Thyroid
The thyroid gland located in the neck, produces thyroid hormone that helps regulate our metabolism. It may occasionally produce too much (hyperthyroidism) or too little (hypothyroidism). An imbalance in either direction can cause an inflammatory reaction in the orbit (eye socket) that may result in eye and vision problems.
The inflammation varies from very mild to severe and is potentially blinding. The disease undergoes an active phase where there is active inflammation and scar tissue being produced in the orbit. This process can persist for 6 months up to 3 years. Once the active phase has “burnt out” the situation for the patient may return to normal or some patients are left with scar tissue that is not going to resolve. These patients may then elect to have surgery to improve their appearance and lessen the symptoms they are experiencing.
We know that there is an association between the thyroid and the inflammatory response that occurs in the orbit (eye socket), however the exact link is not known and therefore we have no exact test to determine the time course of this active phase. This is a clinical diagnosis and may require multiple consultations with A/Prof Wilcsek over time to assess when your disease process has reached the inactive or burnt-out phase.
What are the symptoms?
A staring appearance and dry eyes are often the first symptoms. Early signs also include swelling of the eyelids and tissues around the eye. Swelling of the normal fatty tissue surrounding the eye and eye muscles can push the eye forward and the appearance of a prominent eye can further be exacerbated if the eyelids are retracted (pulled back) by the scarring process of the disease. The degree of this protrusion may vary and may involve one or both eyes.
Swelling of the muscles that move the eye 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. Your doctor can almost always avoid permanent loss of vision with treatment.
What does the treatment involve?
Firstly, the thyroid function must be evaluated and appropriately treated by an Endocrinologist. The eye disease, however, may continue to progress after an Endocrinologist has treated the thyroid abnormality. The disease and therefore the treatment are divided into two periods.
Active Phase - This phase usually lasts between 6 months to 3 years and requires careful monitoring until the problem has stabilized. This involves medical treatment such as, artificial tears (drops) and ointments, and occasionally steroids and radiation treatment. Uncommonly orbital surgery is required. Smokers have a longer and more severe active phase.
Stabilised Phase - This phase involves correcting permanent problems that remain once the active phase has “burnt out”. This is defined as there being no changes in the symptoms/signs of the disease for at least 6 months. These problems include double vision, eye protrusion or eyelid retraction and are generally repaired surgically.
Who is suitable for Thyroid surgery?
An important decision is the timing of surgery. We only operate in the active phase of the disease if there is ongoing visual loss despite maximal medical treatment. The reason it is best to avoid surgery during the active stage is that orbit surgery has the potential to increase existing inflammation and also given that the process is still ongoing things can still change after the surgery and thus further surgery may then again be required.
Surgery is best performed in the inactive phase. A/Prof Wilcsek will discuss with you what is possible in terms of surgical outcome in order to plan the sequence of surgeries that are most likely to give you the best possible result.
Surgery
Generally, surgery for thyroid eye disease is performed in the following sequence (although not every stage is required for every patient): A/Prof Wilcsek will go through each of these with you and determine the best course of action for your specific condition;
Orbital Decompression
Orbital Decompression
This surgery is required by only a small percentage of patients with Thyroid Eye Disease and is not undertaken without due consideration of alternative options. The surgery is effective but as with all surgery there are risks involved although serious complications are rare.
The indications for this surgery are as follows:
- Compression of the optic nerves by enlarged eye muscles causing loss of eyesight.
- Severe protrusion of the eye preventing the closure of the eyelids with exposure of the cornea.
- Severe protrusion of the eyes causing significant cosmetic deformity.
This involves the removal of part of the walls of the orbit (eye socket) separating the orbit from the neighbouring air filled sinuses. This will enlarge the orbits and allow the orbital contents to settle back and thus reduce the degree of protrusion of the eyes. Most patients require removal of two walls of the socket, the outer wall (on the ear side of the orbit) accessed through small cosmetic incision through the laugh lines and the inner wall accessed through the nose with no skin incision at all. At the time of surgery some fat from the orbit behind the eyeball is also removed again allowing the eye to settle back to a more natural position.
Common post-operative problems include double vision and loss of sensation affecting the cheeks, the side of the nose, and the upper teeth. If affected by loss of sensation it can last for months and at times may be permanent. If double vision is not present prior to surgery there is a 30% risk of it occurring post operatively. If double vision is present prior to surgery it may become worse post operatively. Blindness is a rare complication but must be considered prior to surgery. Sometimes radiotherapy and/or steroids may also be required.
Eye muscle surgey
Eye muscle surgey
This surgery attempts to eliminate double vision. It is only undertaken when the deviation of the eyes has been stable for a period of at least six months. Stick on prisms to help reduce the double vision, are fitted to glasses, whenever possible, until surgery is appropriate. This surgery is performed by a small group of ophthalmic sub-specialists and should you require this form of surgery A/Prof Wilcsek will liaise and refer you to the appropriate "squint surgeon" for this part of the surgical pathway.
Eyelid repositioning surgery
Eyelid repositioning surgery
Upper and lower eyelid retraction may be treated by lengthening the tendons of the muscles that open the eyelids. This is usually performed under local anaesthesia, allowing greater accuracy to be achieved with regard to the final height and contour of the upper eyelids.
Complications of such surgery include an under or overcorrection of the retraction requiring further surgery. The aim is for improvement and attaining a completely normal contour is sometimes not possible. Lower eyelid retraction may be treated by means of grafts taken from the hard palate (roof of the mouth) or ear cartilage.