Exploring Thyroid Disease and the Eye

Thyroid disease is common with more than 12% of the US population developing a thyroid condition during their lifetime.¹ In the UK, about 15% have clinically detectable goitres or thyroid nodules, and the lifetime risk of developing a thyroid nodule is around 5-10%.² Eye problems can be the presenting feature of thyroid disease in 10-20% of patients before their thyroid function becomes abnormal.³ Around 60% of patients then develop eye problems within one year of onset of thyroid disease.⁴

Periocular changes secondary to thyroid disease can vary in character and be asymmetric. Patients may present, with or without a systemic thyroid diagnosis, to aesthetic clinics to look for solutions to the changes in their appearance. In this article we aim to educate aesthetic practitioners as to the nature of thyroid eye disease, the clinical signs they may notice in a patient with thyroid disease, how these patients are treated both with regards to their thyroid disease and as to the cosmetic treatment of the periocular changes.

Understanding thyroid eye disease

Thyroid eye disease (TED) is an autoimmune disorder; whilst the pathogenesis is not completely understood, the presence of shared autoantigens between the thyroid and orbit is thought to explain why the disorder affects both tissues.^3,5 The disease mainly affects women in their third to fifth decade of life.⁵ It is most commonly associated with Graves’ disease, which is an autoimmune disorder resulting in hyperthyroidism.⁶ It can cause distressing symptoms for many, with sight-threatening complications for a few.³

Altered appearance can be very upsetting for patients with TED and studies have shown that this can have a significant impact on their quality of life.^7-9 Extraocular muscles and orbital connective tissue become infiltrated with lymphocytes, causing the activation of cytokine pathways driving an inflammatory pathway, and resulting in swelling and oedema of the orbital tissues.^3,5 The orbital fibroblasts have been shown to become activated and add to the increase in tissue volume by secreting excess glycosaminoglycans³ and differentiating into mature adipocytes, causing further expansion of the orbital adipose tissue.⁵ For the patient, this results in visible changes including swelling and redness of the eyelids and conjunctiva, widening of the palpebral fissure, proptosis of the globes, eyelid retraction and changes in the eyelid contour (e.g. temporal flare).^4,5

Up to 20% of patients develop eye disease before their thyroid function becomes abnormal,³ so patients may present directly to aesthetic practitioners with periocular aesthetic concerns that they perceive as involutional. It is therefore important that aesthetic practitioners are aware of some of the common signs of TED which are not to be overlooked.

Thyroid eye disease classically runs a course as described by Rundle in his eponymous curve (Figure 1).^3,10 Rundle’s curve describes how the disease worsens during the dynamic phase, reaches a point of maximum severity and then gradually improves and reaches a plateau phase.¹¹ This course tends to last 18 months on average before reaching the ‘burnt out’ phase.³ At this point, the disease is inactive but the patient is left with morphological changes to the tissues instigated by the active phase. Smoking is the risk factor most strongly linked to a prolonged disease course and more severe disease.¹² Patients diagnosed with thyroid eye disease should be advised of this and supported in their smoking cessation efforts.

Swelling and redness of the eyelids and conjunctiva

Patients may present complaining of ‘puffy eyes’, seeking cosmetic procedures to help with this. This altered periocular appearance can be an early symptom of TED and may be misdiagnosed as allergic conjunctivitis, which also presents with periorbital swelling and redness of the conjunctiva.³

The presence of eyelid retraction, proptosis and/or restriction of eye movements should alert the clinician to the possibility of thyroid eye disease rather than other causes of periorbital oedema.¹² Patients presenting with possible TED wanting cosmetic restoration of the periorbital swelling should be cautioned against early blepharoplasty or other cosmetic procedures to the periorbital area and investigated accordingly. TED can lead to lagophthalmos (the inability to close the eyelids completely). Any procedure which further reduces the lid tissue and, hence, increases this possibility, could result in severe lagophthalmos, corneal scarring and vision loss.¹³ This is particularly applicable in TED where eyelid retraction and proptosis are also contributing towards the possibility of lagophthalmos.

Proptosis of the globes

Proptosis (or exophthalmos) of the globes is the second most common sign of TED with 60% of TED patients exhibiting this sign.¹⁴ It is an anterior displacement of the globe (eyeball) and is caused by the oedema of the extraocular muscles and connective tissue. Proptosis occurs as the globe is displaced anteriorly by the oedematous extraocular muscles and orbital connective tissue.³

Widening of the palpebral fissure and eyelid retraction

Patients develop a characteristic staring gaze,¹⁵ with upper eyelid retraction being the most common presenting sign of TED.¹⁶ Up to 90% of TED patients exhibit upper eyelid retraction.¹⁶ The cause is thought to be multifactorial, due to a combination of proptosis of the globes, increased sympathetic tone causing Müller’s muscle to elevate the upper lid, contraction of the levator muscle and scarring between the lacrimal gland and the levator muscle.¹⁴

