A British Ophthalmological Surveillance Unit (BOSU) study into dysthyroid optic neuropathy in the United Kingdom

Dysthyroid optic neuropathy: a case series at a tertiary ophthalmic referral centre

BACKGROUND/OBJECTIVES

To determine risk factors and treatment outcomes in dysthyroid optic neuropathy (DON) at a single tertiary ophthalmic centre.

METHODS

Retrospective audit of DON patients who have received intravenous methylprednisolone (IVMP) therapy at Royal Victorian Eye and Ear Hospital, Melbourne, Australia from July 2015 to October 2021.

RESULTS

Study included 24 patients (58% female) with an average age of 59.8 ± 14.7 years at DON diagnosis. Majority (92%) had Graves' hyperthyroidism and 77% had a smoking history. At diagnosis, average visual acuity (VA) of worse eye was LogMAR 0.46, and 48% had relative afferent pupillary defect. Proptosis (89%) and diplopia (73%) were most commonly present at diagnosis. 78% showed predominantly extra-ocular muscle enlargement, and apical crowding (52%) on radiology. 38% (n = 9/24) responded to IVMP alone, 58% (n = 14/24) progressed to surgical orbital decompression. The average total cumulative dose of IVMP during DON treatment was 6.8 ± 1.9 g. 29% required further treatment after IVMP and surgical decompression, 4 (17%) had additional radiotherapy, and three (13%) required immuno-modulatory therapy. Average final VA was LogMAR 0.207, with all patients having inactive TED at final follow-up (mean 1.7 years). In refractory DON cases, 71% retained VA ≥ 6/9 and 48% had DON reversal.

CONCLUSIONS

DON patients typically present in late 50s, with a smoking history and predominant extra-ocular muscle enlargement. High-dose IVMP fully resolved DON in only 38%. A considerable proportion required urgent orbital decompression. Most patients retained good vision at final follow-up.

Understanding the clinical and molecular basis of thyroid orbitopathy: a review of recent evidence

Thyroid eye disease (TED) is an autoimmune orbital inflammatory disease which ranges from mild to severe. Tissue remodeling, fibrosis and fat proliferation cause changes in the orbital tissues which can affect esthetics and visual function. In its severe form, it is sight threatening, debilitating, and disfiguring and may lead to social stigma, the embarrassment about which has an impact on the quality of life of those affected and the family members. The pathogenesis of TED, which is influenced by genetic, immunological, and environmental factors, is complex and not fully elucidated. However, it remains unknown what factors determine the severity of the disease. Recent research has revealed a number of diagnostic and prognostic biomarkers of this disease. In this overview of TED, we focus on new insights and perspectives regarding biological agents that may provide a basis for new treatment modalities.

Macular blood flow changes in dysthyroid optic neuropathy after high-dose intravenous pulse methylprednisolone (IVMP)

OBJECTIVE

To investigate the changes in macular vessel density (VD) of the superficial layer of retina (SLR) and deep layer of retina (DLR) in dysthyroid optic neuropathy (DON) after high-dose intravenous pulse methylprednisolone (IVMP).

MATERIALS AND METHODS

Eighteen DON patients (29 eyes) who completed high-dose IVMP and 16 healthy individuals (32 eyes) were enrolled in this study. Optical coherence tomography angiography (OCTA) image analysis and comprehensive ophthalmic examinations were performed, including the SLR macular whole-image VD (SLR-mwiVD) and DLR-mwiVD, best-corrected visual acuity (BCVA), the mean deviation of visual field (VF-MD), pattern standard deviation of visual field (VF-PSD) and the other parameters.

RESULTS

The SLR-mwiVD (41.39 ± 4.71 vs. 48.13 ± 3.68, p < 0.001) and DLR-mwiVD (40.77 ± 5.85 vs. 49.14 ± 7.02, p < 0.001) were decreased in DON compared to control eyes. After IVMP, visual function parameters were improved, and SLR-mwiVD (49.41 ± 3.18, p < 0.001) and DLR-mwiVD (50.41 ± 4.04, p < 0.001) were increased in the DON group compared to pretreatment. The increased SLR-mwiVD and DLR-mwiVD were significantly correlated with improvements in BCVA (Log MAR: from 0.62 ± 0.49 to -0.01 ± 0.03, p < 0.001), VF-MD (from - 6.89 ± 2.89 dB to - 1.75 ± 1.29 dB, p < 0.001) and VF-PSD (from 4.38 ± 2.52 dB to 2.32 ± 1.64 dB, p < 0.001).

