Dry eye disease in head and neck cancer patients undergoing radiotherapy.

Purpose: To study the incidence of dry eye disease (DED) in head and neck cancer (HNC) patients undergoing external beam radiotherapy (EBRT), to find a correlation between tumor location and total radiation dose with DED, and to report various radiotherapy (RT) induced acute toxic effects on ocular and adnexal structures. Methods: A prospective cohort study was conducted at a tertiary eye-care center on 90 patients of HNC undergoing EBRT from March 2021 to May 2022. All underwent a thorough clinical history and complete ophthalmological examination including an ocular surface disease index (OSDI) questionnaire, visual acuity, anterior segment, angle and posterior segment examination, dry eye workup including the Schirmer test, tear meniscus height, tear break-up time, corneal fluorescein staining and grading, and meibography by auto-refractometer and its scoring at each visit. Patients were evaluated before the start of RT and then at 1 week, 4 weeks, and 12 weeks post-RT. Radiation records of all patients were noted. Data were analyzed using percentage and Microsoft Excel. Results: Of the 90 patients, 66 were male and 24 female (M: F ratio of 2.75) with a median age of 52.5 years (range 24 to 80 years). The most common HNC was the carcinoma oral cavity and lip. Most patients received a total radiation dose between 46 to 55 Gy. DED developed in 48 (53.3%) patients. The incidence of DED increased with the increase in total radiation dose (r = 0.987). DED was also found to be correlated with tumor location (r = 0.983). Conclusion: The incidence of DED positively correlated with the total radiation dose and tumor location.