Synonym
Endocrine Ophthalmopathy
Introduction
Endocrine orbitopathy is a disease that affects the eyes and their orbits. It belongs to the group of organ-specific autoimmune diseases. This includes all diseases that attack the body and its organs through misdirected processes and functions of the body’s immune system.
This attack can either be on the whole body (this is then called organ-unspecific) or it can be limited to individual organs or organ systems (i.e. organ-specific), as is the case with endocrine orbitopathy. The majority of patients suffering from endocrine orbitopathy develop this symptom as part of a thyroid dysfunction. In general, it can be said that women are affected by thyroid gland disorders much more often than men.
Endocrine orbitopathy is relatively easy and quick to diagnose even for the medical layman: the eyes of the affected patient protrude from their orbit (in technical jargon this is called exophthalmos) and the upper eyelids appear raised (also called lid retraction), making the eyes appear unnaturally large and wide open. However, the size and volume of the eyes themselves do not change in endocrine orbitopathy. The changes described can be attributed to both structural and volumetric changes in the muscle tissue, connective tissue, and fatty tissue located behind the eyes in each of us.
As a result of its growth and swelling, the eyeballs are pushed forward, so to speak, giving the impression of being swollen themselves. Endocrine orbitopathy almost always occurs in combination with other symptoms. Most often these are an enlarged thyroid (a so-called thyroid goiter) and tachycardia.
These three symptoms are also commonly summarized as the so-called “Merseburg Triad” and they occur classically in Graves’ disease. The name of these symptom triad is derived from their first descriptor, the physician Carl Adolph von Basedow from Merseburg, who published them scientifically under this name in 1840. Endocrine orbitopathy usually occurs on both sides, but in principle it can also occur in only one eye.
In most cases, both eyes are not equally affected (however, there is disagreement in the literature about the study situation). The diagnosis of endocrine orbitopathy is primarily made clinically by the examining physician, i.e. the patient’s appearance already indicates the disease so clearly that the laboratory tests basically only serve to confirm it. Exopthalmus (protrusion of the eyeball), typically in combination with palpitations and an enlarged thyroid gland, is typical of Graves’ disease.
Further diagnostic procedures such as blood tests and imaging techniques are used to determine the severity of the disease and to assess its course. Nuclear magnetic resonance spectroscopy (NMR) has proven to be particularly suitable. In any case, it must be ruled out that a tumor located behind the eye is responsible for the exophthalmos.
If no hormonal involvement can be determined in the blood analyses, it is not an endocrine orbitopathy. In order to document the course of endocrine orbitopathy uniformly, it is divided into six different stages:
- Stage 1: the retraction of the upper eyelids
- Stage 2: the eyelids swell and the conjunctiva of the eyes becomes inflamed
- Stage 3: Exophthalmus
- Stage 4: the eye muscles are restricted in their mobility, double images appear
- Stage 5: the cornea shows first signs of damage
- Stage 6: compression of the optic nerves leads to a deterioration of vision, possibly to glaucoma
Unfortunately, it has not yet been possible to develop a causal therapy. However, it is possible to treat the symptoms and thus help the patients.
Cortisone is the first choice for this purpose. If the effect is not yet sufficient, there are other preparations available. In order to maximize the effectiveness of the therapy, it is important that there is interdisciplinary cooperation, especially between the departments of internal medicine, radiotherapy, ophthalmology and specialized surgeons.
In many cases, patients also describe seeing a psychologist as very relieving and relieving.Despite all efforts, unfortunately only about 30 percent of all affected persons can achieve an improvement of their symptoms. In 60 percent the condition remains unchanged and in 10 percent there is even a deterioration. The therapeutic measures are primarily aimed at containing the inflammatory processes in the eye socket and preventing consequential damage to the eyes.
Due to the constant protrusion of the eyes and the sometimes incomplete lid closure, it is necessary to keep the eyes artificially moist to prevent the cornea from drying out and tearing. Special eye drops and eye ointments can remedy this. In addition, thyroid dysfunction (if it exists) must be treated.
However, a high-dose cortisone therapy also involves certain risks and side effects in the long term: weight gain and mood swings may occur or stomach ulcers may form). Recent studies show that regular intake of selenium can slow down the progression of endocrine orbitopathy. However, it is not yet part of the standard therapy in Germany.
The fact that it is still not possible for physicians to treat endocrine orbitopathy causally is due in no small part to the fact that the exact causes of the disease have not yet been fully researched. Most likely, an inherited autoimmune disease causes the body’s own cells of the immune system to produce autoantibodies against the so-called thyrotropin receptors. These receptors are the “docking sites” for the body’s own hormone thyrotropin (TSH for short), which is secreted to stimulate the thyroid gland to grow.
However, these special thyrotropin receptors are not only found in the thyroid gland but also in the tissue of the eye socket, where they can also react to the released hormone with growth. Endocrine orbitopathy can be observed in about ten percent of all people suffering from some form of thyroid disease. In over 90 percent of cases, it occurs as part of Graves’ disease and in about 60 percent in combination with hyperthyroidism.
However, endocrine orbitopathy does not necessarily occur at the same time as thyroid disease. It can occur years later or even much earlier. Therefore, scientists assume that endocrine orbitopathy has its causes outside the thyroid gland and is subject to the same autoimmune processes as Graves’ disease itself.
It is known that both genetic predisposition and environmental influences are relevant to this disease, which can be described as extremely complex. It has been shown that patients undergoing radioiodine therapy can sometimes develop an endocrine orbitopathy, or that an already existing one deteriorates significantly in its course. More rarely, endocrine orbitopathy and Hashimoto’s thyroiditis (also known as Hashimoto’s disease) may occur together or without any thyroid involvement.
Heavy nicotine consumption has a negative effect on both the severity of the disease and its clinical course. The clinical characteristics associated with the disease are dynamic and primarily characterized by increased levels of inflammation and structural changes in the tissue behind the eyes and the eye muscles. In some patients, the eyes protrude so much or the upper eyelids are pulled upwards so much that a complete closure of the eyelids is no longer possible.
In these cases, this is called lagophthalmus. This in turn promotes the development of corneal ulcers. In general, the course of endocrine orbitopathy varies from patient to patient and the disease is not always consistently active.
Apart from the organic and functional problems associated with this disease, the cosmetic aspect should not be neglected. Patients often feel stigmatized and shunned in everyday life, which leads to a very high psychosocial burden for the individual. Over time, science has been able to establish several treatment methods to combat the symptoms and clinical problems of endocrine orbitopathy.
However, it is not yet possible to eliminate the causes of the disease. Therefore, there is currently no causal therapy available. The development of endocrine orbitopathy is the result of extremely complex, pathologically altered immune processes in the body.These are triggered by the so-called B-lymphocytes and autoreactive T-lymphocytes (white blood cells), which ensure an increased production of antibodies.
These autoantibodies are directed against the structures of the thyrotropin receptors. So-called fibroblasts, a special type of cell located in the tissue behind the eyes, react very strongly to inflammatory stimuli. They cause an increased formation of fat cells and an increase in tissue volume.
The same effect can also be caused by excessive nicotine consumption. Due to these inflammatory processes triggered by the body’s own immune system, the entire tissue behind the eyes swells more and more and, since it has nowhere else to go, pushes the eyeball further and further forward. An exophthalmos (protrusion of the eyeball) develops.
Due to the permanent overstretching, the eye muscles also lose strength and stability and the patients suffer from double vision. A further classical symptom is a diffuse growth of fatty tissue in the area of the eyes, also known as lipomatosis.
