in premium IOL cases
(Image credit: Ophthalmology Times) ASCRS 2025: Neda Shamie, MD, shares her early clinical experience with the Unity VCS system
© 2025 MJH Life Sciences

All rights reserved.