CONCLUSION

The increase in macular VD was significantly correlated with the improvement in visual function in DON after IVMP. Macular VD changes on OCTA may be a useful indicator for the response in DON after IVMP.

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.

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

Background and Aims

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

Methods

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

Results

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

Conclusion

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

Utility of isolated-check visual evoked potential technique in dysthyroid optic neuropathy

PURPOSE

To analyze the utility of isolated-check visual evoked potential (icVEP) for discriminating between eyes with dysthyroid optic neuropathy (DON) and eyes with thyroid-associated ophthalmopathy (TAO) but not DON.

METHODS

Forty-three eyes with TAO but not DON (as non-DON), fifty-three eyes with DON, and sixty healthy eyes (as controls) were included. Comprehensive ophthalmic examinations, including best-corrected visual acuity, refraction, color vision test, intraocular pressure measurement, slit-lamp biomicroscopy, ophthalmoscopy, RAPD, exophthalmometry measurements, pVEP test, icVEP test, standard automated perimetry, and clinical activity score classification of TAO, as well as demographic information, were collected and analyzed.

RESULTS

In the DON group, the signal-to-noise ratio (SNR) value of icVEPs decreased significantly compared with that of the non-DON group as well as control (p < 0.05). The SNR values under 8%, 16% and 32% depth of modulation (DOM) were significantly negatively correlated with BCVA (p < 0.05, r =  - 0.9 ~  - 0.6), papilledema (Y/N) (p < 0.05, r =  - 0.8 ~ 0.4) and DON (Y/N) (p < 0.001, r =  - 0.7 ~  - 0.5). The 8% DOM of icVEP had the largest area under the receiver operating characteristic curve (AUC) (0.842) for discriminating DON from non-DONs. Meanwhile, decision curve analysis (DCA) showed that patients clinically benefit most from 8% DOM of icVEP. Furthermore, the 8% DOM of icVEP combing with papilledema (Y/N) and BCVA (Model 1) has significantly larger AUC than the 8% DOM of icVEP (p = 0.0364), and has better clinical benefit in DCA analysis.

CONCLUSIONS

The SNR of 8% DOM from icVEP may represent a significant ancillary diagnostic method for DON detection. Furthermore, icVEP combined with papilledema (Y/N) and BCVA should be considered as a diagnostic model in future clinical practice.

Update on the surgical management of Graves' orbitopathy

Graves' orbitopathy (GO) is a complex autoimmune disorder of the orbit that causes the eye to appear disfigured. GO is typically associated with Graves' disease, an inflammatory autoimmune condition that is caused by thyrotropin receptor autoantibodies. Although our knowledge of the pathophysiology of GO has improved, its exact pathogenesis remains unclear. Some patients suffer from disfigurement, double vision, and even vision loss rather than hyperthyroidism. The disease severity and activity prompt different treatments, as the signs of GO are heterogeneous, so their management can be very complex. Despite medical advances, the first-line treatment for moderate-to-severe active GO is still glucocorticoids, while surgery can be critical for the treatment of chronic inactive GO. Surgery is sometimes required in the acute phase of the disease when there is an immediate risk to vision, such as in dysthyroid optic neuropathy. Most surgeries for GO are rehabilitative and subdivided into three categories: decompression, strabismus repair, and lid surgery. This review is a basic overview of the field, with up-to-date knowledge of the surgical techniques for GO. We review and summarize recent literature on the advances in surgery for GO to provide up-to-date insights on the optimal surgical treatment for GO.

Reduced contrast sensitivity function correlated with superficial retinal capillary plexus impairment in early stage of dysthyroid optic neuropathy

BACKGROUND

To assess the accuracy of contrast sensitivity function (CSF) in detecting dysthyroid optic neuropathy (DON) at an early stage in thyroid-associated ophthalmopathy (TAO) patients and to examine potential factors that may be linked to early visual impairments in these individuals.

METHODS

A total of 81 TAO patients (50 non-DON and 31 DON), and 24 control subjects participated in the study. CSF was measured with the quick CSF (qCSF) method. Optical coherence tomography angiography (OCTA) images of the ganglion cell complex layer (GCCL), superficial and deep retinal capillary plexuses (SRCP and DRCP) in a 3 mm diameter area around the macula were evaluated.

