What is a glaucoma?
Green Star glaucoma by definition describes optic nerve disease with characteristic changes in the optic nerve head (papilla). Falsely, the term „glaucoma“ is commonly equated with „increased eye pressure“, which is scientifically refuted today. A certain pressure value as such is first of all a non-specific indication.
However, if eye pressure exceeds the tolerable level, it can cause lasting damage to the optic nerve through a series of complicated mechanisms. Here, the intraocular pressure is always to see individually to the nature of the optic nerve. So there are patients whose optic nerve can cope with a higher intraocular pressure very well as well as there are patients with apparently good eye pressure, who suffer from a so-called normal pressure glaucoma.
With glaucoma, of whatever kind, more and more optic nerve fibers die irretrievably, so that a hollowing out in the optic nerve head (papilla excavation) arises. For the affected patient, this loss of advanced stage fiber means visual field defects, including total blindness.
The damage to the optic nerve progresses very slowly and creepingly and affects the central vision only in the final stage. Because of this lack of symptoms (no pain, no bad vision), glaucoma is a very treacherous disease, which is usually only noticed during routine checks. But because the damage is irreparable, the earliest possible detection and treatment is particularly important.
What is the purpose of intraocular pressure?
The eye as a structure needed to ensure the best possible optical image of the incident light, a permanently same and spherical shape. This is achieved by a constant intraocular pressure, which is subject to no major fluctuations as far as possible. At the same time, however, the intraocular pressure may not be so high, as this could possibly affect the blood circulation or optic nerve function.
Which eye pressure is normal?
Due to the variety of a glaucomatous disease, one can never speak of a uniform „good or normal intraocular pressure“. Thus, it can not simply be decided on the basis of a numerical value as of when individual glaucoma threatens, is present or can be expected. Particularly difficult is the fact that nowadays almost 75% of all patients with glaucoma have a so-called normal pressure glaucoma, ie glaucoma without increased intraocular pressure.
In these patients, glaucoma could never be diagnosed via eye pressure. In addition, the pathogenesis (development of a disease) of glaucoma is usually associated with other factors, such as oxygen deficiency of the optic nerve or an altered metabolism. Thus, in a suspected diagnosis glaucoma is always an all-encompassing diagnostics inevitable. Only then can the ophthalmologist provide the patient with a sound diagnosis and, if necessary, pronounce a therapy recommendation.
Glaucoma forms and divisions
In addition to the subdivisions of the known forms of glaucoma, which relate primarily to the anatomical reasons, today also takes a further subdivision in terms of eye pressure values to show the patient that the ocular pressure is often not crucial. Thus one divides a high-pressure glaucoma of a normal pressure glaucoma or a low-pressure glaucoma (low-tension glaucoma).
In addition, there are the following medically defined forms of glaucoma:
Primary open-angle glaucoma
The most common type of glaucoma is primary open-angle glaucoma. The word „open angle“ means that the chamber angle is „open“. The eye or the anterior segment of the eye is thus constructed „normally“ and the increased eye pressure is explained by a drainage disturbance in the area of the trabecular meshwork („blocked drainage“). In the course of life, this runoff disturbance is mainly produced by pigment particles that accumulate in the chamber angle and can not be broken down by the body.
In congenital glaucoma, the drainage pathways are blocked by fine tissue, resulting in the late embryonic phase. Due to the strong extensibility of the infantile eye the ball shape desselbigen is changed by the increased intraocular pressure. This anatomical conspicuousness of the very large eye in babies, which is also visible from the outside, is therefore always a possible indication for this form of glaucoma.
Acute angle-closure glaucoma
Acute angle-block glaucoma can occur in eyes that have an anatomically very narrow chamber angle. Under special circumstances, the iris (iris) acutely blocks the entire chamber angle and leads to an immediate increase in pressure, which is very dangerous and painful within a very short time. Violent headaches, dizziness, nausea and even vomiting are the result. Likewise, a pupil rigidity is to be identified. Acute treatment is usually acute, and later with the addition of conservative drugs.
A so-called secondary glaucoma arises as a result of another eye disease such as an iritis or iridocyclitis. In addition, trauma from accidents or injuries can lead to a displacement of the chamber angle, and thus to the emergence of secondary glaucoma.
