Elevated pulse pressure correlated with reduced retinal peripapillary capillary in thyroid-associated ophthalmology with visual field defect

Retinal perfusion related to visual field within the same asymmetric thyroid-associated ophthalmopathy

PURPOSE

To quantify interocular differences in the retinal microvasculature between disparate eyes and explore associations between the retinal microvasculature and visual field abnormalities within the same asymmetric thyroid-associated ophthalmopathy (TAO) patients.

METHODS

Within the same asymmetric TAO eye, the eye with a severer visual field abnormality (based on the mean deviation [MD]) was considered a severe eye, and the fellow eye was considered mild. The densities of radial peripapillary capillary (RPC) and superficial retinal capillary plexuses (SRCP) were determined using optical coherence tomography angiography. Interocular differences in RPC and SRCP densities were analyzed. A generalized estimating equation (GEE) was used to form a predictive model for visual field abnormalities. Pearson's correlation was used to show the correlation between MD and the densities of RPC and SRCP.

RESULTS

In 57 asymmetric TAO patients, the global RPC density in severe eyes was lower than that in mild eyes (P < 0.001), but there was no significant difference in SRCP density between the two groups (P = 0.114). In a multivariate GEE model with MD as the outcome, MD was associated only with global RPC density (coefficient β=0.327, P < 0.001). The global RPC density was correlated with MD (r = 0.360, P = 0.003) in severe eyes, but not in mild eyes (r = 0.179, P = 0.092). No significant correlation was observed between global SRCP density and MD in either group (Both P > 0.05).

CONCLUSIONS

RPC density decreased significantly and correlated with visual field abnormalities in severe eyes of TAO patients. Alterations in RPC density may contribute to visual field abnormalities in TAO eyes.

Optical coherence tomography angiography in thyroid associated ophthalmopathy: a systematic review

PURPOSE

To evaluate the evidence for alterations of blood flow, vascular and perfusion densities in the choroid, macula, peripapillary region, and the area surrounding the optic nerve head (ONH) in patients with thyroid-associated ophthalmopathy (TAO) based on changes of OCTA parameters.

METHODS

A systematic review of Pubmed, Google Scholar, Scopus, WOS, Cochrane, and Embase databases, including quality assessment of published studies, investigating the alterations of OCTA parameters in TAO patients was conducted. The outcomes of interest comprised changes of perfusion and vascular densities in radial peripapillary capillary (RPC), ONH, superficial and deep retinal layers (SRL and DRL), choriocapillaris (CC) flow, and the extent of the foveal avascular zone (FAZ).

RESULTS

From the total of 1253 articles obtained from the databases, the pool of papers was narrowed down to studies published until March 20th, 2024. Lastly, 42 studies were taken into consideration which contained the data regarding the alterations of OCTA parameters including choriocapillary vascular flow, vascular and perfusion densities of retinal microvasculature, SRL, and DRL, changes in macular all grid sessions, changes of foveal, perifoveal and parafoveal densities, macular whole image vessel density (m-wiVD) and FAZ, in addition to alterations of ONH and RPC whole image vessel densities (onh-wiVD and rpc-wiVD) among TAO patients. The correlation of these parameters with visual field-associated parameters, such as Best-corrected visual acuity (BCVA), Visual field mean defect (VF-MD), axial length (AL), P100 amplitude, and latency, was also evaluated among TAO patients.

CONCLUSION

The application of OCTA has proven helpful in distinguishing active and inactive TAO patients, as well as differentiation of patients with or without DON, indicating the potential promising role of some OCTA measures for early detection of TAO with high sensitivity and specificity in addition to preventing the irreversible outcomes of TAO. OCTA assessments have also been applied to evaluate the effectiveness of TAO treatment approaches, including systemic corticosteroid therapy and surgical decompression.

Artificial Intelligence-based quantitative evaluation of retinal vascular parameters in thyroid-associated ophthalmopathy

PURPOSE

Thyroid-associated ophthalmopathy (TAO) may result in increased metabolism and abnormalities in microcirculation. The fractal dimension (Df) of retinal vessels has been shown to be related to the pathology of a number of ophthalmic disorders, but it hasn't been investigated in TAO.

METHODS

We analyzed 1078 participants aged 18 to 72 (548 healthy volunteers and 530 TAO). Images were captured using a non-mydriatic 45-degree fundus camera. Baseline retinal characteristics, such as vessel width, tortuosity, and Df were measured using semiautomated software from fundus images. The average retinal parameters were compared between the two groups. The receiver operation curve (ROC) was used to assess the diagnostic efficacy of various retinal vascular parameters for TAO.

RESULTS

Despite controlling for potential confounding variables, Df, vessel width, and tortuosity significantly increased in TAO compared to healthy volunteers. Compared to active TAO, patients in the inactive phase had a larger retinal venous caliber (p < 0.05), but there was no difference in Df or arterial caliber. Moderate and severe cases had a higher Df compared with mild cases (EUGOGO guidelines). The area under the ROC for Df, tortuosity, and vascular caliber in the diagnosis of TAO was 0.904 (95% CI: 0.884-0.924), 0.638 (95% CI: 0.598-0.679), and 0.617 (95% CI: 0.576-0.658), respectively.

CONCLUSIONS

Due to its accessibility, affordability, and non-invasive nature, retinal vascular Df may serve as a surrogate marker for TAO and might be used to identify severe cases. With relatively high diagnostic performance, the Df is of some utility for the detection of TAO.

