Abstract
Purpose :
To examine the association between exposure to outdoor air pollutants and risk of incisional glaucoma surgical failure.
Methods :
A retrospective cohort was constructed using the entire population of 2016-18 California (CA) fee-for-service Medicare beneficiaries with a claim for incisional glaucoma surgery (trabeculectomy, tube shunt, or EX-PRESS shunt). Exclusion criteria were: residence outside of CA, age ≤64 years, or missing eye laterality modifier code. The primary exposures were 2015 annual-average outdoor concentrations for three air pollutants, including: carbon monoxide (CO), fine particulate matter with a diameter of 2.5 µm or less (PM2.5), and ozone (O3). Outdoor pollutant concentration was estimated by land use regression models and averaged over the zip code for each beneficiary’s mailing address. Covariates included age, sex, race and ethnicity, dual-Medicaid eligibility, and qualifying for Part D low-income subsidies. Time to failure event was defined as having a claim for revision of index surgery or reoperation. Follow-up time extended through 2019. Time-to-event was modeled using Cox proportional hazards.
Results :
The final sample consisted of 6,460 beneficiaries living in 1,288 unique zip codes in CA. The mean outdoor concentration per beneficiary zip code was 0.33 parts per million (ppm) (standard deviation [SD]: 0.06) for CO, 8.84 µg/m3 (SD: 1.81) for PM2.5, and 50.33 parts per billion (ppb) (SD: 3.00) for O3. In the individual final models adjusting for the covariates above, a 0.1 ppm increase in CO was associated with 1.27 times increased risk of surgical failure (hazard ratio [HR]: 1.07, 95% confidence interval [CI]: 0.99-1.17), a 10 µg/m3 increase in PM2.5 was associated with 1.24 times increased risk of surgical failure (HR: 1.24, 95% CI: 0.93-1.67), and a 10 ppb increase in O3 was associated with 1.24 times increased risk of surgical failure (HR: 1.24, 95% CI: 1.05-1.46).
Conclusions :
Exposure to increased concentrations of outdoor air pollutants was associated with greater risk for incisional glaucoma surgical failure after adjusting for age, sex, race and ethnicity, and proxies for socioeconomic status. This is the first study identifying exposure to air pollutants as a possible risk factor for glaucoma surgical failure. Further studies are necessary to better understand these and other environmental disparities associated with inequitable ophthalmic surgical outcomes.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.