Evaluation of visual functions in Iranian hypothyroid adults

INTRODUCTION: The aim of this study was to investigate the effects of hypothyroidism on visual functions such as visual acuity, refractive errors, colour vision, and contrast sensitivity, among hypothyroid adults. METHODS: Forty‐three patients with clinical hypothyroidism along with 43 age‐ and sex‐matched healthy individuals underwent visual examinations, including visual acuity, refractive errors, eye deviations with the cover test, colour vision with the D15 test, and contrast sensitivity with Pelli‐Robson test. RESULTS: It was indicated that visual acuity, refractive errors, phoria, and colour vision had no significant difference between the hypothyroid and control groups. Contrast sensitivity decreased in hypothyroid subjects as compared with controls. The mean values of binocular contrast sensitivity were 1.85 ± 0.09 log in the hypothyroid group and 1.93 ± 0.09 log in controls, which showed a statistically significant difference (p = .03). CONCLUSIONS: Our findings illustrated a reduced contrast sensitivity in adult hypothyroidism. Since CS is related to functioning and quality of life, a comprehensive and detailed eye examination may be beneficial for hypothyroidism patients.