Update on thyroid-associated Ophthalmopathy with a special emphasis on the ocular surface

Risk Factors for Ocular Surface Irritation Symptoms in Inactive Mild and Moderate-to-Severe Graves' Orbitopathy

INTRODUCTION

This study aims to analyze risk factors for ocular surface irritation symptoms in patients with non-corneal-damage inactive mild and moderate-to-severe Graves' orbitopathy (GO).

METHODS

This retrospective study enrolled 307 patients with non-corneal-damage inactive GO admitted to Sun Yat-sen Memorial Hospital from April 2017 to September 2023. The activity and severity of GO were evaluated using the Clinical Activity Score (CAS) and the European Group on Graves' Orbitopathy (EUGOGO) classification, respectively. Multivariate logistic regression analysis was performed to analyze risk factors for ocular surface irritation symptoms.

RESULTS

Among patients with inactive GO, for mild cases, CAS (P < 0.001), upper eyelid lag (P = 0.049), and extraocular muscle involvement (P = 0.019) in the symptomatic group were greater than those in the asymptomatic group, and multivariate logistic regression analysis demonstrated that upper eyelid lag (P = 0.048), CAS 1 (P < 0.001), CAS 2 (P = 0.005), and extraocular muscle involvement (P = 0.029) were risk factors for ocular surface irritation symptoms; for moderate-to-severe cases, CAS (P = 0.004), extraocular muscle involvement (P < 0.001), marginal reflex distance 1 (MRD1) (P = 0.030), and thyroid-stimulating hormone (TSH) (P = 0.034) in the symptomatic group were greater than those in the asymptomatic group, while multivariate logistic regression analysis indicated that extraocular muscle involvement (P = 0.018) and MRD1 (P = 0.012) were risk factors for ocular surface irritation symptoms.

CONCLUSION

In non-corneal-damage inactive mild and moderate-to-severe GO, eyelid malposition and periocular muscle inflammation are risk factors for ocular surface irritation symptoms.

[Endocrine orbitopathy]

Endocrine orbitopathy (EO), also known as Graves' orbitopathy or thyroid-associated orbitopathy, is a self-limiting, immunologically induced co-reaction of the retrobulbar tissue of the eye triggered by an autoimmune disease of the thyroid gland. It is particularly associated with Graves' disease and is its most common extrathyroidal manifestation. In addition to typical anamnestic data, characteristic local findings and laboratory changes in immunothyroidism, orbital imaging plays a central role in the diagnosis and management of this disease. This review article provides comprehensive insight into various imaging modalities used to assess morphologic changes associated with EO. A detailed presentation of imaging findings provides a better understanding of orbital physiology.

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.

Immunophenotype of Lacrimal Glands in Graves Orbitopathy: Implications for the Pathogenesis of Th1 and Th17 Immunity

Background: Recent studies have reported a wide spectrum of ocular surface injuries in the context of autoimmune reactions in Graves' orbitopathy (GO). Increased expression of inflammatory mediators in tears of GO patients suggests that the lacrimal glands could be a target for immune responses. However, the immunophenotype for GO lacrimal microenvironment is not known. This study aimed to elucidate the pathological changes of GO lacrimal glands. Methods: In this case-control study, lacrimal glands were surgically collected from GO patients who underwent orbital decompression surgery and control subjects who underwent other ocular-related surgery. Bulk RNA-sequencing, flow cytometry with dimensional reduction, and immunohistochemical and multiplexed stainings were conducted. Western blotting and multipathway assays were performed in CD34⁺ fibroblasts derived from lacrimal and orbital tissues. Results: Increased expression of cytokines and chemokines accompanied by a variety of immune cell infiltrations mainly involving T cells, B cells, and monocytes was found in GO lacrimal glands. An in-depth investigation into T cell subsets revealed interferon (IFN)-γ-producing T helper (Th)1 and interleukin (IL)-17A-producing Th17 cell-dominated autoimmunity in the active GO lacrimal microenvironment. Both fibrosis and adipogenesis were observed in GO lacrimal tissue remodeling. IL-17A, not IFN-γ, stimulated transforming growth factor-β-initiated myofibroblast differentiation as well as 15-deoxy-Δ^12,14-prostaglandin J₂-initiated adipocyte differentiation in CD34⁺ lacrimal fibroblasts (LFs) and orbital fibroblasts (OFs), respectively. IL-17A activated many fibrotic and adipogenic-related signaling pathways in CD34⁺ LFs and OFs. A novel anti-IL-17A monoclonal antibody SHR-1314 could reverse the promoting effect of IL-17A on fibrosis and adipogenesis in CD34⁺ LFs and OFs. Conclusions: Our findings provide evidence for the infiltration of different lymphocytes into GO lacrimal microenvironment, where Th1 and Th17 cells characterize the onset of active lacrimal inflammation and contribute to tissue remodeling. These findings may have potential future therapeutic implications regarding the utility of anti-IL-17A therapy, which should be studied in future research.

