Interruption of autoimmunity for thyroid eye disease: B-cell and T-cell strategy

Role of Lysyl Oxidase-Like Protein 3 in the Pathogenesis of Graves' Orbitopathy in Orbital Fibroblasts

Purpose

The lysyl oxidase (LOX) family has been implicated in the pathogenesis of diseases caused by inflammation and fibrosis. Therefore, we aimed to examine the role of lysyl oxidase-like protein 3 (LOXL3) in Graves' orbitopathy (GO) pathogenesis and its potential as a treatment target.

Methods

Quantitative real-time polymerase chain reaction compared the transcript levels of the five LOX family subtypes in orbital tissue explants obtained from patients with GO (n = 18) and healthy controls (n = 15). The effects of LOXL3 inhibition on interleukin (IL)-1β-induced proinflammatory cytokines, transforming growth factor (TGF)-β-induced profibrotic proteins, intracellular signaling molecules, and adipogenic markers were evaluated using Western blotting. Adipogenic differentiation was identified using Oil Red O staining.

Results

LOX and LOXL3 transcript levels were high in GO tissues. Stimulation with IL-1β, TGF-β, and insulin-like growth factor-1 significantly increased LOXL3 messenger RNA expression in GO fibroblasts. Furthermore, silencing LOXL3 attenuated the IL-1β-induced production of proinflammatory cytokines (IL-6, IL-8, and intercellular adhesion molecule-1) and TGF-β-induced production of profibrotic proteins (fibronectin, collagen 1α, and alpha-smooth muscle actin). It also reduced the IL-1β or TGF-β-induced expression of phosphorylated nuclear factor kappa-light-chain-enhancer of activated B cells, protein kinase B, extracellular signal-regulated kinase, and c-Jun N-terminal kinase. Additionally, LOXL3 silencing suppressed adipocyte differentiation and the expression of adipogenic transcription factors (leptin, AP-2, peroxisome proliferator-activated receptor gamma, and CCAAT/enhancer-binding protein).

Conclusions

LOXL3 is crucial in GO pathogenesis. LOXL3 inhibition reduced inflammatory cytokine production, fibrotic protein expression, and fibroblast differentiation into adipocytes. This study highlights LOXL3 as a potential therapeutic target for GO.

Teprotumumab versus intravenous methylprednisolone in thyroid eye disease: A systematic review

Thyroid eye disease (TED), also known as thyroid-associated ophthalmopathy, is an autoimmune disorder caused due to a complex interplay between autoantigens including the thyroid-stimulating hormone receptor and the insulin-like growth factor-I receptor. TED is characterized by progressive proptosis or diplopia. This systematic review aimed to compare the efficacy of the newer monoclonal antibody - teprotumumab and intravenous methylprednisolone (IVMP) in TED patients. We performed a systematic review of previously published studies from 2013 to June 2023. A total of 329 articles were screened; among them, 111 non-duplicate publications were identified. After the screening of titles and abstracts, 156 publications were excluded; then, another 47 published papers were excluded after the full-text screening. The remaining 15 eligible studies were included in this systematic review. The majority of studies used either teprotumumab alone or in combination with others. Among 15 studies, eight studies used teprotumumab in TED patients, whereas remaining 7 studies used a standard treatment regimen. This systematic review provides an overview of the existing treatment options using monoclonal antibody - teprotumumab and IVMP in TED patients. The overall assessment provides a finding that antibody - teprotumumab is is a good choice compared to conventional IVMP for providing better outcomes in patients with TED.

Methotrexate is associated with decreased total thyroxine in patients with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by joint swelling, pain, and deformation. RA patients have an increased risk of thyroid dysfunction, and drugs of RA treatment may have potential effects on thyroid function.

