Initial vision, infiltrate size tied to eye outcomes in microbial keratitis

Several factors contribute to the risk for worse 90-day best-corrected visual acuity (BCVA) in patients with microbial keratitis (MK), and these include initial vision, longer time until presentation, and larger infiltrate size, reports a study.

This multicentre prospective cohort study involved MK patients in the US and India from 23 July 2020 through 1 May 2024. Participants were followed through 90 days. The authors obtained data on history, symptoms, sociodemographics, clinical measures, and BCVA at initial and 90-day visits, carrying BCVA forward for those healed before 90 days.

A summary of features was done overall and by site. Finally, associations with 90-day BCVA were explored using site-stratified multivariable linear regression models.

The analysis included 379 participants, who had an average 90-day BCVA of 1.36 logMAR in the US and 0.70 in India (p<0.0001).

For US patients, worse 90-day BCVA correlated with worse presenting BCVA (β, 0.05 logMAR per 0.1-logMAR unit increase in presenting BCVA; p<0.0001), longer time until presentation (β, 0.01 per day; p<0.0001), no contact lens use (β, 0.46; p=0.0131), and larger stromal infiltrate area (bacterial: β, 0.02 per 1-mm²; p=0.0082; fungal: β, 0.10 per 1-mm² increase in area; p=0.0002; p=0.0017 for interaction).

For India, worse 90-day BCVA correlated with worse presenting BCVA (β, 0.04 logMAR; p<0.0001), longer delays to presentation (β, 0.03 per day; p=0.0004), diabetes mellitus (β, 0.41; p=0.0019), hypopyon (β, 0.27; p=0.0083), no recent ocular trauma (β, 0.21; p=0.0370), and larger stromal infiltrate area (fungal: β, 0.03 per 1-mm²; p<0.001; bacterial: nonsignificant β, p=0.07; p=0.0001 for interaction).

“Systems to mitigate care delays and to support access care are needed … [to] improve vision outcomes,” the authors said.