In vivo confocal microscopy assessment of meibomian glands microstructure in patients with Graves' orbitopathy

BACKGROUND

To evaluate microstructural changes in the meibomian glands (MGs) in patients with active and inactive Graves' orbitopathy (GO), using in vivo confocal microscopy (IVCM), and to investigate the correlations between clinical and confocal findings.

METHODS

Forty patients (80 eyes) with GO (34 eyes with active GO, 46 eyes with inactive GO), and 31 age- and sex-matched control participants (62 eyes) were enrolled consecutively. A researcher recorded the clinical activity score (CAS) for each patient. A complete ophthalmic examination was then performed, including external eye, ocular surface and MGs. IVCM of the MGs was performed to determine the MG acinar density (MAD), MG longest and shortest diameters (MALD and MASD), MG orifice area (MOA), MG acinar irregularity (MAI), meibum secretion reflectivity (MSR), acinar wall inhomogeneity (AWI), acinar periglandular interstices inhomogeneity (API), and severity of MG fibrosis (MF).

RESULTS

All confocal microscopy assessments of MGs significantly differed among groups (all P = 0.000). Compared to controls, GO groups showed lower MOA (1985.82 ± 1325.30 μm2 in active GO and 2021.59 ± 1367.45 μm2 in inactive GO vs. 3896.63 ± 891.90 μm2 in controls, all P = 0.000) and MAD (87.21 ± 32.69 /mm2 in active GO and 80.72 ± 35.54 /mm2 in inactive GO vs. 114.69 ± 34.90 /mm2 in controls, P = 0.001 and 0.000, respectively); greater MALD (118.11 ± 30.23 μm in active GO and 120.58 ± 27.64 μm in inactive GO vs. 58.68 ± 20.28 μm in controls, all P = 0.000) and MASD (44.77 ± 19.16 μm in active GO and 46.02 ± 20.70 μm in inactive GO vs. 27.80 ± 9.90 μm in controls, all P = 0.000); and higher degrees of MAI, MSR, and MF (all P<0.05). Eyes with active GO had higher degrees of MAI (P = 0.015), AWI (P = 0.000), and API (P = 0.000), while eyes with inactive GO had higher degrees of MSR (P = 0.000) and MF (P = 0.017). In GO groups, AWI and API were positively correlated with CAS (r = 0.640, P = 0.000; r = 0.683, P = 0.000, respectively), and MF was negatively correlated with CAS (r = - 0.228, P = 0.042).

CONCLUSIONS

IVCM effectively revealed microstructural changes of MGs in eyes with GO and provided strong in vivo evidence for the roles of obstruction and inflammation in the ocular surface disease process. Furthermore, it revealed discernible patterns of MG abnormalities in eyes with active GO and inactive GO, which are not easily distinguishable by typical clinical examinations.

