Thyroid Eye Disease

Thyroid Eye Disease
The thyroid gland, located in the neck, produces thyroid hormone which helps regulate our metabolism. It may occasionally produce too much thyroid hormone (hyperthyroidism or thyrotoxicosis) or too little (hypothyroidism or myxoedema). Imbalance in either direction can cause eye and vision problems. The precise cause of thyroid eye disease, which may be very variable in its manifestations, remains a mystery.

What are the symptoms of thyroid related eye problems?
A staring appearance and dry eyes are often the first symptoms. Early signs include swelling of the eyelids and tissues around the eye. The eyes can become red and the conjunctiva (the membrane covering the white of the eye) may swell giving a "jelly-like" appearance above the lower eyelids. Swelling of the fatty tissue surrounding the eye and the eye muscles can push the eye forward creating a protrusion of the eye. The degree of protrusion is variable and may involve one or both eyes, adversely affecting the cosmetic appearance and causing irritation, photophobia and watering of the eyes. Swelling of the muscles which move the eyes may produce double vision. In severe cases, the clear covering of the eye (the cornea) may ulcerate, or the optic nerve may be compressed resulting in loss of vision if not treated appropriately.

Can thyroid eye disease occur even if thyroid function tests are normal?
Protrusion and other symptoms and signs of thyroid eye disease may be present even when tests show a normal level of thyroid hormone in the blood. Most patients with eye symptoms, however, have abnormal blood levels of thyroid hormone.

How is thyroid eye disease treated?
Once an overactive thyroid gland is suspected, the thyroid function must be evaluated and appropriately treated by an endocrinologist (a medical doctor or physician who specialises in the treatment of problems with the thyroid gland as well as diabetes and pituitary disorders). The eye disease may continue to progress even after the thyroid function has been corrected. Any eye problems should be followed and, and, if necessary, treated by an ophthalmologist.

Two phases of eye treatment should be considered. The first phase involves treating the active eye disease. The active period, which usually lasts two or more years, requires careful monitoring until stable. The second phase involves correcting unacceptable permanent changes which persist following stabilisation of the active phase.

Treatment during the active phase of the disease focuses on preserving sight, and treating or preventing double vision. Medical treatment, such as artificial tears and ointments, steroids (usually given intravenously on an inpatient basis), orbital surgery, and possible radiation (X-ray treatment) of the orbit, may be required. In the second phase, treatment of permanent changes may require surgical correction of double vision, eye protrusion, eyelid retraction and "eyebags".

With rare exceptions, surgery for thyroid eye disease is performed in the following sequence (although not every stage is required by most patients):

1. Orbital decompression
2. Eye muscle (strabismussurgery
3. Eyelid repositioning surgery
4. Blepharoplasty (cosmetic eyelid surgery)

Orbital decompression
An orbital decompression operation is a surgical procedure undertaken to create more space in the orbit. It is used for patients who have unsightly, uncomfortable protrusive eyes (proptosis). Strabismus surgery

Surgery to deal with double vision is only undertaken when the deviation of the eyes has remained stable for a period of 6 months. Whenever possible, temporary stick on prisms are fitted to glasses to overcome double vision until surgery is deemed appropriate. This surgery is performed by other colleagues who specialize in strabismus (squint) surgery.

What is an orbital decompression operation?
An orbital decompression operation is a surgical procedure undertaken to create more space in the orbit. This is usually performed for the management of a patient with thyroid eye disease.

What are the indications for performing this operation in a patient with thyroid eye disease?
There are a number of indications. These are:

