Association of Postfungal Keratitis Corneal Scar Features With Visual Acuity

Abstract

IMPORTANCE Corneal opacity is a leading cause of visual impairment worldwide; however, the specific features of corneal scars, which decrease visual acuity, have not been well characterized.OBJECTIVE To investigate which features of a postfungal keratitis corneal scar contribute to decreased visual acuity after an episode of infectious keratitis and evaluate whether any corneal features may be used as outcomes for clinical trials. DESIGN, SETTING, AND PARTICIPANTSIn this ancillary, prospective cross-sectional study, a subset of study participants treated for fungal keratitis (n = 71) as part of the Mycotic Ulcer Treatment Trial I (MUTT I) underwent best spectacle-corrected visual acuity (BSCVA) and best contact lens-corrected visual acuity examination, Scheimpflug imaging, and anterior segment optical coherence tomography at a referral hospital in India approximately 2 years after enrollment.

Mediators of the Effect of Corneal Cross-Linking on Visual Acuity for Fungal Ulcers: A Prespecified Secondary Analysis From the Cross-Linking–Assisted Infection Reduction Trial

“…The full trial protocol has been outlined in a previous publication. 4 Briefly, consecutive patients presenting to Aravind Eye Hospital in Madurai, India, with smear-positive filamentous fungal corneal ulcers were randomized in a 2 × 2 factorial design to one of 4 treatment combinations using an adaptive randomization protocol. We used a drop-the-loser adaptive trial design with 24-hour culture result, coded as positive or negative, to perform interim response-adaptive randomization.…”

“…3 This can serve as an objective measure of scar density or corneal haze and has previously been correlated with visual acuity outcomes in fungal keratitis and other corneal diseases, such as Fuchs endothelial corneal dystrophy. 4,5 In this prespecified analysis, we explore how corneal scarring and astigmatism mediate the effect of adjunctive CXL on visual acuity in fungal keratitis.…”

The role of fungi in fungal keratitis

“…Polymicrobial keratitis with fungus and bacteria are more challenging to treat, with a poorer outcome than FK and may need early surgical intervention (Fernandes et al, 2015). In a longitudinal study comparing the visual outcomes of bacterial and fungal corneal ulcers, the best corrected vision of 20/400 or worse at 4 years from the onset of infection was more common in patients with scars due to fungal ulcer compared to scars of bacterial ulcer, even after successful antimicrobial treatment (Menda et al, 2019).…”

Experimental Models for Fungal Keratitis: An Overview of Principles and Protocols

“…Following the resolution of FK, there may be acute or long-term consequences for visual acuity. Long-term visual deficits can be due to corneal scarring, which is mediated by the pro-fibrotic activity of myofibroblasts, as well as the inability of cornea-penetrating blood and lymphatic vessels to resolve after infection, which is documented in fungal, viral, and bacterial keratitis [26][27][28].…”