The Clinical Features of Graves' Orbitopathy with Elevated Intraocular Pressure

Background

To investigate the clinical characteristics of Graves' orbitopathy (GO) with elevated intraocular pressure (IOP) using the European Group of Graves' Orbitopathy (EUGOGO) system.

Methods

In this retrospective study, the clinical data of GO patients with elevated IOP (≥21 mmHg) were collected in Sun Yat-sen Memorial Hospital from January 2010 to June 2016. The demographic characteristics, clinical history of thyroid disease and GO, and ocular examination data were evaluated, and the activity and severity of GO were classified.

Results

Data were collected from 58 eyes of 39 patients. The durations of thyroid disease and GO were 15.9 ± 18.9 months and 7.5 ± 6.2 months, respectively. The average IOP was 24.8 ± 5.3 mmHg (range: 21–55 mmHg). No significant difference in IOP was observed between active and inactive eyes. Eight eyes (13.8%), 29 eyes (50.0%), and 21 eyes (36.2%) were graded as mild, moderate-severe, and sight-threatening disease, respectively, according to the EUGOGO classification. The IOP was not significantly different among the three EUGOGO grades. No glaucomatous optic nerve damage or visual field defects were found.

Conclusion

Increased IOP was evident for every grade of GO severity and activity of the EUGOGO system. IOP, glaucomatous optic nerve damage, and visual fields must be evaluated regularly during follow-up evaluations, regardless of the degree of activity and severity of GO.

Protein tyrosine phosphatase 1B as a therapeutic target for Graves' orbitopathy in an in vitro model

Graves' orbitopathy (GO) is characterised in early stages by orbital fibroblast inflammation, which can be aggravated by oxidative stress and often leads to fibrosis. Protein tyrosine protein 1B (PTP1B) is a regulator of inflammation and a therapeutic target in diabetes. We investigated the role of PTP1B in the GO mechanism using orbital fibroblasts from GO and healthy non-GO subjects. After 24 hours of transfection with PTPN1 siRNA, the fibroblasts were exposed to interleukin (IL)-1β, cigarette smoke extract (CSE), H2O2, and transforming growth factor (TGF)-β stimulations. Inflammatory cytokines and fibrosis-related proteins were analysed using western blotting and/or enzyme-linked immunosorbent assay (ELISA). Reactive oxygen species (ROS) release was detected using an oxidant-sensitive fluorescent probe. IL-1β, tumor necrosis factor (TNF)-α, bovine thyroid stimulating hormone (bTSH), high-affinity human stimulatory monoclonal antibody of TSH receptor (M22), and insulin-like growth factor-1 (IGF-1) significantly increased PTP1B protein production in GO and non-GO fibroblasts. PTPN1 silencing significantly blocked IL-1β-induced inflammatory cytokine production, CSE- and H2O2-induced ROS synthesis, and TGF-β-induced expression of collagen Iα, α-smooth muscle actin (SMA), and fibronectin in GO fibroblasts. Silencing PTPN1 also decreased phosphorylation levels of Akt, p38, and c-Jun N-terminal kinase (JNK) and endoplasmic reticulum (ER)-stress response proteins in GO cells. PTP1B may be a potential therapeutic target of anti-inflammatory, anti-oxidant and anti-fibrotic treatment of GO.

Tear inflammatory cytokines and ocular surface changes in patients with active thyroid eye disease treated with high-dose intravenous glucocorticoids

PURPOSE

To evaluate high-dose intravenous glucocorticoid treatment on tear inflammatory cytokines and ocular surface parameters in patients with active TED. Correlations between tear inflammatory cytokines and clinical parameters were also investigated.

