Assessment of Dry Eye and Corneal Endothelial Cell Changes’ Prevalence Following 106Ru Plaque Brachytherapy for Intraocular Tumors: A Prospective Multiple Test Study

Purpose: This prospective was study designed to report the clinical outcomes of 106Ru plaque brachytherapy in ocular surface and cornea, with an emphasis to provide a framework for preventive strategies to reduce the radiation-related anterior segment complications.Methods: Twenty four patients diagnosed with intraocular tumors from 2015 to 2017, which were candidates for 106Ru plaque brachytherapy were included. The following tests were performed preoperatively, 1 week, 1 month, 3 month and 6 month postoperatively: Ocular Surface Disease Index (OSDI) questionnaire (validated Persian version), Tear osmolarity, Tear Break up Time (TBUT), Schirmer I, Oxford fluorescein staining and Specular microscopy test of cornea. Clinical features of tumors were also evaluated. Patients were divided to dry eye disease group (A) and non- dry eye disease group (B) based on their preoperative examinations. Dry eye was defined according to DEWS II Report 2017 and patients with moderate to severe dry eye were excluded from study.Results: Six of 11 patients (54.50%) and 5 of 13 patients (38.50%) were male in group A and B respectively (P=0.45). Mean age of patients was 46.23±16.26 and 51.81±14.57 in group A and B respectively (P=0.38). Total apex dose (Gy) was 82.50±27.50 and 84.10±27.70 in group A and B respectively (P=0.89). Total sclera contact dose (Gy) was 653.20±546.40 and 570.30±380.80 in group A and B respectively (P=0.68). In preoperative assessments, OSDI score was 31.30±10.30 and 0.30±1.20 in group A and B respectively (P=0.00), however other tests did not show significant difference between groups. At 6 month follow-up assessments, TBUT was 4.60±1.10 and 8.50±2.70 seconds in group A and B respectively (P=0.00), however other tests did not show significant difference between groups. At 6 month follow-up, endothelial cell density showed strong inverse correlation with total sclera contact dose (Pearson correlation= -0.77) (P=0.00).Conclusion: Patients may have dry eye disease before initiation of plaque brachytherapy. In patients with confirmed preoperative dry eye, 106Ru plaque brachytherapy does not deteriorate the ocular surface status significantly. However, it’s recommended to evaluate all patients scheduled for plaque brachytherapy preoperatively, to find subjects with increased susceptibility. OSDI could be an important tool to identify such susceptible patients.