Glaucoma is one of the most common causes of the irreversible blindness worldwide. According to data from 2020, the number of patients with glaucoma globally was 76 million. Glaucoma is a chronic and progressive disease that causes damage to the optic nerve and irreversible blindness in the event of its fibers’ atrophy.

The exact cause of glaucoma is not yet determined, but possible risk factors include:

• Increased Intraocular Pressure (IOP);
• Age (increased prevalence in people over 40);
• Family history;
• Use of corticosteroids during long period of time;
• High Myopia;
• Diabetes;
• Ocular trauma.

Most patients do not have any complaints in the early stages of the disease, as the central vision isn’t impaired, and characteristic visual field defects remain unnoticed for a long time. Unfortunately, patients often notice visual deterioration only when the peripheral vision is significantly lost and irreversible atrophic changes in the optic nerve have already developed.

Normal vision and peripheral vision alterations at different stages of glaucoma

The front part of the eye is filled with a transparent fluid (the aqueous humor), which contributes to the nutrition of the transparent structures of the eye and the maintenance of a steady intraocular pressure. The aqueous humor is produced within the eye by the cilliary body. It is drained to the venous system through a complex of tiny channels that looks like a sponge and they are called the trabecular meshwork (drainage angle). In order to maintain steady intraocular pressure, there should be a balance between the production of the aqueous humor and its outflow from the eye.  Normal intraocular pressure varies from 10 mmHg to 21 mmHg.

Types of glaucoma are classified based on the appearance of the drainage system in the eye:

• Open Angle Glaucoma is the most common type of the disease  and is caused by the functional disability of the drainage angle that results in increase of intraocular pressure.
• Angle-Closure Glaucoma is due to the anatomical predisposition when the drainage angle of the eye if partially or permanently blocked.  This type of glaucoma can present as an acute angle closure glaucoma with the symptoms of severe pain, nausea/vomiting. The condition is ophthalmic emergency and requires urgent treatment.    

Aqueous humor outflow changes in open angle glaucoma

 Aqueous humor outflow changes in angle-closure glaucoma

• Normal Tension Glaucoma is charachterised with the intraocular pressure within normal range, however there are changes in optic nerve disc that might be due to the reduced blood flow to the optic nerve.
• Secondary Glaucoma is usually a result of trauma or severe ocular inflammation.
• Congenital Glaucoma is caused by  anatomic abnormalities and usually manifests within the first months of life.

It is important to perform the below tests for the diagnosis of glaucoma:

• Measurment of intraocular preasure (tonometry);
• Examination of the drainage angle of the eye (gonioscopy);
• Evaluation of the optic nerve disc (ophthalmoscopy);
• Measurment of corneal thickness (pachymetry) to accurately evaluate the level of intraocular pressure.

In case of suspicion of glaucoma more specialised tests must be performed, such as Computerized Perimetry for the assesment of visual field and Optical-Coherence Tomography (OCT) for the analysis of the retinal nerve fyber layers. These tests are necessary not only for the diagnosis of the disease but for the follow-up and assesmnet of the treatment efficacy.

The main goal of the glaucoma treatment is to stop the progression of the disease. Visual acuity decreased due to glaucoma can’t be restored as it is caused by the damage to the optic nerve and is irreversible. The choice of rational treatment depends on the type of the glaucoma.

Medical treatment of glaucoma consists of anti-glaucoma medications that reduce the intraocular pressure either by reduction of aqueous humor production or by enhancement of the drainage or both. In order to achieve maximum efficacy of the medical treatment, the patient must be compliant.  The patient should never change or stop medications unless agreed with the doctor.

If the patient is prescribed anti-glaucoma drops, they should follow the instructions below:

• Washing of hands is mandatory;
• Keep the bottle upside down. Lean you head backwards. Take the bottle in one hand and keep it 5-10 cm above the eye and squeeze at least one drop into the pocket created by pulling down the lower eyelid;
• Close your eyes or press on the inner corner of the eyelids with your finger for 1-2 minutes significantly reducing the amount of medication that goes through the nose and increasing the efficacy of it.

Medical treatment requires harmonious cooperation between doctor and patient in order to achieve maximum efficacy and reduce the possible side effects. Your ophthalmologist can prescribe you the anti-glaucoma treatment but only you can be responsible for being compliant with it.  

When the medical treatment options are not adequate to stop the progression of the disease, laser and/or surgical treatment is recommended.

The mechanism of the laser treatment is different for open angle and angle-closure glaucoma. In open angle glaucoma, the drainage angle itself is treated. The laser is used to widen the drainage opening and to help control the intraocular pressure. In angle-closure glaucoma, when immediate treatment is required, the laser creates a small hole in the iris (iridotomy) in order to improve the flow of the aqueous humor from a collateral drainage pathway. This hole may also be created by microsurgical manipulation.

When the above-mentioned treatment options are not adequate to stop the progression of the disease, surgical treatment is recommended which is aimed to decrease the intraocular pressure.

Early diagnosis and addeqaute timely treatment are the only ways to prevent the irreversible blindness caused by glaucoma. At early stages of glaucoma the patient usually doesn’t have any complaints and thus, in presence of risk-factors after the age of 40 regular ophthalmic check-ups are required once a year and if the person has a family history of glaucoma then every six months.

Thus, if you have a family history of glaucoma or you were diagnosed with it, eye clinic „Akhali Mzera“ offers cutting-edge technologies for the diagnosis and treatment of the disease. Decsion about the treatment method and the frequency of the follow-up visits is made individually in each clinical case based on the mutual agreement between the ophthalmologist and the patient.