Epidemiology of ocular surface squamous neoplasia in veterans: a retrospective case-control study

BACKGROUND: A number of risk factors have been evaluated in ocular surface squamous neoplasia, but few studies have assessed risk factors specific to the armed forces veteran population. METHODS: We conducted a retrospective case-control study on 55 patients and 55 age-matched controls with biopsy-proven ocular surface squamous neoplasia from the Miami Veterans Administration Hospital Eye Clinic to investigate potential risk factors encountered by veterans, including service-specific exposures. Veteran-specific risk factors included ionizing radiation exposure, Agent Orange exposure, deployment to Southwest Asia, and exposure to the series of biochemical warfare tests known as Project Shipboard Hazard and Defense. Data was analyzed with SPSS (SPSS Inc., Chicago, IL) using t-tests, chi-squared, and logistic regression analysis, with a p-value of < 0.05 considered statistically significant. RESULTS: The strongest risk factor for ocular surface squamous neoplasia was lifetime sun exposure both directly assessed via historical quantification of exposure by dermatology practitioners (Odds Ratio (OR) 5.4, 95% Confidence Interval (CI) 2.27–12.847, p < 0.005), and using the surrogate markers of basal cell carcinoma (OR 3.157, 95% CI 1.286–7.748, p = 0.010) and pingueculae (OR 5.267, 95% CI 2.104–13.186, p < 0.005). Of the veteran-specific risk factors, Agent Orange exposure and Southwest Asia deployment were not associated with an increased risk of ocular surface squamous neoplasia. Exposure to ionizing radiation and involvement in Project Shipboard Hazard and Defense were not documented among any cases or controls. CONCLUSIONS: The results of our study are consistent with prior established risk factors, namely highlighting the important role of sun exposure in ocular surface squamous neoplasia among veterans.