The term thyroid ophthalmopathy or thyroid orbitopathy refers to the eye and periocular changes associated with thyroid diseases. Although thyroid ophthalmopathy (OT) can be seen in any type of thyroid disease, the vast majority of cases occur in patients with Graves’ disease (hyperthyroidism). OT rarely occurs in patients who are primarily hypothyroid or even in patients with no evidence of thyroid disease. In the latter case, hyperthyroidism often appears months or years after the diagnosis of the OT.
Palpebral retraction and exophthalmos in patient with thyroid orbitopathy
Hyperthyroidism can lead to a variety of eye problems, including red eyes, irritation, photophobia, periocular edema, double vision, loss of vision, palpebral retraction and protrusion of the eyes. It is important to know that there are different degrees of OT, and having one of these symptoms does not mean that the rest will appear.
In Barcelona we have a unique service for these patients. Since in the same space we can offer you a multidisciplinary service formed by anendocrinologist specialized in thyroid, a thyroid surgeon and an oculoplastic surgeon. This integration of subspecialties is unique in Spain and is designed to offer the best care for patients with thyroid ophthalmopathy, without having to visit specialists in different centers and with full communication between them.
Once the eye disease appears, it usually remains active for a period that can range from 6 months to 2 years. During this time there is an active inflammatory process, so the appearance of the eyes and the severity of the disease may vary. During this period of inflammatory activity it is advisable not to intervene surgically except if there is a risk to vision, but there are many other measures that can help improve the patient’s symptoms. Once the eye disease is stabilized, it is very rare for the process to be reactivated. In some patients, the eyes will return to normal, while in others the changes will be permanent. At this time, some patients will be candidates for surgery to improve eye protrusion, double vision or palpebral retraction.
Several theories have tried to explain why Thyroid Orbitopathy occurs. The most accepted theory suggests that there are certain molecules that are present both in the thyroid gland and in the orbit, so the antibodies produced by the autoimmune process would react against the gland and against the orbital tissues. At the orbital level, the antibodies react selectively against the orbital fat tissue and the extraocular muscles, which are responsible for eye movement.
It is well known that thyroid disease and eye disease can follow different courses. That is, the eye disease may appear before the thyroid disease, after it, or progress significantly even when thyroid function has stabilized. However, there is evidence that controlling thyroid function influences eye disease. For example, we know that in the process of treating hyperthyroidism, phases of hypothyroidism should be avoided, or that treatment with radioactive iodine may temporarily worsen the eye disease. Communication between your endocrinologist and your orbital specialist is essential for optimal control of your orbitopathy.
The orbit and eyelid specialist is an ophthalmologist who has specialized in diseases affecting the ocular appendages. As an ophthalmologist, he knows better than anyone else the periocular structures and their involvement in this disease.
Often the OT patient, frustrated by his unfortunate illness, consults several specialists in search of immediate solutions. This is an illness that can have a long course and requires patience. It is highly advisable to put yourself in the hands of an orbital specialist who will guide you through the entire OT process. It will help you understand your illness and treat the disease at each stage. In addition, you will always be in touch with your endocrinologist to find out the status of your thyroid function and make decisions together. While the disease is active, simple measures such as eye lubrication or sleeping with the head slightly elevated to decrease palpebral edema can be very helpful. The specialist will also determine when your condition has stabilized and if you are a candidate for surgery. A third very important role of the orbitologist will be to detect the possible appearance of more serious complications such as loss of vision or corneal involvement, which may require urgent treatment.
Dryness, irritation and photophobia are by far the most common symptoms of the disease. Ocular protrusion, together with palpebral retaction (eyes too open) cause the eye surface to be much more exposed to the environment. Because of this, the tears evaporate much faster and do not manage to protect the eye surface. Frequent use of preservative-free artificial tears can greatly alleviate these symptoms. These eye drops do not have any harmful effect, even if used every 30 minutes, as they do not contain any medication, only lubricating agents. Sometimes it is also advisable to use lubricating gels at night, especially if the patient has incomplete eyelid closure.
Thyroid orbitopathy causes inflammation and scarring in the muscles that move the eyes, affecting their function. When both eyes do not move exactly the same, double vision or diplopia occurs. One eye is seeing an image while the other eye is seeing the same image slightly offset. In some patients this phenomenon is only present in certain eye positions, while in others it is constantly present, which is very disabling. Diplopia can fluctuate throughout the course of the disease, and in some patients it may even disappear once the disease is stabilized. When the disease is stable and double vision persists, surgery may be considered.
It is largely responsible for the startled or frightened look that OT patients have. This is because the inflammatory and scarring changes also affect the muscles responsible for opening the eyelids. This is a very common phenomenon in this disease. Whenever possible, surgery should await stabilization of the disease. It is very helpful for you to provide photographs from previous years so that the specialist can get an idea of when the changes began and what your eyelids looked like before the disease. The purpose of the surgery is to return the eyelids to a normal position, which will radically improve the patient’s appearance and the eye surface will be more protected.