METHODS

This is a single-center cross-sectional study including 281 inpatients with RA in the First Affiliated Hospital of Guangzhou University of Chinese Medicine. The purpose of this study is to explore the correlation between RA therapeutic drugs and thyroid function. The medical records of 281 inpatients with RA were collected, including general data, laboratory examination, complications, and RA treatment. Spearman correlation analysis was used to explore the association of independent variables with thyroid function and antibodies in RA patients. Multinomial logistics and binary logistic regression were used for multivariate analysis. The statistically significance level was set as P < 0.05. SPSS 22.0 was used for statistical analysis.

RESULTS

Patients taking methotrexate (OR = 0.067, 95%CI: 0.008-0.588, P = 0.015) had lower levels of total thyroxine (TT4) (TT4 < 78.38 nmol/L). There was a negative correlation between glucocorticoids (r = - 0.153, P = 0.010) and total triiodothyronine (TT3) level (TT3 ≥ 1.34 nmol/L), but it was not significant in the multivariate regression model of TT3, although the regression model was statistically significant (P = 0.001).

CONCLUSION

Methotrexate is associated with decreased TT4 levels in RA patients, and glucocorticoids is associated with decreased TT3 levels. Drugs of RA treatment may affect the thyroid function of patients while treating RA, which may be one of the causes of secondary thyroid diseases in RA patients.

Monoclonal antibodies for the treatment of Graves' ophthalmopathy: A systematic review and meta-analysis

PURPOSE

The traditional standard of care for Graves' ophthalmopathy (GO) is glucocorticoid therapy, which is associated with many long-term side effects. The aim of this systematic review and meta-analysis was to compare the traditional therapy to novel monoclonal antibodies (e.g. rituximab [RTX], teprotumumab, and tocilizumab [TCZ]).

METHODS

We searched the Medline, Embase, and Cochrane Central Register of Controlled Trials databases. We included randomized controlled trials (RCTs) that compared different monoclonal antibodies (e.g. RTX, teprotumumab, and TCZ) with glucocorticoids or placebo in patients with GO. We evaluated the clinical activity score (CAS), proptosis, subjective diplopia using the Gorman score, quality of life (QoT), adverse events, change in lid fissure, NOSPECS score, and TSH receptor antibody (TRAb) levels. The odds ratio (OR) was used to represent dichotomous outcomes. The continuous outcomes were represented as standardized mean difference (SMD). Data were pooled using the inverse variance weighting method. Risk of bias was assessed using the revised Cochrane risk-of-bias tool for randomized trials.

RESULTS

Six (n = 571) RCTs were deemed eligible. The different monoclonal antibodies were significantly more efficacious than glucocorticoid/placebo in terms of reduction in CAS (SMD = -1.44, 95% confidence interval (CI): -1.91--0.97, P < 0.00001, I² = 74%), change in proptosis (SMD = -4.96, 95% CI: -8.02--1.89, P = 0.002, I² = 99%), QoL (SMD = 2.64, 95% CI: 0.50-4.79, P = 0.02, I² = 97%), and Gorman score for diplopia (OR = 3.42, 95% CI: 1.62-7.22, P = 0.001, I² = 8%). However, monoclonal antibodies have shown higher rates of adverse events (OR = 2.91, 95% CI: 1.12-7.56, P = 0.03, I² = 62%). No significant difference was found with respect to lid fissure, NOSPECS, and TRAb levels.

CONCLUSION

This meta-analysis demonstrated that monoclonal antibodies were associated with more favorable clinical outcomes than standard steroid therapy or placebo, especially with regard to CAS, change in proptosis, diplopia, and QoL, with teprotumumab being superior. In addition, only minor safety concerns were identified with monoclonal antibodies though less worrisome than using traditional steroids.

Teprotumumab for the treatment of thyroid eye disease

INTRODUCTION

Thyroid eye disease (TED) is an autoimmune disease characterized by inflammation of orbital and extraocular muscles. It induces proptosis and diplopia, leading to a worsening of quality of life (QoL) because of its impact on physical appearance, and visual function. The natural history involves an 'active TED,' which is an autoimmune inflammatory response targeting orbital soft tissues, and 'inactive TED,' where there is tissue expansion remodeling. To date, glucocorticoids represent the main medical therapy, even if often ineffective and associated with side effects.

