Glaucoma Explained In Layman’s Terms

Glaucoma is one of the leading cause of blindness in the word, second only to cataract. It refers to eye conditions that damage the optic nerve in the eye leading to irreversible eye damage. While glaucoma can be treated, its effects cannot be reverse. That is why information and early diagnosis is very important.

In the eye, there is a nerve called the optic nerve. This nerve is responsible for sending visual information to the brain. These visual information, transported as tiny electrical impulses, are processed by the brain into what we know as our vision. What occurs in glaucoma is that there is a high pressure on the optic nerve. This pressure is known as intraocular pressure or IOP. This pressure is responsible for the damage on the optic nerve, causing irreversible damage. Once the optic nerve is damaged, the brain can no longer receive information from the eye, leading to loss of vision.

Types of Glaucoma

There are two main types of glaucoma

1. Open Angle Glaucoma (also known as Chronic Glaucoma), and

2. Closed Angle Glaucoma (also known as Acute Glaucoma).

There are also two less common types: Congenital Glaucoma and Secondary Glaucoma.

The ‘angle’ in both open angle and closed angle glaucoma is short for the ‘anterior chamber angle’. There is a fluid in the eye called the ‘Aqueous Humour’. This fluid produced at the back of the eye, fills the eye and flows out the anterior chamber angle, or angle for short. The problem arises when the passage for the fluid, the acqueous humour, is blocked or slowed. When this happens, the fluid begin to build up pressure inside the eye. When the intraocular pressure becomes too much, the optic nerve at the back of the eye become damaged gradually leading to loss of vision.

Open Angle Glaucoma

This is the most common of all glaucoma cases. The ‘open angle’ means that the channel for fluid to flow out of the eye is still open. Usually, the pressure in this case slowly builds up over an extended period of time without any symptom. Because the channel is still open, it can only be diagnosed during a medical eye examination.

The symptom of the open angle glaucoma begins with a gradual loss of side vision. Left unattended to, it can lead to complete blindness.

This is why regular eye examination is recommended. Open Angle Glaucoma can go on for several years before the patient can begin to notice the effects. Furthermore, individuals of African, Hispanic and Asian descent have a greater risk of having this type of glaucoma.

Closed Angle Glaucoma

[Image source: Wikimedia Commons. Author: Jonathan Trobe, M.D.]

This is a more acute case. As inferable from the name, it means that the channel is severely clogged or completely bocked. Unlike the open angle glaucoma, this occurs rather very quickly with a sharp pain accompanying it. As such, it is treated as an ocular emergency and given prompt attention.

If this isn't immediately addressed, permanent damage to the optic nerve cells will occur, followed by immediate loss of vision. Patients who have suffered from closed angle glaucoma in one eye are at a great risk of suffering it in the other eye. This is while it is important they stay on a course of preventative treatment. Eye drops and treatments should only be administered based on a qualified eye specialist recommendation as they could trigger another another attack.

General symptoms include a reddening of one eye, decreased or clouded vision, one eye feeling swollen, a sudden and severe pain in one eye, rainbow-like halos appearing around lights, nausea and vomiting.

Congenital Glaucoma

This type of glaucoma is hereditary. It means that the patient was born with the condition. Since this occurs in successive generation, it is usually noticed very early and treated prompted.

General symptoms include a cloudiness of the front of one or both eyes, enlargement of one or both eyes, a reddening of one or both eyes, a sensitivity to light or extra tearing.

Secondary Glaucoma

This type of glaucoma is trigged by primary eye diseases such as Uveitis. It can also be triggered by drugs such as orticosteroids, and systemic diseases that affect the whole body.

Testing Glaucoma

Regular eye test. These are very important, especially for people who have a history of glaucoma in their family or are of African, Asian or Hispanic descent. Here, the eye specialist may simply look though the pupil after dilating the pupils using dilating eye drops and then proceeding to a complete eye examination.

Tonometry test. This is used to check the intraocular pressure in the eye. This isn't very reliable as about twenty five percent of people with glaucoma still have stable eye pressure, referred to as normal tension glaucoma. In cases like this, optic nerve damage can still be caused by other problems.

Gonioscopy. This is the use of a special lens to check the outflow channels of the anterior chamber angle.

Other tests including optic nerve imaging to take pictures of the inside of the eye, retinal examination, visual acuity test amongst others.

Treating glaucoma

The focus of any glaucoma treatment is to reduce the intraocular pressure in the affected eye. This can be achieved through drugs/medication or surgery depending on the type and extent of the condition.

Open angle glaucoma treatment

For most people, the open angle glaucoma can be treated with glaucoma eye drops. There are also oral pills that help to lower intraocular pressure. In some cases, surgery or laser treatment may be needed to unblock a channel or open a new one. It is important to discuss with your eye specialist as regards the best course of treatment to follow.

Close angle glaucoma treatment

This is treated as an optical emergency as it could lead to permanent blindness in a few days. Generally, pills, drops and intravenously medication are administered to reduce the pressure.
In serious cases, an emergency operation called an Iridotomy is carried out. This is a procedure that uses a laser to create a new channel in the iris to reduce the pressure and prevent another attack.

Quick and accurate diagnosis followed by speedy treatment is required in this case.

Congenital glaucoma treatment

This is usually resolved by created another outflow channel in the angle. Early diagnosis is very important. Prompt treatment usually ensure that the patient has no further problems

In conclusion

Glaucoma is a terrible eye condition and should be given prompt attention. Prevention helps to prevent irreversible eye damage. Take the first step, get your eye examined today.

Blessings

Please note that the information provided here is purely for educational purposes only. Kindly refer to an eye specialist for accurate diagnosis and treatment.

References

1. Ethos
2. Optometry Students