Changes in the eyelid contour

Patients may notice a change in the contour of their retracted upper eyelid. Lateral flare is an appearance that is almost pathognomonic for TED.¹⁷ It is specifically the scarring between the lacrimal gland and the levator muscle which gives rise to the lateral flare.¹⁸

Treatment of the cosmetic changes caused by TED

The underlying thyroid disease should be treated under endocrinology or the patient’s general practitioner in order for them to achieve a euthyroid state.¹⁹ It is important to remember that surgical or non-surgical rehabilitation for patients with thyroid eye disease is generally reserved for inactive disease and is carried out in the sequence of orbital decompression, followed by extraocular muscle surgery with eyelid procedures performed last.¹² This is because each stage may have an impact on the next, and therefore are addressed in turn.¹²

Surgical management

The general principle with regards to surgical management of TED would be to reserve surgical treatment for patients in the burnt-out inactive stage of the disease, with a view to rehabilitate them.¹²

Intervening whilst the patient still has active TED is likely to result in the patient requiring further surgery in the future.¹² The exception to this would include patients with sight-threatening TED requiring orbital decompression in order to avoid vision loss.¹⁹ As mentioned previously, the surgical sequence would generally be orbital decompression first (if required), followed by surgery to the extraocular muscles (if required), and then finishing with eyelid procedures last.¹² This order is so that if changes are induced by a previous step, they can be corrected at the next procedure.¹²

With regards to addressing the cosmetic changes to the periocular area, procedures undertaken are generally performed to address altered eyelid position, and finally to address excess skin and eyelid fat left following the swelling and oedema to the periocular tissues that occurs during the active phase.

The most common indication for lid surgery is upper eyelid retraction.¹⁹ Treatment aims to lower the upper eyelids to their previous position, and address asymmetry. This is achieved by weakening the muscles that lift the eyelid; the levator muscle and/or the Muller’s muscle.¹⁹ A similar procedure can be performed on the lower eyelids in order to reduce the amount of inferior scleral show, which can appear unnatural and give the patient a ‘staring’ gaze. This often involves recession of the lower lid retractors which can raise the lower lids by about 1mm.¹⁹ If further distance is required then a graft or spacer may be used by some surgeons.¹⁹

Addressing the excess skin and fat with a blepharoplasty is generally the final surgical procedure a TED patient will undergo.¹⁹ It is important that this is done with caution so as not to take too much skin that the patient cannot close their eyes fully.¹² Patients with TED are more likely to have a negative vector orbit;²⁰ where the anterior surface of the globe protrudes past the malar eminence. As ‘bulging eyes’ is often considered a poor aesthetic attribute, patients may seek correction of this.²¹ A negative vector is often considered a warning sign when considering a patient for lower lid blepharoplasty as the procedure can result in the globe appearing even more prominent.²²

Non-surgical management

Non-surgical treatments can also play a role in achieving some cosmetic rehabilitation. However, expectations need to managed carefully. It is important that before embarking on any non-surgical treatments, aesthetic practitioners ensure that the patient has reached the burnt-out phase of the disease, and has had any surgical intervention required first by their specialist. Patients can develop deep glabellar furrows secondary to overaction of the accessory muscles for eyelid closure; the glabellar muscles corrugator supercilia and procerus.²³ The resultant frown lines or glabellar furrows can be treated with botulinum toxin.^23,24

Patients may also develop a tear trough deformity due to excess periorbital fat bags and mid-face descent leading to the appearance of periorbital hollows.²¹ This can potentially be ameliorated with a conservative lower lid blepharoplasty or with a hyaluronic acid (HA) filler injection into the tear trough area.²⁴

Conclusion

Thyroid eye disease can result in cosmetic and functional changes affecting the periorbital area that can be distressing to patients and affect their quality of life. The periorbital cosmetic changes may precede a diagnosis of endocrine abnormality, so patients may present via way of cosmetic clinics. It is important that aesthetic practitioners are familiar with the common cosmetic changes that occur with thyroid eye disease and are aware that these patients require referral to an endocrinologist for diagnosis and management of the underlying thyroid condition.

Surgical treatments to achieve cosmetic rehabilitation are generally reserved for patients in the inactive phase of the disease to prevent the need for successive surgeries. Surgical options generally include procedures to address the altered eyelid position, and blepharoplasty to address the excess skin and fat that may be left following the swelling and oedema of the periorbital tissues. It is important to be conservative with surgical blepharoplasty in order to avoid lagophthalmos post-operatively. Non-surgical options such as botulinum toxin to treat the glabellar furrows that result from the recruitment of secondary muscles for eyelid closure can be used, as well as HA filler to the tear trough area.