Glaucoma is a disease of the eye, also known colloquially as “green star”. Most diagnosed cases are so-called high-pressure glaucoma, which is associated with increased intraocular pressure. However, there can also be normal -pressure glaucoma (also called low -pressure glaucoma), in which the pressure in the eye is not increased. Normal-tension glaucoma differs significantly from the more frequently observed high-pressure glaucoma in some respects, which is why it requires special attention.
What is normal tension glaucoma?
Normal – tension glaucoma or low -tension glaucoma is a chronic eye disease. If undetected, it can lead to severe, irreversible damage to the eye with permanent consequences such as damage to the optic nerve, restricted field of vision and blindness. The disease can occur at any age. See aviationopedia for Heatstroke Explanations.
In some cases glaucoma is also congenital, for example a maldeveloped chamber angle. Even if high pressure glaucoma is diagnosed much more frequently, namely in 70 to 90 percent of cases, experts now assume that almost every second glaucoma in Europe is normal pressure glaucoma.
Therefore, many patients do not know that they suffer from this disease. For this reason, it is often only recognized when serious consequences have already occurred.
In contrast to the much more frequently diagnosed high pressure glaucoma, which is characterized by increased intraocular pressure and can damage the optic nerve in this way, normal pressure glaucoma has other, less obvious causes. These are mostly of a vascular (vessel-related) nature. Various forms of fluctuating blood pressure that tends to be low (hypotension) can trigger normal pressure glaucoma.
Flammer syndrome can also be a cause, a dysregulation of the blood supply. In addition to many other organs, the sensitive small vessels of the eye in particular can be affected. Fluctuations in blood pressure lead to a lack of nutrients in the eye. Sleep apnea patients in particular, who suffer from constant breathing pauses at night, are at risk of developing normal pressure glaucoma.
Symptoms, Ailments & Signs
Normal-tension glaucoma does not cause any symptoms at first, since both forms of glaucoma do not cause pain. They are also initially not detected in preventive examinations that consist of measuring the eye pressure, which are often carried out with a so-called tonometer.
All forms of glaucoma can damage the optic nerve and gradually lead to a reduction in the field of vision or even complete loss of vision. One symptom is therefore the deterioration of vision, which, due to its slowly progressing course, is usually not recognized by the patient himself or only very late.
Diagnosis & course of disease
Tonometry, in which the patient’s intraocular pressure is measured using a small puff of air delivered into the eye, is only suitable for detecting hypertension glaucoma and is therefore not indicated for diagnosing normal tension glaucoma. The ophthalmologist also has the option of examining the fundus of the eye with the help of ophthalmoscopy.
Here he can recognize typical glaucoma damage, even if the intraocular pressure in the tonometry was normal. Typical damage is, for example, indentations and hemorrhages at the edge of the papilla. Furthermore, perimetry, the so-called visual field examination, can provide important information for the diagnosis. Here it can be recognized whether there are typical defects in the edge area of the visual field.
The measurement of the optic nerve by the so-called Heidelberg tomograph (scanning laser tomography) is also possible. In the case of late-detected glaucoma, this can prove to be useful. Other diagnostic methods are OCT (optical coherence tomography), GDx (scanning laser polarimetry) and RTA (retinal thickness measurement).
All of these imaging procedures are in the area of individual health services (IGeL) and, with a few exceptions, have to be paid for by the statutory insured patient himself. Because low-tension glaucoma can be triggered by fluctuating blood pressure, doctors often order a 24-hour blood pressure test. For this purpose, the attending ophthalmologist and the patient’s family doctor exchange information by means of a referral.
Although a sufferer does not feel ill, regular use of the drops prescribed by the doctor is important to stabilize the intraocular pressure. If side effects occur, the Deutsches Ärzteblatt mainly lists changes in taste, lowering blood pressure and drowsiness, the patient should not simply stop taking the medication, but should always consult their doctor first.
There are many different medications that can lower intraocular pressure, so switching medications can often help. A kind of “natural therapy” against normal pressure glaucoma are the so-called “radical scavengers”, which are contained in many types of vegetables. Their proportion in green tea, dark chocolate and red wine is particularly high.
Dietary supplements that are often prescribed when glaucoma occurs include calcium channel blockers and magnesium granules. A diet-conscious patient can avoid this by avoiding salty foods and foods high in animal protein and phosphate. Sunflower seeds, almonds and walnuts have a high magnesium content.
Scientists go so far as to use the statement “sick eye in a sick body” for normal pressure glaucoma. However, this also means that the person affected can do a lot to stabilize their intraocular pressure and the adjacent vessels.
When should you go to the doctor?
If there is a gradual change in vision, a doctor’s visit is recommended. In principle, the eyesight should be measured at regular intervals. In this way, abnormalities can be noticed as quickly as possible. Since normal pressure glaucoma is only rarely noticed in the early stages, it is advisable to take part in the check-ups that are offered.
If there are complaints and irregularities in vision in everyday life, these should be examined. Short-sightedness, pain in the eye or a feeling of pressure inside the head are signs of an existing disease and must be clarified by a doctor. If people or objects are not seen clearly or outlines can no longer be seen in the usual quality, a doctor’s visit is necessary.
