4 Types of Glaucoma

Are There Different Types of Glaucoma?

The term glaucoma is used to describe a group of similar conditions. All of these conditions share certain signs and symptoms and are different types of glaucoma.

Defining Glaucoma

There is not a certain definition or feature that makes a condition glaucoma, but the presence of multiple signs and symptoms defines the disease.

Glaucoma is always a chronic, long term disease, not something that can come and go or only last a short period of time.

Glaucoma is always associated with some damage to the optic nerve and often a related change in the visual field.

Glaucoma can be caused because of another condition, but it cannot be a symptom of another disease.

With these features defining glaucoma, it is possible to further classify glaucoma into four major types.

Types of Glaucoma

There are many ways to classify glaucoma, but there are generally four categories or types of glaucoma. The four types are Primary Open Angle Glaucoma, Angle Closure Glaucoma, Normal Tension Glaucoma, and Secondary Glaucoma.

Primary Open Angle Glaucoma

In Primary Open Angle Glaucoma, the optic nerve is damaged due to an increased pressure inside the eye, known as the intraocular pressure or IOP.

The increased eye pressure is due to a factor other than angle closure, which is the physical closing of the natural drainage of the fluid within the eye.

Possible causes of increased eye pressure in Primary Open Angle Glaucoma include overproduction of fluid within the eye and reduced outflow of fluid from the eye.

Primary Open Angle Glaucoma is the most common type of glaucoma by a large margin and is often the first thing thought of when the term glaucoma is used.

This type of glaucoma is very slow to progress and often only causes symptoms after many years with the disease.

Symptoms are typically reduced peripheral vision or noticing an increase in clumsiness due to vision changes.

Angle Closure Glaucoma

Angle Closure Glaucoma is different from Primary Open Angle Glaucoma in that the cause of the high eye pressure is a physical closing of the natural drain of the fluid in the eye.

The term angle closure comes from the location of the anatomical drain in the eye which is located within the corneal angle at the edge of the cornea and within the eye.

If the corneal angle closes, or narrows significantly, it can stop the flow of fluid from the eye and raise the eye pressure rapidly.

This type of glaucoma is associated with extreme eye pain and a very sudden onset. Despite the sudden onset, this condition becomes a long-term concern even with appropriate treatments.

Normal Tension Glaucoma

In Primary Open Angle Glaucoma and Angle Closure Glaucoma, the key factor causing damage to the optic nerve is an increase in eye pressure.

In Normal Tension Glaucoma, however, there is not a significant increase in the eye pressure and the damage to the optic nerve is caused by a mix of other factors.

Despite the normal eye pressure, Normal Tension Glaucoma still creates the same signs, symptoms, and concerns as other types of glaucoma.

Secondary Glaucoma

If there is another condition which leads to the development of glaucoma, then it is termed Secondary Glaucoma.

In these cases, the eye pressure is usually elevated due to the existing condition and the Secondary Glaucoma develops due to the prolonged high eye pressure.

Conditions such as recurrent inflammation of the eye, prolong steroid use, and cataracts can lead to the development of secondary glaucoma.

Treating Glaucoma

To treat glaucoma, the only factor that can be altered is eye pressure. Lowering the eye pressure using eye drops or surgery are the two main options for treating all types of glaucoma.

If the Secondary Glaucoma cause can be treated, it can also reduce the risk of developing further damage from the glaucoma.

Long-term management by an eye doctor is vital for all types of glaucoma.