Corneal biomechanical properties in hyperthyroidism and thyroid eye disease

M Reza Razeghinejad; Amir R Farsiani; Ramin Salout; Naser Owji; Masoumeh Masoumpour; Alireza Kharmandar; Mohammad Zamani

doi:10.4103/1319-4534.322605

Corneal biomechanical properties in hyperthyroidism and thyroid eye disease

Saudi J Ophthalmol. 2021 Jul 29;34(4):251-255. doi: 10.4103/1319-4534.322605. eCollection 2020 Oct-Dec.

Authors

M Reza Razeghinejad^{1

2}, Amir R Farsiani^{1

3}, Ramin Salout^{1

4}, Naser Owji¹, Masoumeh Masoumpour¹, Alireza Kharmandar⁵, Mohammad Zamani⁴

Affiliations

¹ Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
² Glaucoma Research Center, Wills Eye Hospital, Philadelphia, PA, USA.
³ Department of Ophthalmology, School of Medicine, Zanjan University of Medical sciences, Zanjan, Iran.
⁴ Salouti Eye Research Center, Salouti Eye Clinic, Shiraz, Iran.
⁵ Endocrine and Metabolism Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.

Abstract

Purpose: The purpose of this study is to compare the corneal biomechanical properties of hyperthyroids without ophthalmopathy (HWO), thyroid eye disease (TED), and euthyroid participants.

Methods: In this prospective comparative study, one eye per patient included in the analysis and according to exclusion criteria, 38 eyes of 40 HWO patients, 31 eyes of 40 TED patients, and 150 eyes of 160 age- and sex-matched euthyroid participants were enrolled. All participants were evaluated by an endocrinologist and oculoplastic surgeon for evaluation of thyroid function and orbitopathy, respectively. Measurements of corneal biomechanical properties were performed using ocular response analyzer and Corvis ST tonometers.

Results: In the HWO group, applanation-1 length (A1 L), applanation-2 velocity (A2V) (P < 0.001), and corneal resistant factor (P = 0.043) were higher than the control group and corneal hysteresis (CH) was lower (P = 0.018). In the TED group, A1 L, A2V (P < 0.001), and highest concavity radius (HCR) (P = 0.027) were higher than the control group, and the CH (P = 0.007) and highest concavity deformation amplitude (HCDA) (P = 0.001) were lower. Furthermore, the level HCDA in the TED group was lower than HWO group (P = 0.011). The level of upper scleral show and palpebral fissure had a negative correlation with CH and HCDA. The amount of exophthalmos level had a positive correlation with HCR.

Conclusion: Corneal biomechanical properties in the HWO and TED groups were different from the normal euthyroid individuals and may be taken into account in managing situation like glaucoma and refractive surgeries.

Keywords: Corneal biomechanics; corvis; ocular response analyzer; thyroid eye disease.