1. Compressive optic neuropathy. This is the main indication for this type of surgery. Compressive optic neuropathy refers to visual loss due to compression of the optic nerve at the back of the orbit. Occasionally it is due to extreme stretching of the optic nerve. The optic nerve is compressed by swollen muscles at the apex of the orbit where there is a confined space. An orbital decompression may be considered as the main management of this problem or it may be used for patients in whom alternative treatments e.g. steroids, radiotherapy have failed or have caused intolerable side effects.
2. Exposure keratopathy. This refers to a situation where the cornea is exposed due to severe proptosis (protrusion of the eye) with poor closure of the eye resulting in drying of the cornea and even ulceration in advanced cases.
3. Chronic pain. Some patients have constant aching orbital pain due to congestion of the orbital tissues which can be relieved by a decompression procedure.
4. Subluxation of the eye. This distressing situation is where the eyes are so protrusive that they may prolapse out of the orbit especially on attempting to look up. The eyelids may close behind the eye.
5. Patients undergoing eye muscle surgery. In some patients whose eyes are quite protrusive, the eyes may become more protrusive following eye muscle surgery to improve double vision. In such patients a decompression operation may be considered desirable prior to such eye muscle surgery.
6. Severe eyelid retraction. In some patients, a satisfactory result cannot be obtained by eyelid lengthening procedures alone as extreme protrusion of the eyes is the main cause of the lid retraction. Such patients require an orbital decompression.
7. Cosmetic deformity. Decompressive surgery is being requested more and more frequently to improve the cosmetic appearance of patients as the surgical results and safety of the surgery have improved considerably over recent years. Most orbital surgeons would regard such surgery as rehabilitative (as opposed to “cosmetic”) with an attempt being made to restore a patient’s appearance to that which existed prior to the onset of this disease process.However, such goals are rarely achieved completely.

At what stage is a decompression performed?
This very much depends on individual circumstances, the stage and activity of the disease. If it is to be performed (only a small proportion of patients with thyroid eye disease undergo such surgery), it is usually performed before any surgery is advised for double vision or for eyelid retraction.

How is a surgical decompression performed?
This depends on a number of factors:

1. The indication(s) for the surgery
2. The relative expertise of the surgeon

Ideally the type of orbital decompression performed should be tailored to the individual requirements of the patient. There are basically 2 types of surgical decompression procedure which can be used separately or in combination:

1. A removal of orbital fat
2. A removal of bone from two or more walls of the orbit

A removal of fat depends on the findings on preoperative scans (a CT scan usually). If a patient has involvement of the fat behind the eye as opposed to enlargement of the eye muscles, the fat itself can be debulked. This can be performed alone or it can be used to gain additional decompressive effect in patients undergoing a bony decompression. The incisions for such surgery are usually made in the conjunctiva (as in squint operations) and/or in the eyelids.

In a bony decompression, the medial (inner) wall is usually removed along with the lateral (outer) wall of the orbit to create a “balanced” decompression. The floor of the orbit is usually left intact unless there is an extreme degree of protrusion of the eye.

The bony walls can be accessed in a variety of ways. Each of these approaches has its advantages and disadvantages.

1. Via a simple incision in the lower eyelids beneath the lashes
2. Via an incision in the conjunctiva on the inside of the eyelid with a small skin incision at the outer aspect of the eyelids (a swinging eyelid flap approach)
3. Via an upper eyelid skin crease incision combined with a transcaruncular conjunctival incision
4. Via a large scalp incision behind the hairline (a bi-coronal flap approach)
5. Via the nose using an endoscope (an endoscopic approach)
6. Via an incision in the mouth above the upper teeth
7. Via an incision on the side of the nose in the inner corner of the eye

The endoscopic approach avoids the need for any skin incisions and is excellent for access to the apex of the orbit in patients who are losing vision due to compression of the optic nerve from enlarged eye muscles. It does not, however, allow the additional safe removal of orbital fat. It does not allow a simultaneous removal of the lateral wall which is commonly advocated to balance the decompression to avoid the chances of postoperative double vision. If the lateral wall is decompressed at the same time a skin incision is required and removes this advantage of the use of an endoscope.

A bicoronal flap is a much more invasive operation which, in an era of small incision surgery, does not have many firm indications. It requires a greater amount of theatre and anaesthetic time (a precious resource in the modern health service). It requires a much longer inpatient stay placing pressure on inpatient beds. It commits the surgeon to performing a bilateral operation which runs a risk, albeit small, of visual loss. The alternative approaches permit one orbit to be decompressed at a time. In addition it runs the risk of creating a permanent palsy of one or both eyebrows. It is commonly associated with a large area of loss of sensation in the forehead and scalp. In male patients, loss of hair leaves a large visible scar.