RESULTS

Compared with the controls, the area under the log contrast sensitivity function (AULCSF) and SRCP density were significantly reduced in non-DON and DON patients (all P < 0.05). The GCCL thickness of the DON patients was thinner than that of the controls and non-DON patients (all P < 0.05). The AULCSF was significantly correlated with spherical equivalent refractive error, muscle index, SRCP density and GCCL thickness in TAO patients, respectively (all P < 0.05). However, stepwise multi-regression analysis showed that the AULCSF was only significantly correlated with SRCP density (P < 0.001). Receiver operating characteristic curve analysis showed that the AULCSF produced the most accurate discrimination between non-DON and DON patients from the controls (AUC = 0.831, 0.987, respectively; all P < 0.001).

CONCLUSIONS

CSF change in the early stage of DON is related to SRCP density. It can be an early indicator of visual impairments associated with DON in TAO patients.

Selective deficits of S-cone in thyroid-associated ophthalmopathy patients without clinical signs of dysthyroid optic neuropathy

Purpose

We explored whether thyroid-associated ophthalmopathy (TAO) patients without clinical signs of dysthyroid optic neuropathy (DON) would have a selective deficit mediated by S-cone.

Methods

Thirty-two TAO patients without clinical signs of DON (non-DON, 42.03 ± 9.59 years old) and 27 healthy controls (41.46 ± 6.72 years old) participated in this prospective, cross-sectional study. All observers were tested psychophysically after passing color screening tests and a comprehensive ocular examination. Isolated L-, M-, and S-cone contrast thresholds were measured at 0.5 cyc/deg using Gabor patches. We calculated the area under the receiver operating characteristic (ROC) curve to quantify the ability of chromatic contrast sensitivity to detect the early visual function changes in non-DON patients.

Results

S-cone contrast sensitivity in non-DON patients was found to be lower than that of healthy controls (P < 0.001), whereas the sensitivities to L- and M-cone Gabor patches were similar between these two groups (P = 0.297, 0.666, respectively). Our analysis of the ROC curve revealed that the sensitivity to S-cone had the highest index to discriminate non-DON patients from healthy controls (AUC = 0.846, P < 0.001). The deficit of S-cone was significantly correlated with muscle index in non-DON patients (R = 0.576, P = 0.001).

Conclusion

There is a selective S-cone deficit in the early stage of TAO. S-cone contrast sensitivity could serve as a sensitive measure of visual impairments associated with early DON in patients with TAO.

Management of patients with dysthyroid optic neuropathy treated with intravenous corticosteroids and/or orbital decompression surgery

Purpose

To assess the characteristics and long-term outcomes of adult patients with dysthyroid optic neuropathy (DON) who underwent orbital decompression surgery and/or received intravenous (IV) methylprednisolone.

Methods

Retrospective chart review of 98 eyes of 49 patients who were diagnosed and treated with bilateral DON between 2007 and 2018 at the Department of Ophthalmology and Optometry and Oral and Maxillofacial Surgery of the Medical University of Vienna.

Results

The mean follow-up period was 4.1 ± 2.7 years. The most common presenting symptoms were eyelid and periorbital swelling (45%) representing active inflammation. Upgaze restriction was the most common clinical finding (73%). At time of diagnosis, the mean clinical activity score was 4 ± 1/4 ± 1 (right/left eye, respectively). Sixty-three percent (31/49) of the patients were treated both with IV methylprednisolone and underwent orbital decompression surgery, 22% (11/49) were treated with IV methylprednisolone alone and 14% (7/49) underwent surgical decompression only. Seventy-one percent (30/42) of the patients underwent 3-wall decompression. The mean reduction of proptosis in patients treated with both IV methylprednisolone and orbital decompression surgery was 4/5 mm. Mean of reduction in proptosis in patients receiving IV methylprednisolone only was 1/0 mm and in patients with surgical decompression only was 5/5 mm. Mean VA was 0.1 ± 0.5/0.1 ± 0.5 logMAR at baseline and 0.05 ± 0.7/0.05 ± 0.7 at final follow-up. In 92% (45/49), VA was preserved or improved at final follow-up.

Conclusions

The majority of patients with DON were treated both with IV corticosteroids and 3-wall decompression surgery. Vision could be successfully preserved in most cases and reduction of proptosis was achieved, especially after orbital decompression surgery.

