Prominent Premalar and Cheek Swelling: A Sign of Thyroid-associated Orbitopathy

Clinical and demographic predictors of buccal fat pad volume in thyroid eye disease

PURPOSE

To understand how thyroid eye disease (TED) impacts buccal fat pad (BFP) volume.

METHODS

In this cohort study, computed tomography (CT) scans and charts of adult patients with and without TED were obtained from an institutional database. The primary outcome was BFP volume in cubic centimeters. Three independent, blinded observers analyzed scans using Horos, a free, open-source medical image viewing software. Bivariate and multivariable analyses were performed. We determined sample size using an effect size based on published reports of the minimum amount of fat excision needed to notice a clinical difference. Equivalence testing against upper and lower bounds set by the same effect size was conducted to assess practical significance of the results.

RESULTS

Our sample was sufficient to detect a difference as large as 1.5cc with 95% power. 72 scans were included in our study, 24 TED patients and 48 controls. Mean BFP volume was not statistically different between TED patients and controls (3.96 cc vs 4.06 cc, p = .778). Analysis of covariance adjusting for relevant patient factors (age, sex, and BMI) also failed to find a significant difference between groups. Equivalence testing was significant (p < .001) and revealed the observed difference between groups was less than any clinically meaningful difference. For an effect size of 1.5cc, the data suggests there is a 5% risk of a false negative.

CONCLUSIONS

TED was not associated with a significant difference in BFP volume, suggesting that the BFP is spared from TED-related soft-tissue expansion.

The Arched Rainbow Brow in Thyroid Eye Disease

PURPOSE

To morphologically describe and mathematically quantify a novel clinical feature of thyroid eye disease (TED).

METHODS

A retrospective study was conducted of TED patients and age-sex-matched normal controls. The arched Rainbow Brow appearance in TED patients was determined by unanimous agreement of 3 oculoplastic surgeons. Eyebrow curvature was assessed by plotting 15 points along the eyebrow in ImageJ. The fourth-degree polynomial ( y = ax4 + bx3 + cx2 + dx + e ) was fitted to each eyebrow.

RESULTS

Two hundred seventy-one eyes were analyzed (200 TED and 71 age-sex-matched normal controls). A Rainbow Brow was identified in 42% of TED patients. A unilateral Rainbow Brow was seen in 15% of patients. The fourth-degree polynomial coefficients yielded significant differences between Rainbow Brow patients and age-sex-matched normal controls for the coefficients a, b, c , and d . Similar analysis of TED patients with and without a Rainbow Brow showed differences in coefficients a and b . Age >50 years ( p = 0.009) and the presence of brow fat expansion ( p < 0.001) were associated with the presence of a Rainbow Brow. Proptosis >24 mm showed a trend toward association with the presence of a Rainbow Brow ( p = 0.057). When considering the contribution of these features in a multivariable analysis, only brow fat expansion was a significant contributing factor ( p = 0.009).

CONCLUSIONS

The Rainbow Brow is a distinct entity in TED and is likely consequent to brow fat pad expansion. Patients with a Rainbow Brow have different eyebrow curvature as compared to both normal age-sex-matched controls and TED patients without a Rainbow Brow.

Thyroid eye disease: Redefining its management-A review

Thyroid eye disease (TED) is a debilitating, vision threatening disease that dramatically alters patients' quality of life. Until recently, the management of TED is a long arduous course with supportive therapy, followed by an extensive surgical treatment plan to reverse the disease endpoints. Teprotumumab offers an early, safe therapeutic intervention to help reverse disease end points such as diplopia and proptosis and improve quality of life.

Thickness of Retro- and Sub-Orbicularis Oculi Fat in Thyroid Eye Disease: Comparison With Controls and Its Influential Factors

PURPOSE

To compare the thickness of the retro- and sub-orbicularis oculi fat (ROOF and SOOF) between patients with thyroid eye disease (TED) and controls via MRI and to determine factors influencing fat thickness.

METHODS

This retrospective, comparative, case-control study included 136 patients (272 sides) with TED and 50 control patients (50 sides). The thickness of the ROOF and SOOF was measured on the quasi-sagittal plane through the optic nerve (the central plane) and 6 mm lateral and medial to the central plane at the level through the superior orbital rim and at the level just below the orbital septum in the lower eyelid, respectively.

RESULTS

The ROOF and SOOF were thickest on the lateral plane (p < 0.050; Tukey Kramer post hoc test) and were significantly thicker in patients with TED than controls on all planes (p < 0.050; Student t test). Multivariate stepwise analysis showed that age, sex, clinical activity score, Hertel exophthalmometric values, and number of enlarged extraocular muscles are significant predictors of the ROOF and SOOF thickness in patients with TED (p < 0.050).

CONCLUSIONS

Patients with TED had thicker ROOF and SOOF on all planes than controls with various factors influencing the thickness. These results may be helpful in planning rehabilitative blepharoplasty with removal of the ROOF and SOOF for correction of eyelid fullness in TED.

Anatomical Study and Clinical Observation of Retro-orbicularis Oculi Fat (ROOF)

OBJECTIVE

To study the anatomical location of retro-orbicularis oculi fat (ROOF) in the upper eyelid and to investigate how ROOF affects the appearance of the upper eyelid.

