Prevention of Orbitopathy by Oral or Intravenous Steroid Prophylaxis in Short Duration Graves' Disease Patients Undergoing Radioiodine Ablation: A Prospective Randomized Control Trial Study

Predictive factors for treatment response in active thyroid eye disease

INTRODUCTION/OBJECTIVE

Active moderate-to-severe thyroid eye disease (TED) is a major therapeutic challenge. Pulse therapy with intravenous glucocorticoids is the standard treatment, with variable response. Radioactive iodine therapy (RAI) was reported as a risk factor for onset or worsening of TED. We evaluated putative predictive factors for response to intravenous methylprednisolone in patients with active TED.

METHODS

Data were collected for 64 consecutive patients (45 women) with active moderate-to-severe TED treated with a minimum cumulative dose of 4.5g methylprednisolone. Patients were classified as responders (R) or non-responders (NR) on Clinical Activity Score (CAS), and clinical features were compared between groups.

RESULTS

Sixty-two patients had Graves' disease (GD), and 2 had Hashimoto's thyroiditis (HT). Median age at thyroid dysfunction diagnosis, TED manifestation and pulse therapy was 46, 48 and 51 years, respectively; 56.2% were euthyroid when TED manifested. Among them, 73.4% were responders. R and NR were comparable for gender, age, thyroid function, serum antibodies, disease duration, pre-treatment CAS, smoking, lipid profile, and adverse events. Forty-nine patients were treated with RAI for GD: 15 before the active phase of TED (before pulse therapy), 16 during, 17 after, and 1 both before and after pulse therapy. Response rate was higher in patients who received RAI during than after pulse therapy (P=0.032) and similar to those not treated with RAI at all (P=0,599).

CONCLUSION

Pulse therapy was effective in the majority of patients. The only factor associated with response to pulse therapy was the timing of RAI, suggesting that it seems to be safe when used concomitantly with pulse therapy.

Decision Variables for the Use of Radioactive Iodine in Patients with Thyroid Cancer at Intermediate Risk of Recurrence

The use of radioactive iodine (RAI) after total thyroidectomy for patients at the American Thyroid Association (ATA) who are at intermediate risk of recurrence is controversial. This is due to the lack of prospective randomized trials proving a benefit to recurrence or survival of RAI therapy in this group. In the absence of such evidence, clinicians struggle to recommend for or against this therapeutic approach which frequently results in overtreatment. This review describes key elements in the decision-making process that help clinicians more comprehensively evaluate the need for RAI therapy in patients with thyroid cancer at intermediate risk of recurrence. A clear definition of the purpose of RAI therapy should be conveyed to patients. In this sense, adjuvant RAI therapy intends to decrease recurrence, and ablation therapy is used to facilitate surveillance. Better stratification of the intermediate risk category into a low-intermediate subgroup and an intermediate-high-risk subgroup results in less heterogeneity and a more precise prediction of recurrence risk. The evaluation of post-operative thyroglobulin levels may prevent the overtreatment of low-intermediate-risk patients when their thyroglobulin level is <2.5 ng/mL. the integration of tumor genomics (when available) alongside pathologic features can enhance the ability of the clinician to predict iodine concentration in thyroid cancer cells. Finally, a detailed consideration of the adverse effects of RAI, patients' comorbidities, and patient preferences will result in a patient-centered personalized approach. Systematic examination of these variables will ultimately provide a framework for making more educated decisions on the use of RAI in patients at intermediate risk of recurrence that will prevent overtreatment and minimize harm.

[Interdisciplinary Management of Orbital Diseases]

Diagnosis and therapy of orbital diseases is an interdisciplinary challenge, in which i.e. otorhinolaryngologists, ophthalmologists, radiologists, radiation therapists, maxillo-facial surgeons, endocrinologists, and pediatricians are involved. This review article describes frequent diseases which both, otolaryngologists and ophthalmologists are concerned with in interdisciplinary settings. In particular the inflammatory diseases of the orbit including orbital complications, autoimmunological diseases of the orbit including Grave´s orbitopathy, and primary and secondary tumors of the orbit are discussed. Beside describing the clinical characteristics and diagnostic steps the article focusses on the interdisciplinary therapy. The review is completed by the presentation of most important surgical approaches to the orbit, their indications and possible complications. The authors tried to highlight the relevant facts despite the shortness of the text.

