Choroidal vascularity index in thyroid-associated ophthalmopathy: a cross-sectional study

Changes in choroidal thickness and choroidal vascularity index in thyroid eye disease: a systematic review

PURPOSE

To evaluate the evidence for changes in choroidal thickness and choroidal vascularity index (CVI) in people with thyroid eye disease (TED), stratified by severity, as measured by optical coherence tomography (OCT).

METHODS

Systematic review, including quality assessment, of published studies investigating choroidal thickness in TED. Outcomes of interest included CVI, subfoveal choroidal thickness, mean choroidal thickness, and peripheral choroidal thickness in four quadrants (superior, inferior, medial, lateral).

RESULTS

Nineteen studies were included which contained measurements from 1067 eyes in 798 patients with TED. Most studies found an increased CVI and increased choroidal thickness in patients with TED compared to normal controls, especially in the subfoveal region. In addition, several studies reported an increased thickness in patients with active vs. inactive TED, although the results are equivocal. Finally, many studies reported associations between increased choroidal thickness and worsened clinical measurements of disease activity, such as Clinical Activity Score (CAS).

CONCLUSIONS

This systematic review provided evidence for an association between increased CVI/choroidal thickness and TED, suggesting a potential for OCT-measured CVI/choroidal thickness as an objective clinical marker. Given heterogeneity, future studies are needed to assess the role of measuring the choroidal changes in diagnosis and management of TED.

Correlation between choroidal vascularity and retrobulbar ocular blood flow changes and thyroid-associated ophthalmopathy activity: a cross-sectional study

OBJECTIVE

To evaluate the alterations in retrobulbar color Doppler imaging (CDI) parameters and retinal/choroidal optical coherence tomography angiography (OCTA) parameters and their association with the clinical activity and severity in thyroid-associated orbitopathy (TAO) patients.

METHODS

In this study, the retrobulbar flow parameters including resistance index (RI), Pulsatile Index(PI), peak systolic velocity (PSV) and end diastolic velocity (EDV) in posterior ciliary artery (PCA), central retinal artery (CRA) and ophthalmic artery (OA) were determined by CDI. Moreover, the retina and choroidal vascularity including the superficial vessel density (SVD), deep vessel density (DVD), choroidal thickness (ChT) and choroidal vascularity, including total choroidal area (TCA), luminal area (LA), stromal area (SA) and Choroidal Vascularity Index (CVI), were determined by OCTA. All patients grouped as active TAO and inactive TAO based on Clinical activity score (CAS). We picked the severe eye among the subjects and compared all parameters between two groups. We analyzed the correlations among those parameters.

RESULTS

There was a significant difference in CAS score, proptosis value, ChT, LA, CVI between patients with active TAO and inactive TAO. In the active group, PSV and EDV of PCA were significantly higher than the inactive group. On logistic regression analysis, CAS was closely associated with PSV-PCA. On multiple linear regression, proptosis value was closely associated with ChT, LA, SA and CVI.

CONCLUSION

Choroidal vascularization and retrobulbar blood flow were concurrently higher in active TAO patients and several variables in choroid circulation was closely related to TAO clinical features.

Choroidal thickness in thyroid eye disease and its correlation with disease activity

CONTEXT

This study adds to the existing body of literature on the role of optical coherence tomography (OCT) parameters in active thyroid eye disease (TED) among the Indian population.

PURPOSE

Comparison of choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT) in active and inactive TED.

SETTINGS AND DESIGN

An observational, cross-sectional analytical study conducted at a tertiary eye care hospital in North India that included patients with active and inactive TED.

METHODS

Demographic details and clinical evaluation were performed for all TED patients. SFCT was determined with OCT by using the Cirrus linear measurement tool. CVI was calculated using Image J software. The SFCT and CVI measurements were compared between both groups.

STATISTICAL ANALYSIS USED

Comparison between active and inactive TED groups was done using Mann-Whitney U test for non-parametric data and Student t test for parametric data. Multivariate regression analysis was performed with SFCT and CVI as dependent variables.

RESULTS

Sixty-two eyes of 31 patients were included. Thirteen eyes had active TED, and 49 eyes had inactive TED. SFCT was significantly lower in eyes with higher clinical activity score (CAS) and older age. No significant difference was found in CVI between active and inactive TED eyes.

CONCLUSION

SFCT was lower in eyes with higher CAS and older age. Our findings differ from previous studies, which showed a positive correlation between SFCT and CAS. There was no significant difference in CVI between active and inactive TED eyes.

Automated evaluation of parapapillary choroidal microvasculature in thyroid eye disease

PURPOSE

The purpose of the study was to investigate the parapapillary choroidal microvasculature in thyroid eye disease (TED) using optical coherence tomography angiography (OCTA).

