Measurement of Sub-Foveal Choroidal Thickness in Hyperthyroid Patients with Thyroid Associated Ophthalmopathy, Using Spectral Domain OCT

Background Thyroid associated ophthalmopathy (TAO) is an auto-immune orbitopathy, associated with thyroid dysfunction. It results in compression of the orbital contents, impairment of the blood flow and thus affects the choroidal and retinal microstructure and function. Aim of the Work The purpose of this study is to measure the central choroidal thickness in active and inactive TAO using Optical Coherence Tomography (OCT) and compare it to the control group. Patients and Methods The cross section study was conducted on participants recruited from the ophthalmology clinic of the National Institute of Diabetes and Endocrinology (NIDE). The study included 160 eyes from 80 participants (40 hyperthyroidism patients and 40 control subjects). Data was collected during the period of December 2019 to June 2020. Results There was no significant difference regarding age, gender, vision and IOP between TAO patients (either active or inactive) and normal subjects. Our study showed that there was a significant increase in sub-foveal choroidal thickness in patients with TAO compared to the control group. It also showed a significant increase in sub-foveal choroidal thickness in the active subgroup more than the inactive subgroup. In addition, a decrease in central foveal thickness was found in patients with TAO compared to the control group, but there was no significant difference found between active and inactive subgroups. Conclusion The findings of this study suggest that there is a significant affection of sub-foveal choroidal thickness and central foveal thickness in thyroid-associated-ophthalmopathy (TAO) patients.