Effect of Intraorbital Mechanical Compression on Retinal Microvascular Perfusion in Quiescent Thyroid-Associated Ophthalmopathy Based on Ocular Biomechanics Measured by Corvis ST

INTRODUCTION

To analyze the correlation between orbital compliance and retinal vessel density (VD) based on dynamic Scheimpflug analyzer (Corvis ST) and optical coherence tomographic angiography (OCT-A).

METHODS

In this prospective observational study, 65 eyes of 44 patients with thyroid-associated ophthalmopathy (TAO) in quiescent stage were included (15 males and 29 females). The whole eye movement (WEM) was detected by Corvis ST. The superficial capillary plexus VD (SCP-VD) and deep capillary plexus VD (DCP-VD) were obtained by scanning the 3 × 3 mm area around the fovea using OCT-A, while the peripapillary vessel density (ppVD) was obtained by scanning the 4.5 × 4.5 mm area around the optic disk. Covariances including biomechanically corrected intraocular pressure (bIOP), axial length, age and gender were adjusted during data analysis.

RESULTS

The mean WEM of the participants was 0.235 ± 0.066 mm. The mean SCP-VD and DCP-VD in whole image were 46.20% ± 3.77% and 50.51% ± 3.96%; the mean whole pp-VD was 49.75% ± 2.01%. WEM was positively correlated with SCP-VD (r = 0.327, p = 0.01) and the whole pp-VD (r = 0.394, p < 0.01) after adjusting by gender, axial length (AL), age and bIOP, but it was not significantly correlated with DCP-VD (r = 0.072 p = 0.581).

CONCLUSION

Increase in orbital pressure might reduce retinal microvascular perfusion. Our data suggest orbital mechanical compression may be an important cause of retinal VD changes in quiescent patients with TAO.

Reduced contrast sensitivity function correlated with superficial retinal capillary plexus impairment in early stage of dysthyroid optic neuropathy

BACKGROUND

To assess the accuracy of contrast sensitivity function (CSF) in detecting dysthyroid optic neuropathy (DON) at an early stage in thyroid-associated ophthalmopathy (TAO) patients and to examine potential factors that may be linked to early visual impairments in these individuals.

METHODS

A total of 81 TAO patients (50 non-DON and 31 DON), and 24 control subjects participated in the study. CSF was measured with the quick CSF (qCSF) method. Optical coherence tomography angiography (OCTA) images of the ganglion cell complex layer (GCCL), superficial and deep retinal capillary plexuses (SRCP and DRCP) in a 3 mm diameter area around the macula were evaluated.

RESULTS

Compared with the controls, the area under the log contrast sensitivity function (AULCSF) and SRCP density were significantly reduced in non-DON and DON patients (all P < 0.05). The GCCL thickness of the DON patients was thinner than that of the controls and non-DON patients (all P < 0.05). The AULCSF was significantly correlated with spherical equivalent refractive error, muscle index, SRCP density and GCCL thickness in TAO patients, respectively (all P < 0.05). However, stepwise multi-regression analysis showed that the AULCSF was only significantly correlated with SRCP density (P < 0.001). Receiver operating characteristic curve analysis showed that the AULCSF produced the most accurate discrimination between non-DON and DON patients from the controls (AUC = 0.831, 0.987, respectively; all P < 0.001).

CONCLUSIONS

CSF change in the early stage of DON is related to SRCP density. It can be an early indicator of visual impairments associated with DON in TAO patients.

Decreased macular choriocapillaris in thyroid-associated ophthalmopathy: focusing on chorioretinal folds with and without optic disc edema

Purpose

The aim of this study was to evaluate the vessel density (VD) of the macular choriocapillaris (CC) and retina in thyroid-associated ophthalmopathy (TAO) patients with chorioretinal folds (CRFs) with and without optic disc edema (ODE) and the correlations of these characteristics with visual function.

Method

This was a cross-sectional study. Twenty TAO patients with CRFs (35 eyes) and 20 normal subjects (normal group, 40 eyes) were recruited at the Ophthalmology Department of the Sun Yat-sen Memorial Hospital from March 2018 to October 2022. Then, CRF patients were divided into two groups, the ODE and non-ODE groups (NODE), based on the presence or absence of ODE. All the patients underwent optical coherence tomography angiography (OCTA) and the VD of the macular CC and retina was computed. The correlation of VD and visual function was analyzed.

Results

Compared with the normal group, the macular whole-image VD in the retinal superficial layer (SLR-mwiVD: 49.82 ± 3.38 in the normal group, 42.44 ± 5.40 in the NODE group, and 42.51 ± 5.37 in the ODE group), deep layer (DLR-mwiVD: 51.05 ± 6.23 in the normal group, 45.71 ± 6.66 in the NODE group, and 46.31 ± 5.48 in the ODE group), and CC (CC-mwiVD: 70.23 ± 2.47 in the normal group, 68.04 ± 3.73 in the NODE group, and 63.09 ± 6.51 in the ODE group) was decreased in the NODE (all p < 0.05) and ODE group (all p < 0.01). There was no difference in these parameters except CC-mwiVD between the ODE and NODE groups. The CC-mwiVD in the ODE group (63.09 ± 6.51) was significantly reduced compared with that in the NODE group (68.04 ± 3.73, p = 0.004). All these VD parameters were negatively correlated with BCVA, VF-PSD, and P100 latency and positively associated with VF-MD, P100 amplitude, and HRR scores (all p < 0.05).

Conclusions

There was a significant decrease in the VD of the macular CC and retina of patients with CRFs with or without ODE, which was correlated with visual dysfunction. The VD of the macular CC in CRF patients with ODE was significantly reduced compared with that in the NODE group, but similar results were not observed in the retina.