Abstract: We found four RCTs that met the inclusion criteria of this review. The total number of included participants was 611 (612 eyes), ranging from 30 to 500 participants per trial. One trial was included in the previous version of the review, and we identified three additional trials through the updated searches in July 2014. One of the three smaller trials was a pilot study of the largest study: the Steroids for Corneal Ulcers Trial (SCUT). All trials compared the treatment of bacterial keratitis with topical corticosteroid and without topical corticosteroid and had follow-up periods ranging from two months to one year. These trials were conducted in the USA, Canada, India, and South Africa. All trials reported data on visual acuity ranging from three weeks to one year, and none of them found any important difference between the corticosteroid group and the control group. The pilot study of the SCUT reported that time to re-epithelialization in the steroid group was 53% slower than the placebo group after adjusting for baseline epithelial defect size (hazard ratio (HR) 0.47; 95% confidence interval (CI) 0.23 to 0.94). However, the SCUT did not find any important difference in time to re-epithelialization (HR 0.92; 95% CI 0.76 to 1.11). For adverse events, none of the three small trials found any important difference between the two treatment groups. The investigators of the largest trial reported that more patients in the control group developed intraocular pressure (IOP) elevation (risk ratio (RR) 0.20; 95% CI 0.04 to 0.90). One trial reported quality of life and concluded that there was no difference between the two groups (data not available). We did not find any reports regarding economic outcomes. Although the four trials were generally of good methodological design, all trials had considerable losses to follow-up (10% or more) in the final analyses. Further, three of the four trials were underpowered to detect treatment effect differences between groups and inconsistency in outcome measurements precluded meta-analyses for most outcomes relevant to this review. There is inadequate evidence as to the effectiveness and safety of adjunctive topical corticosteroids compared with no topical corticosteroids in improving visual acuity, infiltrate/scar size, or adverse events among participants with bacterial keratitis. Current evidence does not support a strong effect of corticosteroid, but may be due to insufficient power to detect a treatment effect.

Plain-language summary: We found four studies in which antibiotics alone had been compared with antibiotics plus corticosteroids for the treatment of bacterial keratitis. These studies were conducted in the USA, Canada, India, and South Africa, and included a total of 612 eyes of 611 participants. The largest study included 500 participants followed for one year. The three smaller studies followed participants for two to three months. The evidence is current to July 2014. None of the four studies reported an important difference between topical corticosteroid therapy and placebo or control treatment for reduction in ulcer size, change in visual acuity, adverse events, or quality of life. One study reported that healing or cure time in the steroid group was slower than the placebo group (for every 100 people cured in the control group, only 47 were cured in the steroid group during the same time period), but the largest study did not report any difference (for every 100 people cured in the control group, 92 were cured in the steroid group during the same time interval). For adverse events, none of the studies found a difference between the two groups, except that one study reported that more eyes in the control group developed intraocular pressure (IOP) elevation. We did not find any information on economic outcomes. Generally, the quality of the evidence based on the four studies we identified was moderate due to the proportions of participants who were not included in the final study analyses and the inconsistency of outcomes assessed across the four studies. In addition, three studies enrolled too few participants (30 to 42) to reach scientifically valid conclusions.