Corneal biomechanical properties in patients with Hashimoto's thyroiditis

Background. Hashimoto's thyroiditis (HT) is an autoimmune endocrine disorder that results from a dysregulation of the immune system leading to an immune attack on the thyroid gland. It has potential effects on different organs and tissues. Objectives. The aim of the study was to investigate the effect of HT on corneal biomechanical properties using the ocular response analyzer (ORA). Material and methods. A total of 48 patients with HT and 49 healthy subjects were enrolled in the study. The mean age of the patients and healthy subjects was 42.33 +/- 11.96 and 40.20 +/- 12.60 years, respectively (p = 0.39). All of the subjects underwent a full ophthalmological examination, including visual acuity, corneal pachymetry with topography, biomicroscopy, and funduscopy. Corneal biomechanical properties, including corneal hysteresis (CH) and corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg) and corneal compensated IOP (IOPcc) were measured with the ORA. Results. Central corneal thickness (CCT) in the patient group and the control group were not significantly different (p = 0.65). Corneal hysteresis of the HT patients was significantly lower than that of the control group (p = 0.005). There were no statistically significant differences in CRF between the 2 groups (p =0.53). Goldmann-correlated IOP and IOPcc were higher in the HT patients, but only IOPcc showed a statistically significant difference (p = 0.001). Conclusions. In conclusion, our data shows that HT affects corneal biomechanical properties by decreasing CH. Thus, 10Pcc measured with the ORA should be taken into account when determining accurate IOP values in patients with HT.