Unveiling Promising Modalities and Enhancing Patient Outcomes in Graves' Disease Treatment: A Systematic Review and Meta-Analysis

Graves' disease (GD) is an autoimmune condition of the thyroid. The hyperthyroidism manifested by patients affected by this disease is caused by the production of autoantibodies against the thyroid-stimulating hormone (TSH, or thyrotropin) receptor (TSHR), which mimic the effects of the hormone on thyroid cells, thereby stimulating autonomic production of thyroxine and triiodothyronine. Deciding on a therapeutic approach to this condition presents intricate dilemmas for both clinicians and patients. Each of the three available treatment modalities is grounded in evidence-based medicine, affirming its efficacy. This systematic review and meta-analysis aimed to assess the effect of carbimazole (CBM), radioactive iodine (RAI), and surgery in treating GD and provide evidence-based recommendations for healthcare providers regarding the optimal management of the condition based on a comprehensive analysis of effectiveness, safety, patient satisfaction, and recovery outcomes. This systematic review and meta-analysis adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We used the PubMed and Google Scholar databases to conduct a thorough web search for articles published between January 2019 and September 2023. The meta-analysis was carried out using Resource Manager (Revman) 5.4.1. The study found that propylthiouracil (PTU) or methimazole/carbimazole (MMI/CBM) treatment increases the risk of hyperlipidemia in patients with hyperthyroidism. Once in a euthyroid state, glucose tolerance increases; for children with GD, a computer model for customized dosing has been created. To sum up, CBM, surgery, and RAI are all useful treatment options for GD. Using steroids in conjunction with radiation therapy may help prevent Graves' ophthalmopathy (GO).

Current Therapeutic Approaches for Graves' Orbitopathy - are Targeted Therapies the Future?

Graves' orbitopathy is an autoimmune disease of the orbit that most frequently occurs with Graves' hyperthyroidism. The occurrence of autoantibodies directed against the TSH receptor (TRAb) is of central importance for the diagnosis and pathogenesis. These autoantibodies are mostly stimulating, and induce uncontrolled hyperthyroidism and tissue remodelling in the orbit and more or less pronounced inflammation. Consequently, patients suffer to a variable extent from periocular swelling, exophthalmos, and fibrosis of the eye muscles and thus restrictive motility impairment with double vision. In recent decades, therapeutic approaches have mainly comprised immunosuppressive treatments and antithyroid drug therapy for hyperthyroidism to inhibit thyroid hormone production. With the recognition that TRAb also activates an important growth factor receptor, IGF1R (insulin-like growth factor 1 receptor), biological agents have been developed. Teprotumumab (an inhibitory IGF1R antibody) has already been approved in the USA and the therapeutic effects are enormous, especially with regard to the reduction of exophthalmos. Side effects are to be considered, especially hyperglycaemia and hearing loss. It is not yet clear whether the autoimmune reaction (development of the TRAb/attraction of immunocompetent cells) is also influenced by anti-IGF1R inhibiting agents. Recurrences after therapy show that the inhibition of antibody development must be included in the therapeutic concept, especially in severe cases.

Thyroid Eye Disease: Epidemiology, Natural History, and Risk Factors

BACKGROUND

Thyroid eye disease (TED) is an autoimmune disorder of the orbit and the most frequent extrathyroidal manifestation of Graves' disease but it may rarely occur in euthyroid/hypothyroid patients with chronic autoimmune thyroiditis.

EPIDEMIOLOGY

TED is a relatively infrequent disorder, particularly in its severe forms. Men tend to have more severe TED at an older age. The prevalence of TED is lower than in the past among patients with recent onset Graves' hyperthyroidism, and moderate-to-severe forms requiring aggressive treatments are no more than 5% to 6% of all cases.

NATURAL HISTORY

After an initial inflammatory (active) phase and a plateau phase, TED stabilizes and eventually inactivates (inactive or burnt-out phase) after an estimated period of 18-24 months. Minimal-to-mild TED often remits spontaneously, but complete restitutio ad integrum almost never occurs when TED is more than mild.

