Factors Associated with Vision Outcomes in Microbial Keratitis

Abstract

Purpose

To investigate factors associated with 90-day vision in patients with microbial keratitis (MK).

Design

Multicenter prospective cohort study recruited patients with MK from the United States and India from July 23, 2020, through May 1, 2024, and followed them for 90 days.

Participants

Individuals ≥ 15 years of age with MK of > 2 mm² in stromal infiltrate area without prior corneal surgery or gluing, impending corneal perforation or keratoplasty, no light perception vision, current pregnancy, or incarceration.

Methods

Data on sociodemographics, history, symptoms, clinical measures, and best-corrected visual acuity (BCVA) (as logarithm of the minimum angle of resolution [logMAR] units) at initial and 90-day visits were gathered, with BCVA carried forward for those healed before 90 days. Features were summarized overall and by site. Site-stratified multivariable linear regression models were investigated for associations with 90-day BCVA.

Main Outcome Measures

Ninety-day logMAR BCVA.

Results

Of 479 participants analyzed, after exclusions (n = 31) and participants without a 90-day BCVA (n = 52), participants had an average 90-day BCVA of 1.36 ± 1.40 logMAR in the United States (US) and 0.70 ± 0.99 logMAR in India (P < 0.0001). For the US, worse 90-day BCVA was associated 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 the India, worse 90-day BCVA was associated 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 < 0.0001]; bacterial: nonsignificant β [P = 0.07]; P = 0.0001 for interaction).

Conclusions

Initial vision, longer time until presentation, and larger infiltrate size conferred risk for worse 90-day BCVA, whereas other factors were unique. Systems to mitigate care delays and to support access care are needed would support clinicians and improve vision outcomes.

Financial Disclosure(s)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.