Therapeutic difference between orbital decompression and glucocorticoids administration as the first-line treatment for dysthyroid optic neuropathy: a systematic review

To assess all available data to compare the efficacy of glucocorticoids treatment and orbital decompression for dysthyroid optic neuropathy (DON). PubMed, EMBASE, the Cochrane Library databases as well as other sources were searched by two independent reviewers followed by extensive hand-searching for the identification of relevant studies. The primary outcomes were the improvement in visual acuity and responder rate. Secondary outcomes were the proptosis reduction, change in diplopia, and clinical activity score (CAS). One randomized controlled trial, three retrospective case series and one prospective case series met the inclusion criteria. They were divided into intravenous high-dose glucocorticoids (ivGC) group and orbital decompression (OD) group. Both groups demonstrated improvement in visual acuity. In addition, the proportion of patients with improved vision in OD group was higher than that in ivGC group (P<0.001). Post-treatment proptosis reduction was also reported in both groups. Overall, weighted mean in proptosis reduction estimated at 1.64 and 5.45 mm in patients treated with ivGC and OD respectively. This study also presented results regarding pre-existing and new-onset diplopia. Apart from diplopia, a wide variety of minor and major complications were noted in 5 included studies. The most common complication in ivGC group and OD group was Cushing's syndrome and epistaxis respectively. The present systematic review shows that both glucocorticoids treatment and OD are effective in treating DON and OD may work better in improving visual acuity and reducing proptosis. However, high-quality, large-sample, controlled studies need to be performed in the future.

Teprotumumab for Dysthyroid Optic Neuropathy: Early Response to Therapy

A 45-year-old male presented with active progressive thyroid eye disease refractory to intravenous steroids and right orbital radiation. Visual acuity, left relative afferent pupillary defect, and Humphrey visual field defects were consistent with worsening left dysthyroid optic neuropathy. Orbital MRI demonstrated extraocular muscle enlargement and effacement of the left optic nerve sheath. After 2 infusions of teprotumumab, the patient's visual acuity, relative afferent pupillary defect, Humphrey visual fields, proptosis, and extraocular muscle size improved. This is the first report of dysthyroid optic neuropathy responsive to teprotumumab, and it supports the need for further studies to better understand the role of teprotumumab in treating sight-threatening thyroid eye disease.

Early efficacy of teprotumumab for the treatment of dysthyroid optic neuropathy: A multicenter study

Purpose

To study post-interventional findings in patients with dysthyroid optic neuropathy (DON) treated with teprotumumab.

Observations

In this multicenter observational Case series, patients with DON were treated with teprotumumab, an insulin-like growth factor I receptor inhibitor (10 mg/kg for the first infusion then 20 mg/kg for subsequent infusions, every three weeks for a total 8 infusions). This study included patients with acute and chronic thyroid eye disease (TED) with DON who had failed conventional therapies and were not candidates for surgical decompression. Data collected included best corrected visual acuity (BCVA), color vision, RAPD when present, and orbital CT or MRI. Proptosis, clinical activity score (CAS), Gorman diplopia score (GDS), and Humphrey visual fields (HVF) were also evaluated.

Ten patients (6 women, 4 men) with an average age 64 years old were included in this study. Mean follow up after completion of infusions was 15 weeks. Baseline visual acuity (VA) impairment ranged from hand motion (HM) to 20/25 in affected eyes. All patients had pre-treatment orbital CT or MRI that confirmed orbital apex compression. Seventy percent of patients had objective improvement in DON after 2 infusions of teprotumumab measured as significant improvement in visual acuity, resolution of RAPD, or both. After completion of treatment, affected eyes had a mean BCVA improvement of 0.87 logMAR (p=0.0207), proptosis reduction of 4.7 mm (p<0.00001), CAS improvement of 5.25 points (p<0.00001), and GDS improvement of 0.75 points (p=0.160). All 6 patients who presented with an RAPD had resolution or improvement of RAPD. All 7 patients who presented with color vision deficits had normalization or improvement of color vision.

Conclusions and Importance

Teprotumumab infusions resulted in medical decompression and objective resolution or improvement of dysthyroid optic neuropathy. Most patients had rapid improvement of visual acuity and reversal of RAPD. Post-infusion imaging demonstrated reduction in extraocular muscle size that correlated with improvement in visual dysfunction. However, patients who presented with longstanding severe visual loss had limited improvement. There was no recurrence of DON after completion of teprotumumab in our cohort.

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Teprotumumab is effective for the treatment of dysthyroid optic neuropathy.

