Extraocular muscle problems in thyroid eye disease

Histopathologic Findings in Idiopathic Orbital Myositis

PURPOSE

To report the histologic and clinical features of idiopathic orbital myositis (IOM) patients who underwent extraocular muscle (EOM) biopsy over 20 years, to provide the first methodical reference to the expected histopathologic findings, and to discuss the histopathologic differences from common differential diagnoses.

DESIGN

Cohort study.

PARTICIPANTS

All patients with a diagnosis of IOM who underwent EOM biopsy from 2000 through 2019 were included. Patients who had a different final diagnosis were excluded.

METHODS

Tissue samples of EOM and medical records of all participants were reviewed.

MAIN OUTCOME MEASURES

Histopathologic features of muscle biopsy, including tissue morphologic features and cellular composition.

RESULTS

Thirteen patients met both inclusion and exclusion criteria, and their tissue samples were revisited. Nine patients showed histopathologic findings that suggested a conclusive diagnosis of IOM, and the study focused on them. The average age at presentation was 49 years, and 66.7% of patients were women. The most commonly biopsied EOM was the medial rectus (44.4%). The most common indications for biopsy were nonresolving orbital disease with inadequate response to corticosteroids (44.4%) or a high suspicion of malignancy because of known pre-existing systemic malignancy or the presence of an atypical orbital mass in addition to enlarged muscles (44.4%). The histopathologic findings that suggested a diagnosis of IOM were splaying of muscle fibers by inflammatory infiltrates (n = 9) and mild fibrosis (n = 8) in the endomysium or replacing muscle fibers, with no granulomas or vasculitis. The inflammatory infiltrates identified were of chronic inflammatory cells, consisting of lymphocytes (n = 9), plasma cells (n = 6), and histiocytes (n = 6). Other less commonly identified cells were eosinophils (n = 4), polymorphonuclears (n = 1), and giant cells (n = 1). Muscle fiber degeneration or regeneration was evident in 5 patients. Four patients from the initial cohort showed inconclusive histologic findings on revision and were reassigned as suspected IOM.

CONCLUSIONS

The histopathologic features of involved muscles in IOM resemble those seen in idiopathic orbital inflammation and differ from those seen in common differential diagnoses. Extraocular muscle biopsy should be strongly considered whenever the presentation of orbital myositis is not typical or when significant underlying conditions are a possibility.

The impact of orbital bony or fat decompression on the outcome of strabismus surgery in patients with Graves' ophthalmopathy

BACKGROUND/PURPOSE

To compare the outcomes of strabismus surgery in patients with Graves' ophthalmopathy (GO) who had undergone bone removal orbital decompression (BROD) or fat removal orbital decompression (FROD) with those who had not undergone any orbital decompression.

METHODS

The records of patients with GO who underwent strabismus surgery over a period of 66 months were retrospectively reviewed.

RESULTS

Eighty-nine patients with a mean age of 55.1 ± 11.9 years were identified in this study. Twenty-two patients had prior BROD, 20 patients had prior FROD and 47 patients had no orbital decompression. Patients who had prior orbital decompression had an average of 1.6 strabismus surgeries per patient which was significantly higher compared to 1.2 strabismus surgeries in patients who had no orbital decompression (p = 0.02). The overall success rate of strabismus surgery was 68.2%, 80.0% and 80.9% following BROD, FROD and no orbital decompression respectively. The overall success rate of strabismus surgeries in patients with GO was 61% after the first surgery and 78% after the final surgery.

CONCLUSION

The management of strabismus in GO is complex and difficult. Prior orbital decompression is associated with more strabismus surgeries per patient with a trend towards a lower success rate for strabismus surgery. FROD is comparable to BROD with regards to its effects on the outcome of subsequent strabismus surgeries.

IgG4 Staining in Thyroid Eye Disease

IgG4-related ophthalmic disease is increasingly widely recognized. Moreover, IgG4 staining can occur in other inflammatory diseases. The authors report a case of IgG4 staining of an enlarged, inflamed levator palpebrae superioris in a patient with a past history of thyroid eye disease. A 78-year-old woman with quiescent hyperthyroidism had clinical and radiological evidence of levator palpebrae superioris inflammation without superior rectus involvement. A biopsy was consistent with IgG4-related ophthalmic disease. There was a marked but incomplete response to an orbital injection of triamcinolone. The authors discuss the association between thyroid eye disease and IgG4 staining and the diagnostic issues that arise when IgG4-related ophthalmic disease criteria are fulfilled in patients with other orbital inflammatory conditions.

