What is glaucoma?

Place your cursor on the picture

The term "glaucoma" (from Greek for "green colour of the sea") is found as early as 400 B.C. in works by Hippocrates. However, the modern concept of glaucoma began to form only in the middle of the 9th century A.D. At present, the term "glaucoma" is applied to a big group of ailments, often of different origin and different courses. Until now, there is no single opinion on what is the cause of the disorder. With no treatment these seemingly different diseases result in one outcome – atrophy of the optic nerve and blindness.

Glaucoma may appear at any age, but more often the disorder develops at an elderly age.

According to the World Health Organization, glaucoma is the major disorder which results in irreversible blindness if untreated. Over 5 million people have been blinded by glaucoma and this accounts for 13.5% of all the blind in the world.

Reasons for glaucoma progression

A healthy eye maintains a constant pressure (18–22 mm of the mercury column) due to the balance in the inflow and outflow of fluid. Glaucoma disrupts fluid circulation. The fluid is accumulated and the intraocular pressure begins to grow. The optic nerve and other eye structures are exposed to additional stress, and the blood circulation in the eye is disrupted. It results in atrophy of the optic nerve, and the vision signals no longer reach the brain. The eyesight is no longer clear, the peripheral vision is distorted and blindness is the final result.

The optic nerve disc in normal state	The optic nerve disc affected by glaucoma

Glaucoma is irreversible and it is, therefore, very important to receive timely treatment. Ophthalmologists draw attention to the fact that there may be sudden loss of vision due to an acute attack of glaucoma.

Symptoms of glaucoma

Very often the affected person has dimness of vision, pain in the eyes, a feeling of weight in the eyes, and a reduction in the field of vision. During the darker hours at night, eyesight is much worse. Iridescent circles appear before the eyes when facing bright light.

Forms of glaucoma

• Open angle glaucoma
• Closed angle glaucoma

Open angle glaucoma accounts for over 90 % of the cases of this disorder. In open angle glaucoma, the natural drainage system is open but its functions are distorted. This leads to gradual increase in intraocular pressure. As a rule, open angle glaucoma displays practically no symptoms in its development. Since the vision field narrows very gradually (the process may take several years), the person may suddenly discover that he sees with only one eye. In some cases there may be complaints about the periodic appearance of iridescent circles when facing a bright light, foggy vision, complaints about asthenopia associated with bad accommodation.

Closed angle glaucoma results in accumulation of intraocular fluid due to the lack of outlet to the natural drainage system of the eye – the iris obstructs the corner of the frontal chamber. This increases pressure resulting in a possible acute attack of glaucoma which brings about:

• Sharp pain in the eye and the corresponding headache;
• Obvious vision disorder (blurring or sudden drop of eyesight up to blindness)
• Red eyes (dilatation of the blood vessels in the frontal area of the eyeball), swelling of the cornea, reduced depth of the frontal chamber, dilatation of the pupil and no reaction to light;
• Appearance of halos around the source of light;

Closed angle glaucoma

Diagnostics of glaucoma

In order to identify the beginning of the disorder, it is not enough merely to measure the intraocular pressure. What is needed is a detailed study of the ocular fundus and the optical nerve disc. It is also essential to study the field of vision, i.e. a comprehensive diagnostic testing is required.

Specialists at Excimer Eye Clinics perform examination with help of a set of modern computerized equipment which includes :

• An examination of the vision field (using a computer perimeter);
• Refraction measurement (ability of the ocular system to refract light rays);
• Measurement of intraocular pressure;
• Ultrasonic examinations;
• Estimation of the depth of the ocular frontal chamber and the thickness of the crystalline les (since quite often the reason for high intraocular pressure lies in the shift or growth of the lens);
• Gonyoscopic examination helps to evaluate the structure of the frontal chamber corner which provides the outflow of ocular fluid.

Also in the course of diagnostics, eye fundus analysis is obligatory. It is performed with a special unit (there are only few in Russia) and also with a computer perimeter. This makes it possible to identify the initial manifestations which precede the earliest changes in the vision field and to stop the process.

Treatment for glaucoma

The Excimer doctors select an individual program of treatment depending on the type, stage, and accompanying disorders. Medication treatment is mainly aimed at reducing intraocular pressure. It is important to bear in mind that eye drops do not restore the balance of fluid in the eye, but only maintain it artificially.

As far as surgical treatment is concerned, the non penetrating deep sclerectomy (NPDS) allows restoring the natural balance of fluid flows in the eye in open angle type of glaucoma.

Closed angle glaucoma calls for both traditional surgery and ablation of the transparent crystalline lens with the following IOL implantation (if there is a discrepancy between the size of the lens and that of the eye).

Remember that postponing treatment you run the risk of vision disorder. Without timely identification of the ailment and early treatment, your vision is getting irreversibly lost.