Researchers recently found no benefit to adding corneal crosslinking (CXL) to the treatment regimen for moderate filamentous fungal ulcers. In fact, the procedure may actually result in decreased visual acuity for some patients.

This outcome-masked, randomized controlled clinical trial evaluated consecutive patients who presented with moderate vision loss from a smear-positive fungal ulcer. The team assigned study eyes to one of four treatment groups: topical natamycin 5%, topical natamycin 5% with CXL, topical amphotericin 0.15% and topical amphotericin 0.15% with CXL. They assessed the microbiological cure at 24 hours on repeat culture, best spectacle-corrected visual acuity (BSCVA) at three weeks and three months, percentage of study participants with epithelial healing at three days, three weeks and three months, infiltrate and scar size at three weeks and three months and adverse events.

The investigators discovered that those randomized to CXL, regardless of medication, had 1.32-fold increased odds of 24-hour culture positivity, although this was not statistically significant. They were also unable to find a difference in 24-hour culture positivity between those randomized to amphotericin compared with natamycin, regardless of whether they received CXL.

They note that, after controlling for baseline visual acuity, those who received CXL, regardless of medication, had worse BSCVA at both the three-week and three-month mark compared with those who did not undergo CXL. They add that there was no difference in infiltrate or scar size, percentage epithelialized or adverse events when comparing groups who did or did not have CXL.

Prajna NV, Radhakrishnan N, Lalitha P, et al. Cross-linking assisted infection reduction (CLAIR): a randomized clinical trial evaluating the effect of adjuvant cross-linking on microbiological and clinical outcomes in fungal keratitis. Ophthalmology. September 4, 2019. [Epub ahead of print].