Lateral rectus muscle resection following maximal recession of the medial rectus muscle in thyroid eye disease

BACKGROUND

Rectus muscle restriction is a common finding in thyroid eye disease (TED). Typically, restricted muscles are recessed to address strabismus and diplopia. However, some patients have residual strabismus following maximal recession of a restricted muscle. The purpose of this study was to report outcomes following resection of the lateral rectus muscle after maximal recession of the medial rectus muscle in patients with TED.

METHODS

The medical records of patients with TED who underwent lateral rectus resection between 1998 and 2015 were reviewed retrospectively. Information regarding thyroid disease history and surgical treatment, including history of orbital decompressions, rectus muscle recessions, rectus muscle resections, and pre- and postoperative alignment was collected. Adjustable suture was used in all cases. Success was defined as a postoperative orthotropia with ≤2^Δ of phoria at distance and a phoria at near.

RESULTS

A total of 11 patients were included. Of these, 10 (91%) required postoperative adjustment. A successful outcome was achieved in 10 cases (91%).

CONCLUSIONS

Lateral rectus muscle resection to address residual esotropia and diplopia was effective at reducing residual esotropia following medial rectus recession in our study cohort.

The role of rectus muscle myectomy in the management of large-angle strabismus for Graves' ophthalmopathy

PurposeRetrospective noncomparative case series to investigate the role of rectus muscle myectomy for the treatment of large-angle strabismus in patients with Graves' ophthalmopathy.Patients and methodsData from 47 consecutive patients with Graves' ophthalmopathy who underwent complete myectomy for large-angle strabismus (strabismus greater than 25 prism diopters (PDs)) were collected retrospectively. Pre- and postoperative deviations in primary and reading position were measured in PDs. Postoperative deviation of <5 diopters in primary gaze and functional binocular vision in central 30° field were considered as successful surgical outcomes.ResultsPatients undergoing complete myectomy of the restricted muscles in large-angle strabismus achieved a 78.7% success rate after the first surgery. Reoperation performed on seven patients resulted in 85.7% success rate in reoperation group. The overall success rate was 91.5%. The mean efficacy of the isolated rectus muscle myectomy was 34.3±7.7 PDs.ConclusionsThe complete rectus muscle myectomy technique is effective and predictable in the treatment of large-angle strabismus in patients with Graves' ophthalmopathy.

Fractional anisotropy and diffusivity changes in thyroid-associated orbitopathy

INTRODUCTION

To investigate the extraocular muscle (EOM) changes in thyroid-associated orbitopathy (TAO) on DTI and the correlations between DTI parameters and clinical features.

METHODS

Twenty TAO patients and 20 age- and sex-matched controls provided informed consent and were enrolled. Ten-directional DTI was acquired in orbit. Fractional anisotropy (FA), mean, axial, and radial diffusivities were obtained at medial and lateral EOMs in both orbits. EOM thickness was measured in patients using axial CT images. FA and diffusivities were compared between patients and controls. The relationships between DTI values and muscle thickness and exophthalmos were evaluated. DTI values compared between patients in active and inactive phases by clinical activity score of TAO. DTI values were also compared between acute and chronic stages by the duration of disease.

RESULTS

In medial EOM, FA was significantly lower in patients (p < 0.001) and negatively correlated with muscle thickness (r = -0.604, p < 0.001). Radial diffusivity was significantly higher in patients (p = 0.010) and correlated with muscle thickness (r = 0.349, p = 0.027). In lateral EOM, DTI values did not differ between patients and controls. In the acute stage, the diffusivities of the medial rectus EOM were increased compared with the chronic stage. DTI values of the medial and lateral rectus EOM did not differ significantly between active and inactive phases.

CONCLUSION

DTI can be used to diagnose TAO with FA and radial diffusivity change in EOM. Diffusivities can be used to differentiate acute and chronic stage of TAO. However, DTI values showed limitation in reflecting TAO activity according to the CAS.

