Microbial Keratitis Severity Associated With Patient Characteristics, Location

Patients with microbial keratitis (MK) could have the severity of their disease informed by characteristics and where they lived at presentation, according to a study published in JAMA Ophthalmology. This could help to inform future research on social risk factors.

Social determinants of health (SDOH) are “the conditions where people are born, play, work, learn, live, worship, and age that affect health.” Social risk factors (SRFs) explain how these SDOH affect individuals. Chronic eye conditions have been the focus of SRF, with SRFs being linked to worse outcomes and vision loss in the United States for various chronic eye conditions. However, this relationship has not been explored in MK. This study aimed to “understand if neighborhood-level SRFs were associated with severity of MK at clinical presentation, as measured by visual acuity, after adjusting for individual-level sociodemographic factors.”

The Epic electronic health record (EHR) was used to collect data for patients with a diagnostic code for MK treated at the Kellogg Eye Center and its satellite clinics between August 1, 2012, and February 28, 2021. The diagnoses were obtained from the first visit by the patient. The patients’ best corrected visual acuity (BCVA) was obtained for the affected or worse eye; BCVA was measured as hand motions, light perception, no light perception, and count fingers and then approximated to the Snellen equivalent. Age, self-reported race, and self-reported sex were also collected. Neighborhood sociodemographics were collected from the 2015 to 2019 American Community Survey and neighborhood-level socioeconomic variables included the Area Deprivation Index (ADI).

There were 2990 patients with MK that were included in the study that had a mean (SD) age of 48.6 (21.3) years and 57.6% of whom were female. A total of 84.4% participants identified as White and 7.8% as Black, among other races reported. Most participants had unilateral infections, with 47.0% having right eye only MK and 49.8% having left eye only MK compared 3.2% who had MK in both eyes. A total of 93.6% had BCVA at presentation.

The mean national ADI rank of patients with MK was 49.6 (25.6) with a median (IQR) rank of 46 (29-70). The median renter cost burden was a mean of 29.8% (10.4%) of income. A mean of 38.8% (25.1%) of participants had 30% or more of their household income that went toward the rent of their home.

The median owner cost burden was 17.4% (3.6%) of income and a mean of 19.7% (10.5%) of owners had 30% or more of their household income going toward homeowner’s costs. A mean of 5.7% (8.3%) did not own a car in neighborhoods where participants with MK lived and the mean number of cars per household was 1.8 (0.4).

Demographic characteristics were associated with presenting BCVA in MIK, with a larger percentage of men having a BCVA worse than 20/40 compared with women (56.9% vs 51.7%, respectively). White and Black participants also had higher percentages of a BCVA below 20/40 compared with Asian patients (White, 54.8%; Black, 57.9%; and Asian, 32.2%). Non-Hispanic patients also had worse BCVA than 20/40 compared with Hispanic patients (54.4% vs 39.8%, respectively). Patients who had a lower BCVA were also older than those with better BCVA.

A univariate analysis found that a BCVA that was worse than 20/40 were associated with SDOH, with those presenting with BCVA that was worse than 20/40 having worse neighborhood deprivation compared with those who had 20/40 or better (mean ADI, 54.2 [24.7] vs 40.4 [25.6], respectively). Participants with worse BCVA also lived in neighborhoods with no household cars (mean, 6.1% [8.5%] vs 5.0% [7.6%], respectively) or less household cars (mean, 1.83 [0.39] vs 1.88 [0.39], respectively).

Data for neighborhoods was only from 2015 to 2019, which left out 3 years of data on patients with MK. The American Community Survey did not provide data on sociodemographics if the sample size was too small. Primary race was reported which could have limited the findings for multiracial patients. The study was only held in 1 eye center. The study also had a majority of White participants, which could limit the generalizability.

The researchers concluded that this study found that the place that a patient with MK lives could be associated with the severity of their visual impairment at presentation.

Reference

Hicks PM, Niziol LM, Newman-Casey PA, Salami K, Singh K, Woodward MA. Social risk factor associations with presenting visual acuity in patients with microbial keratitis. JAMA Ophthalmol. Published online June 15, 2023. Accessed June 19, 2023. doi:10.1001/jamaophthalmol.2023.2415