# What is Glaucoma and How is It Treated?

Source page: https://www.kudretgozistanbul.com/en/blog/eye-diseases/what-is-glaucoma-and-how-is-it-treated

**Author:** Kudret Eye İstanbul | **Medical Approval:** Op. Dr. Mehmet Ali Özdil | **Date:** 2026-09-08

> **Summary:** Glaucoma occurs when the pressure within the eye rises and damages the optic nerves at the back of the eye; it is linked to a build-up of the fluid the eye produces when its drainage system is disturbed. Open angle glaucoma, the most common type, usually causes no symptoms and is found at eye examinations, while acute angle closure causes severe headache, eye pain and blurred vision. Untreated, it leads to permanent sight loss; treatment with drops, laser or surgery aims to lower eye pressure.

## Quick Facts
- **Normal eye pressure:** Between 10 and 21 mmHg; readings above 21 mmHg are considered high and call for an assessment for glaucoma; pressure changes through the day, so it needs regular follow-up
- **Types:** Open angle (gradual, painless, most common) and narrow or closed angle (acute, sudden)
- **Treatment:** Eye drops first, for life if they work; laser or surgery if pressure does not fall
- **Who is at risk:** Family history, over forty, narrow drainage angle, migraine, diabetes, high myopia, eye injury, low or high blood pressure, thin cornea

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## What is Glaucoma?
The eye continuously produces a clear fluid (aqueous humour) that nourishes its inner structures; in a normal eye it flows through the channels between the cornea and the iris. In glaucoma the resistance in those channels rises, fluid gathers, the pressure within the eye rises steadily and presses on the optic nerves, which are damaged. Most people with glaucoma are unaware of it; it most often emerges during eye examinations, and if treatment is left too late sight loss follows. It can affect one eye while the other functions normally, and can be met even in newborn babies as well as in people over forty.

## Risk Factors
- Family members with glaucoma (a far greater risk)
- Being over forty
- A narrow drainage angle in the eye
- Conditions such as migraine and diabetes
- High myopia
- Injuries to the eye
- Low or high blood pressure
- A cornea thinner than it should be

## Symptoms
Open angle glaucoma usually gives no symptoms, so regular check-ups matter for early identification.

Symptoms of acute angle closure glaucoma:
- Enlarged pupils
- Redness of the eye
- Severe headache
- Severe eye pain
- Seeing haloes when looking at lights
- Nausea
- Blurred vision

Symptoms of childhood glaucoma (easier to observe, so diagnosis is more straightforward):
- Enlargement of the eye
- Wateriness and tearing of the eyes
- Redness of the eyes
- Pain in the eye

## Types of Glaucoma
- **Closed (narrow) angle glaucoma:** develops acutely and appears suddenly. The angle between the cornea and the iris is very narrow; the iris lies close to the drainage angle and can obstruct it completely. Pupil changes and eye pain can occur; an ophthalmologist should be seen immediately.
- **Open angle glaucoma:** the most common type. Fluid is not drained because an obstruction forms in the channels; it develops gradually over years, causes no pain and does not show itself, so it emerges through regular eye examinations.

## Diagnosis
An eye examination is essential. The eye is checked with special instruments; the area within the optic nerve formed by the vessels at its centre is examined, and widening there can point to glaucoma. A definite diagnosis is then made with other methods before treatment begins.

## Treatment
- If the eye pressure is not far above the maximum limit, medication is used: drops bring the pressure back to normal, the patient is followed continually and, if the drops work, continues them for life.
- If the pressure does not fall despite medication, laser treatment or surgery is used.
- In both medication and surgery the main aim is to lower the patient's eye pressure. Regular check-ups support early diagnosis.