In severe TED there are two quite distinct problems. The first is management of the acute or active orbital inflammation (usually in the first 12-18), which is when vision threatening problems may occur. The second is the chronic or inactive orbital fibrosis (usually after 18 months), particularly affecting the external eye muscles. It is important to realise that all treatments may have undesirable side effects.
The following treatments are available:
The most common treatment for severe TED is high dose steroid therapy. The dose regimen varies from centre to centre but steroid treatment is initially given at a high dose and must be gradually reduced (over several weeks) to prevent the disease rebounding (returning). Steroids (oral or intravenous) may be very effective at treating vision threatening optic nerve compression and symptoms due to swelling, but have less effect on proptosis or double vision. However they may be used during the period when surgery is planned for these problems.
Steroids have a wide range of well recognised side effects both in the short and long term. These include: change in facial appearance (Cushingoid facies), weight gain, high blood pressure, increased susceptibility to some infections (for example tuberculosis), cataracts, glaucoma, osteoporosis and mental problems. To allow the dose of steroid to be reduced and limit its complications, other immunosuppressive agents may be used in combination with steroid therapy.
Cyclosporin A and Azathioprine are two such agents that is effective in combination and may also be used alone with moderate TED. Units or hospitals with facilities for plasma exchange (which clean the blood, removing the antibodies which are thought to be causing TED) have reported good results with this technique. However,may rebound or recur unless immunosuppression is commenced or plasmapheresis is repeated (which is time consuming and not without complications). Rituximab is a humanised mouse monoclonal antibody to CD20, it has been shown in a small case controlled study to improve TED.
Radiotherapy although controversial has been used for many years to treat TED and may be combined with steroids (allowing them to be reduced). It reduces the problems of TED very much like steroids and, while the effects take longer to work, it has the advantage that the improvement is more prolonged. Usually the radiotherapy is given over a period of 2 weeks divided into 10 sessions. The true long-term advantages of radiotherapy are somewhat controversial, but it appears to have good effect on swelling and reduces optic neuropathy (compression). Proptosis and squint, however, are not generally improved. Complications of radiotherapy are rare, particularly with low dose modern treatments. Cataracts, dry eyes and retinal problems are unusual (but may be more likely in diabetics), however, it is recommended that radiotherapy treatment is not repeated because of these risks.
In cases with sight threatening compression of the optic nerve, where medical treatment is not effective, then urgent surgery is necessary. This is called orbital decompression. The orbit (the bony socket that contains the eye) can be thought of as a box or room with an opening in the front, with a roof, a floor and two walls at the sides. These bones are thin and partial removal of one or more creates space for the enlarged muscles and fat surrounding the eye. This removes pressure on the optic nerve and may allow the eye to return to its normal position (also helping protect the front surface of the eye).
There are many methods of orbital decompression, the choice of which depends on the extent of the proptosis (eyeball protuberance); the need to achieve a balanced result and individual surgeons preference. Some operations involve an incision on the skin around the eye, others may be made inside the eyelid or it may be possible to operate through the mouth or more commonly via the nose (endoscopic decompression). It may be necessary to combine more than one approach. Surgery is usually performed under general anaesthesia. Complications of surgery include: infection, bleeding, under- or over-correction of proptosis and damage to nerves or eye muscles. Very very rarely the vision may be made worse This surgery is essential when there is significant optic nerve compression with risk of blindness, but it may also be used to treat the cosmetic problem of a prominent eye.
The main problems of inactive TED are double vision (diplopia) , exposure of the surface of the front of the eye and the cosmetic appearance. Until the acute, active situation has settled it is crucial that no surgery is considered (examination stable or unchanged for at least 6 months). The following treatments are available:
Before and after eyelid lowering
Before and after endoscopic orbital decompression
Surgery to the upper and lower eyelids can improve the patient's appearance and is the most common surgery that TED patients undergo. It may improve protection of the front surface of the eye as well as give a better cosmetic appearance. Eyelid surgery should take place after strabismus surgery (which should take place after a decompression if planned). Tarsorrhaphy, partially closing the eyelids, is simple and like most lid operations can be performed under local anaesthetic. Upper lid retraction may be improved by surgery to weaken or lengthen the muscles that lift the lid. This may involve an incision through the back of the lid or through the skin (hidden in the eyelid skin crease). Lengthening the eyelid muscle may require insertion of some extra tissue as a spacer (not visible from the outside). This tissue is usually taken from other sites where there is excess in the body, for example ear cartilage, inner lining of the mouth (hard palate) or nasal septum. Improving the lower lid postion may require similar surgery. Improvement of the lid position can mask small to moderate degrees of proptosis (prominence of the eyes). Cosmetic surgery (blepharoplasty) can also help the appearance of TED sufferers, particularly by removing the bulges of fat in the upper and lower lid. It is important that bleeding is prevented in this surgery since this may in very rare cases cause visual loss.
Double vision may be very disabling and is caused by the external eye muscles becoming fibrosed (scarred). This can be corrected by 'squint-type' surgery (adjusting the eye muscles) and aims to give single vision in a straight-ahead position and in down gaze (for example when reading). It is often not possible to correct diplopia in all positions. In order to balance the eyes it may be necessary to operate on both eyes even if only one eye appears affected. Sometimes sutures are used that are adjustable to help get the best position for the muscles (the sutures are tied a few hours after surgery with the patient awake). In the majority of cases (up to 80%) it is possible to correct diplopia with one operation, however, others may require several operations over a period of years. Complications of surgery are rare, but it may make the position of the lower lid worse in some cases. Squint surgery should be performed after decompression if one is necessary.
Orbital decompression may be used in inactive TED if the eye is very protuberant causing exposure of the eye surface or poor cosmesis (appearance). It can be very successful at repositioning the eyeball back in its socket (the orbit). If an orbital compression is thought necessary, it should be performed before either lid or squint surgery. This surgery is explained along with the treatment of active TED where decompression is used in cases with vision threatening optic nerve compression.
Before and after surgery