Glaucoma: Types, Symptoms, Treatment, and Risk of Blindness

What is Glaucoma?

Glaucoma is an eye condition that affects the optic nerve—the structure that transmits visual information from the retina to the brain, creating a risk of blindness.

In most cases, the disease occurs because intraocular pressure (eye pressure) rises above normal values, that is, above 20–21 mmHg. This increase exerts constant pressure on the optic disc (the area through which nerve fibers leave the eye to form the optic nerve) and, consequently, on the optic nerve. Over time, this process leads to irreversible damage to the nerve fibers.

Diagram of the eye showing how increased intraocular pressure affects the optic nerve in glaucoma

Main Types of Glaucoma

There are several forms of glaucoma, including:

• open-angle glaucoma

• angle-closure glaucoma

• normal-tension glaucoma

• congenital glaucoma (present at birth)

Although they differ in how they develop, they all have the same final outcome if left untreated: progressive and irreversible damage to the optic nerve.

Progression and Symptoms

The consequence of glaucoma is a gradual narrowing of the visual field. The disease begins by affecting the peripheral areas and, in advanced stages, may also compromise central vision.

Blind spots (scotomas) are noticed by patients only in advanced stages, when optic nerve damage is already significant and irreversible. For this reason, glaucoma is known as the “silent thief of sight”.

Simulation of the progressive loss of the visual field caused by glaucoma

The Importance of Regular Checkups

Because the disease progresses for a long time without symptoms, it is essential for everyone over 40 to have their intraocular pressure measured at least once every two years.

In addition, because glaucoma also has a hereditary component, family members of affected individuals should undergo examinations earlier and more frequently.

How Intraocular Pressure Increases

Eye pressure is determined by aqueous humor, the fluid that maintains the shape of the eyeball. It is produced continuously and must also be eliminated through a drainage system.

An imbalance between production and elimination leads to fluid accumulation and increased intraocular pressure.

Measuring Eye Pressure

Tonometers are used to assess eye pressure. The most widely used types require local anesthesia in the form of eye drops because they touch the eye for a few seconds. There are also non-contact tonometers, which use a puff of air and do not require medication.

Both methods are quick, painless, and safe.

Characteristics of the Different Forms of Glaucoma

Open-Angle Glaucoma – occurs when the trabecular system (the drainage channel for aqueous humor) becomes less efficient. In some rare cases, the cause may be excessive production of aqueous humor.
Angle-Closure Glaucoma – the internal structure of the eye causes the drainage angle to become narrowed or blocked, preventing fluid from being eliminated.
Normal-Tension Glaucoma – occurs in people who are more sensitive to intraocular pressure, in whom the optic nerve becomes damaged even though measured values are normal.
Exceptions – some people have elevated intraocular pressure but never develop glaucoma.

Glaucoma Treatment:

The damage to the optic nerve caused by glaucoma is irreversible. Therefore, the goal of treatment is stopping or slowing disease progression by keeping intraocular pressure under control.

First-line treatment: eye drops that reduce the production of or increase the elimination of aqueous humor.
Second-line treatment: when medications are not sufficient, laser procedures or surgery may be recommended to improve drainage and reduce eye pressure.

Support for Treatment Tolerance:

Because treatment with anti-glaucoma eye drops is long-term, unpleasant reactions such as dry or irritated eyes may sometimes occur. In these cases, Alocross gel may be used as an adjunct to reduce adverse effects and improve ocular comfort, helping the patient follow the treatment more easily.

Final Recommendation

Do not self-medicate! Regular ophthalmological examinations are essential for the early detection of glaucoma and for choosing the appropriate treatment. Only an ophthalmologist can confirm the diagnosis and adjust the therapy to protect vision in the long term.