Long-term visual outcomes in the Steroids for Corneal Ulcers Trial

Abstract

 

Purpose

 

The Steroids for Corneal Ulcers Trial (SCUT) was a multi-center randomized clinical trial comparing topical steroids versus placebo as adjunctive therapy for bacterial keratitis. Patients were followed at regular intervals using standardized methodology, providing an ideal cohort to study the natural history of bacterial keratitis. Recently, we performed a 4-year follow-up visit on a subset of SCUT patients to assess the long-term outcomes of patients with bacterial keratitis.

 

Methods

 

During SCUT, 500 patients were enrolled at 4 centers over 3.5 years, and followed at 3 weeks, 3 months, and 12 months. In the current study, we invited a subset of study subjects from the Madurai study site for examination approximately 4 years following enrollment in the study. We attempted to examine as many study subjects as possible whose enrollment dates in the SCUT fell between October 2007 and August 2008. Subjects were refracted using the ETDRS visual acuity chart, and the number of letters read converted into logMAR units. Visual acuity was compared at different time periods using a Wilcoxon sign rank test. The steroid and placebo groups were compared with linear regression, adjusting for baseline vision.

 

Results

 

Of 80 SCUT subjects eligible for follow-up examination, we examined 50 (62.5%). The median follow-up interval since the original presentation was 48.7 months (range 42.9-54.4 months; interquartile range [IQR] 45.9-52.0 months). Visual acuity data are presented in Tables 1 and 2. None of the patients had undergone penetrating keratoplasty or cataract surgery since enrollment in the study. There was a statistically significant improvement in visual acuity from month 3 to month 12 (P=0.03), but not from month 12 to month 48 (P=0.86). After controlling for visual acuity at enrollment, visual acuity was not significantly different between the steroid and placebo group at month 48 (P=0.53).

 

Conclusions

 

Following bacterial keratitis, visual acuity may improve over the first 12 months, but further improvement is unlikely. This may guide surgeons in determining the appropriate timing of corneal surgery. In this subset of bacterial keratitis patients, there was no long-term benefit of treatment with topical steroids.

 

 

Table 1. Median best spectacle-corrected visual acuity (BSCVA) at each study visit.

 

 

Table 2. Change in BSCVA during each study time period. Negative values indicate improvement. 0.1 logMAR = 1 logMAR line of vision.

 

Keywords: 479 cornea: clinical science • 487 corticosteroids • 754 visual acuity