Glaucoma

The term “glaucoma” (green star) refers to a group of eye diseases that primarily affect the optic nerve. In most cases, elevated intraocular pressure leads to progressive damage and ultimately destruction of the optic nerve. The optic nerve transmits visual information from the retina to the brain. Left untreated, this damage can lead to blindness.

Worldwide, glaucoma is the second most common cause of blindness.

At the Eye Center Nymphenburger Höfe, we offer state-of-the-art approaches for the prevention and treatment of glaucoma.

How Does Glaucoma Develop?

Intraocular pressure is maintained by a balanced system consisting of the ciliary body (a tissue behind the lens that produces aqueous humor), the trabecular meshwork (the eye’s drainage system), and Schlemm’s canal. Through this canal, the aqueous humor is drained via the eye’s veins. In a healthy state, there is a balance between the production and drainage of aqueous humor.

The ideal eye pressure is a maximum of 22 mmHg. With elevated eye pressure, there is a risk that glaucoma will develop, progressively damaging the optic nerve. However, there are people in whom even lower intraocular pressure can lead to optic nerve damage. In such cases, this is referred to as glaucoma without elevated eye pressure, also known as low-tension or normal-tension glaucoma.

The causes of glaucoma can be varied.

Three main groups can be distinguished:

1. Primary Glaucomas: These do not develop as a consequence of other general or eye diseases and typically manifest in both eyes. A genetic component is also suspected.
2. Secondary Glaucomas: These occur as a result of other underlying conditions, such as inflammation, injuries, diabetes, vascular occlusions, corticosteroid therapy, surgeries, or eye hemorrhages. Treatment involves lowering intraocular pressure as well as treating the underlying condition.
3. Congenital Glaucomas: These have their cause in a developmental defect of the chamber angle. In children, primary congenital glaucoma, which occurs without further accompanying changes, must be distinguished from other developmental glaucomas with additional anomalies.

The most common forms of glaucoma belong to the group of primary glaucomas, which occur in two variants: angle-closure glaucoma and open-angle glaucoma.

Diagnostics

With modern diagnostic devices, we can precisely document changes in the optic nerve and the retinal nerve fiber layer and detect alterations. In addition to measuring and correctly assessing intraocular pressure, these methods are suitable for evaluating glaucoma damage to the optic nerve and retina as well as the effectiveness of treatment measures.

The following procedures are used:

1. Visual Field Test (Goldmann and 30-degree static perimetry)
2. OCT (optical coherence tomography) for measuring the retinal nerve fiber layer
3. Pachymetry: Modern methods of direct eye pressure measurement must also take corneal thickness into account for accurate assessment of measured intraocular pressure. The determination of corneal thickness is called pachymetry.

OPTICAL COHERENCE TOMOGRAPHY (OCT)

OCT has established itself worldwide as the standard in the diagnosis of retinal diseases, especially of the macula, as well as optic nerve diseases such as glaucoma.

It is the most important instrument for diagnosing macular diseases and plays a crucial role in the diagnosis and monitoring of glaucoma. Our shared goal is the preservation of nerve fibers in the optic nerve.

The principle is based on measuring the reflection of a light beam sent into the eye and converting it into a visible image using digital technology. The resolution is 10 micrometers. This procedure is painless and completely harmless.

OCT is not part of the benefits catalog of statutory health insurance and must therefore be billed as a private medical service.

Perimetry

Perimetry encompasses various methods used to determine a patient’s visual field. The most commonly used method is static perimetry. The patient fixates with one eye on a light in the center of a hemispherical test screen while the other eye is covered. Light points appear spontaneously at various locations on the screen, which the patient perceives and signals by pressing a button. If the patient does not respond to a light stimulus, the computer automatically increases the light intensity and records the response. After 10–20 minutes, the other eye is tested. Afterward, the doctor can evaluate the results and compare them with normal findings.

An older method is kinetic perimetry, which is rarely used. Here, light points move from the periphery of the screen toward the center, and the measurement occurs when they appear in the patient’s visual field.

Perimetry is used in various fitness examinations, for example, to assess the flight fitness of pilots. Another area of application is the diagnosis of visual disturbances, where the doctor attempts to localize the disruption in the eye, optic nerve, or brain. Particularly important is the monitoring of glaucoma patients to detect early visual field restrictions and adjust therapy accordingly.

Treatment

Although medical therapy for glaucoma has advanced in modern medicine, surgical treatment remains the only option in some cases. The selection of the appropriate procedure always depends on the individual situation and the underlying cause of the glaucoma.

Selective Laser Trabeculoplasty (SLT)

Selective Laser Trabeculoplasty (SLT) is a gentle laser treatment aimed at reducing intraocular pressure in open-angle glaucoma. In the eye, a fluid called aqueous humor is produced. This aqueous humor normally flows through a sponge-like system called the trabecular meshwork, located in the chamber angle between the iris and the cornea. SLT uses a laser to modify this system, thereby improving the drainage of aqueous humor and lowering intraocular pressure.

During the gentle SLT laser treatment, specialized laser pulses are delivered to the trabecular meshwork, primarily targeting melanocytes (pigment cells). This process promotes regeneration and increases the drainage of aqueous humor, ultimately leading to a reduction in intraocular pressure.

The treatment is painless, and generally no side effects are expected. SLT can be used as a supplement to or instead of eye drops for lowering eye pressure. It is repeatable and is particularly used when intraocular pressure cannot be sufficiently reduced despite medication, medications are not well tolerated, or glaucoma surgery is not desired or advisable.

iStent inject

The iStent inject® is the smallest implant (0.36 millimeters) designed for use in the human body and aims to lower intraocular pressure in glaucoma. The tiny stent is placed in the trabecular meshwork in the chamber angle to reduce the outflow resistance of the aqueous humor and thereby achieve an effective reduction in intraocular pressure.

In many cases, this procedure enables the reduction or even elimination of intraocular pressure-lowering medications. It is a minimally invasive surgical procedure of short duration with a high safety profile and minimal burden for patients. The iStent inject® can also be used during cataract surgery.

More information about iStent can be found on the Glaukos website.

Trabeculectomy

In this procedure, a drainage channel is created from the anterior chamber of the eye through the sclera under the conjunctiva. This allows excess aqueous humor to be drained and intraocular pressure to be reduced.

This surgical procedure is an established gold standard for treating open-angle glaucoma that no longer responds to medical therapy. It has been applied for decades. However, this so-called fistulating operation unfortunately often leads to severe scarring and therefore requires extensive use of postoperative medications.

Iridectomy/Iridotomy

In iridotomy, a small opening is created at the edge of the iris using a laser beam or minimally invasive surgery. This allows improved pressure equalization between the anterior and posterior chambers of the eye as well as deepening of the anterior chamber. This therapy is applied when the chamber angles are very narrow or when there is a risk of an acute glaucoma attack due to obstruction of the chamber angle.

Hydrus

Similar to the iStent, the Hydrus implant is also placed in the trabecular meshwork in the chamber angle to reduce the outflow resistance of the aqueous humor and thereby achieve an effective reduction in intraocular pressure. This implant can also be used during cataract surgery.

Preserflo

In this procedure, a drainage tube is placed from the anterior chamber of the eye through the sclera under the conjunctiva. This allows excess aqueous humor to be drained and intraocular pressure to be reduced.

Compared to the iStent and Hydrus, this surgical procedure represents a more aggressive method for treating open-angle glaucoma that no longer responds to medical therapy. This so-called fistulating operation unfortunately often leads to severe scarring and therefore requires extensive use of postoperative medications.