AREAS COVERED

In TED, the autoimmune process leads to production of TSH-R and IGF-1 R autoantibodies. This induces inflammatory changes in the orbital tissue, and activation of fibroblasts with accumulation of glycosaminoglycans, leading to consequent proptosis, and diplopia. In two previous randomized, double-masked, placebo-controlled, parallel-group, multicenter trials, teprotumumab has been shown to be effective in improving proptosis, inflammation, diplopia, and QoL. More recently, it has been shown that teprotumumab is also effective in chronic-inactive TED. Teprotumumab was approved by the FDA on 21 January 2020 for the treatment of TED.

EXPERT OPINION

For the above-mentioned reasons teprotumumab represents a potential first line therapy for TED that could replace the use of steroids in the next future.

The Role of Insulin-like Growth Factor-1 and Its Receptor in the Eye: A Review and Implications for IGF-1R Inhibition

PURPOSE

FDA approval of teprotumumab for thyroid eye disease in January 2020 reinforced interest in the pharmacologic potential of insulin-like growth factor-1 (IGF-1) and its receptor, IGF-1R. Despite recent approval and adaptation for ophthalmic use, IGF-1R inhibitors are not a new therapeutic class. In 1986, Yamashita described aIR3, a monoclonal antibody to IGF-1R (anti-IGF-1R), that inhibited the effect of IGF-1 on growth hormone release. Given the widespread presence of IGF-1R, interrupting this receptor can lead to systemic physiologic effects, some adverse. We aim to review what is known about IGF-1/IGF-1R in the eye and consider the possible local side effects, unintended consequences, and potential uses of this medication class.

METHODS

A PubMed database search utilizing the keywords "insulin-like growth factor-1, eye, inhibitor, antibody, side effect" was performed to identify publications discussing IGF-1 in the human eye from January 2011 to August 2021. Criteria for acceptance included studies discussing human subjects or human tissue specifically related to the eye.

RESULTS

Out of a total of 230 articles, 47 were organized in 3 subject groups for discussion: thyroid-associated orbitopathy, cornea and the ocular surface, and the retina and neovascularization. Review of the literature demonstrated that IGF-1 affects growth and development of the eye, epithelial proliferation, retinal angiogenesis, inflammation, and is associated with thyroid-associated orbitopathy.

CONCLUSIONS

IGF-1R exists throughout in the human body, including the cornea, retina, and orbit. Research regarding ocular effects of IGF-1/IGF-1R outside thyroid eye disease is limited. Carefully designed studies and clinical assessments of patients undergoing treatment with anti-IGF-1R may identify ocular side effects and foster consideration of the role of anti-IGF-1R in ocular therapeutics. Given the increasing use of anti-IGF-1R antibodies, understanding their ocular effects, side effects, and potential systemic implications for use in disease is critical.

Thinking inside the box: Current insights into targeting orbital tissue remodeling and inflammation in thyroid eye disease

Thyroid eye disease (TED) is an autoimmune disorder that manifests in the orbit. In TED, the connective tissue behind the eye becomes inflamed and remodels with increased fat accumulation and/or increased muscle and scar tissue. As orbital tissue expands, patients develop edema, exophthalmos, diplopia, and optic neuropathy. In severe cases vision loss may occur secondary to corneal scarring from exposure or optic nerve compression. Currently there is no cure for TED, and treatments are limited. A major breakthrough in TED therapy occurred with the FDA approval of teprotumumab, a monoclonal insulin-like growth factor 1 receptor (IGF1R) blocking antibody. Yet, teprotumumab therapy has limitations, including cost, infusion method of drug delivery, variable response, and relapse. We describe approaches to target orbital fibroblasts and the complex pathophysiology that underlies tissue remodeling and inflammation driving TED. Further advances in the elucidation of the mechanisms of TED may lead to prophylaxis based upon early biomarkers as well as lead to more convenient, less expensive therapies.

