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Factors Associated with Vision Outcomes in Microbial Keratitis: A Multisite Prospective Cohort Study
Maria A Woodward1, Emily L Vogt2, Leslie M Niziol2
1Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan; Institute for Healthcare Policy and Innovation, University of Michigan, Ann Arbor, Michigan.
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.
Insights
Microbial keratitis (MK) patients with poorer initial vision, delayed presentation, and larger infiltrates face worse 90-day vision outcomes. Improving care access and reducing delays are crucial for better vision in MK patients.
Area of Science:
- Ophthalmology
- Infectious Diseases
- Public Health
Background:
- Microbial keratitis (MK) is a significant cause of vision loss worldwide.
- Understanding factors influencing visual outcomes in MK is critical for effective management.
- This study investigates predictors of 90-day vision in a diverse MK patient cohort.
Purpose of the Study:
- To identify factors associated with 90-day best-corrected visual acuity (BCVA) in patients with microbial keratitis.
- To compare these factors between patients in the United States and India.
Main Methods:
- A multicenter prospective cohort study involving 479 patients with MK across the US and India.
- Data collected included sociodemographics, clinical measures, and BCVA (logarithm of the minimum angle of resolution units) at baseline and 90 days.
- Site-stratified multivariable linear regression models were used to analyze associations with 90-day BCVA.
Main Results:
- Average 90-day BCVA was 1.36 logMAR in the US and 0.70 logMAR in India.
- In the US, worse 90-day BCVA was linked to worse presenting BCVA, longer presentation delays, no contact lens use, and larger infiltrate size.
- In India, worse outcomes were associated with worse presenting BCVA, longer delays, diabetes, hypopyon, no recent ocular trauma, and larger infiltrate size.
Conclusions:
- Initial visual acuity, time to presentation, and stromal infiltrate size are key predictors of 90-day vision outcomes in MK.
- Specific risk factors varied between the US and India, highlighting the need for tailored interventions.
- Implementing systems to reduce care delays and improve access is essential for enhancing vision outcomes in MK patients.
