What is glaucoma?

What is glaucoma?

Glaucoma is an eye disease in which fluid pressure increases within the eye; if left untreated, the patient can lose sight and even become blind.

Glaucoma is relatively common and can cause damage to the optic nerve if left untreated, particularly in older adults.

In this post, we’ll discuss the causes, symptoms, and glaucoma treatment. We will also clarify the various types of possible surgical procedures.

Fast facts on glaucoma:

  • Glaucoma has been called the silent thief of sight.
  • The main types of glaucoma are open-angle and closed-angle.
  • Age and thyroid problems increase the risk of glaucoma.
  • Symptoms can include severe eye pain.
  • Treatment includes surgery and medications.

What is glaucoma?

In short, glaucoma is a build-up of pressure that causes damage to the optic nerve inside the eye.

In the front of the eye there is a small space, called the anterior chamber. This fluid nourishes and bathes surrounding tissues. Clear liquid flows in and out of the anterior chamber. When a patient has glaucoma the fluid drains out of the eye too slowly. This contributes to build-up of blood, which increases pressure within the eye.

If this pressure is reduced and regulated, the optic nerve and other sections of the eye can get weakened, causing vision loss.

Though one may be more seriously affected than the other, the disease generally affects both eyes.

Treatments for glaucoma

Treatments include either increased fluid flow from the eye, decreasing it’s production or both:

Eyedrops for glaucoma

A man using eyedrop
Eyedrops are a common and effective treatment for glaucoma.

In most cases, initial glaucoma treatment involves eye droplets.

Compliance is vital to best results and to prevent harmful side effects – that means carefully following the instructions of the doctor.

Examples of eyedrops include:

  • prostaglandin analogues
  • carbonic anhydrase inhibitors
  • cholinergic agents
  • beta blockers

Side effects of eye drops may include stinging, redness, eyelash growth, eye color change and sometimes retinal detachments and breathing difficulties. If eyedrops are not adequately successful the doctor may prescribe an inhibitor of oral carbonic anhydrase.

Side effects are less when consumed in the course of meals. Initial side effects may include tingling in the fingers and toes, and frequent urination – but they usually improve within a few days.

Less often, when drinking fizzy drinks, there is a risk of rashes, kidney stones, stomach ache, weight loss, impotence, tiredness and a weird taste.

Causes of glaucoma

Doctors are uncertain about the exact causes of glaucoma but there are two categories of cases:

  • Primary glaucoma – this means that the cause is unknown.
  • Secondary glaucoma – the condition has a known cause, such as a tumordiabetes, an advanced cataract, or inflammation.

There are several risk factors for glaucoma:

  • Old age.
  • Ethnic background – East Asians, African Americans, and those of Hispanic descent have a higher risk of developing glaucoma, compared with Caucasians.
  • Some illnesses and conditions – like diabetes or hypothyroidism.
  • Eye injuries or conditions.
  • Eye surgery.
  • Myopia (nearsightedness).


Long-term corticosteroid patients have an increased risk of developing different conditions like glaucoma. With eye drops containing corticosteroids the risk is even greater.

Types of glaucoma

A man having eyes examination by doctor
Glaucoma is one of the most common eye diseases.

There are two main types: open-angle and closed-angle glaucoma.

Closed-angle glaucoma (acute angle-closure glaucoma)

That may happen suddenly; the patient normally experiences pain and rapid loss of vision.

Fortunately, the signs of pain and discomfort make the patient seek medical attention, which leads to timely care, which typically avoids any permanent damage.

Primary open-angle glaucoma (chronic glaucoma)

The form is progressing very slowly. The patient may experience no symptoms; even slight vision loss can go unnoticed. Many people don’t get medical attention with this form of glaucoma until there has already been irreversible damage.

Low-tension glaucoma

It is a more unusual type of glaucoma not well understood by experts. While eye pressure is normal, it still causes damage to the optic nerves. This may be attributed to insufficient flow of blood to the optic nerve.

Pigmentary glaucoma

This form of open angle glaucoma develops usually during early or middle adulthood. Within the eye are scattered pigment cells that originate from the iris. If these cells build up in the channels that drain fluid from the eye, they can disrupt the normal fluid flow in the eye, causing eye pressure to rise.

What are the symptoms of glaucoma?

There are very specific signs and symptoms of primary open-angle glaucoma and acute angle-closure glaucoma:

Symptoms of primary open-angle glaucoma

  • Peripheral vision is gradually lost. This nearly always affects both eyes.
  • In advanced stages, the patient has tunnel vision.

Symptoms of closed angle glaucoma

  • Eye pain, usually severe.
  • Blurred vision.
  • Eye pain is often accompanied by nausea and sometimes vomiting.
  • Lights appear to have extra halo-like glows around them.
  • Red eyes.
  • Sudden, unexpected vision problems, especially when lighting is poor.

Surgery for glaucoma

If medications don’t work, or if the patient can’t handle them, the alternative could be surgical intervention. Typically the aim of the surgery is to bring down the pressure inside the eye. Examples of the operations include:

  • Trabeculoplasty – a laser beam is used to unblock clogged drainage canals, making it easier for the fluid inside the eye to drain out.
  • Filtering surgery (viscocanalostomy) – this may be carried out if nothing else works, including laser surgery. Channels within the eye are opened up to improve fluid drainage.
  • Drainage implant (aqueous shunt implant) – this option is sometimes used for children or those with secondary glaucoma. A small silicone tube is inserted into the eye to help it drain out fluids better.

Acute angle-closure glaucoma

Acute glaucoma to the angle closure is regarded as a medical emergency. Drugs which reduce pressure are administered immediately. Typically a laser procedure is performed that produces a tiny hole in the iris that allows fluids to move through the trabecular meshwork (the eye drainage system)-this procedure is called an iridotomy.

Even if only one eye is affected, the doctor can wants to treat both because the other eye is often affected by this type of glaucoma too.


There is no known way to avoid glaucoma, but recognizing it early means treating it more efficiently, and reducing vision loss. Since, sometimes, there are no signs, it’s important to get your eyes checked regularly; particularly for those at higher risk.

For example, older adults, people of African or Hispanic descent and people with diabetes should be checked every year or 2 years after age 35. Tell your doctor how often you will get a check-up.