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Most patients demonstrated rapid objective improvement after 2 infusions.

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Visual acuity improved and relative afferent pupillary defect resolved after treatment.

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Orbital imaging showed improvement of orbital apex crowding after treatment.

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Patients with longstanding severe vision loss had limited improvement in visual acuity.

[Orbital decompression in Graves' orbitopathy-Experiences and results]

Hintergrund

Die endokrine Orbitopathie ist die häufigste extrathyreoidale Manifestation des Morbus Basedow und tritt bei schätzungsweise 25–50 % der betroffenen Patienten auf. Krankheitsbedingt kommt es zu einer entzündlichen Schwellung der Orbitaweichteile. Die Behandlung erfolgt meist konservativ. Bei schweren Fällen mit beeinträchtigendem Exophthalmus oder akuter, steroidrefraktärer Visusbedrohung kann eine chirurgische Orbitadekompression die Beschwerden der Patienten lindern oder das Sehvermögen erhalten. Ein wesentlicher Aspekt der Versorgungsqualität besteht in der Vermeidung postoperativer Doppelbilder.

Ziel der Arbeit

Erfahrungs- und Ergebnisbericht von 100 chirurgischen Orbitadekompressionen bei 62 Patienten an einem interdisziplinären Orbitazentrum. Patienten mit Kompression der Orbitaspitze wurden mittels pterionaler Dekompression behandelt. Patienten ohne Hinweise auf Orbitaspitzenbeteiligung wurden mittels tiefer lateraler Wandresektion oder pterionaler Dekompression behandelt.

Methodik

Retrospektive Datenanalyse.

Ergebnisse

Die mittlere Exophthalmusreduktion betrug 2,9 mm. Augen mit visusbedrohendem Schweregrad gewannen im Mittel 2,2 Zeilen an Sehschärfe, der Visus bei rehabilitativer Indikation blieb stabil. Die Komplikationsrate betrug 4 %. Neue Doppelbilder wurden nach 2 Eingriffen beobachtet. Bei einem Patienten kam es zu einer Visusminderung von 0,8 auf 0,1. In 9 Fällen führte die Operation zu einem vollständigen Rückgang zuvor beklagter Doppelbilder.

Diskussion

Visusgewinn, Exophthalmusreduktion und Komplikationsrate sind in diesem Kollektiv vergleichbar mit zuvor publizierten Arbeiten. Diese Studie bestätigt die Rolle der Orbitadekompression bei visusbedrohender und schwer beeinträchtigender endokriner Orbitopathie.

Dysthyroid optic neuropathy: evaluation and management

BACKGROUND

Dysthyroid optic neuropathy (DON) is a serious complication of Graves orbitopathy (GO) from optic nerve dysfunction that may result in permanent loss of vision.

PURPOSE

This paper reviews the current knowledge of DON, including its pathogenesis and epidemiology, clinical and radiologic features, and management choices and outcomes.

METHODS

Literature review and author retrospective case series.

RESULTS

Over 90% of DON cases are related to nerve compression by enlarged extraocular muscles (EOM) while the remainder are caused by stretching of the optic nerve without compression. DON's incidence is 5-8% of GO cases. Risk factors include advancing age, male gender, smoking and diabetes mellitus, and these cases should be referred promptly to an ophthalmologist or GO clinic to rule out DON and for ongoing care. Clinical features of DON may include reduction in central and colour vision (unexplained by other ocular disorders), afferent pupil defect and/or optic disc edema. Since most cases are associated with enlarged EOM, restricted motility and soft tissue venous congestion are common. Visual fields and optical coherence tomography (OCT) help confirm the diagnosis while CT or MRI Scans show apical optic nerve compression or proptosis with optic nerve stretch. Standard therapy includes iv/oral corticosteroids (CS) with partial response in most cases, but often relapse with tapering. Radiotherapy may delay or avoid surgery and may prevent the onset of DON when combined with CS in high-risk individuals. The benefits of newer biologic targeted therapy are not clear. Orbital decompression surgery often has positive outcomes, even in cases of severe vision loss or delayed surgery. The most common surgical complication is worsening strabismus, which may worsen visual function and quality of life. In rare cases, permanent vision loss from DON may occur despite full therapy.

CONCLUSIONS

Although DON may cause vision loss, most cases are reversible if recognized and managed in a timely manner.