METHODS

Twenty-eight Chinese hemifacial cadaver specimens were used (14 male cadavers; age range 52-82 years). In 28 hemifaces, the eyelids were dissected from the superficial to deep layers, and the appearance, location, extent, and surrounding tissue of ROOF were observed. Additionally, we observed the relationship between the upper eyelid morphology and ROOF of the upper eyelid in surgical patients who were treated in the plastic surgery department of Tongji Hospital affiliated with Huazhong University of Science and Technology in 2018.

RESULTS

ROOF is a type of fascia adipose tissue that is located in a fat compartment between the muscles (the orbicularis oculi and frontalis muscles) and the orbital septum/frontalis fascia. In patients with hypertrophic ROOF, the upper eyelid appears as a heavy eyelid and as a drooping eyelid. And in patients with atrophic ROOF, the upper eyelid appears as a sunken eyelid.

CONCLUSION

ROOF is located in the fat compartment between the orbicularis muscle and the orbital septum/frontalis fascia. ROOF covers the entire upper eyelid and appears thinner medially and thicker laterally. It is continuous with the fat under the frontalis muscle and affects the appearance of the upper eyelid. It represents an important factor in upper eyelid surgery.

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Thyroid Eye Disease: How A Novel Therapy May Change The Treatment Paradigm

Thyroid eye disease (TED) is a complex, debilitating autoimmune disease that causes orbital inflammation and tissue remodeling, resulting in proptosis, diplopia, and in severe cases, loss of vision. TED can lead to facial disfigurement and severely impact patients’ quality of life. Although the course of TED was identified over 60 years ago, effective treatment options have proved to be challenging. Current treatments such as glucocorticoid therapy and orbital radiation focus on reducing orbital inflammation. However, these therapies fail to modify the disease outcomes, including proptosis and diplopia. Recent advances in the understanding of the molecular basis of TED have facilitated the development of targeted molecular therapies such as teprotumumab, an insulin-like growth factor-1 receptor inhibiting monoclonal antibody. In recent phase 2 and phase 3 randomized placebo-controlled trials, teprotumumab rapidly achieved improvement in clinical endpoints defining TED, including improved proptosis and diplopia. Dramatic improvement in clinical outcomes achieved after teprotumumab therapy during active TED are heretofore singular and comparable only to surgical therapies achieved during the inactive phase of TED. The advent of effective medical therapy can lead to a paradigm shift in the clinical management of TED. This review will provide an overview of TED, its epidemiology, insight into the molecular biology of the disease, clinical characteristics and diagnosis, and current and emerging treatment modalities.

Characterisation of human orbital fibroblasts cultivated from intraconal, nasal and central adipose tissues

PURPOSE

To investigate the characteristics of human orbital fibroblasts (OFs) cultivated from intraconal, nasal and central adipose tissues.

METHODS

Intraconal adipose tissues were obtained during orbital decompression surgery for severe proptosis in nine patients with Graves' orbitopathy (GO). Nasal and central adipose tissues were obtained during upper eyelid blepharoplasty in nine patients with no history of GO. Human OFs were separately cultured from GO intraconal, non-GO nasal, non-GO central orbital adipose deposits. Human dermal fibroblasts were also cultured from redundant resected skin tissue obtained during upper eyelid blepharoplasty in normal controls. Expression of insulin-like growth factor 1 (IGF-1) and thyroid-stimulating hormone (TSH) receptors were investigated using real-time quantitative reverse transcription PCR. Protein levels of interleukin-1β (IL-1β)-induced inflammatory cytokines and generated intracellular reactive oxygen species (ROS) were determined.

RESULTS

IGF-1 and TSH receptor RNA expressions of GO intraconal OFs and non-GO nasal OFs were higher than non-GO central OFs and dermal fibroblasts. The expression of IL-1β induced the IL-6, IL-8, intercellular adhesion molecule-1 and cyclooxygenase-2 of GO intraconal OFs, and non-GO nasal OFs were higher than non-GO central OFs and dermal fibroblasts. Intracellular ROS generation in GO intraconal OFs and non-GO nasal OFs were higher than in non-GO central OFs and dermal fibroblasts, although the differences were not statistically significant.

CONCLUSIONS

Non-GO nasal OFs had similar characteristics to GO intraconal OFs. We recommend the use of nasal adipose tissue in order to culture OFs as a normal control involving in vitro experiments.

Management of graves myopathy: Orbital imaging in thyroid-related orbitopathy

A broad understanding of the different imaging modalities used to assess the physiologic changes seen in Graves' orbitopathy complement clinical examination. Subtle applications of radiographic imaging techniques allow for a better understanding of the overall physiology of the orbit, quantify progression of disease, and differentiate it from orbital diseases with overlapping features. A nuanced approach to interpreting imaging features may allow us to delineate inactive from active thyroid eye disease, and advances within this field may arm clinicians with the ability to better predict and prevent dysthyroid optic neuropathy.