Outcomes and risk factors of surgical management of thyroid eye disease-related diplopia

OBJECTIVES

To evaluate the outcomes of strabismus surgery in patients with thyroid eye disease (TED) and to assess the influence of preceding treatments such as steroid administration, orbital decompression and radiotherapy.

METHODS

Retrospective study on a cohort of patients with TED undergoing strabismus surgery. Data collection included clinical features, smoking status, preceding steroid therapy, orbital radiation therapy and orbital decompression. Qualitative evaluation, assessing diplopia and quality of life and quantitative evaluation, assessing the eye misalignment were analysed 1 year after the last squint surgical procedure.

RESULTS

Seventy-nine patients were identified. Ninety-five surgical procedures were performed on 92 eyes. A significant overall improvement of ocular motility was registered (p < 0.001, paired t-test). Forty-five (57%) patients had excellent outcomes, twenty-three (29%) had good outcomes and eleven (14%) had poor outcomes. The average number of muscles operated was significantly greater in patients who underwent orbital bone decompression (1.58 ± 0.63; p = 0.0082; 95% CI 1.413-10.214). Quantitative and qualitative outcomes were not associated with the preceding therapy: steroid (p = 0.75), radiotherapy (p = 0.95) or orbital bone decompression (p = 0.25). The success rate was no different between adjustable and fixed sutures (p = 0.8).

CONCLUSION

Strabismus surgery in TED patients resulted in a high success rate in reducing diplopia and improving ocular motility. The success rate was not negatively associated with previous therapies. Indeed, resolution of diplopia required more squint procedures in patients who have previously undergone to orbital decompression.

[Monoclonal antibodies in the treatment of thyroid eye disease]

Thyroid eye disease (TED) is an autoimmune condition affecting extraocular muscles and orbital fat that is most often a manifestation of the Graves' disease or Hashimoto thyroiditis. This disease significantly worsens the quality of life of patients, and therefore requires the use of effective treatment methods. Traditional therapy involves glucocorticosteroids and x-rays aimed at reducing the inflammatory process, rather than proptosis and diplopia, while targeted therapy is better able to influence the clinical course of the disease. The review presents a modern understanding of the pathogenesis of TED and analysis of clinical studies concerning the use of monoclonal antibodies for its treatment.

Inhibition of Fibrotic Contraction by Sirolimus (Rapamycin) in an Ex Vivo Model of Thyroid Eye Disease

BACKGROUND

Thyroid eye disease (TED) is characterized by orbital inflammation and complicated by extraocular muscle fibrosis. Treatment with rapamycin/sirolimus has been reported to improve ocular motility and disease manifestations in TED. Whether this resulted from a primary antifibrotic effect on fibroblasts or was secondary to immune-suppression is unclear.

METHODS

In vitro contractility studies of primary orbital fibroblasts. Cells from patients with TED and controls were treated with rapamycin [mechanistic target of rapamycin an (mTOR) inhibitor] and MHY1485 (an mTOR stimulator) as well as inhibitors upstream in the same signaling cascade (saracatinib and befatinib).

RESULTS

At concentrations consistent with the therapeutic dosing range in humans, rapamycin/sirolimus significantly reduces fibrosis in orbital fibroblasts from TED patients and controls in vitro. This effect is separate from, and in addition to, its immune suppressive effect. mTOR-driven fibrotic activity is greater in TED-derived fibroblasts and can be blocked also upstream of mTOR by inhibition of src. There was no adverse effect on cell survival.

CONCLUSION

The authors present evidence for a direct antifibrotic effect of rapamycin/sirolimus in primary orbital fibroblasts. Targeting mTOR signaling presents a further and adjunctive treatment of TED alongside other immune-suppressive agents. By acting downstream of IGF1-R, sirolimus may offer a cost-effective alternative to teprotumumab therapy. Clinical case reports, now supplemented by this in vitro evidence, support the initiation of a clinical trial to treat the fibrotic sequelae of TED with this already-approved agent. Such an "off-the-shelf" therapy is a welcome prospect for TED treatment, particularly one available at a low price.

