Assessment of tear-evaporation rate in thyroid-gland patients

Ali Abusharaha,1 Abdulaziz A Alturki,1 Saud A Alanazi,1 Raied Fagehi,1 Naji Al-Johani,2 Gamal A El-Hiti,1 Ali M Masmali1 1Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh 11433, Saudi Arabia; 2Department of Endocrinology and Thyroid Oncology, Comprehensive Cancer Center, King Fahad Medical City, Riyadh 11433, Saudi Arabia Objective: To assess the tear-evaporation rate in thyroid-gland patients using a VapoMeter.Methods: Twenty thyroid gland patients aged 18–43 years (mean 34.3±6.3 years) completed the study. Additionally, an age-matched control group of 20 patients aged 18–43 years (32.2±5.1 years) was enrolled in the study for comparison purposes. An Ocular Surface Disease Index dry-eye questionnaire was completed, followed by a test to determine the tear-evaporation rate using the VapoMeter. The test was performed three times per subject by the same examiner. Two readings were obtained each time.Results: Significant differences (P<0.05) were found between mean Ocular Surface Disease Index and tear-evaporation-rate scores within the study and control groups. The average tear-evaporation rate was much higher in the study group (median 41.2 [IQR 41.4] g/m2·h) than the control group (15.7 [13.7] g/m2·h). Moreover, the average Ocular Surface Disease Index score for thyroid-gland patients was much higher (15.6 [23.4]) compared to the control group (5.5 [7.50]).Conclusion: The tear-evaporation rate in thyroid-gland patients was found to be much higher than normal-eye subjects. Keywords: thyroid gland, thyroid-associated ophthalmopathy, Graves’s ophthalmopathy, dry eye, tear-evaporation rate, evaporative dry eye&nbsp