Comparing isolated-check visual evoked potential, pattern visual evoked potential, and standard automated perimetry in dysthyroid optic neuropathy eyes

Objective

To determine the diagnostic ability of isolated-check visual evoked potential (icVEP), pattern visual evoked potential (pVEP), and standard automated perimetry (SAP) between dysthyroid optic neuropathy (DON) and thyroid-associated ophthalmopathy (TAO) without DON (non-DON).

Methods

This is a case-control study, 49 bilateral patients (26 DON and 23 non-DON) were included. icVEP, pVEP, and SAP were conducted in all the subjects, icVEP parameters compared were signal-to-noise ratios (SNRs) under 8, 16, and 32% depth of modulation (DOM). pVEP parameters compared were amplitude and latency. SAP parameters were mean deviation (MD) and pattern standard deviation (PSD). The area under the receiver operating characteristic (ROC) curve (AUC), net reclassification index (NRI), integrated discrimination index (IDI), and decision curve analysis (DCA) were applied for analysis.

Results

In icVEP, values of SNR in DON were significantly smaller than non-DON (p < 0.05). In pVEP, P100 latent time in DON was significantly larger than non-DON (p = 0.0026). In SAP, value of PSD in DON was larger than non-DON (p = 0.0006), and value of MD in DON was smaller (p = 0.0007). AUC, NRI, and IDI among the three tests were not significantly different. DCA showed that SNR of icVEP under 8% DOM was the farthest from the two extreme curves.

Conclusions

icVEP, pVEP, and SAP have equal diagnostic capabilities to discern between DON and non-DON. In addition, icVEP may represent a significant ancillary diagnostic approach to DON detection, with more clinical benefit.

Strategies in Surgical Decompression for Thyroid Eye Disease

Surgical management of thyroid eye disease- (TED-) associated morbidity has been plagued by the complex interplay of different operative techniques. Orbital decompression is the well-recognized procedure for disfiguring exophthalmos and dysthyroid optic neuropathy (DON). There are numerous published techniques described for the removal of the orbital bone, fat, or a combination. The diverse studies are noncomparative as they include different indications, stages of disease, and methods of evaluation. Thus, it is difficult to conclude the most efficient decompression technique. To obtain effective and predictable results, it is therefore important to propose a logical and acceptable clinical guideline to customize patient treatment. Herein, we developed an algorithm based on the presence of DON, preoperative existing diplopia, and severity of proptosis which were defined by patient's disabling symptoms together with a set of ocular signs reflecting visual function or cosmesis. More specifically, we aimed to assess the minimal but effective surgical technique with acceptable potential complications to achieve therapeutic efficacy. Transcaruncular or inferomedial decompressions are indicated in restoring optic nerve function in patients with DON associated with mild or moderate to severe proptosis, respectively. Inferomedial or fatty decompressions are effective to treat patients with existing diplopia associated with mild or moderate to severe proptosis, respectively. Fatty or balanced decompressions can improve disfiguring exophthalmos in patients without existing diplopia associated with mild to moderate or severe proptosis, respectively. Inferomedial or 3-wall decompressions are preferred to address facial rehabilitation in patients associated with very severe proptosis but without preoperative diplopia.

Subclinical dysthyroid optic neuropathy: tritan deficiency as an early sign of dysthyroid optic neuropathy

PURPOSE

The aim of this research was to investigate the subclinical findings of dysthyroid optic neuropathy (DON) and to look for early indicators for optic nerve compression in patients with Graves' orbitopathy.

PATIENTS AND METHODS

In this observational, retrospective study, the medical charts of 24 patients (32 eyes) with a diagnosis of DON between 2008 and 2019 were included. Our goal was to identify potential pathological signs in patients with DON prior to the definitive diagnosis of DON.

RESULTS

We discovered that the earliest pathological sign in the subclinical cases was tritan deficiency obtained with a standardised colour vision test by Arden. In all cases but one, regardless of the visual field (VF) defects, the tritan values were pathological (based on a threshold of ≥8%) in the subclinical phase. The mean tritan value was 19.12% (range 6.9-80.8%) at the time of the subclinical phase and 32.16% (range 6.3-100.0%) at the time of the diagnosis of DON. The sensitivity of the colour vision test was 20% for protan and 96.67% for tritan in the subclinical phase. At the time of the definitive diagnosis of DON, the sensitivity of protan was 48.15% compared to 96.30% for tritan.