Visual morbidity in thyroid eye disease in Asian Indian patients

Purpose:

To describe visual morbidity in thyroid orbitopathy in Asian Indians and the factors influencing its onset.

Methods:

A retrospective chart review was performed for patients with thyroid related orbitopathy seen between May 2014 and April 2019. Three hundred and one patients were included in the study. Relevant history, clinical findings, investigations, and treatment were documented.

Results:

Nineteen percent of patients had at least 1 visual morbidity feature such as compressive optic neuropathy, exposure keratopathy or diplopia, requiring intravenous glucocorticoid. Male gender, older age, and diabetes were the significant risk factors for high visual morbidity (all P < 0.05). Systemic thyroid status, degree of proptosis, and duration of disease were not significant. Average dose of intravenous glucocorticoid needed was 3.8 g; 24 (7.9%) patients required orbital decompression, and 13 (4.3%) needed eyelid surgery. At the last follow-up, 97% of patients had vision 6/12 or better in both eyes.

Conclusion:

There is significant visual morbidity found in Indian patients with TED, even with moderate proptosis and systemic control of thyroid status. This is the first set of data on the subject.

Α Case of Severe Thyroid Eye Disease Treated with Tocilizumab

This is a case report describing a patient with severe thyroid eye disease complicated with dysthyroid optic neuropathy that was unresponsive to intravenous steroids and orbital radiotherapy but responded well to intravenous tocilizumab.

Systemic diseases and the cornea

There is a number of systemic diseases affecting the cornea. These include endocrine disorders (diabetes, Graves' disease, Addison's disease, hyperparathyroidism), infections with viruses (SARS-CoV-2, herpes simplex, varicella zoster, HTLV-1, Epstein-Barr virus) and bacteria (tuberculosis, syphilis and Pseudomonas aeruginosa), autoimmune and inflammatory diseases (rheumatoid arthritis, Sjögren's syndrome, lupus erythematosus, gout, atopic and vernal keratoconjunctivitis, multiple sclerosis, granulomatosis with polyangiitis, sarcoidosis, Cogan's syndrome, immunobullous diseases), corneal deposit disorders (Wilson's disease, cystinosis, Fabry disease, Meretoja's syndrome, mucopolysaccharidosis, hyperlipoproteinemia), and genetic disorders (aniridia, Ehlers-Danlos syndromes, Marfan syndrome). Corneal manifestations often provide an insight to underlying systemic diseases and can act as the first indicator of an undiagnosed systemic condition. Routine eye exams can bring attention to potentially life-threatening illnesses. In this review, we provide a fairly detailed overview of the pathologic changes in the cornea described in various systemic diseases and also discuss underlying molecular mechanisms, as well as current and emerging treatments.

Lessons Learned from Targeting IGF-I Receptor in Thyroid-Associated Ophthalmopathy

Complex immunological mechanisms underlie the pathogenesis of thyroid-associated ophthalmopathy (TAO). Historical models of Graves’ disease and TAO have focused almost entirely on autoimmune reactivity directed against the thyrotropin receptor (TSHR). The insulin-like growth factor-I receptor (IGF-IR) has been proposed as a second participating antigen in TAO by virtue of its interactions with IGFs and anti-IGF-IR antibodies generated in Graves’ disease. Furthermore, the IGF-IR forms with TSHR a physical and functional complex which is involved in signaling downstream from both receptors. Inhibition of IGF-IR activity results in attenuation of signaling initiated at either receptor. Based on the aggregate of findings implicating IGF-IR in TAO, the receptor has become an attractive therapeutic target. Recently, teprotumumab, a human monoclonal antibody IGF-IR inhibitor was evaluated in two clinical trials of patients with moderate to severe, active TAO. Those studies revealed that teprotumumab was safe and highly effective in reducing disease activity and severity. Targeting IGF-IR with specific biologic agents may result in a paradigm shift in the therapy of TAO.