RISK FACTORS

Several risk factors contribute to its development on a yet undefined genetic background. Cigarette smoking is the most important of them, but thyroid dysfunction (both hyper- and hypothyroidism), radioactive iodine therapy (if not accompanied by low-dose steroid prophylaxis), elevated thyrotropin receptor antibodies, and, probably, hypercholesterolemia represent relevant modifiable risk factors. Early diagnosis, control and removal of modifiable risk factors, and early treatment of mild forms of GO (local treatment and selenium) may effectively limit the risk of progression to more severe forms.

Dysthyroid Optic Neuropathy

PURPOSE

Dysthyroid optic neuropathy (DON) is a sight-threatening complication of thyroid eye disease (TED). This review provides an overview of the epidemiology, pathogenesis, diagnosis, and current therapeutic options for DON.

METHODS

A literature review.

RESULTS

DON occurs in about 5% to 8% of TED patients. Compression of the optic nerve at the apex is the most widely accepted pathogenic mechanism. Excessive stretching of the nerve might play a role in a minority of cases. Increasing age, male gender, smoking, and diabetes mellitus have been identified as risk factors. Diagnosis of DON is based on a combination of ≥2 clinical findings, including decreased visual acuity, decreased color vision, relative afferent pupillary defect, visual field defects, or optic disc edema. Orbital imaging supports the diagnosis by confirming apical crowding or optic nerve stretching. DON should be promptly treated with high-dose intravenous glucocorticoids. Decompression surgery should be performed, but the response is incomplete. Radiotherapy might play a role in the prevention of DON development and may delay or avoid the need for surgery. The advent of new biologic-targeted agents provides an exciting new array of therapeutic options, though more research is needed to clarify the role of these medications in the management of DON.

CONCLUSIONS

Even with appropriate management, DON can result in irreversible loss of visual function. Prompt diagnosis and management are pivotal and require a multidisciplinary approach. Methylprednisolone infusions still represent first-line therapy, and surgical decompression is performed in cases of treatment failure. Biologics may play a role in the future.

Postradioiodine Graves' management: The PRAGMA study

OBJECTIVE

Thyroid status in the months following radioiodine (RI) treatment for Graves' disease can be unstable. Our objective was to quantify frequency of abnormal thyroid function post-RI and compare effectiveness of common management strategies.

DESIGN

Retrospective, multicentre and observational study.

PATIENTS

Adult patients with Graves' disease treated with RI with 12 months' follow-up.

MEASUREMENTS

Euthyroidism was defined as both serum thyrotropin (thyroid-stimulating hormone [TSH]) and free thyroxine (FT4) within their reference ranges or, when only one was available, it was within its reference range; hypothyroidism as TSH ≥ 10 mU/L, or subnormal FT4 regardless of TSH; hyperthyroidism as TSH below and FT4 above their reference ranges; dysthyroidism as the sum of hypo- and hyperthyroidism; subclinical hypothyroidism as normal FT4 and TSH between the upper limit of normal and <10 mU/L; and subclinical hyperthyroidism as low TSH and normal FT4.

RESULTS

Of 812 patients studied post-RI, hypothyroidism occurred in 80.7% and hyperthyroidism in 48.6% of patients. Three principal post-RI management strategies were employed: (a) antithyroid drugs alone, (b) levothyroxine alone, and (c) combination of the two. Differences among these were small. Adherence to national guidelines regarding monitoring thyroid function in the first 6 months was low (21.4%-28.7%). No negative outcomes (new-onset/exacerbation of Graves' orbitopathy, weight gain, and cardiovascular events) were associated with dysthyroidism. There were significant differences in demographics, clinical practice, and thyroid status postradioiodine between centres.

CONCLUSIONS

Dysthyroidism in the 12 months post-RI was common. Differences between post-RI strategies were small, suggesting these interventions alone are unlikely to address the high frequency of dysthyroidism.