METHODS

Only one eye of each subject was included in the study. Patients with TED and controls were included in the study. Participants were divided into three groups: control, inactive TED (ITED) and active TED (ATED). OCTA scans of the optic discs were obtained in a 4.5 × 4.5-mm rectangular area. Radial peripapillary capillary (RPC) density and peripapillary retinal nerve fibre layer (pRNFL) thickness were automatically calculated by the device software. Parapapillary choroidal microvasculature (PPCMv) density was automatically calculated using MATLAB software.

RESULTS

Forty-one patients with TED and 40 controls were included in the study. RPC density was significantly decreased in the ATED and dysthyroid optic neuropathy (DON) group compared to the controls and ITED group. There was significant increase in pRNFL in the ATED group. PPCMv density increased in the ATED group compared to the controls in whole ring area. The RPC density was significantly correlated with the TSHr Ab level (r < - 0.396, p < 0.001). Clinical activity score correlated positively with PPCMv density (r = 0.349, p = 0.001) but negatively with RPC density (r = - 0.321, p = 0.004).

CONCLUSION

Changes in peripapillary microvascular perfusion may play a role in the development of DON. As the severity of TED increases with clinical activity, so do the changes observed in peripapillary parameters. The decrease in RPC density may be due to compression caused by optic disc oedema, which may result in reduced blood flow. The increase in PPCMv density may be related to factors such as orbital congestion.

A Comparison of Observational Studies on Subfoveal Choroidal Thickness Measured with OCT according to the Level of Thyroid Eye Disease Activity-Systematic Review and Meta-Analysis

This study aims to systematise subfoveal choroidal thickness (SFCT) measured using optical coherence tomography (OCT) in patients with different severities of thyroid eye disease (TED) compared with healthy subjects. The PubMed, Web of Science and Scopus databases were searched for the following terms: ((Graves' ophthalmopathy) OR (thyroid eye disease) OR (Graves' orbitopathy) OR (thyroid-associated orbitopathy)) AND (choroidal thickness) AND ((optical coherence tomography) OR (OCT)). The pool of papers was narrowed down to articles published until 31 January 2023 (26, 26 and 96 papers, respectively). Twenty-five (25) articles were taken into consideration, which were original papers and included the choroidal thickness measurements among TED patients in their results. Finally, eight papers were included in the comparative analysis of the SFCT parameter in TED patients and a group of healthy controls, and seven papers in the comparative analysis of the same parameter between active and inactive TED patients. The mean value of the difference between the TED group and the healthy group was 38.79 μm, with a confidence interval (CI) from 0.09 to 77.49 μm (p = 0.0495). The mean difference between the active TED group and inactive TED group was 38.02 μm, with a CI from 8.62 to 67.42 μm (p = 0.0113). All the results were statistically significant.

Optical coherence tomography and optical coherence tomography — angiography used in endocrine ophthalmopathy

The literature review presents the results of optical coherence tomography and optical coherence tomography — angiography used for Graves’ orbitopathy. The data on the thickness of the inner layers of the retina, microcirculation in the peripapillary and macular regions, parameters of the choroid, lamina cribrosa and extraocular muscles were analyzed as possible diagnostic criteria of the condition.

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.

Orbital and ocular perfusion in thyroid eye disease

Thyroid eye disease (TED) is characterized by enlargement of extraocular muscles, an increase in retrobulbar fat, orbital fibrosis, and fluctuations in plasma thyroid hormone levels in most patients, often associated with raised autoantibody titers. The occurrence of orbital space conflict compromises the orbital perfusion, unchecked progression of which results in irreversible loss of visual acuity and visual fields. The quantitative assessment of orbital perfusion can be done by measurement of blood flow velocities in the superior ophthalmic vein (SOV), ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary artery by color Doppler imaging. The retinal and choroidal microvasculature is studied by optical coherence tomography and optical coherence tomography angiography. The orbital and ocular perfusion fluctuates during the course of TED. Orbital congestion is reflected by the reduction or reversal of SOV flow and an increase in subfoveal choroidal thickness. The active phase is characterized by high blood flow velocities of the OA and CRA. The onset of dysthyroid optic neuropathy is associated with reduced arterial perfusion and reduction in parafoveal and peripapillary vascular density. Orbital decompression improves the SOV flow and decreases the resistivity index of CRA. Sequential evaluation of orbital hemodynamic changes can thus supplement the clinical scoring systems for monitoring and planning intervention in TED.

Detection and Correlation Analysis of Serum Uric Acid in Patients with Thyroid-Associated Ophthalmopathy

Purpose

To probe the property of serum uric acid in evaluating the activity of patients with thyroid-associated ophthalmopathy.