Steroid-Resistant Graves' Orbitopathy Treated with Tocilizumab in Real-World Clinical Practice: A 9-Year Single-Center Experience

This study aimed to assess the effectiveness and safety of tocilizumab use for the treatment of active steroid-resistant Graves’ orbitopathy (GO). A retrospective longitudinal study was conducted by reviewing the medical records at a single center between November 2009 and December 2018. A total of 114 patients with steroid-resistant Graves’ orbitopathy were examined and treated with tocilizumab, of which 54 adults met the inclusion criteria. No concomitant medication for the treatment of orbitopathy was used. The main primary outcomes included changes from baseline in the Clinical Activity Score (CAS) and thyrotropin receptor antibody (TRAb) levels throughout therapy with tocilizumab. The absolute responses to treatment were defined as the achievement of CAS ≤ 1 and TRAb ≤ 10 U/L. A composite ophthalmic score including CAS, proptosis, eyelid retraction, and diplopia was used to evaluate individual improvement in GO. Adverse drug reactions were also assessed. Analysis of the patient’s CAS and TRAb levels showed meaningful reductions during tocilizumab treatment. Differences between values at baseline and subsequent time points were statistically significant (p < 0.001 for all comparisons). The absolute CAS response (CAS = 0 or 1) was achieved in 74% (37/50) of patients after the fourth dose of tocilizumab (at week 16), with a TRAb response being achieved in 55% (23/42) of patients. The relative CAS response (reduction ≥ 2 points) was achieved in 90.9% of patients (40/44) after the first dose of tocilizumab (at week 4). Measurements of proptosis (reduction ≥ 2 mm in 78% of patients, 42/54) and eyelid retraction (reduction ≥ 2 mm in 75%, 33/44), and the prevalence of diplopia (improvement in 68%, 19/28) were significantly reduced after the last dose of tocilizumab (p < 0.001 for all comparisons). GO improved in 98% (53/54) of patients when at least two criteria of the composite evaluation were required. Four patients exhibited disease recurrence, defined as an increase in CAS of ≥2 points in the six months following the date of inactivation. Most adverse drug reactions were mild or moderate in severity. In conclusion, our data suggest that a course of at least 4 months (one monthly dose) of tocilizumab therapy provides a significant benefit to patients with active moderate-to-severe steroid-resistant GO.

Optic neuropathy and diplopia from thyroid eye disease: update on pathophysiology and treatment

PURPOSE OF REVIEW

Thyroid eye disease (TED) is a disfiguring disease that can lead to neuro-ophthalmic manifestations including diplopia and optic neuropathy. The aim of this review is to shed light on the diagnosis of TED based on clinical examination findings and diagnostic imaging. We will also discuss gold standard as well as newly emerging therapies for TED.

RECENT FINDINGS

We discussed diagnostic criteria for TED and differentiating TED from other causes of binocular diplopia. We also reviewed the pathophysiology and differential diagnoses for dysthyroid optic neuropathy as well as recent developments on controversial causes. New imaging techniques are available for evaluation and prognosis of TED comorbidities. Most of the recent developments in TED have been focused on new treatment modalities that have thus far had promising results. We reviewed recently approved and novel potential therapies that are helpful in treating both diplopia and dysthyroid optic neuropathy.

SUMMARY

TED is a complicated disorder with many clinical manifestations as well as treatment modalities. Our aim of this review was to outline new developments in the diagnosis and management of TED.

