Reviewed by Bennie H. Jeng, MD, MS
Baltimore—The Steroids for Corneal Ulcers Trial (SCUT) is an important study that provides high-level scientific evidence to guide care of patients with bacterial corneal ulcers, said Bennie H. Jeng, MD, MS.
Based on the results of SCUT, ophthalmologists can feel more comfortable using topical corticosteroids as an adjunct to antibiotics to treat a bacterial corneal ulcer in many circumstances, assuming there is no impending or present perforation, he noted.
In addition, the study data suggest that starting the steroid earlier after diagnosis, within 2 or 3 days, may be better than delaying its initiation.
“SCUT is not without its limitations,” said Dr. Jeng, professor and chairman, Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore. “However, it was a rigorously designed well-powered study. While it did not show any obvious benefit of steroid use as an adjunct to a topical antibiotic regarding the primary endpoint, it also found no serious safety concerns.”
“Therefore, keeping in mind that clinical judgment is always needed because every corneal ulcer is different, SCUT is a valuable study because it allays some long-standing fears about the use of steroids in eyes with bacterial keratitis,” he said.
Although theoretically, steroid treatment could improve visual outcomes by controlling inflammation that could lead to tissue destruction and scarring, there has long been concern surrounding steroid use due to the potential for delayed epithelial healing and worsening of the infection, particularly when Pseudomonas aeruginosa is the pathogen.
However, as stated in the American Academy of Ophthalmology’s Preferred Practice Pattern Guidelines on bacterial keratitis version available prior to SCUT, “there is insufficient evidence to make an official recommendation.”
“Before SCUT, the only evidence available was from animal studies, retrospective studies, and three small randomized trials from outside the United States that enrolled between 30 and 42 patients and generated some conflicting results,” Dr. Jeng said.
Sponsored by the National Eye Institute, SCUT was a randomized, double-masked, placebo-controlled trial. It was conducted at two centers in the United States (Francis I. Proctor Foundation, University of California-San Francisco and Dartmouth-Hitchcock Medical Center) and one in India (Aravind Eye Care); the latter site enrolled the vast majority of the 500 patients in the study population.
Eligible patients had a culture positive bacterial ulcer and were randomly assigned to a 3-week tapering regimen with prednisolone sodium phosphate 1.0% solution or placebo beginning as early as 48 hours after starting topical moxifloxacin 0.5% (Vigamox, Alcon).
The primary endpoint was best spectacle-corrected visual acuity (BSCVA) at 3 months. Secondary endpoints included BSCVA at 3 weeks, infiltrate/scar size, time to re-epithelialization, and adverse event rates, including corneal perforation. For all of those measures, there were no significant differences between the steroid and control group.