Pseudoexfoliation glaucoma (PEX glaucoma / syndrome)
Pseudoexfoliation glaucoma (PEX glaucoma), a special form of glaucoma disease, causes obstruction of the trabecular meshwork by self-released microparticles. These are shed off through the thick, endogenous lens and the daily performed narrow and wide position of the pupil and get into the drainage path. A PEX glaucoma should therefore always be treated primarily with the removal of the body’s own lens (cataract surgery) and is secondary if necessary, conservatively further supplied. Because the chamber angle is otherwise normal, one speaks here of a secondary glaucoma.
What are the risks for the development of glaucoma?
Intraocular pressure: A risk factor for the development of glaucoma may be an increased intraocular pressure. The higher the eye pressure, the more likely it is that the optic nerve is damaged. Eye pressure values above 27 mmHg are usually to be regarded as direct indicators of predominant glaucoma.
However, with higher intraocular pressure, there is still the variant of the so-called „ocular hypertension“, that is an eye pressure which, although seemingly high, is accepted by the eye and, as it were, accompanied by glaucoma. This shows that the eye pressure is not decisive.
Familial clustering: In the meantime, individual genes have been identified that are associated with the occurrence of certain forms of glaucoma. If glaucoma is known in the family, the probability of having one’s own disease increases. Thus one quantifies the increased risk meanwhile to approximately 70%. It is also characteristic here that occasionally a generation is skipped and a transfer then occurs only in the next generation.
Anyone who has glaucoma patients in their relatives, has his own cause for particular caution and should tell his ophthalmologist, or have regular checks. A glaucoma patient should educate his close relatives about his illness and advise glaucoma to an early counteract the risk.
Skin Color: Statistically, people with dark skin pigmentation are more prone to glaucoma. This is due to the structure of the pigment and thus to the partial attachment in the drainage channels of the eye (see above).
How is glaucoma diagnosed?
At the beginning, the ophthalmological basic examination including eye pressure measurement should always be available. This glaucoma check-up in Germany is a so-called hedgehog performance, and must therefore be paid yourself, but is a prerequisite to even make any statement about the glaucoma situation.
In addition to the pressure measurement, the ocular fundus, and thus the optic nerve, is examined. The shape of the optic nerve head gives the experienced examiner a first indication of any glaucoma that may be present.
Further diagnostics are only necessary if the optic nerve and / or the intraocular pressure appears conspicuous. In this case the following examinations are necessary:
OCT (Optical Coherence Tomography)
The most important study is an OCT measurement (optical coherence tomography). This measurement, which is the only one that can detect the so-called early defects on the optic nerve, is, similar to an MRI in the hospital, a recording of the optic nerve, which takes place without radiation exposure and takes only a few minutes. Without this early diagnosis by means of OCT, no glaucoma, at any stage, can be clearly diagnosed and, as it were, treated. By means of the detailed evaluation, the patient can also be visually „shown“ a glaucoma here.
Visual field testing
The examination of the visual field (perimetry) provides information on neurological deficits of the optic nerve fibers, which may have already occurred due to glaucoma.
In the visual field examination, the patient looks into a computer-controlled apparatus, which offers points of light in different places on a uniform background in different intensities. The patient gives a signal to the computer at the push of a button when he has perceived the points of light. Finally, the computer calculates the unrecognized point of light, taking into account the respective age.
Daily eye pressure profile
To measure any fluctuations in intraocular pressure over several days, a 3-day eye pressure profile is created. For this, the patient has the daily eye pressure measured several times a day. The result is a profile curve from which the fluctuations are readable. This is important to be able to use a possible later therapy correctly.
Finally, there are a number of other studies that are applied in individual cases for specific issues and then presented to you accordingly. These include, for example, the pachymetry (thickness measurement of the cornea using Pentacam), in order to assess the measured eye pressure in doubt even more accurate and correct.
How often should I investigate?
The control examinations for glaucoma are to be determined individually for each patient. However, regular checks should be carried out at least every 3 months. It should be noted once again that glaucoma is gradual and asymptomatic.
Can the Glaucoma be treated?