METHODS

This prospective pilot study included 15 moderate-to-severe and active TED patients. Control group consist of 15 sex and age-matched healthy subjects. All TED patients were treated with high-dose intravenous methylprednisolone with cumulative dose of 4.5 g during the therapy subdivided into 12 weekly infusions. Tear concentrations of interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-17A, tumor necrosis factor (TNF)-α, and vascular endothelial growth factor (VEGF) were measured by multiplex bead analysis in TED patients at baseline and 12 weeks after treatment. Ocular surface disease index (OSDI), tear break-up time (TBUT), corneal fluorescent staining, and Schirmer's test were obtained from TED and controls.

RESULTS

All baseline cytokine levels except for IL-17A were significantly elevated in active TED patients compared with controls. Concentrations of IL-1β, IL-6, IL-8, TNF-α, and VEGF were significantly decreased at 12 weeks compared with baseline. OSDI and TBUT showed significant improvement at 6 and 12 weeks. There were significant positive correlations between IL-6, IL-8, and CAS, and negative correlation was found between IL-6 level and TED duration before methylprednisolone treatment. The reduction of IL-6, IL-8, and VEGF were positive correlated with the reduction in CAS at 12 weeks.

CONCLUSIONS

High-dose glucocorticoids treatment improved ocular surface symptom, increased the tear film stability, and decreased tear inflammatory cytokines in active TED. The reduction of the inflammatory cytokines is consistent with the improvement of clinical parameters.

Enhanced orbital adipogenesis in a mouse model of T-cell-mediated autoimmunity, zymosan A-treated SKG mice: Implications for Graves' ophthalmopathy

Inflammation and remodelling of orbital tissue associated with enhanced adipogenesis commonly occur in Graves' ophthalmopathy (GO), however, the underlying mechanisms that link immune cells and adipocytes in orbital inflammation are not well-known. The primary aim of this study was to elucidate how a genetically determined shift in the T-cell repertoire toward self-reactive T-cells could drive orbital adipogenesis. To induce the T-cell-mediated autoimmune response, SKG mice were intraperitoneally injected with zymosan A once at 8 weeks of age. After three months, orbital magnetic resonance imaging (MRI), histopathologic studies, and in vitro analyses were performed to evaluate inflammation and adipogenesis. The eyes of the zymosan A-treated SKG mice displayed proptosis and blepharitis. A detailed analysis of orbital adipose tissue showed enhanced orbital adipogenesis and cellular infiltration compared to controls. In addition, increased secretion of adipokines and other cytokines in the periorbital tissue was observed, together with elevated serum concentration of inflammatory cytokines. Orbital adipogenesis was enhanced in zymosan A-treated SKG mice, a novel mouse model for GO-like inflammatory adipose phenotypes most likely induced by T-cell mediated autoimmune responses. This mouse model gives us the opportunity to examine the underlying molecular mechanisms of enhanced adipogenesis in GO, ultimately providing a potential therapeutic target alternative to conventional GO treatment.

Does the Epstein-Barr Virus Play a Role in the Pathogenesis of Graves' Disease?

Graves’ disease (GD) it the most common chronic organ-specific thyroid disorder without a fully recognized etiology. The pathogenesis of the disease accounts for an interaction between genetic, environmental, and immunological factors. The most important environmental factors include viral and bacterial infections. The Epstein-Barr virus (EBV) is one of the most common latent human viruses. Literature has suggested its role in the development of certain allergic and autoimmune diseases. EBV also exhibits oncogenic properties. The aim of the study was to analyze and compare the presence of EBV DNA in peripheral blood mononuclear cells (PBMCs) in patients with newly recognized GD and to find a correlation between EBV infection and the clinical picture of GD. The study included 39 untreated patients with newly diagnosed GD and a control group of 20 healthy volunteers who were gender and age matched. EBV DNA was detected with reverse transcription polymerase chain reaction (RT PCR) assay. The studies showed a significantly higher incidence of EBV copies in PBMCs among GD patients compared to the control group. Whereas, no significant correlations were found between the incidence of EBV copies and the evaluated clinical parameters. Our results suggest a probable role of EBV in GD development. EBV infection does not affect the clinical picture of Graves’ disease.

