Corneal topography findings among patients with thyroid dysfunction

Abstract

Background Hormonal dysregulation impacts the metabolism of the cornea and could be linked to keratoconus. Previous research has suggested an association between keratoconus and autoimmune thyroid disorders. Aim The aim of this study was to compare the topographic corneal changes in patients with thyroid dysfunction. Patients and methods This is a cross-sectional study of 200 patients with thyroid dysfunction attending the Endocrinology Clinic at the Faculty of Medicine, Alexandria University. The corneal topography of patients was examined with TMS. Serum levels of thyroid-stimulating hormone, free thyroxine, and free triiodothyronine were measured. Results Two hundred patients with thyroid dysfunction were enrolled in the study. Of them, 129 were hypothyroid patients and 71 were hyperthyroid patients. The study included 137 females and 63 males with a mean age of 32.4 ± 8.2 years. Corneal keratometry readings, including K1, K2, and K max readings, were measured. The mean value of K1 was 45.86 ± 4.69 D, mean K2 was 47.89 ± 5.08 D and the mean corneal thickness was 475 ± 0.36 µm, no relation was found between any of these parameters and serum thyroid-stimulating hormone, free triiodothyronine, or free thyroxine levels. Conclusion In our study, more topographic changes in favor of a thin cornea and steep cornea rather than a true keratoconus were detected in patients with thyroid dysfunction, making cautious analysis of corneal topography important, especially before refractive surgery.