Seasonal variations and environmental factors associated with allergic ocular surface disease: A prospective observational study of clinical presentation patterns in South Asian region.

BACKGROUND

Allergic ocular surface disease affects 20-40% of populations globally, with seasonal patterns undocumented in south Asian populations, limiting evidence-based resource planning in resource-constrained settings.

METHODS

This prospective cross-sectional study enrolled 201 consecutive patients (mean age 33.1 years, 49.8% female) from a tertiary care ophthalmology outpatient department over 12 months. Participants underwent standardized assessment: Ocular Surface Disease Index (OSDI ≥ 23), Schirmer's test (< 5 mm/5 min), and tear break-up time (TBUT < 5 s). Environmental data were obtained from the Meteorological Department.

PRIMARY OUTCOME: seasonal clustering of disease presentation.

RESULTS

Disease severity was significantly elevated during high-prevalence seasons: OSDI 40.99 versus 34.04 (difference 6.95; 95% CI: 2.83-11.07; p < 0.001); Schirmer's test 2.71 mm versus 3.40 mm (p = 0.006); TBUT 2.38 versus 3.48 s (p < 0.001; Cohen's d =  - 0.831). Diagnostic criterion achievement was 58.3% versus 35.0% (p = 0.001). Season emerged as the independent predictor (OR 0.363; 95% CI: 0.199-0.663; p = 0.001), with each 1 °C temperature increase associated with 0.041-s TBUT reduction (r =  - 0.313; p < 0.001).

CONCLUSIONS

Allergic ocular surface disease exhibited pronounced seasonal clustering driven primarily by temperature-mediated tear film destabilization. These findings support anticipatory healthcare resource planning-seasonal appointment augmentation and pharmacotherapy stockpiling-for resource-constrained facilities.