Methods

A total of 443 patients with TAO admitted to our hospital from March 2016 to February 2021 were selected for the observation group. Simultaneously, 443 healthy subjects were selected for the control group. The observation group was divided into the active group (n = 254) and the inactive group (n = 189) according to the clinical activity score (CAS). Besides, the patients were divided into mild group (n = 201), moderate severe group (n = 133) and extremely severe group (n = 109) based on the severity of TAO. Serum uric acid, free triiodothyronine (FT3), free thyroid hormone (FT4), thyrotropin stimulating hormone (TSH) and glycosylated hemoglobin (HbA1c) levels were detected and analyzed in each group.

Results

Serum UA, FT3, FT4, TSH and HbA1c in the active group were significantly enhanced than those in the other two groups (P < 0.05), and there was no significant difference between the inactive group and the control group (P > 0.05). In different disease severity groups, the serum UA level of patients in the active group was significantly promoted than that in the inactive group and control group (P < 0.05) and was decreased successively in extremely severe group, moderate severe group and mild group, with statistical significance (P < 0.05). Pearson's analysis showed that UA was positively correlated with FT3, FT4, and HbA1c (r = 0.652, P = 0.031; r = 0.571, P = 0.042; r = 0.737, P = 0.024), while was reversely correlated with TSH level (r = -0.137, P = 0.262). There was no correlation between UA and FT3, FT4, and HbA1c levels in the inactive group. UA detection showed the average sensitivity and specificity of TAO activity were 94.3% and 85.2%, respectively. There was no significant correlation between the severity of disease and serum UA in inactive patients (P = 0.135). There was a positive correlation between the severity of disease and serum UA in active patients (P = 0.005).

Conclusion

UA may be used as a laboratory indicator for quantitative clinical diagnosis of thyroid-associated ophthalmopathy (TAO) and as a parameter for the presence of TAO activity.

Choroidal structural evaluation in inactive Graves' ophthalmopathy

PURPOSE

To investigate the changes in the choroidal structure in patients with inactive Graves Ophthalmopathy (GO).

DESIGN

A prospective, masked, observational cross-sectional study.

METHODS

Changes in choroidal vascularity index (CVI) were studied in the patients with inactive GO using binarization on enhanced depth imaging optical coherence tomography (EDI-OCT) images. Choroidal area, subfoveal choroidal thickness (SFCT), stromal area, luminal area, CVI and retinal nerve fiber layer (RNFL) thickness was used to compare the eyes of sixty-four age-, gender-matched healthy subjects. All measurements were done separately both subfoveal (1500 µm) and total choroidal area (7500 µm). The relation between CVI or SFCT and age, gender, duration of disease, the severity of disease, TRAb (thyrotropin receptor autoantibody), smoking status, and exophthalmometer readings were evaluated.

RESULTS

There were 56 patients (30 female, 26 male; mean age: 39.5 ± 11.4 years) in the GO group and 64 patients (34 female, 30 male; mean age: 42.2 ± 5.6 years) in the healthy subject group. There was no statistically significant difference between subjects with GO and healthy controls regarding age (p = 0.24) and gender distribution (p = 0.55). Patients with GO had significantly higher intraocular pressure (p = 0.001) and exophthalmometer readings (p = 0.0001) than the healthy controls. The SFCT, CVI₁₅₀₀ and the stromal area1500 was significantly different between the groups (p = 0.009, p = 0.009, p = 0.011, respectively). Multivariate analysis showed that age (-0.871, p = 0.02) was highly correlated with the decreased SFCT, and duration of disease (0.524, p = 0.001) was significantly positively correlated with SFCT. Luminal area1500 (-0.416, p = 0.0001)and stromal area1500 (-0.657, p = 0.0001) were significantly negatively correlated with CVI₁₅₀₀ in the patients with GO.

CONCLUSION

Although higher CVI₁₅₀₀ was observed in GO patients than in healthy controls, the degree of increase was not the same in the CVI₇₅₀₀. Age and duration of disease significantly affect the SFCT, and luminal area₁₅₀₀ and stromal area₁₅₀₀ significantly affect the CVI₁₅₀₀.

THE EFFECT OF HYPERBARIC OXYGEN THERAPY ON RETINA, CHOROIDAL THICKNESS, AND CHOROIDAL VASCULARITY INDEX

PURPOSE

To determine the acute and cumulative effect of hyperbaric oxygen therapy (HBOT) on retina and choroid tissue in healthy eyes.