Clinical Pearls and Management Recommendations for Strabismus due to Thyroid Orbitopathy

Thyroid orbitopathy causes a unique form of strabismus with adult-onset diplopia. Prisms can be a temporizing measure, but many patients require strabismus surgery, which can be challenging. In this article, we highlight clinical guidelines for addressing strabismus due to thyroid orbitopathy and review our surgical experience.

Postoperative shift in ocular alignment following single vertical rectus recession on adjustable suture in adults without thyroid eye disease

PURPOSE

To determine whether overcorrection shifts occur after vertical rectus recession on adjustable suture in the absence of thyroid eye disease.

METHODS

The medical records of patients without thyroid eye disease who underwent vertical rectus recession surgery from 2001 to 2008 were retrospectively reviewed for shifts in alignment between suture adjustment at postoperative day 1 and 2 months' follow-up. Superior rectus and inferior rectus recessions were compared. In addition, we compared the use of a nonabsorbable polyester suture to an absorbable polyglactin 910 suture in nonthyroid patients undergoing inferior rectus recessions.

RESULTS

A total of 59 patients were included (superior rectus, 30; inferior rectus, 29). We found a mean undercorrection shift of 1.1 (range, 17.5(Δ) undercorrection to 16(Δ) overcorrection) and 1.0(Δ) (range, 12(Δ) undercorrection shift to 6(Δ) overcorrection shift) for superior and inferior rectus recessions, respectively, between 1 day and 2 months postoperatively.

CONCLUSIONS

There was no trend toward overcorrection following unilateral vertical rectus adjustable suture recessions in patients without thyroid eye disease, suggesting that thyroid myopathy may account for overcorrection shifts seen with this surgery.

Postoperative drift in patients with thyroid ophthalmopathy undergoing unilateral inferior rectus muscle recession

BACKGROUND

Extraocular muscles of patients with thyroid ophthalmopathy (TO) may respond differently to strabismus surgery than those of other strabismic patients. This study reports postoperative alignment changes in patients with TO compared with patients with non-restrictive strabismus following unilateral inferior rectus muscle recession (IRR).

METHODS

We reviewed records of patients with and without TO who underwent unilateral IRR. Group A had adjustable muscle sutures, while Group B had permanent or semi-adjustable sutures. Controls were patients undergoing adjustable unilateral IRR for other indications.

RESULTS

Mean preoperative hypotropias were 17 ± 9, 21 ± 7, and 11 ± 4 PD for groups A (n=13), B (n=14), and controls (n=19), respectively. Postoperative day one (POD1) measurements after adjustment were 1.2 ± 2.5, 3.7 ± 4.9, and 0.3 ± 2.4 PD, respectively, representing overall undercorrections in all cases (the preoperative deviation was given a positive (+) value and overcorrections were deemed negative (-) deviations). Dose response from linear regression analysis of thyroid patients compared with control patients for IRR was 3.26 PD/mm (SE 0.18) vs 2.38 PD/mm (SE 0.18) (p=0.001). Mean final measurements were -0.7 ± 5.6 (overcorrection), 2.7 ± 5.7, and 1.7 ± 5.7 PD of hypotropia, respectively. Final overcorrections occurred in 23%, 14%, and 16% of patients, for adjustables, permanent sutures, and control subjects, respectively. Drifts from POD1 measurements after adjustment to final measurements were -1.9 ± 4.3, -1.0 ± 4.6, and 1.4 ± 5.9 PD respectively (p=0.05 for comparison between Group A and controls).

CONCLUSIONS

TO patients with adjustable sutures drift toward postoperative overcorrection.

Double vision in a patient with thyroid disease: what's the big deal?

A 70-year-old woman with a 46-year history of Graves disease had significant thyroid related orbitopathy (TRO) requiring previous bilateral orbital decompressions and one previous strabismus procedure for an exotropia of 60 PD. At the initial neuro-ophthalmology assessment, she had an exotropia of 20 PD and was scheduled for further surgery, but at the time of a second assessment a few weeks later, her strabismus had markedly changed. Accordingly, the patient underwent a neostigmine bromide test that demonstrated evidence of co-existing myasthenia gravis.

