Orbital Decompression Surgery
Orbital Decompression Surgery
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 although it is sometimes undertaken for other conditions e.g. to improve the appearance of lower lid retraction in patients with large myopic (short-sighted) or otherwise prominent eyes, or following lower lid blepharoplasty surgery in a patient with relatively prominent eyes.
Orbital Decompression Surgery
What are the indications for performing this operation in a patient with thyroid eye disease?
There are a number of indications. These are:
- 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.
- 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.
- Chronic pain. Some patients have constant aching orbital pain due to congestion of the orbital tissues which can be relieved by a decompression procedure.
- 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.
- 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.
- 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.
- Cosmetic deformity. Orbital decompression 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 an orbital 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, including:
- The indication(s) for the surgery
- 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:
- A removal of orbital fat
- 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.
- Via a simple incision in the lower eyelids beneath the lashes
- 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)
- Via an incision in the conjunctiva at the inner aspect of the eye (a transcaruncular approach) combined with a lateral upper eyelid skin crease incision
- Via an incision in the upper eyelid crease
- Via a large scalp incision behind the hairline (a bi-coronal flap approach)
- Via the nose using an endoscope (an endoscopic approach)
- Via an incision in the mouth above the upper teeth
- 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. (If necessary, it can be used in conjunction with an endoscope to gain an excellent view of the apex of the medial wall.) 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. In some patients an incision can be made in the upper eyelid crease avoiding any visible scars.
Another minimally invasive approach which can be used involves a conjunctival incision at the inner aspect of the eye (a transcaruncular approach) combined with an incision in the upper eyelid skin crease which allows access to the lateral orbital wall.
The surgical approach to be used should be tailored to the individual needs of the patient.
Who should perform an orbital decompression?
At present a number of different types of surgeon perform orbital decompressions:
- Orbital surgeons
- Maxillo-facial surgeons
- Plastic surgeons
- ENT surgeons
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 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:
- Loss of sensation in the cheek, side of the nose and front teeth
- 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:
- 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.
- The size of the eye muscles. It is difficult to gain good cosmetic results for patients who have massively enlarged eye muscles.
- The size of the bony orbit. Some patients have shallow orbits which are difficult to enlarge.
- 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.
- 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.
It can be extremely difficult to explain the complexities surrounding decompressive surgery to patients in the relatively short time available in consultations. In my practice I have found it extremely helpful to be able to advise the patient to contact the Thyroid Eye Disease Society, frequently in advance of their consultation (their details and a leaflet can be obtained by contacting my secretary at the address below). Many 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.
Orbital Decompression Surgery
You will visit the clinic to have a preoperative consultation with your surgeon. This usually lasts 30-45 minutes. You will be asked to complete a healthcare questionnaire, providing information about:
- Your specific aims
- Your current and past general health
- Any previous eye, eyelid or facial surgery or treatments including refractive surgery or laser eye surgery
- Any past dermatology history e.g. cold sores, eczema, rosacea, skin cancer
- Any history of a dry eye problem
- Any contact lens wear
- Any previous non-surgical aesthetic treatments e.g. Botox injections.
- Any allergies
- Any medications you take (including over the counter products e.g. Aspirin, Indomethacin, Nurofen, Diclofenac or vitamin supplements)
- Any history of smoking
It is very helpful if you have old photographs which you can bring along to the consultation. If you are happy to email us digital photographs of your current appearance in advance of the consultation with details of your concerns, this is also enormously helpful and saves time. Your photographs will be kept confidential and will form part of your clinical record.
- You will have your blood pressure checked by the nurses. You may also be required to have a physical examination of your heart and lungs by the anaesthetist to make sure it is safe for you to have a general anaesthetic if this is required in your case. You may need to have some routine laboratory tests, such as urinalysis (tests of your urine), a chest x-ray, or a blood cell count. These should reveal potential problems that might complicate the surgery if not detected and treated early. No testing is usually necessary, however, if you are in good health and younger than age 55.
- The nurses are also happy to answer any further questions and to show you the facilities at Face & Eye, including the operating theatre if it is not in use.
- Please answer all questions completely and honestly as they are asked only for your own wellbeing, so that your cosmetic surgery can be planned as carefully as possible. The information is treated confidentially. 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 as long as these are not medically essential. You might need to check this with your GP. Any anti-inflammatory medicines e.g. Ibuprofen, Nurofen must be discontinued at least 2 weeks before surgery. These medicines predispose you to excessive bleeding. You will be given a leaflet advising you on what medications, foods, and vitamin supplements to avoid prior to surgery. Your blood pressure should also be under good control if you take medications for hypertension. This is very important.
- If you can, try to stop smoking at least six to eight weeks prior to surgery. Smoking has an adverse effect on healing and damages your eyelid skin and supporting tissues and your eyes (it can result in premature cataract formation and age related macular degeneration with a loss of central vision). Smoking also makes thyroid eye disease considerably worse.
- Your vision in each eye is measured. Your eyes are examined carefully using a slit lamp (a special ophthalmic microscope). Your tear film status is determined and the back of the eyes (called the retina) are examined as well as the eyelids themselves.
What happens after thyroid eye disease surgery?
After thyroid eye disease surgery, the eyes are initially covered with pressure dressings for approximately half an hour to reduce postoperative swelling and the wounds are treated with antibiotic ointment. The dressings are then removed and replaced with cool packs. Activity is restricted for 2 weeks to prevent bleeding.
You will be asked to clean the eyelids very gently using clean cotton wool and Normasol (sterile saline) or cooled boiled water and repeat the application of antibiotic ointment (usually Chloramphenicol or Soframycin) to the wounds 3 times a day for 2 weeks. The sutures used for a levator aponeurosis advancement are dissolvable but are usually removed in clinic after 2 weeks. The sutures used for a Muller’s muscle resection are removed in clinic after 5-7 days.
The skin around the eyes should be protected from direct sunlight, by avoidance if possible or by using protective sunglasses. Wearing make-up should be avoided for at least 2 weeks. After 2 weeks the use of mineral make-up is recommended. (The aesthetics nurses at the clinic Face & Eye can demonstrate this to you). It is important to devote a lot of time to your aftercare for the first 2 weeks and some patients find this somewhat labour intensive.
A realistic period of recovery must be expected. Postoperative bruising usually takes at least 2-3 weeks to subside completely. Swelling takes much longer. Most of the swelling disappears after 3-4 weeks but this can vary considerably from patient to patient as does the extent of the swelling. The final result is not seen for at least 3-4 months. This should be taken into consideration when scheduling the operation. You should arrange this surgery after holiday periods or important professional or social events and not before so that you are available for postoperative review and just in case any surgical adjustments are required.
The scars gradually fade to fine white marks within a few months. Those in the upper eyelid are hidden within the skin crease unless an additional skin incision is required to remove a “dog-ear” of excess skin just below the tail of the eyebrow.
You will need to use frequent artificial tears for the first 2-3 weeks following surgery. It is preferable to use preservative free drops. These will be prescribed for you e.g. Xailin gel (or Theoloz Duo drops, Hyabak drops or Hylotears), and Xailin Night ointment (or Lacrilube or Vitapos ointment at bedtime).
Contact lenses should not be worn for a few weeks following this type of surgery.