Updates on the understanding and management of thyroid eye disease

Thyroid eye disease (TED) is a complex disease associated with myriad clinical presentations, including facial disfigurement, vision loss, and decreased quality of life. Traditionally, steroid therapy and/or radiation therapy were commonly used in the treatment of active TED. While these therapies can help reduce inflammation, they often do not have a sustainable, significant long-term effect on disease outcomes, including proptosis and diplopia. Recent advances in our understanding of the pathophysiology of TED have shifted the focus of treatment toward targeted biologic therapies. Biologics have the advantage of precise immune modulation, which can have better safety profiles and greater efficacy compared to traditional approaches. For instance, the insulin-like growth factor-1 receptor (IGF-1R) has been found to be upregulated in TED patients and to colocalize with the thyroid-stimulating hormone receptor (TSHR), forming a signaling complex. Teprotumumab is an antibody targeted against IGF-1R. By inhibiting the IGF-1R/TSHR signaling pathway, teprotumumab may reduce the production of proinflammatory cytokines, hyaluronan secretion, and orbital fibroblast activation in patients with TED. Due to promising phase II and III clinical trial results, teprotumumab has become the first biologic US Food and Drug Administration (FDA)-approved for the treatment of TED. In addition, there are currently ongoing studies looking at the use of antibodies targeting the neonatal Fc receptor (FcRn) in various autoimmune diseases, including TED. FcRn functions to transport immunoglobulin G (IgG) and prevent their lysosomal degradation. By blocking the recycling of IgG, this approach may dampen the body's immune response, in particular the pathogenic IgG implicated in some autoimmune diseases. Advances in our understanding of the pathophysiology of TED, therefore, are leading to more targeted therapeutic options, and we are entering an exciting new phase in the management of TED. This review will cover recent insights into the understanding of TED pathophysiology and novel treatment options as well as ongoing studies of new potential treatment options for TED.

Mechanisms That Underly T Cell Immunity in Graves' Orbitopathy

Graves' orbitopathy (GO), also known as thyroid-associated ophthalmopathy, is the most common ocular abnormality of Graves' disease. It is a disfiguring, invalidating, and potentially blinding orbital disease mediated by an interlocking and complicated immune network. Self-reactive T cells directly against thyroid-stimulating hormone receptor-bearing orbital fibroblasts contribute to autoimmune inflammation and tissue remodeling in GO orbital connective tissues. To date, T helper (Th) 1 (cytotoxic leaning) and Th2 (antibody leaning) cell subsets and an emerging role of Th17 (fibrotic leaning) cells have been implicated in GO pathogenesis. The potential feedback loops between orbital native residential CD34^- fibroblasts, CD34⁺ infiltrating fibrocytes, and effector T cells may affect the T cell subset bias and the skewed pattern of cytokine production in the orbit, thereby determining the outcomes of GO autoimmune reactions. Characterization of the T cell subsets that drive GO and the cytokines they express may significantly advance our understanding of orbital autoimmunity and the development of promising therapeutic strategies against pathological T cells.

Anaesthesia for ophthalmic procedures in patients with thyroid eye disease

Thyroid eye disease is an autoimmune inflammatory disorder of the orbit in adults. It causes inflammation, expansion and fibrosis of orbital fat, muscles and the lacrimal gland, leading to facial disfigurement, functional disability and, in severe cases, blindness. Overall, approximately 20% of affected patients need some form of surgical intervention requiring anaesthesia. This narrative review explores the background of thyroid eye disease, surgical procedures performed and their implications for anaesthesia. General anaesthesia is used for orbital decompression procedures, strabismus correction surgery and complex oculoplastic procedures. Local anaesthetic infiltration or regional anaesthesia under monitored anaesthesia care are the techniques most commonly employed for eyelid retraction surgery. It is important to limit the volume of local anaesthetic agent used during infiltration and continuously monitor the orbital volume and ocular pressure with a ballottement technique. In addition, the contralateral eye should be checked and, if necessary, protected against corneal exposure. Retrobulbar, peribulbar and sub-Tenon's blocks are best avoided. Topical anaesthesia has been used for some strabismus correction surgery but its use is limited to motivated and cooperative patients only.