The incision on the side of the nose is favoured by some surgeons but leaves a very visible scar. The approach via the mouth is favoured by some ENT surgeons but again does not permit the safe removal of orbital fat. It is uncomfortable for the patient.

The swinging eyelid flap approach leaves a cosmetically excellent scar and permits access to the inner and outer walls of the orbit and the floor of the orbit. Another good approach is the combination of an upper lid skin crease incision and a transcaruncular conjunctival incision. Orbital fat can be safely removed via this approach. These approaches rely on good postoperative compliance on the part of the patient who is instructed to massage the eyelids to prevent any contraction of the wound. Patients undergoing such surgery are usually in hospital for only one night.

Who should perform an orbital decompression?
At present a number of different types of surgeon perform orbital decompressions:

1. Orbital surgeons
2. Maxillo-facial surgeons
3. Plastic surgeons
4. ENT surgeons
5. Neurosurgeons

In the past there have been too few orbital surgeons available to undertake many of these operations. This situation has now changed with the appointment around the country of ophthalmic surgeons who have been suitably trained to undertake such orbital surgery. An orbital surgeon has an appreciation of the complexities of thyroid eye disease and is aware of the treatment options and of the goals of decompressive surgery. He/she can also perform orbital fat excision safely and can protect the eye during surgery.

What are the risks associated with orbital decompressive surgery?
Serious complications from decompressive surgery e.g. loss of vision, are extremely rare. The major potential complication which must be considered is postoperative double vision. The incidence of this complication varies considerably from centre to centre. It is much more of a problem in patients who have some double vision prior to surgery with a risk of up to 30% that this may be worse postoperatively. In patients with no pre-existing double vision, the risk is considerably reduced (>5%). It is rare for any patients who suffer this complication to be left with a significant problem following corrective eye muscle surgery. This risk must, however, be considered very carefully in a patient who wishes to improve cosmesis as this has implications for driving. It may be necessary to wait for some months before muscle surgery can be undertaken to improve double vision. In some patients temporary prisms can be fitted to glasses to improve double vision.

Other potential complications which should be considered:

1. Bleeding
2. Infection
3. Loss of sensation in the cheek, side of the nose and front teeth
4. Retraction of the lower and/or upper eyelid

Are the results of surgery predictable?
No. The outcome of surgery is dependent on a number of factors. For this reason it is not always helpful for patients to meet patients who have undergone such surgery as direct comparisons cannot be made and expectations may be raised to a level which cannot be achieved.
The variables include:

1. The stage of the disease. Patients with chronic disease tend to have scarring within the orbital fat which does not prolapse into the spaces created by the surgery. Such fat may also be difficult to remove.
2. The size of the eye muscles. It is difficult to gain good cosmetic results for patients who have massively enlarged eye muscles.
3. The size of the bony orbit. Some patients have shallow orbits which are difficult to enlarge.
4. The size of the eye. Short-sighted (myopic) patients tend to have large eyes compounding the problem of protrusive eyes and create problems in achieving good results from cosmetic decompressive surgery.
5. The size of the sinuses adjacent to the orbit. Some patients have under-developed sinuses which do not permit a great deal of soft tissue prolapse from the orbit.

What happens before surgery?
You will visit the hospital a few weeks before the date of your surgery, to have a preoperative consultation with your surgeon. He will ask you questions about your current and past health, and will need to know about any allergies you may have, medications you are taking (including over the counter products e.g. aspirin, indomethacin or vitamin supplements), previous surgery, and whether you smoke. You may also be required to have a physical examination of your heart and lungs by your GP to make sure it is safe for you to have an anaesthetic. You may need to have some routine laboratory tests, such as urinalysis (tests of your urine), chest x- rays, or complete blood cell counts. These should reveal potential problems that might complicate the surgery if not detected and treated early. It is very important for the anaesthetist to have an up-to-date thyroid function test result.

Please answer all questions completely and honestly as they are asked only for your own wellbeing, so that your surgery can be planned as carefully as possible. If you are unsure of the names of any medications, bring them with you. You will be told whether or not to stop any medications at this preoperative clinic visit. For example, if you are taking aspirin-containing medicines or anticoagulants, they may need to be temporarily withdrawn or reduced in dose for two weeks before the procedure. If you can, try to stop smoking at least six to eight weeks prior to surgery.