Basically, one must know: An already occurred optic nerve damage can usually not be completely reversed! However, the treatment of glaucoma is basically very possible and nowadays mostly successful in that a progression can be slowed down or prevented. Glaucoma therapy is all about avoiding or limiting damage, so early and all-encompassing diagnostics are of fundamental importance.
Which types of treatment are available?
The treatment of glaucoma takes place via medications, micronutrients and surgical (invasive or non-invasive) procedures (laser treatment and / or surgery) or various combinations thereof.
The aim of the treatment is always to prevent the optic nerve damage, or at least not continue to progress. In addition, partially damaged areas can be revived.
In a special way, the therapy by means of selective laser trabeculoplasty (SLT laser) and the intake of micronutrients with the ingredient resveratrol distinguished. In this process, pigment particles are removed from the drainage channels and, as it were, the metabolism of the optic nerve fibers is stimulated. In OCT, the treatment is followed by significant improvements of the fibers over months and years, which also leads to an improvement of the underlying glaucomatous disease.
Your ophthalmologist will determine the right path for you as a patient in consultation with you, taking all aspects and test results into account.
Medicinal glaucoma therapy
The drug treatment, usually as eye drops, is the form of therapy that is mainly used in high-pressure glaucoma. In some cases, oxygen-promoting eye drops can also be administered to enrich the metabolic system of the optic nerve in normal or low-pressure glaucoma.
It should always be noted that any medication can always have a side effect on the whole organism, so that eye drops are possible to use only limited. The side effects are mostly of a local nature (dry, red and watery eyes) or systemic problems such as cardiovascular disease and bronchial asthma. Patients usually describe burning and reddened eyes, but occasionally blurred vision.
Far more gentle and in normal pressure glaucoma, which can not be treated by eye drops, always apply, are the so-called micronutrients with the ingredient resveratrol. This is a natural substance derived from the red grape. This is able to stimulate the cell metabolism, incorporate more mitochondria into the cell and thus permanently the basis of normal pressure glaucoma, a reduced metabolism and the resulting poisoning of the cell to stop and to improve the overall situation again.
Laser treatment for glaucoma (selective laser trabeculoplasty / SLT) takes place on an outpatient basis in practice. It is tissue-friendly and can therefore always be repeated. Above all, it leads to a balanced intraocular pressure level and to improved pulp circulation.
As a hypotensive alternative, there is the YAG iridotomy, which can be used in an acute angle-closure glaucoma and an insufficient drop in pressure by means of drops. In this case, a small hole is created peripherally in the iris, which connects the anterior and posterior chamber of the eye. Since it is a treatment with possible side effects and it causes an artificial change of the eye, this therapy should be used only in case of absolute urgency.
All glaucoma operations have in common that they are performed under sterile conditions and usually in local anesthesia, as needed on an outpatient or inpatient basis. Before deciding to undergo surgery, the risk of surgery should always be weighed against its benefits. In severe cases, however, an operation should always be considered to preserve the optic nerve. Fortunately, these days, fortunately, most of the time it’s only a few minutes of surgery, far less traumatic to the eye than in the past.
Types of operations:
iSTent® / XEN
In modern glaucoma surgery, the implantation of a stent is usually used today. In the eye, this represents an artificially created drainage path, which is supposed to counteract a permanently high intraocular pressure that can not be treated with medication. The surgery takes only a few minutes under general anesthesia.
Follow-up will continue for several weeks, as usual, and will be continued after regular glaucoma examinations. Often, no or only a few eye drops need to be taken after surgery. Since this is a gentle, surgical treatment compared to older methods, this is currently used frequently.
Other well-known surgical procedures include trabeculotomy (called clogging pads), as well as surgical iridectomy.
An undiscovered or incorrectly treated glaucoma continues to be a possible disease of disability and must be communicated and diagnosed accordingly. An early and repetitive check-up should therefore be important to every patient. Although this does not represent a benefit of the statutory health insurance in Germany, the cost-benefit factor is unequal, because the disease and its progression is irreversible.
Fortunately, glaucoma is fortunately easy and universally treatable today. The patient should attach importance to a careful diagnosis and do not shy away from a certain time and possibly also financial expenditure. Your ophthalmologist will be able to prevent the potential for blindness, as well as to provide early-stage glaucoma, so that no visual impairment will ever arise.