Altered Corneal Nerves in Chinese Thyroid-Associated Ophthalmopathy Patients Observed by In Vivo Confocal Microscopy

BACKGROUND Thyroid-associated ophthalmopathy (TAO) is a common endocrine autoimmune disease. The present study explored corneal nerve changes in TAO patients. MATERIAL AND METHODS Thirty-eight Chinese TAO patients and 20 healthy individuals were included in the study. Central corneal subbasal nerve density and morphology were evaluated with in vivo laser scanning confocal microscopy and quantified using automated CCmetrics software. RESULTS The values of the central corneal subbasal nerve plexus parameters of both active and inactive TAO patients were significantly decreased compared with those of controls, including corneal nerve fiber density (CNFD) (P<0.001 for both), corneal nerve branch density (CNBD) (P<0.001 for both), corneal nerve fiber length (CNFL) (P<0.001 for both), corneal nerve fiber total branch density (CTBD) (P<0.001 for both), corneal nerve fiber area (CNFA) (P<0.001 for both), corneal nerve fiber width (CNFW) (P=0.046, P=0.027, respectively), and corneal nerve fiber fractal dimension (ACNFrD) (P<0.001 for both). In addition, CNFD and ACNFrD values were significantly lower in the active TAO patients compared with those in the inactive TAO patients (P=0.020, P=0.002, respectively). There were significant correlations between CNFD, CNBD, CNFL, CTBD, CNFA, and ACNFrD and the ocular surface parameters and activity assessment items. CONCLUSIONS Abnormal corneal subbasal nerves were observed in both active and inactive Chinese TAO patients, suggesting that nerve degeneration is associated with the disease. However, the exact underlying mechanisms remain to be elucidated.

Insulin-like Growth Factor-I Receptor and Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is a complex disease process presumed to emerge from autoimmunity occurring in the thyroid gland, most frequently in Graves disease (GD). It is disfiguring and potentially blinding, culminating in orbital tissue remodeling and disruption of function of structures adjacent to the eye. There are currently no medical therapies proven capable of altering the clinical outcome of TAO in randomized, placebo-controlled multicenter trials. The orbital fibroblast represents the central target for immune reactivity. Recent identification of fibroblasts that putatively originate in the bone marrow as monocyte progenitors provides a plausible explanation for why antigens, the expressions of which were once considered restricted to the thyroid, are detected in the TAO orbit. These cells, known as fibrocytes, express relatively high levels of functional TSH receptor (TSHR) through which they can be activated by TSH and the GD-specific pathogenic antibodies that underpin thyroid overactivity. Fibrocytes also express insulin-like growth factor I receptor (IGF-IR) with which TSHR forms a physical and functional signaling complex. Notably, inhibition of IGF-IR activity results in the attenuation of signaling initiated at either receptor. Some studies suggest that IGF-IR-activating antibodies are generated in GD, whereas others refute this concept. These observations served as the rationale for implementing a recently completed therapeutic trial of teprotumumab, a monoclonal inhibitory antibody targeting IGF-IR in TAO. Results of that trial in active, moderate to severe disease revealed dramatic and rapid reductions in disease activity and severity. The targeting of IGF-IR with specific biologic agents may represent a paradigm shift in the therapy of TAO.

Assessment of tear-evaporation rate in thyroid-gland patients

Objective

To assess the tear-evaporation rate in thyroid-gland patients using a VapoMeter.

Methods

Twenty thyroid gland patients aged 18-43 years (mean 34.3±6.3 years) completed the study. Additionally, an age-matched control group of 20 patients aged 18-43 years (32.2±5.1 years) was enrolled in the study for comparison purposes. An Ocular Surface Disease Index dry-eye questionnaire was completed, followed by a test to determine the tear-evaporation rate using the VapoMeter. The test was performed three times per subject by the same examiner. Two readings were obtained each time.

