Glaucoma

The visual field defects themselves are usually only noticed when the disease is very advanced. If left untreated or inadequately treated, glaucoma can lead to blindness. But it doesn’t have to come to that. Depending on the form, glaucoma can be treated with medication, laser treatment or surgery. Careful early detection is also important.

Founder’s cataract is not a single disease. Rather, glaucoma is a collective term for various eye diseases in which the optic nerve is damaged. This causes visual disturbances and visual field damage. This is also known as visual field loss. If glaucoma progresses untreated, there is a risk of blindness in the worst case.

There are two main forms:

Primary glaucoma

Primary glaucoma is an eye disease in its own right. The subtypes of primary glaucoma include

• primary open-angle glaucoma incl. glaucoma without increased eye pressure (normal pressure glaucoma),
• primary narrow-angle glaucoma and acute glaucoma and
• congenital (congenital) glaucoma.

Secondary glaucoma

Secondary glaucoma, on the other hand, is the result of an existing eye disease or general illness, a medical procedure, an injury or an undesirable side effect of a medication.

The term glaucoma is derived from the Greek word “glaukos” for “bluish, greenish, sea-colored”, as the iris of those affected appears bluish-gray. This is why glaucoma is also commonly known as “green star”.

In most cases, poor drainage of aqueous humor in the anterior eye (aqueous humor) leads to increased eye pressure. The production of aqueous humor is usually not altered. This individually increased eye pressure damages the optic nerve through pressure and impairs the blood supply to the optic nerve. However, glaucoma can also develop with “normal pressure values”.

Glaucoma – frequency and age

Around one to two percent of the population suffer from glaucoma. In western industrialized countries, glaucoma is one of the most common causes of irreversible blindness.

Glaucoma can occur in anyone, although the incidence increases with age – in Caucasians in particular from the age of 50 and earlier in African-Americans. From the age of 65, around two to four percent are affected.

Glaucoma: causes and risk factors

The exact causes of the eye disease depend on the particular form of glaucoma. What all forms of glaucoma have in common is that it is a progressive (chronic) eye disease in which the optic nerve is increasingly and irreversibly damaged.

Increased eye pressure is usually responsible for this. This occurs when the natural drainage of the aqueous humor in the so-called chamber angle is disturbed. The aqueous humor is a fluid that supplies the inner structures of the eye that are not supplied with blood, such as the lens and cornea.

As a result, the eye pressure rises. This can damage the sensitive optic nerve over time. The optic nerve can then no longer transmit all the visual information to the brain. Visual field restrictions occur. These so-called visual field defects are a typical sign of glaucoma.

In the case of secondary glaucoma, another disease, the intake of medication or other treatment measures, such as surgery, are responsible for the increased eye pressure.

As glaucoma can also develop with “normal eye pressure”, experts suspect other causes. Circulatory disorders in the optic nerve and retina may also play a role in the development of glaucoma in some forms of glaucoma.

There are also various risk factors for primary open-angle glaucoma. These include age over 50, a family history of glaucoma, diabetes mellitus, high blood pressure, severe eye inflammation, a thin cornea with increased eye pressure, cortisone treatment and short-sightedness.

An acute attack of glaucoma with a narrow chamber angle is caused by an eyeball that is too short (e.g. with long-sightedness or a lens that becomes thicker with age).

In the case of congenital glaucoma, a hereditary predisposition is responsible for the development of the eye disease.

Symptoms: Glaucoma

Glaucoma initially progresses without any recognizable symptoms and therefore often remains undetected in the early stages. Various symptoms can occur during the course of the eye disease.

• Primary open-angle glaucoma: Acutely increased eye pressure can lead to so-called epithelial edema. Water is deposited in the outermost and middle layer of the cornea. As a result, those affected sometimes see colored rings or halos around light sources or simply as if through a fog. Visual field defects may occur in the later stages. If open-angle glaucoma is not treated in time or not sufficiently, those affected can go blind.
• Glaucoma attack (acute glaucoma): A glaucoma attack usually only affects one eye. Typical symptoms include a red eye on one side, a hard eyeball when light pressure is applied to the closed eye, an unresponsive, moderately wide pupil, eye pain and visual disturbances. In addition, a glaucoma attack can cause severe one-sided headaches, nausea and vomiting. The general complaints are often in the foreground.
• Primary congenital glaucoma: This congenital disease is already noticeable in the first months of life. The eyes of affected infants may water more, are sensitive to light and the eyelids are cramped. The eyes can also be very large.
• Secondary glaucoma: Secondary glaucoma can progress without symptoms, but can also cause various complaints. These are similar to those of a primary open-angle glaucoma or, in the case of an acute increase in pressure, a glaucoma attack.