The characteristics and surgical outcomes of medial rectus recessions in Graves' ophthalmopathy

PURPOSE

To evaluate the clinical characteristics and surgical outcomes of medial rectus (MR) recessions in patients with Graves' ophthalmopathy.

PATIENTS AND METHODS

The clinical records of 32 patients with Graves' ophthalmopathy who underwent MR recessions with adjustable sutures for restrictive esotropia were reviewed. The clinical characteristics of patients, the size of the esodeviations, the limitations of ductions, the surgical doses, and observed responses to surgery were recorded and analyzed. Main outcome measures included the ratio of predicted to observed correction for MR recessions, improvement in ductions, and restoration of binocular status.

RESULTS

The mean age of the 32 patients (20 women, 12 men) at surgery was 54.1+/-11.4 years. The mean duration of thyroid eye disease was 4.3+/-5.4 years (range, 1 to 24 years). The ratios of predicted to observed correction for esodeviations at distance and near, respectively, were 2.21+/-1.24 and 2.16+/-1.81 at the time of adjustment and 1.61+/-0.37 and 1.84+/-0.90 at final follow-up. The limitation of abduction improved from -2.3+/-1.3 to -0.75 +/-0.98. Binocular single vision was achieved in 73% of patients, and a further 10% of patients were able to fuse with prisms. A history of decompression was present in 75% of cases. Patients with a history of decompression had more restriction in abduction (-2.49 vs -1.78, P =.061), more frequently required bilateral surgery (75% vs 62.5%), and had a higher ratio of predicted to observed correction (1.71 -0.37 vs 1.37+/-0.28, P = .043).

CONCLUSIONS

Patients with Graves' ophthalmopathy who undergo MR recession for restrictive esotropia are prone to undercorrection. A history of decompression is associated with a less favorable clinical outcome. Augmented surgery, adjustable sutures, or both are recommended for improved surgical outcomes.

Thyroid-associated orbitopathy: a clinicopathologic and therapeutic review

PURPOSE OF REVIEW

To review the literature related to thyroid-associated orbitopathy and to emphasize recent developments in its pathophysiology, diagnosis, and therapy. Current therapeutic trends and controversies are discussed.

RECENT FINDINGS

Expression of thyroid stimulating hormone receptor is highest in the fat and connective tissue of patients with thyroid-associated orbitopathy, where fibroblasts have the potential for adipogenesis. Electrophysiology can now detect subclinical optic neuropathy, and somatostatin-receptor scintigraphy can help justify immunomodulation. Other than steroids, radiotherapy can control inflammation, but its use is controversial. Current trends in orbital decompression are to camouflage incisions and to limit strabismus with balanced decompression, deep lateral wall techniques, fat removal, and onlay implants. Proptosis reductions of 0.9 to 12.5mm are possible by the use of various algorithms. Before or after decompression, botulinum toxin can correct strabismus, intraocular pressure elevation, and retraction. The latter is now also treated with full-thickness blepharotomy.

SUMMARY

As knowledge of the pathophysiology of thyroid-associated orbitopathy grows, there is a slow movement from nonspecific and invasive measures to more directed treatments causing less morbidity.

Muscle surgery in patients with Graves' disease using topical anesthesia

PURPOSE

To report our experience in extraocular muscle surgery for Graves' disease using topical anesthesia.

DESIGN

Retrospective, noncomparative, observational case series.

PARTICIPANTS

In 135 patients with Graves' disease, a total of 200 ocular muscles were operated during the past 20 years at the Department of Ophthalmology, Ludwig-Maximilian-University, Munich, Germany.

METHODS

Surgery was performed under topical anesthesia with tetracaine hydrochloride 1% eyedrops. Because of the restrictive nature of the motility impairment, recession of the muscles was used in all patients. The exact amount of recession was determined during the operation with active cooperation from the patient.

MAIN OUTCOME MEASURES

Binocular single vision and the angle of deviation were evaluated preoperatively and postoperatively.

RESULTS

Postoperative binocular single vision in the primary position was achieved by 78.7% of the patients on the first postoperative day. Subsequent evaluation demonstrated binocular single vision in 91.9% of all patients and in 96.4% of the group with only 1 muscle (inferior rectus) operated.

