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

Effect of orbital decompression surgery on the choroidal profile in patients with thyroid eye disease

This study aimed to investigate the effect of orbital wall decompression surgery and reduction of proptosis on the choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT) in patients with thyroid eye disease (TED). Fifty-one eyes from 38 patients with controlled TED and proptosis were enrolled in this study. The majority of the patients (50.9%) had a clinical activity score (CAS) of zero, and none had a CAS greater than 2. The patients underwent a complete baseline ophthalmologic examination, and their choroidal profile alterations were monitored using enhanced depth imaging optical coherence tomography (EDI-OCT) before and during the three months after surgery. Changes in SFCT, luminance area (LA), total choroidal area (TCA), and the choroidal vascularity index (CVI) were measured as the ratio of LA to TCA in EDI-OCT images. The participants had an average age of 46.47 years, and 22 were female (57.9%). The SFCT of the patients exhibited a significant reduction over the follow-up period, decreasing from 388 ± 103 to 355 ± 95 µm in the first month (p < 0.001) and further decreasing to 342 ± 109 µm by the third month compared to baseline (p < 0.001). The CVI exhibited a drop from 0.685 ± 0.037 at baseline to 0.682 ± 0.035 and 0.675 ± 0.030 at 1 and 3 months post-surgery, respectively. However, these changes were not statistically significant, indicating comparable decreases in both LA and TCA. There was a significant correlation between improved proptosis and reduction in SFCT (p < 0.001) but not with CVI (p = 0.171). In conclusion, during the three months of follow-up following orbital wall decompression, CVI did not change, while SFCT reduced significantly. Additionally, SFCT was significantly correlated with proptosis reduction, whereas CVI was not.

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.

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.

Macular retinal and choroidal thickness profile in patients with thyroid-associated orbitopathy compared to healthy individuals: A cross-sectional study

Background and Aims

To evaluate the macular thickness profile and central subfoveal choroidal thickness in patients with thyroid-associated orbitopathy (TAO) compared to healthy subjects.

Methods

We used the convenience sampling method and divided all participants into the patients and control groups. Based on the clinical activity score (CAS) in the first examination, the patient group was divided to two subgroups: the patients with CAS < 3 and the patients with CAS ≥ 3. Complete ophthalmologic examinations and optical coherence tomography imaging were performed for all participants.

Results

The mean ± SD of central choroidal thickness was 277 ± 76.58 microns for the control and 326.07 ± 56.574 micron for the patient group which was statistically significant (p = 0.003). We also found that the parafoveal inner thickness is significantly lower in patients compared to healthy subjects (p = 0.02). A comparison of neuro-structural data between the two subgroups of patients showed a significant difference in central choroidal thickness (p = 0.05).

Conclusion

This study showed that central choroidal thickness in patients with CAS ≥ 3 compared to those with CAS < 3 and also in the patient group compared to healthy individuals have a significantly increasing trend.

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.

Early Massive Fibrosis of a Single Extraocular Muscle Causing Severe Unilateral Euthyroid Graves’ Ophthalmopathy in a Patient with Hypercholesterolemia Who Smokes

Background

Graves' ophthalmopathy (GO) is an autoimmune manifestation of orbit affecting approximately 25% of patients with Graves' disease (GD). Autoreactive T cells involved in thyroid autoimmunity can recognize the thyroid-stimulating receptor (TSHr) expressed in orbital tissues of GO patients. Clinical manifestations of GO are rather different depending on the presence of some risk factors, such as smoking, hyperthyroidism duration, age, biological activity of anti-TSHr antibodies (TSH-R-Ab) and metabolic diseases.

Case Presentation

Here, we present a rare case of euthyroid single muscular GO in a 50-year-old patient who was a smoker and had dyslipidemia for several years. The patient experienced a very rapid and severe depression of ocular motility of the right eye that caused uncorrectable and constant diplopia, severely affecting his quality of life. He was euthyroid, and TSH-R-Ab plasmatic levels were only slightly elevated. Intravenous corticosteroid pulse therapy was partially effective, and two rounds of wall orbital surgical decompression were necessary. Massive mono-muscular fibrosis was evidenced by biopsy of the right inferior rectus muscle.

Conclusion

Severe unilateral, mono-muscular GO in a euthyroid Graves' patient was found to be sustained by rapid and massive fibrosis of the inferior rectus muscle of the right orbit. Clarification of the pathogenetic mechanisms of these GO clinical forms requires further studies.

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.

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.