More information
It can be extremely difficult to explain the complexities surrounding decompressive surgery to patients in the relatively short time available in consultations. It extremely helpful to contact the Thyroid Eye Disease Society in advance of a consultation (their details and a leaflet can be obtained by contacting your surgeon’s secretary). Patients then arrive in clinic well informed about their disease making a consultation a much more fruitful exercise for the patient as well as the surgeon.

Unless you have been told otherwise please do not use aspirin or any aspirin containing medications, or any anti-inflammatory agents for at least 3 weeks prior to the surgery. This may include a number of arthritis medications. If in doubt please ask.

Please Note:
If you are insured it is important that you clarify in advance with your insurance company the level of reimbursement they will allow for this surgery. Unfortunately, some insurance companies grossly under-estimate the expertise and time required for this type of treatment and leave patients with a shortfall. We will be happy to provide your insurance company with details of your proposed treatment along with a quote of the costs.

Patient with thyroid eye disease with proptosis and eyelid retraction

Same patient 3 months following a right 2 wall orbital decompression with removal of orbital fat and 2 weeks following the same procedure on the left side.

Consultants who undertake this procedure:

Brian Leatherbarrow
Saj Ataullah

Eyelid repositioning surgery
Upper and lower eyelid retraction may be treated by lengthening the tendons of the eyelid retractor muscles. This is often performed via an incision on the side of the eyelids, avoiding an external scar. This is usually performed under “twilight” anaesthesia for the upper eyelids. This allows greater accuracy to be achieved with regard to the final height and contour of the upper eyelids to achieve the best cosmetic result. Nevertheless it may be very difficult to achieve symmetry and to avoid a flaring of the outer aspect of the upper eyelids. Complications of such surgery include an under or overcorrection of the degree of retraction requiring further surgery. Lower eyelid retraction may be treated by means of grafts taken from the hard palate (roof of the mouth) usually under general anaesthesia, or using dermal grafts (taken from the lower outer quadrant of the abdominal wall or buttock area). Often lower eyelid retraction surgery is not required in patients who have undergone an orbital decompression as the lower eyelid retraction often resolves following such surgery. Upper lid retraction responds occasionally but less predictably.

What are the risks of eyelid repositioning surgery?
The risks of eyelid repositioning surgery include infection, bleeding and reduced vision, but these complications occur very infrequently. A temporary inability to fully close the eye after surgery is not uncommon. Lubricant drops and ointments are frequently useful in this situation. It is also important to know that although improvement of the lid height is usually achieved, perfect symmetry in the height and contour of the two eyelids and full eyelid movement is sometimes not achieved. More than one operation is occasionally required.

What happens after eyelid repositioning surgery?
You will be asked to clean the eyelids and repeat the application of antibiotic ointment to the eyelid wound 3 times a day for 2 weeks. The sutures used are usually dissolvable but can be removed after 2 weeks if necessary. Wearing make-up should be avoided for at least 2 weeks. Postoperative bruising usually takes 2-3 weeks to subside. The upper eyelid is often too low initially following surgery, but rises gradually with time. Postoperative swelling may take a few weeks to subside and the final result of surgery is not usually seen for 3-4 months. The upper eyelid scar following a levator recession is hidden within the upper eyelid skin crease. Occasionally the surgery is performed on the inside of the eyelids leaving no visible scars.

Blepharoplasty
Severe eyelid swelling in thyroid eye disease may leave the eyelids with a very "baggy" appearance and with excess skin. Blepharoplasty, a cosmetic eyelid surgery operation, involves the removal of excess skin and fat from the lids. This may improve the appearance of the lids but cannot restore normality.

Unless you have been told otherwise please do not use aspirin or any aspirin containing medications for at least 3 weeks prior to the surgery. This may include a number of arthritis medications. If in doubt please ask.

What happens before and after surgery? – see under blepharoplasty

Consultants who undertake this procedure:

Saj Ataullah
Anne Cook
Brian Leatherbarrow