Assessment of optic disc parameter changes in head and neck cancer patients undergoing radiotherapy based on OCT

Background: Radiotherapy to the head and neck is an important treatment modality for malignant head and neck tumors, but it often leads to various ocular complications, including optic neuropathy. The optic disc, as a key part of the visual conduction pathway, is an important indicator for evaluating radiation-related ocular complications. Optical coherence tomography (OCT) can provide detailed structural information of the retina and optic disc, which is helpful for early detection of minor structural changes in the optic disc. Methods: This study is a prospective cross-sectional study, including 60 healthy examinees and 60 patients with malignant head and neck tumors. All patients underwent OCT examinations before radiotherapy, at the end of radiotherapy, and 3 and 6 months after radiotherapy. OCT was used to measure optic disc parameters such as retinal nerve fiber layer thickness (RNFL) and choroidal vascular index (CVI). Radiotherapy was performed using a megavoltage linear accelerator for external irradiation, following a conventional high-dose fractionation regimen. Statistical analysis was conducted using SPSS software, with Mann-Whitney U test and t-test used to compare differences between the two groups. Results: A total of 120 participants were included in the study. Radiotherapy had a significant impact on macular thickness (MT) in different regions and time points. The lateral nasal macular thickness significantly thinned 3 and 6 months after radiotherapy (P