Subconjunctival orbital fat prolapse and thyroid associated orbitopathy: a clinical association

Background

Thyroid associated orbitopathy (TAO) comprises a spectrum of well-recognized clinical signs including exophthalmos, eyelid retraction, soft tissue swelling, ocular misalignment, keratopathy as well as a number of less common manifestations. Subconjunctival fat prolapse is a rare clinical condition occurring typically spontaneously in elderly patients with a mean age of 65–72 years. We describe subconjunctival prolapse of orbital fat as an uncommon clinical association of TAO.

Materials and methods

Observational study of six patients presenting with a subconjunctival protrusion under the lateral canthus in a series of 198 consecutive cases with TAO examined at a tertiary care referral center.

Results

A superotemporally located yellowish, very soft, freely mobile subconjunctival protrusion developed unilaterally in two and bilaterally in four patients with TAO (incidence 3.03%). It was one of the presenting manifestations of TAO in four of ten eyes studied and incited the diagnostic work-up for TAO in two of six patients in this series. Magnetic resonance imaging of the orbit indicated fat density in continuity with intraorbital fat in the area of protrusion. A male to female preponderance of 4:2 and an advanced mean age at onset of TAO is noteworthy for these six patients compared to the pool of 192 patients (64.8 versus 51.8 years, respectively, P=0.003) not bearing this sign.

Conclusion

Subconjunctival orbital fat prolapse, a clinically impressive age-related ocular lesion, may occasionally predominate amid other clinical manifestations of TAO. It is a nonspecific sign developing most commonly among patients with a relatively advanced age at presentation. Awareness of this association may alert to the diagnosis of thyroid orbitopathy and reassure the patient and physician as to the benign character of the lesion.

Radiographic evidence of prominent retro and suborbicularis oculi fat in thyroid-associated orbitopathy

PURPOSE

To compare the radiological differences in retro-orbicularis oculi fat (ROOF) and suborbiculars oculi fat (SOOF) among patients with thyroid-associated orbitopathy (TAO) and normal subjects using computed tomography (CT).

METHODS

A retrospective analysis of orbital CTs was performed in 39 consecutive patients, who were imaged between October 2005 and June 2009. Bilateral orbital CTs of 16 patients with a final report significant for thyroid orbitopathy and 23 normal subjects were evaluated. All of the CTs consisted of 0.75 mm thick axial slices with 1.5 mm coronal reconstructions. Using the axial soft tissue windows, the ROOF and SOOF tissues were identified. The maximum ROOF thickness was measured perpendicular to the frontal bone, immediately superior to the supraorbital rim. Similarly, the maximum SOOF thickness was measured perpendicular to the zygomatic bone, immediately inferolateral to the infraorbital rim. The radiologist was blinded to the CT reports while conducting the measurements. Multivariable analysis of the two groups was then performed for comparison.

RESULTS

Seventy-eight ROOF and SOOF measurements were obtained from 16 TAO patients with and 23 patients without TAO. The female-to-male ratio was 6:1 in the TAO group and only 3:2 among the normal subjects. The mean axial ROOF thicknesses was 3.8 ± 1.9 for TAO patients and 2.8 ± 1.0 mm in patients without TAO, while the SOOF thickness was 4.4 ± 1.0 and 3.4 ± 1.0 mm in the 2 groups, respectively. To account for bilateral measurements, the mixed model analysis was used. After controlling for age, gender, and ethnicity, the mean TAO ROOF and SOOF thicknesses were 1.0 mm (p = 0.04) and 0.9 mm (p < 0.01) greater than the control group, respectively.

CONCLUSION

Retro-orbicularis oculi fat (ROOF) and suborbicularis oculi fat (SOOF) hypertrophy are two additional radiologic CT measurements that may be valuable in establishing the diagnosis of thyroid-associated orbitopathy.

Histopathology of brow fat in thyroid-associated orbitopathy

PURPOSE

We propose that brow enlargement seen in patients with thyroid-associated orbitopathy (TAO) occurs secondary to the autoimmune process in Graves disease and that the changes in brow fat are histologically identical to those seen in orbital fat.

METHODS

With informed consent, brow and orbital fat was obtained from patients with TAO and from patients with no significant past medical history undergoing orbital decompression, blepharoplasty, and/or brow fat removal. Histologic examination was performed on the orbital and brow fat.

RESULTS

Fat histologies obtained from patients with TAO and those without known systemic disease were compared. Specimens from patients with TAO showed an increase of fibrosis and fibrous septae. Furthermore, certain biologic markers, including insulin-like growth factor 1 receptor β (IGF-1Rβ) and thyroid-stimulating hormone receptor (TSHR), were increased in the fat obtained from patients with TAO. This was identical in both the brow and the orbital fat. Fat from patients with no significant past medical history showed normal fat histology, absence of fibrous septae, and decreased marker expression.

CONCLUSION

Graves disease is a systemic autoimmune disease that affects patients in a variety of ways. In addition to the orbital changes seen in these patients, we have observed an increase in the brow fat compartment. We are intrigued to find that the histologic changes are identical in both the orbital and the brow fat of patients with TAO. The increased IGF-1Rβ and TSHR expression in both the brow and the orbital fat further support their role as putative markers in patients with Graves disease.