Current concepts regarding Graves' orbitopathy

Graves' orbitopathy (GO) is an orbital autoimmune disorder and the main extrathyroidal manifestation of Graves' disease, the most common cause of hyperthyroidism. GO affects about 30% of Graves' patients, although fewer than 10% have severe forms requiring immunosuppressive treatments. Management of GO requires a multidisciplinary approach. Medical therapies for active moderate-to-severe forms of GO (traditionally, high-dose glucocorticoids) often provide unsatisfactory results, and subsequently surgeries are often needed to cure residual manifestations. The aim of this review is to provide an updated overview of current concepts regarding the epidemiology, pathogenesis, assessment, and treatment of GO, and to present emerging targeted therapies and therapeutic perspectives. Original articles, clinical trials, systematic reviews, and meta-analyses from 1980 to 2021 were searched using the following terms: Graves' disease, Graves' orbitopathy, thyroid eye disease, glucocorticoids, orbital radiotherapy, rituximab, cyclosporine, azathioprine, teprotumumab, TSH-receptor antibody, smoking, hyperthyroidism, hypothyroidism, thyroidectomy, radioactive iodine, and antithyroid drugs. Recent studies suggest a secular trend toward a milder phenotype of GO. Standardized assessment at a thyroid eye clinic allows for a better general management plan. Treatment of active moderate-to-severe forms of GO still relies in most cases on high-dose systemic-mainly intravenous-glucocorticoids as monotherapy or in combination with other therapies-such as mycophenolate, cyclosporine, azathioprine, or orbital radiotherapy-but novel biological agents-including teprotumumab, rituximab, and tocilizumab-have achieved encouraging results.

Update on thyroid eye disease: Regional variations in prevalence, diagnosis, and management

Thyroid eye disease (TED) is a rare disease that can lead to decreased quality of life, permanent disfigurement, and vision loss. Clinically, TED presents with exophthalmos, periorbital edema, extraocular muscle dysfunction, and eyelid retraction, and can lead to vision-threatening complications such as exposure to keratopathy and dysthyroid optic neuropathy (DON). Over the last several years, significant advancements have been made in the understanding of its pathophysiology as well as optimal management. Ethnic variations in the prevalence, clinical presentation, and risk of vision-threatening complications of TED are summarized, and risk factors associated with TED are discussed. Additionally, significant advances have been made in the management of TED. The management of TED traditionally included anti-inflammatory medications, orbital radiation therapy, orbital surgical decompression, and biologic therapies. Most recently, targeted therapies such as teprotumumab, an insulin-like growth factor-1 receptor antagonist, have been studied in the context of TED, with promising initial data. In this review, updates in the understanding and management of TED are presented with a focus on the international variations in presentation and management.

Drug safety in thyroid eye disease - a systematic review

INTRODUCTION

The autoimmune-induced thyroid eye disease (TED) is a frequent extrathyroidal manifestation of Graves' disease and less frequently of Hashimoto's thyroiditis. Pathognomonic clinical signs, i.e. exophthalmos, double vision, and inflammation of the orbital tissue cause physical, ophthalmic, and socio-psychological limitations.

AREAS COVERED

PubMed and MeSH database were searched for specific guidelines, randomized controlled trials, prospective clinical studies, systematic reviews and meta-analyses pertaining to the safety profile of currently administered immunosuppressive agents for the treatment of TED. Occurred adverse events (AE), severe AE (SAE), side effects (SE), and severe SE (SSE) were classified according to the standardized medical dictionary for regulatory activities (MedDRA).

EXPERT OPINION

This novel systematic analysis offers an overview of potential AE, SAE and SE for currently recommended immunosuppressive drugs for the treatment of TED. Non-specific, anti-inflammatory drugs and more specific, targeted biologicals are treatment options for active and severe TED. Critical evaluation of the pertinent literature confirms an evidence-based, beneficial efficacy/risk ratio of the current first-line and second-line treatment recommendations endorsed by the European Society of Endocrinology. However, further large, well-conceived trials are mandatory to enhance our knowledge and experience with novel specific small molecules and/or monoclonal antibodies targeting the key autoantigens in TED.

Management of Graves' hyperthyroidism: present and future

INTRODUCTION

Graves' disease (GD) is an autoimmune disorder due to loss of tolerance to the thyrotropin receptor (TSHR) and ultimately caused by stimulatory TSHR antibodies (TSHR-Ab). GD may be associated with extrathyroidal manifestations, mainly Graves' orbitopathy. Treatment of GD relies on antithyroid drugs (ATDs), radioactive iodine (RAI), thyroidectomy. The major ATD limitation is the high recurrence rate after treatment. The major drawback of RAI and thyroidectomy is the inevitable development of permanent hypothyroidism.

AREAS COVERED

Original articles, clinical trials, systematic reviews, meta-analyses from 1980 to 2021 were searched using the following terms: Graves' disease, management of Graves' disease, antithyroid drugs, radioactive iodine, thyroidectomy, Graves' orbitopathy, thyroid-eye disease.

