Evaluation of retinal and choroidal variations in thyroid-associated ophthalmopathy using optical coherence tomography angiography

Abstract

Background: To investigate the difference in retinal nerve fiber layer (RNFL) thickness, choroidal thickness (CT) and superficial retinal vessels between thyroid-associated ophthalmopathy (TAO) patients and healthy controls. To identify the potential influencing factors for these parameters and evaluate their diagnostic abilities in TAO.Methods: 20 active TAO patients, 33 inactive TAO patients and 29 healthy participants were enrolled. TAO patients were divided according to the clinical activity score (CAS). RNFL thickness and CT were measured by HD-OCT, while foveal avascular zone (FAZ), vascular density and perfusion density were measured by optical coherence tomography angiography (OCTA). SPSS software was used for statistical analysis.Results: Active TAO patients had thinner RNFL thickness than the other two groups (P<0.001, P<0.001). Both active and inactive TAO patients had significantly higher CT in the macular region (all P<0.05). The FAZ area in the active TAO group was significantly larger than the other two groups (P=0.045, P=0.001). The inactive TAO group had significantly higher vascular density than the other two groups (all P<0.05). With regard to the perfusion density, significant differences were observed in the temporal and inferior areas (P=0.045, P=0.001), as well as the average values (P=0.032). The FAZ area was positively correlated with intraocular pressure (r=0.274, P=0.013), while it was negatively correlated with axial length (r=-0.344, P=0.002). The vascular density and perfusion density were not significantly correlated with different clinical variables (all P>0.05). The AUC analysis indicated these parameters also exhibited a significant discriminatory power in TAO diagnosis.Conclusions: TAO patients had significant variations in RNFL thickness, choroidal thickness, FAZ area and superficial retinal vessels. These parameters appeared to be potential adjuncts in the evaluation of TAO patients.

Retinal nerve fiber layer and ganglion cell complex thickness as a diagnostic tool in early stage dysthyroid optic neuropathy

“…Dave et al 10 found an increased RNFL thickness in active TED eyes compared to inactive eyes and healthy eyes. Yu et al, 11 on the other hand, reported that active TAO patients had thinner RNFL thickness than inactive and healthy subjects. Casini et al 12 reported that the RNFL thickness was comparable among Graves’ orbitopathy(GO) patients, Graves’ Disease(GD) patients without GO and healthy subjects.…”

“…For the DON patients in the sight-threatening group, the edema of the optic disc could cause pRNFL thickening. The results of the thinning, thickening and no significant change of pRNFL in TAO patients in the literature [8][9][10][11][12] may be related to different grouping methods and different pathogenesis, in addition to ethnic differences. Casini et al 12 and Guo J, et al 14 reported that Ganglion cell layer (GCL) was thinned in the TAO group, and Yufei Wu et al 15 reported that GCC was thinned in the DON group.…”

“…Previous studies on RNFL and GCC thickness in TAO patients using OCT have been contradicting. [8][9][10][11][12][13][14][15] Our study is not merely to investigate the changes of peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell complex (mGCC) thickness with different severity groups of TAO patients, but also to observe the changes of pRNFL and mGCC thickness after glucocorticoids treatment. Based on the above studies, we analyzed the correlation and the area under curve (AUC) in order to judge the value of pRNFL and mGCC for early stage DON in TAO patients.…”

Analysis of macular blood flow changes in thyroid associated ophthalmopathy

“…Previous studies on TAO macular blood flows using OCTA showed that superficial vessel density was lower in active TAO [13], while the superficial vessel density in inactive TAO varied in different studies. Yu [14]and Cetin [15] found a significantly higher retinal vascular density in inactive TAO, while Frazil [16] and Dave [17] found retinal vessel density values were similar in inactive TAO to healthy subjects. Moreover, Natasha [18] observed a decrease in macular VD in inactive TAO patients.…”