Postoperative Risk and Climate Exposure: A Retrospective Study of Incisional Glaucoma Surgery Outcomes

To evaluate associations between ambient temperature and surgical failure after incisional glaucoma surgery.

Individual-level clinical data were obtained from electronic medical records. Ambient temperature was estimated via spatiotemporal bilinear interpolation. Multivariable random-effects Cox proportional hazards models, incorporating restricted cubic splines and segmented regression, assessed the temperature-outcome relationship. Stratified analyses identified potentially susceptible populations. Likelihood ratio tests examined interactive effects between air pollution and ambient temperature on both multiplicative and additive scales.

Although conventional linear analyses did not show a significant association between ambient temperature and surgical failure risk, a spline-based nonlinear models suggested a U-shaped, asymmetric nonlinear association between ambient temperature and surgical failure risk within prolonged exposure windows (P_nonlinearity < 0.0001). Under these nonlinear specifications, exposure to temperature extremes relative to the mid-range was associated with an increased estimated risk of surgical failure. These nonlinear patterns appeared more evident in older patients and those with primary open-angle glaucoma. Air pollutants showed statistically significant effect modification in interaction analyses of the temperature-outcome association 180 days after surgery. With the exception of O₃, common air pollutants demonstrated negative interaction terms with temperature, suggesting that the modeled association between lower temperatures and surgical failure risk was stronger at higher pollutant concentrations.

Nonlinear modeling suggested potential heterogeneity in risk across temperature ranges, with the estimated associations varying by PM₂.₅ exposure strata and other air pollutant levels. These findings are model-dependent and warrant confirmation in independent cohorts and prospective studies.

Under spline-based nonlinear modeling, postoperative ambient temperature showed a U-shaped association with glaucoma surgical failure risk, with the estimated relationship differing across levels of concurrent air pollutant exposure. These findings are hypothesis-generating and suggest that environmental conditions may warrant consideration in postoperative risk assessment.