MATERIAL AND METHODS

Thirty-five subjects who were planned to undergo HBOT for non-ophthalmologic indications comprised the population of this prospective study. Central macular thickness (CMT), retinal nerve fiber layer (RNFL), and choroidal thickness (CT) (3 points: subfoveal area, 500 µm nasal and fovea temporal) were measured using spectral-domain optical coherence tomography (SD-OCT) before HBOT and half an hour after the 1st and 20th sessions of HBOT. The subfoveal choroidal area was segmented using ImageJ software with the binarization technique on enhanced depth imaging (EDI) OCT images. Choroidal area (CA), luminal area (LA), and stromal area (SA) were calculated. Choroidal vascularity index (CVI) was determined as the ratio between LA and CA.

RESULTS

The right eyes of 35 patients aged between 22 and 59 years were enrolled in the study. The mean CMT values of the patients were 259.36 ± 22.31 µm, 256.94 ± 22.72 µm, and 254.58 ± 23.02 µm before HBOT, after the 1st session, and after the 20th session, respectively. The change in CMT values before and after HBOT was statistically significant (p=0.001). When the patients' RNFL, CT, CA, SA, LA, and CVI changes before and after the HBOT were examined, no statistically significant difference was found (p>0.05).

CONCLUSIONS

Our study is the first to jointly evaluate the effect of HBOT on the vascular and stromal components of the choroid and macula in healthy eyes. Due to its thinning effect on the macula, it can be preferred as an adjunctive and facilitating treatment option in addition to current treatments in patients with macular edema due to retinal vascular disorders.

Choroidal vascularity index in thyroid eye disease: comparison with controls and application in diagnosing non-inflammatory active disease

PURPOSE

To report the differences in choroidal vascularity index (CVI) in thyroid eye disease (TED) and normals and its discriminatory value for differentiating various stages of TED.

METHODS

Prospective, cross-sectional, non-interventional imaging study. Ninety-four eyes of 54 patients were included and divided into 5 groups - normal controls (C), inactive TED (I), active TED (A), non-inflammatory active TED (NIA) and systemic hyperthyroid disorder but no TED (SYS). Choroidal images were acquired using the swept-source optical coherence tomography and the choroid was binarized to calculate the CVI.

RESULTS

Ninety-four eyes were included. Mean age was 44.52 ± 10.02 years (median 46 years, range 19-65 years). Mean IOP was 16.1 ± 3.37 mm Hg (median 16 mm Hg, range 16-24 mm Hg). Mean Spherical equivalent (SE) was -0.08 ± 1.86 diopters (median 0, range -2.5 to +2.25). Intra-rater agreement was 0.84 (p < 0.001). Inter-rater agreement was noted to be 0.85 (p < 0.001) for consistency and 0.77 (p < 0.001) for absolute agreement. CVI in the A group was 70.11 ± 3.38% and in the NIA group was 69.32 ± 3.5%. Both were comparable to each other and significantly higher than the C, I and SYS groups (p < 0.001). Multiple regression showed that the Clinical Activity Score (CAS) had a positive effect and spheroequivalent had a negative effect on the CVI. At CVI of 66.83%, active TED can be diagnosed with sensitivity of 91.67% and specificity of 82.14%                 .

CONCLUSIONS

CVI is significantly higher in active TED and NIA TED compared to other groups. It has a good value in differentiating the non-inflammatory active TED eyes from the inactive eyes.

Change of intraocular blood flow during treatment for thyroid eye disease

To report a sequential observational study of changes in the retinal and choroidal blood flow during medical and surgical treatments for a thyroid eye disease (TED) patient, using optical coherence tomography angiography (OCTA) and laser speckle flowgraphy (LSFG). A 28-year-old man with a history of Graves’ disease diagnosed 8 months prior was presented in the active phase of TED. His clinical activity score (CAS) was 6, but without diplopia or visual loss. Intraocular pressure measurement was OD 20 mmHg and OS 24 mmHg. Thyrotropin receptor antibody (TRAb) and thyroid-stimulating antibody levels were 18.8 IU/L and 4347%. Magnetic resonance imaging revealed enlargement of both extraocular muscles and fat compartments in both orbits. The patient underwent IV pulsed steroid therapy (1 g/day, 3 days) followed by an oral prednisone for 1 month. His CAS score decreased to 4. Bilateral orbital fat decompression decreased his final CAS score to 1 in both eyes. Intraocular blood flow was measured using laser speckle flowgraphy (LSFG), and OCTA was performed. Retinal blood flow increased slightly, but choroidal blood flow showed a robust increase. Choroidal blood flow measured using both LSFG and OCTA was negatively correlated with the CAS score and TRAb. In our case report, the ocular perfusion, especially choroidal blood flow, may decrease in active TED, which may be reversed by medical and surgical treatment.