If the person affected finds that their vision is reduced in direct comparison to the vision of those around them, they should consult a doctor. If minor accidents occur in everyday life, this can be related to reduced vision. There is cause for concern as the symptoms usually increase as the disease progresses. Headaches, sleep disorders, inner restlessness or behavioral problems indicate discrepancies in the organism. The symptoms should be discussed with a doctor so that the cause can be investigated.
Treatment & Therapy
The treatment of normal-tension glaucoma consists primarily of finding the actual cause and treating it. This requires close cooperation between the ophthalmologist and the attending general practitioner or internist. A high-salt diet can lead to an increase in blood pressure levels, which is currently a common treatment approach, depending on the underlying disease.
However, this is not suitable for all patients, especially if there are other underlying diseases. While the treatment of high-pressure glaucoma generally consists of lowering the intraocular pressure using eye drops, this method is sometimes also used for normal-pressure glaucoma, even if the intraocular pressure is not generally increased here.
This is because lower eye pressure leads to a better supply of nutrients to the eye. Frequently prescribed medications are miotics, which narrow the pupil and thus widen the vessels so that the aqueous humor that creates pressure can drain off. Prostaglandin derivatives, also known under the trade name Latanoprost (R), also improve the fluidity of the aqueous humor.
Outlook & Forecast
Excessive internal pressure in the eye can have various causes. These are crucial for the further course of the disease and the prognosis. Healings as well as chronic developments are conceivable. Comprehensive medical care should be sought under all circumstances, otherwise the eyesight will deteriorate further and the general risk of accidents will increase significantly. In addition, the causative disorder must be treated, since life-threatening changes can occur here.
Drug therapy normalizes the internal pressure in most patients. Lifelong treatment is often necessary because normal-tension glaucoma has developed into a chronic condition. Discontinuation of the drugs consequently leads to a relapse. If the symptoms occur due to sleep apnea, it must be clarified whether it can be completely cured. With the alleviation of the symptoms of the underlying disease, a reduction in the health complaints for the impaired vision is also possible.
A complete freedom from symptoms can therefore be achieved depending on the underlying disease. In the case of diseases of the circulatory system and thus irregularities in blood pressure, this must be treated medically. As soon as the values are in the normal range, the internal pressure of the eye returns to a normal level. However, the symptoms can be expected to return as soon as a blood pressure problem occurs again.
Normal tension glaucoma is very difficult to prevent. Targeted prophylaxis can hardly be carried out here. Prevention therefore lies in observing the causes that may be present as the underlying disease. Sleep apnea patients, patients with blood pressure fluctuations and those with Flammer syndrome are considered to be particularly at risk and should be monitored regularly by an ophthalmologist.
Regular glaucoma screening at the ophthalmologist is also an option, but this is not covered by statutory health insurance, the costs are borne by the patient. An accumulation of glaucoma within the family is another risk factor for developing glaucoma yourself, which is why intensive preventive care is advisable here as well. The better the patient is informed about his underlying disease, the sooner normal pressure glaucoma can be recognized.
If normal-tension glaucoma is treated surgically, conscientious follow-up care is required. The intensive follow-up treatment usually takes about two weeks. Usually eye drops are administered. Sometimes the patient also receives eye injections near the eyeball or eyeball massages.
Even after outpatient glaucoma surgery, the patient is observed until they are able to go home. However, he is not allowed to drive a car himself. If he uses public transport, it is recommended that another person accompany him. Alternatively, you can also take a taxi.
The ophthalmologist prescribes an eye ointment or eye drops for the patient as follow-up treatment. It is important to use these consistently and regularly. In some cases, a painkiller is also taken for the first few days after the procedure.
The subsequent check-ups also play an important role in aftercare. The patient is given an appointment for the next examination on the day of the operation. This appointment must be strictly adhered to. The eye bandage is usually removed.
During the follow-up examinations, the ophthalmologist checks the healing process. Among other things, the postoperative findings and visual acuity are checked. As a result of the operation, the eye initially reacts particularly sensitively to mechanical damage. Therefore, the patient should temporarily refrain from using shampoos, soap or skin creams.
You can do that yourself
Anyone who has been diagnosed with normal tension glaucoma should first make lifestyle changes. In addition to regular exercise, which regulates the intraocular pressure, a diet rich in vitamins is recommended. Fruit, vegetables and the like promote blood circulation in the eyes, which can improve vision again. Smokers should stop smoking and, if possible, avoid nicotine altogether to avoid further eye strain.
If, despite all measures, the symptoms increase, medical advice is always required. The doctor may be able to give further tips or prescribe a suitable preparation to alleviate the visual problems and improve the well-being of the person concerned in the long term. Finally, possible triggers for the development of normal pressure glaucoma must be found. The eye condition can result from eye strain, such as affects office workers and people with excessive exposure to pollutants. Too much sun exposure and dehydration are also possible causes that need to be identified and addressed.
Normal tension glaucoma itself cannot be cured in this way, but the risk of going blind from the disease can be greatly reduced. If you wear a suitable visual aid in addition to the measures mentioned, you optimally support the drug therapy.