CONCLUSIONS

The authors have demonstrated that topical anesthesia is a feasible and reliable method for performing extraocular muscle surgery in patients with Graves' disease. Intraoperative patient discomfort seemed insignificant, and the active cooperation of the patient in finding the appropriate extent of surgery was advantageous. The overall results showed that deviation surgery with the use of topical anesthesia is highly successful in restoring binocular single vision in patients with endocrine orbitopathy.

Orbital pathology

This overview of orbital pathology deals with different kinds of tumors, inflammatory, vascular, and traumatic diseases, which may involve the orbit. Depending on the respective orbital compartment of the globe, the intrakonal, extrakonal and optic nerve the most important and most frequent lesions are presented with their specific clinical symptoms. Their specific presentation on CT- and MR-imaging is discussed in detail, including the most important differential diagnosis.

Controversies in the clinical evaluation of active thyroid-associated orbitopathy: use of a detailed protocol with comparative photographs for objective assessment

Despite many learned publications over recent decades, the assessment of active thyroid-associated orbitopathy (TAO) remains difficult and controversial. There are no biochemical, immunological or imaging investigations which can identify active disease reliably, and clinical assessment is still of paramount importance. We therefore review the strengths and weaknesses of all methods of clinical assessment. A new atlas for clinical assessment of soft tissue signs has been developed, and its reproducibility assessed. It details a suggested protocol that could help standardize descriptions of TAO and allow more objective assessment of its activity and severity. This is relevant to general endocrinologists, who have a crucial role in the identification of patients who require ophthalmological assessment. Certain aspects are more relevant to ophthalmologists and endocrinologists who have a special clinical and research interest in TAO. Unless a reproducible system of assessment is devised and widely adopted, it will remain difficult to interpret research meaningfully, particularly if results appear to contradict.

The incidence of diplopia following coronal and translid orbital decompression in Graves' orbitopathy

PURPOSE

Firstly, to assess the incidence of induced diplopia following orbital decompression in patients with Graves' orbitopathy. Secondly, to assess patient satisfaction after orbital decompression. Thirdly, to determine the factors that contribute to the variable reported incidence of diplopia complicating decompression surgery.

METHODS

We present a retrospective analysis of the alterations of ocular motility in a consecutive series of 81 patients with Graves' orbitopathy who underwent orbital decompression by either a coronal or a translid approach. We assessed patient satisfaction by a telephone survey, and we reviewed the literature.

RESULTS

Eleven patients underwent decompressive surgery for dysthyroid optic neuropathy (DON); 5 of them had a three-wall coronal decompression, the other 6 had a two-wall translid decompression. One of the 5 (20%) coronal versus 2 of the 6 (33%) traslid patients experienced worsening of their existing diplopia. Seventy patients underwent surgery for disfiguring proptosis; 41 of them had a coronal decompression and 29 had a translid decompression. Eight of the 41 coronal patients (20%) and 4 of the 29 translid patients (14%) experienced aggravation of their motility impairment. There was no statistically significant difference between these percentages (chi-squared, p > 0.05). Three of 26 coronal patients (12%) without pre-operative motility impairment developed diplopia in all directions. Twenty-five per cent needed strabismus surgery (9% multiple times). High satisfaction scores were noted after both types of orbital decompression. Through a review of the literature, several factors that may add to heterogeneous results were identified, including definition of diplopia, inclusion criteria and type of surgery.

CONCLUSIONS

Induced diplopia is seen after any type of orbital decompression (19% overall), and its incidence is determined by various factors. To facilitate comparative studies between decompression techniques, a standardised protocol for orthoptic evaluation should be developed.

Flashing lights in thyroid eye disease: a new symptom described and (possibly) explained

BACKGROUND/AIMS

Some patients with restrictive thyroid ophthalmopathy, referred for consideration of extraocular muscle surgery, complained of flashing lights in the superior visual field on upgaze. The frequency was assessed and the pathogenesis of this previously unreported symptom explored.

METHODS

30 patients were recruited, all of whom had tight inferior recti and were in the burnt out phase of thyroid eye disease. They were directly questioned regarding any symptoms of photopsia and their records were examined with respect to disease status and treatment, ocular motility, intraocular pressure, retinal status, and surgical intervention. Magnetic resonance imaging (MRI) and cine MRI scans were reviewed for evidence of globe compression. The frequency of symptoms was compared with an age and sex matched control group.