EXPERT OPINION

ATDs are the first-line treatment worldwide, are overall safe and usually given for 18-24 months, long-term treatment may decrease relapses. RAI is safe, although associated with a low risk of GO progression, particularly in smokers. Thyroidectomy requires skilled and high-volume surgeons. Patients play a central role in the choice of treatment within a shared decision-making process. Results from targeted therapies acting on different steps of the autoimmune process, including iscalimab, ATX-GD-59, rituximab, blocking TSHR-Ab, small molecules acting as antagonists of the TSHR, are preliminary or preclinical, but promising in medium-to-long perspective.

[Treatment of Graves' disease in patients with thyroid eye disease]

Graves' disease (GD) is an autoimmune disease that is often complicated by thyroid eye disease (TED). Clinical presentations of TED can develop simultaneously with the manifestation of GD, after the manifestation of GD amid treatment, and before the development of thyrotoxicosis. Treatment of such patients is a difficult task, because on the one hand, it is necessary to take into account the clinical picture of thyrotoxicosis, and on the other - the symptoms of eye damage. The combination of the two pathologies determines the need for simultaneous treatment of GD and TED, and the choice of a treatment method for GD will depend on the manifestations of TED. This article presents current views on the treatment of GD with concomitant TED. The choice of GD treatment method will be largely determined by the clinical manifestations of TED and will be conducted jointly by endocrinologists and ophthalmologists.

Orbital inflammatory disorders: new knowledge, future challenges

PURPOSE OF REVIEW

This review aims to bring together recent advances in basic, translational and clinical research on the pathogenesis and treatment of orbital inflammatory conditions.

RECENT FINDINGS

Basic science studies provide mechanistic insights into why the orbit is targeted for inflammation by autoimmune inflammatory disorders. Using Graves' disease as a test case reveals that endocrine pathways, such as the TSH and IGF1 receptor pathways play important roles in stimulating orbital inflammation. Furthermore, orbital tissues contain high concentrations of retinoids - byproducts of the visual pathway that diffuse across the sclera and can activate de novo transcription of inflammatory cytokines. Such cytokine expression places the orbit in a hyper-inflammatory 'resting' state, prone to respond to any additional systemic or local pro-inflammatory signals. The HIF2A--LOX pathway appears important for orbital tissue fibrosis. Lastly, bench-to-bedside studies of the IGF1R pathway have led to an FDA-approved drug, teprotumumab that represents a novel treatment approach for Graves' orbitopathy. Unfortunately, high drug costs and misplaced insurance company 'step-therapy' policies may block patients from receiving therapy that can protect vision and improve quality of life.

SUMMARY

Improved understanding of orbital inflammatory conditions has led to a new drug and promises additional breakthroughs. Translational research is successful, but requires time, resources, and patience.

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.

A Clinical Debate: What Is the Therapeutic Choice for Recurrent Graves' Hyperthyroidism?

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[Role and effectiveness of radioactive-iodine therapy for the treatment of Grave's disease]

The treatment of Graves' disease is based on three therapies: medical treatment with synthetic antithyroid agents, surgery and radioactive-iodine therapy. The purpose of our study was to study the role and effectiveness of radioactive-iodine therapy for the treatment of Graves' disease. We conducted a retrospective, descriptive study of the epidemiological, clinical, paralclinical and therapeutic features of 54 patients with Graves' disease managed and treated with iodine-131 as well as of their short- and medium-term remission rate. The sex ratio was 0.45. The average age of patients was 38,33 ± 12.7 years. The most common functional signs were weight loss, tremors and palpitations. Mean FT4 was 54,51 ± 19,56 ng/dl (ranging from 8,90 and 100). Mean TSHus was 0,074 ± 0,29 µIU/ml. Synthetic antithyroid drugs were used in 49 patients; 83,67% of cases had persistent hyperthyroidism. Radioactive-iodine therapy was used as first-line therapy in 9,3% of cases and as second-line therapy in 90,7% of cases. Mean activity was 13,29 mCi ± 1,46 ranging from 10 to 15 mCi. The first assessment of hormonal status was performed after an average post-treatment period of 1,91 months; 29 patients (53,7%) achieved remission (eu- or hypo-thyroidism). After a 12 month-follow-up, patients' course was marked by remission in 88,88% of cases (euthyroidism in 14,8% and hypothyroidism in 74% of cases). Radioactive-iodine therapy is an effective treatment for Graves' disease. High radioactive iodine dose provides high remission rate.