CONCLUSION

We found that changes in vision affecting the blue-yellow (tritan) colours resulting from the compression of optic nerve, even in affected patients with normal VF tests, are a reliable early sign of DON.

Graves' disease

Graves' disease (GD) is an autoimmune disease that primarily affects the thyroid gland. It is the most common cause of hyperthyroidism and occurs at all ages but especially in women of reproductive age. Graves' hyperthyroidism is caused by autoantibodies to the thyroid-stimulating hormone receptor (TSHR) that act as agonists and induce excessive thyroid hormone secretion, releasing the thyroid gland from pituitary control. TSHR autoantibodies also underlie Graves' orbitopathy (GO) and pretibial myxoedema. Additionally, the pathophysiology of GO (and likely pretibial myxoedema) involves the synergism of insulin-like growth factor 1 receptor (IGF1R) with TSHR autoantibodies, causing retro-orbital tissue expansion and inflammation. Although the aetiology of GD remains unknown, evidence indicates a strong genetic component combined with random potential environmental insults in an immunologically susceptible individual. The treatment of GD has not changed substantially for many years and remains a choice between antithyroid drugs, radioiodine or surgery. However, antithyroid drug use can cause drug-induced embryopathy in pregnancy, radioiodine therapy can exacerbate GO and surgery can result in hypoparathyroidism or laryngeal nerve damage. Therefore, future studies should focus on improved drug management, and a number of important advances are on the horizon.

The Therapeutic Effect of Combination of Orbital Decompression Surgery and Methylprednisolone Pulse Therapy on Patients with Bilateral Dysthyroid Optic Neuropathy

PURPOSE

To investigate the synergic effect of combination of orbital decompression surgery and methylprednisolone pulse therapy (MPT) and MPT alone on the visual function in patients with bilateral dysthyroid optic neuropathy (DON).

METHODS

For each involved patient with bilateral DON, only one eye was treated with orbital decompression surgery which was conducted by the same doctor, and each of them received MPT after surgery. If the visual function deteriorated despite treatment, patients would switch to the other treatment. All the patients were followed up for 3 months after surgery. Clinical features of patients including best corrected visual acuity (BCVA), intraocular pressure (IOP), proptosis, upper eyelid retraction, and clinical activity score (CAS) before and after surgery were analyzed, respectively. Visual field and visual evoked potential (VEP) tests were also performed. Paired t-test and Wilcoxon matched-pairs signed ranks sum test were used to analyze the data.

RESULT

A prospective cohort of 23 patients with bilateral DON was enrolled in this cohort study. No patients failed to the therapy or switched to another treatment. The quantitative variables were shown as means and standard deviations (SD). After 3 months of combined treatment of orbital decompression surgery and MPT, BCVA (logMAR) improved, proptosis was reduced and the upper eyelid retraction was relieved in both eyes of patients; however, these improvements were more significant in the operated eyes than in the fellow (nonoperated) eyes. IOP decreased significantly in the operated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (.

CONCLUSION

A combination of orbital decompression and MPT can significantly improve visual function in patients with DON, reduce intraocular pressure, and relieve clinical symptoms such as upper eyelid retraction and proptosis, while MPT alone has a limited effect. For DON patients, orbital decompression should be performed promptly to improve the visual function.

Update on the clinical assessment and management of thyroid eye disease

PURPOSE OF REVIEW

To offer an update on advances and controversies in the assessment, investigation and treatment of thyroid eye disease (TED), a disfiguring orbital autoimmune disease, which can manifest with diplopia and threaten not only sight - but also life.

RECENT FINDINGS

Developments in biomarkers and imaging are helping to tailor the management of patients. Emerging therapies target different pathways in the disease and are informed by studies into TED pathogenesis: the last 2 years has, for example, seen the culmination of a two-decade long bench-to-bedside story in which an original focus on the IGF1 receptor has translated into an effective treatment for proptosis in thyroid eye disease. Whether this will result in a real-world reduction in TED-related morbidity will depend on access; commercial pricing decisions may preclude widespread adoption of novel therapies.

SUMMARY

Thyroid eye disease research is enjoying a renaissance with advances in both monitoring and treatment coupled with a renewed emphasis on a holisitic approach, which includes aesthetic care for patients; this is perhaps the most exciting time to be part of the international thyroid eye disease community in decades - for physicians, surgeons and patients. The commercial window for break-through drugs are narrowing with an array of new therapeutic agents in the pipeline over the coming decade.