A study on observing the central macular choroidal thickness of thyroid-associated ophthalmopathy patients with spectral-domain optical coherence tomography

Abstract

Objective: To compare the differences in the central macular choroidal thickness (CMCT) between thyroid-associated ophthalmopathy (TAO) patients in active and inactive stages, and the healthy subjects used spectral-domain optical coherence tomography (SD-OCT) and assess the potential of using CMCT as an indicator for follow-up of TAO patients. Methods: Cross-sectional study. Eleven active stage TAO patients (22 eyes, active TAO group) and 21 inactive stage TAO patients (42 eyes, inactive TAO group) who received treatment at the Department of Ophthalmology, First People's Hospital of Nantong during January 2015 and December 2017 were enrolled. Twenty-three healthy subjects (46 eyes) with comparable ages to the two TAO groups were enrolled in the healthy control group. TAO activity was assessed using the TAO clinical activity score (CAS) system. All subjects underwent best corrected visual acuity, slit lamp examination, Goldmann tonometer for intraocular pressure measurement, direct ophthalmoscopy, A-superelocular measurement, ocular protrusion measurement, and SD-OCT detection of CMCT. The variance analysis was used to compare the differences of intraocular pressure, eyeball protrusion and CMCT between the three groups. The correlation between CMCT and various clinical indicators was analyzed by univariate linear regression analysis and multivariate linear regression analysis. Results: The intraocular pressure and eyeball protrusion indicators of the active TAO group, the inactive TAO group, and the control group were (20.16±3.49) mmHg (1 mmHg=0.133 kPa) and (18.68±1.64) mm, (15.42±2.49) mmHg and (15.64±1.01) mm, (15.72±2.38) mmHg and (12.02±0.83) mm, respectively. The intraocular pressure and ocular protrusion of the active TAO group were higher than those of the inactive TAO group and the healthy control group, the differences between the groups are of statistical significance (all P<0.001). The CMCT value of the active TAO group, the inactive TAO group and the healthy control group were (391.27±33.89) μm, (317.31±29.62) μm, and (304.26±42.26) μm, respectively. The CMCT of the active TAO group was significantly higher than the inactive group and the healthy control group, the differences between the groups are of statistical significance (all P<0.001). Based on univariate analysis, thicker CMCT was significantly associated with intraocular pressure (t=4.600, P<0.001); after correction of intraocular pressure, thicker CMCT was significantly associated with CAS (β=0.848, 95%CI 15.608-21.499, P<0.001). Multivariate analysis showed a correlation between thicker CMCT and CAS scores (P<0.001), thyroid function (P<0.001), and intraocular pressure(P=0.039). Conclusions: The CMCT in the eyes of active TAO patients is higher than that of the inactive TAO patients and healthy people. The CMCT examination is of referential value, and may be used as a tool for assessing the activity of lesions in patients with TAO and clinical follow-up. (Chin J Ophthalmol, 2018, 54: 688-693).