Glaucoma: Diagnosis with us

To make an accurate diagnosis of glaucoma, the ophthalmologist will carry out various examinations.

This primarily includes a complete eye examination of vision, anterior and posterior segments of the eye and, above all, eye pressure measurement (tonometry). However, an eye pressure examination alone is not always conclusive. Glaucoma can also occur with “normal” values. Doctors speak of values in the normal range when the eye pressure is between 9 and 21 millimeters of mercury (mmHg). For some people, such normal pressure is sometimes enough to damage the optic nerve. In other people, increased eye pressure does not automatically cause glaucoma (ocular hypertension).

It is therefore not enough to simply measure the eye pressure to make a reliable diagnosis. It is important to examine the optic nerve, check the visual field (perimetry) and examine the nerve fibers (usually using optical coherence tomography). Corneal thickness is also usually measured as an independent risk factor. Today it is also possible to measure the biomechanics (“stiffness”) of the cornea and to look at the blood supply to the retina and around the optic nerve. In some cases, it also makes sense to monitor the course of the disease over several months and years in order to make a reliable diagnosis.

Glaucoma: prevention, early detection, prognosis

It is not yet possible to prevent glaucoma directly.

However, if you have certain risk factors for glaucoma, you can detect the disease early with early detection (screening) and thus treat it in good time. Many ophthalmologists therefore offer their patients early detection. Ophthalmologists recommend annual glaucoma screening from the age of 50 for Caucasians and from the age of 40 for African-Americans and Latin Americans. The reason for this is that eye pressure increases with age.

It is important thateye pressure measurement with or without ophthalmoscopy is not theonly method of early detection. In both cases, the results are not meaningful. You should therefore make sure that your ophthalmologist always carries out additional examinations and not just have your eye pressure measured by an ophthalmologist who is not an ophthalmologist. In some cases, for example, computer tomography or magnetic resonance imaging examinations are necessary.

Progression and prognosis of glaucoma

The course of glaucoma depends crucially on the form of the eye disease:

Primary open-angle glaucoma progresses over years or even decades and gradually damages the optic nerve. Targeted treatment can slow down or even stop the progression of the disease.

If an attack of glaucoma (acute glaucoma) is recognized and treated in time, the chances of recovery are good. The situation is different if acute glaucoma remains untreated for a long time or recurs. In this case, those affected can quickly go blind.

Even in the case of congenital glaucoma, early treatment can often prevent blindness. However, despite the therapy, vision may be impaired.

The course of secondary glaucoma depends on the cause of the secondary glaucoma and also on whether and how consistently the underlying cause is treated. The prognosis varies greatly between the different secondary glaucomas.

Glaucoma: Treatment

In many cases, glaucoma can be successfully treated if detected at an early stage. There are various options and procedures available to the ophthalmologist for this purpose:

• Primary open-angle glaucoma: If diagnosed in good time, the doctor usually uses eye drops from different drug classes. They are designed to reduce eye pressure. They either reduce aqueous humor production or improve the outflow of aqueous humor. If this does not have the desired effect, laser treatment can also be carried out to reduce the eye pressure. However, the effect is usually only slight and often not long-lasting. Surgical intervention is then often necessary to improve the drainage of the aqueous humor. Today there are a variety of surgical procedures available. Your ophthalmologist will discuss the most suitable procedure and alternatives with the patient and make a joint decision on an individual therapy.
• Glaucoma attack (acute glaucoma): A glaucoma attack (acute glaucoma) is a medical emergency and requires immediate action. Initially, those affected receive medication that quickly reduces the eye pressure. This is followed by an operation. This procedure usually offers good chances of recovery. In this case, blindness can also be prevented.
• Primary congenital glaucoma: If glaucoma is congenital, it is treated surgically as early as possible. However, several operations are often necessary in the course of a lifetime.

Secondary glaucoma: Depending on the cause, it is important to treat the underlying cause first. Otherwise, treatment is similar to that for primary open-angle glaucoma.