Results

Significant differences (P<0.05) were found between mean Ocular Surface Disease Index and tear-evaporation-rate scores within the study and control groups. The average tear-evaporation rate was much higher in the study group (median 41.2 [IQR 41.4] g/m²⋅h) than the control group (15.7 [13.7] g/m²⋅h). Moreover, the average Ocular Surface Disease Index score for thyroid-gland patients was much higher (15.6 [23.4]) compared to the control group (5.5 [7.50]).

Conclusion

The tear-evaporation rate in thyroid-gland patients was found to be much higher than normal-eye subjects.

An overview of the contribution of acupuncture to thyroid disorders

Thyroid dysfunction, affecting people of all ages, not only damages human growth and energy metabolism but is also comorbid with other illnesses such as cardiovascular disease, kidney disease and gastrointestinal disorders. With the increasing acceptance of alternative and complementary therapies, acupuncture, a traditional Chinese medical practice, has also been employed to address this problem. Analysing 29 clinical projects that were retrieved from 29 major digital databases and include 1757 patients aged 7-79 years from China, Italy, Korea, Macedonia and Russia, this narrative review offers an overview of the efficacy, and evaluated the safe and cost-effective use of acupuncture against hyperthyroidism, hypothyroidism and thyroid-relevant illnesses. Findings indicated reductions in patient symptoms and improvements in biomarkers where acupuncture was used alone or in combination therapy. In addition to showing the role of acupuncture as an alternative and complementary medicine or as an adjunctive therapy for curative and rehabilitative purposes, more well-designed researches are needed to achieve reliable data.

Orbital decompression surgery for the treatment of Graves' ophthalmopathy: comparison of different techniques and long-term results

AIM

To evaluate the long-term results of different orbital decompression techniques performed in patients with Graves' ophthalmopathy (GO).

METHODS

Totally 170 cases with GO underwent orbital decompression between 1994 and 2014. Patients were divided into 4 groups as medial-inferior, medial-lateral (balanced), medial-lateral-inferior, and lateral only according to the applied surgical technique. Surgical indications, regression degrees on Hertel exophthalmometer, new-onset diplopia in the primary gaze and new-onset gaze-evoked diplopia after surgery and visual acuity in cases with dysthyroid optic neuropathy (DON) were compared between different surgical techniques.

RESULTS

The study included 248 eyes of 149 patients. The mean age for surgery was 42.3±13.2y. DON was the surgical indication in 36.6% of cases, and three-wall decompression was the most preferred technique in these cases. All types of surgery significantly decrease the Hertel values (P<0.005). Balanced medial-lateral, and only lateral wall decompression caused the lowest rate of postoperative new-onset diplopia in primary gaze. The improvement of visual acuity in patients with DON did not significantly differ between the groups (P=0.181).

CONCLUSION

The study show that orbital decompression surgery has safe and effective long term results for functional and cosmetic rehabilitation of GO. It significantly reduces Hertel measurements in disfiguring proptosis and improves visual functions especially in DON cases.

Challenges in Orphan Drug Development: Identification of Effective Therapy for Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO), the ocular manifestation of Graves' disease, is a process in which orbital connective tissues and extraocular muscles undergo inflammation and remodeling. The condition seems to result from autoimmune responses to antigens shared by the thyroid and orbit. The thyrotropin receptor (TSHR), expressed at low levels in orbital tissues, is a leading candidate antigen. Recent evidence suggests that another protein, the insulin-like growth factor-I receptor (IGF-IR), is overexpressed in TAO, and antibodies against IGF-IR have been detected in patients with the disease. Furthermore, TSHR and IGF-IR form a physical and functional complex, and signaling initiated at TSHR requires IGF-IR activity. Identification of therapy for this rare disease has proven challenging and currently relies on nonspecific and inadequate agents, thus representing an important unmet need. A recently completed therapeutic trial suggests that inhibiting IGF-IR activity with a monoclonal antibody may be an effective and safe treatment for active TAO.