RESULTS

Three patients spontaneously complained of flashing lights. A further nine patients had this symptom when directly questioned. 18 patients had no symptoms. None of the 33 control patients had symptoms on direct questioning. Sagittal MRI and cine MRI failed to demonstrate globe compression by the inferior rectus muscle even in cases that showed an intraocular pressure rise in upgaze.

CONCLUSION

A new symptom of flashing lights in upgaze has been identified in thyroid eye disease patients with tight inferior recti. It is suggested that the lights are likely to be phosphenes as a result of either compression of the globe by a tight inferior rectus or traction on the insertion of the inferior rectus. The small amount of globe compression required to produce phosphenes seems to be beyond the resolution limit of MRI.

An ultrastructural and systemic analysis of glycosaminoglycans in thyroid-associated ophthalmopathy

PURPOSE

To determine the ultrastructural localisation of glycosaminoglycans (GAGs) in the extraocular muscles (EOMs) of patients with thyroid-associated ophthalmopathy (TAO) and to see whether the quantity and type of GAGs present in blood and urine are markers of the disease.

METHODS

Biopsies of affected EOMs were taken and studied by transmission electron microscopy (TEM). These were either fixed conventional for TEM, or in 0.5% tannic acid and others for immunogold staining. Serum hyaluronan (HA) was measured using a radioimmunoassay in patients with TAO as well as control subjects, and urinary GAG levels assessed by photometric quantitation of hexuronic acid after reaction with carbazole. The excretion pattern of the urinary GAGs was determined by discontinuous electrophoresis.

RESULTS

TEM showed that there is a marked expansion of the endomysial space in TAO EOM biopsies as compared with non-TAO strabismus specimens. This is caused by an increased number of collagen fibres, interspersed with a granular amorphous material surrounding striated collagen fibres shown to be hyaluronan by immunogold staining. In contrast, serum hyaluronan concentrations were similar in TAO and control patients, although there was a statistically significant difference in the urinary GAG excretion between the two groups of patients examined. By discontinuous electrophoresis, chondroitin sulphate and heparan sulphate were present in both patients and controls.

CONCLUSION

GAGs and in particularly HA are present at the EOM level in patients with recently inactive TAO. However, serum levels of HA and urinary GAGs are not sensitive indicators for their presence within the EOMs.

Surgical treatment of thyroid eye disease

Thyroid eye disease may result in exophthalmos, diplopia, and eyelid malpositions, which can be corrected with different surgical procedures. Several techniques for decompressing the orbit have been described, and the advantages and disadvantages of the techniques are discussed. Our own results of the transantral approach are briefly summarized. Eye muscle surgery should be performed after an orbital decompression, and it is not unlikely that more than one muscle operation will be needed in order to achieve single vision. A number of operative procedures for eyelid surgery have been described, and the results of the various methods are generally good.

Magnetic resonance imaging in thyroid eye disease

We examined 25 patients with thyroid eye disease, using both the STIR (Short Tau Inversion Recovery) sequence and cine MRI techniques. A number of characteristic features can be seen on the cine MRI. There is muscle enlargement with restriction of movement and, in the burnt-out phase of the disease, reduced elasticity of the muscles is manifest as their failure to stretch on eye movement. This is in contrast to the active phase of the disease, where although the muscles are enlarged, muscle stretching is clearly visible. The STIR sequence gives an assessment of muscle water content, and hence a high signal is seen in active disease. Combining these techniques is useful in assessing the level of disease activity in thyroid eye disease, and helps in planning further management.

Extraocular muscles: basic and clinical aspects of structure and function

Although extraocular muscle is perhaps the least understood component of the oculomotor system, these muscles represent the most common site of surgical intervention in the treatment of strabismus and other ocular motility disorders. This review synthesizes information derived from both basic and clinical studies in order to develop a better understanding of how these muscles may respond to surgical or pharmacological interventions and in disease states. In addition, a detailed knowledge of the structural and functional properties of extraocular muscle, that would allow some degree of prediction of the adaptive responses of these muscles, is vital as a basis to guide the development of new treatments for eye movement disorders.