Remission Rate of Graves' Disease and the Trend of Changes in Serum TSH Receptor Antibodies in Prolonged Antithyroid Drug Treatment

Context: Graves’ disease is an autoimmune disease caused by thyrotropin receptor antibodies (TRAb). These antibodies can be measured and used for the diagnosis, prediction of remission, and risk of Graves’ orbitopathy development. There are three treatments for Graves’ disease that have remained unchanged for the last 75 years: Antithyroid drugs, radioiodine, and surgery. Antithyroid drugs are the first treatment option worldwide and are usually used for 12 - 18 months. Recent reports suggest the use of antithyroid drugs for more than 18 months with better outcomes. This review focuses on two aspects of treatment with antithyroid drugs: The impact of using antithyroid drugs for more than 12 - 18 months on remission rates and the trend of TRAb during prolonged antithyroid drug treatment. Evidence Acquisition: A review was performed in Medline on the published work regarding the duration of ATD treatment and remission of Graves' disease and also ATD treatment and TRAb status during the 1990 - 2019 period. Results: Remission rates are variable (30% - 80%), and many clinical and genetic factors serve as predictors. The long-term use of antithyroid drugs appears to increase remission rates. TRAb values usually decline during ATD treatment, but the trend could occur in two ways: Becoming negative or showing a fluctuating pattern. However, approximately 10% of the patients will remain TRAb-positive after five years of treatment with antithyroid drugs. Conclusions: Antithyroid drugs can be used for long periods with an increase in remission rates, and a gradual decrease in TRAb levels, with the disappearance of TRAb in 90% of the patients after 60 months.

Diagnosis and Management of Graves' Disease in Thailand: A Survey of Current Practice

BACKGROUND

The data on clinical practice patterns in the evaluation and management of Graves' disease (GD) are limited in Asia. The aims of this survey were to report the current practices in the management of GD in Thailand and to examine any international differences in the management of GD.

METHODS

Members of the Endocrine Society of Thailand who were board certified in endocrinology (N = 392) were invited to participate in an electronic survey on the management of GD using the same index case and questionnaire as in previous North American and European surveys.

RESULTS

One hundred and twenty responses (30.6%) from members were included. TSH receptor antibody measurement (29.2%), thyroid ultrasound (6.7%), and isotopic studies (5.9%) were used less frequently to confirm the etiology compared with those in North American and European surveys. Treatment with an antithyroid drug (ATD) was the preferred first choice of therapy (90.8%). Methimazole at 10-15 mg/day with a beta-blocker was the initial treatment of choice. The preferred ATD in pregnancy was propylthiouracil in the first trimester and methimazole in the second and third trimesters, which was similar to the North American and European surveys.

CONCLUSION

Ultrasound and isotopic studies will be requested only by a small proportion of Thai endocrinologists. Higher physician preference for ATD is similar to Europe, Latin America, and other Asian countries. Geographical differences in the use of ATD, radioactive iodine, and thyroidectomy exist.

Epidemiology, Natural History, Risk Factors, and Prevention of Graves' Orbitopathy

GO is the most frequent extrathyroidal manifestation of Graves' disease, although it may rarely occur in euthyroid/hypothyroid patients with chronic autoimmune thyroiditis. It is a relatively infrequent disorder, and men tend to have more severe ocular involvement at an older age. The prevalence of GO is lower than in the past among patients with recent onset Graves' hyperthyroidism, and moderate-to-severe forms requiring aggressive treatments are no more than 5-6% of all cases of GO. After an initial inflammatory (active) phase and a phase of stabilization (plateau phase), GO tends to improve and eventually inactivates (inactive or burnt-out phase). Minimal-to-mild GO often remits spontaneously, but complete restitutio ad integrum almost never occurs when GO is more than mild. Several risk factors contribute to its development on a yet undefined genetic background. Cigarette smoking is the most important of them. Early diagnosis, control and removal of modifiable risk factors, early treatment of mild forms of GO may effectively limit the risk of progression to more severe forms, which have a profound and dramatic impact on the quality of life of affected individuals, and remain a therapeutic challenge, often requiring long-lasting and multiple medical and surgical therapies.