The orbit is the bony cavity in which the eye and its attached structures are housed. Inflammation of the orbital tissues causes an increase in their volume. Since the orbit is a bony cavity and therefore not extensible, the increased volume of its contents results in a protrusion of the eye forward. In some patients the orbital tissues are more rigid and do not allow the eyeball to move forward, so the increased orbital volume results in orbital congestion.
Ocular protrusion or exophthalmos can be treated surgically once the disease has stabilized. This treatment is called orbital decompression and consists of increasing the volume of the orbital cavity to better accommodate the orbital tissues enlarged by the inflammation, thus getting the eyes to return to a more normal position.
It can happen for different reasons. The first of these is corneal involvement, which is caused by exposure of the eye surface by ocular protrusion and palpebral retraction. In many cases it can be treated simply by an intense pause in eye lubrication. In more severe cases, surgical measures will be necessary to ensure corneal protection. The other cause of visual loss is compression of the optic nerve. The optic nerve is responsible for carrying visual information from the eye to the cerebral cortex. When orbital congestion compresses the optic nerve, there is a loss of vision that can be either very marked or slow and subtle and difficult for the patient to detect. Fortunately, this occurs in less than 5% of OT patients. Treatment varies on a case-by-case basis but may include intravenous steroid guidelines, radiation therapy, or surgery.
There is currently no evidence that smoking induces ophthalmopathy. However, it is well known that tobacco increases your chances of getting more severe forms of the disease. Tobacco increases your risk of vision loss in this disease. Also, if you are a smoker, you have more numbers of disease recurrences, and your surgery may have a lower success rate. On many occasions we find patients who notice a very significant improvement in their ocular symptomatology within a week of quitting smoking.
A patient with thyroid ophthalmopathy in the inflammatory phase. The great improvement in his appearance was noted a month after quitting
Proper control of hyperthyroidism is essential to increase your chances of better control and less severity of your ophthalmopathy. This may include the use of oral medication, radioiodine and in borderline cases thyroidectomy. A close relationship between your endocrinologist and your oculoplastic surgery specialist is essential.
Exophthalmos and palpebral retraction contribute to further drying of the eye surface, so we always recommend the use of artificial tears and lubricating gels.
Different brands of lubricating eye drops
These are high-dose intravenous steroids. Weekly treatments are carried out for 6 weeks, in descending doses. They are mainly used when there is optic neuropathy by compression or in cases of severe inflammation even if there is no neuropathy.
The use of new therapies is gaining acceptance in the treatment of thyroid ophthalmopathy. In cases of severe inflammation with little response to steroids or when steroids are not indicated, Tocilizumab has proven effective. It is a humanized monoclonal antibody that binds to the interleukin-6 cell receptor. This interleukin plays an important role in the immune response and is involved in the pathophysiology of several diseases. It is administered intravenously in several sessions.
There are different procedures that can help us return the patient’s gaze.
When the exophthalmos is significant, orbital decompression surgery is essential. This surgery basically consists of improving the “fit” of the eye and its tissues within the orbital cavity. This can be achieved in two ways: by enlarging the space of the orbital cavity (bone decompression) and by reducing its fat content (fat decompression). Usually a combination of both procedures is performed.
Bone decompression consists of gaining space in the orbit at the expense of the ethmoid and maxillary sinuses (medial and inferior decompression), or reducing the volume of the lateral bone wall (lateral decompression). Medial and inferior decompression can be performed through a transconjunctival approach without a scar, while lateral decompression can be performed through a small incision hidden in the upper eyelid crease.
This surgery is performed under general anesthesia but does not require admission. Its complications are rare when properly performed. These include, for example, the occurrence of diplopia (double vision) which may require further correction by strabismus surgery.
The retraction of the upper eyelid is done by weakening the muscles in charge of lifting the eyelid (Muller’s muscle and eyelid lift muscle). This is done through the conjunctival route, with local anesthesia and without a scar. For slight retractions only the Muller muscle is usually worked on (mullerectomy), while for larger retractions the weakening of the eyelid lift muscle is added.
Patients with ophthalmopathy who have strabismus require surgery to correct their double vision. Strabismus in this disease is of a restrictive type, due to rigidity of the ocular musculature. Most often, an eye deviation towards the nose (endotropy) or downwards (hypotropy), or both, will occur. This can be corrected or improved by so-called “recession” of the affected muscles. It is performed under local anesthesia without admission. In complex cases more than one intervention may be necessary.
Strabismus surgery schematically
Many patients with thyroid ophthalmopathy have an appearance of premature aging of the eyelids. This is mainly due to the increase in volume of the orbital and periorbital fat tissue, which leads to the appearance of ‘bags’. Once the exophthalmos, double vision and palpebral retraction (if any) have been treated, a blepharoplasty may be considered.