GLAUCOMA, SECOND LEADING CAUSE OF BLINDNESS

Glaucoma is a group of eye diseases that can cause vision loss and blindness by damaging the nerve in the back of the eye called the optic nerve. It's usually caused by fluid building up in the front part of the eye, which increases pressure inside the eye. The front part of the eye contains a clear fluid, the aqueous humour. This fluid nourishes the eye and gives it shape. The eye constantly produces this fluid and drains it away through a drainage system. If a person has glaucoma, the fluid drains very slowly out of the eye. When this happens, fluid builds up, and pressure inside the eye rises. If this pressure is not managed, it may damage the optic nerve and other part of the eye leading to vision loss.

TYPES OF GLAUCOMA

There are several types of glaucoma. Some glaucoma are caused by other medical conditions and these are termed as secondary glaucoma. But there are others, that are not caused by another medical condition and this is termed as primary glaucoma. The following are the different types of glaucoma;

OPEN- ANGLE GLAUCOMA

This type of glaucoma is the most common type of glaucoma. It develops slowly, and a person may not notice any symptoms until they begin to lose their vision. This type of glaucoma may be caused by pressure building up in your eye. The pressure damages the optic nerve, which affects your vision. This can eventually lead to blindness.

ANGLE- CLOSURE GLAUCOMA

This is also called closed- angle glaucoma. This type of glaucoma happens when someone's iris is very close to the drainage angle in their eye. The iris can end up blocking the drainage angle. When the drainage angle gets completely blocked, eye pressure rises very quickly. This can present symptoms like intense pain of the eye, sudden vision loss, nausea, vomiting , redness of the eye, headache and seeing rainbows or halos. This condition is a medical emergency and you should seek medical treatment immediately.

CONGENITAL GLAUCOMA

This type of glaucoma is very rare and affect infants. It occurs due to abnormal development of the drainage angle of the eye, which slows or prevent normal fluid drainage. Symptoms of congenital glaucoma often include cloudy eyes, sensitivity to light  and excessive tearing.

LOW PRESSURE/ NORMAL TENSION GLAUCOMA

It is also a rare form of glaucoma characterised by damage to the optic nerve and vision loss regardless of intraocular pressure being normal. It could also be as a result of poor blood flow to the optic nerve.

PIGMENTED GLAUCOMA

In this type of glaucoma, pigments dislodged from the iris slowly builds up in the eye's drainage systems and causes intermittent increase in intraocular pressure. Some people with pigmentary glaucoma may see halos or have blurry vision after activities like jogging and playing basketball.

NEOVASCULAR GLAUCOMA

It happens when the eye makes extra blood vessels that cover the part of your eye where fluid would normally drain. Its usually caused by another medical condition like diabetes or high blood pressure.

PSEUDOEXFOLIATIVE GLAUCOMA

It is caused by the accumulation of a fibrillary, protein material in the drainage angle and other structures of the eye. this prevents adequate drainage of fluid from the eye.

RISK FACTORS OF GLAUCOMA

There are certain factors which increase your risk of getting glaucoma. They include; 

⦁ Age - people who are 40 years and above for black and Hispanic people and 60 years and older for white people.

⦁ Family history of glaucoma

⦁ Race - people who are African , Hispanic or Asia Heritage are of high risk

⦁ Having underlying health conditions like diabetes.

⦁ Having an eye injury or condition.

⦁ Use of long-term steroid medications.

⦁ Previous eye surgery

⦁ Severe myopia or hyperopia

⦁ High blood pressure

⦁ Having corneas that are thin in the centre.

⦁ Having thinning of the optic nerve

DIAGNOSIS

The diagnosis of glaucoma is a complete eye exam. During a glaucoma exam, your ophthalmologist may perform these tests;

1. Tonometry - a test which measures the intraocular pressure.

2. Pachymetry - a test which measures the thickness of your cornea.

3. Perimetry -  this is used to test your peripheral (side) vision.

4. Gonioscopy exams - an examination used to inspect your eye's drainage angle.

5. Optic Nerve Scanning -  To take a picture or computer measurement of your optic nerve.

6. Ophthalmoscopy - This is used to examine the inner part of the eye.

TREATMENT OF GLAUCOMA

Doctors use different types of treatment for glaucoma including medicines , laser treatment and surgery. If you have glaucoma, it's important to start treatment right away. Treatment won't undo any damage to your vision, but it can stop it from getting worse.

MEDICATION

The most common treatment for glaucoma is prescription eye drops. They work by lowering the pressure in your eye and preventing damage to your optic nerve. Some of the medications include

⦁ Prostaglandins; Travatan Z (Travoprost)

⦁ Rho Kinase Inhibitor; Rhopressa (Netarsudil)

⦁ Nitric Oxides; Vyzulta (latanoprostene bunod)

⦁ Miotic or cholinergic agents; Isopto Carpine (pilocarpine)

LASER TREATMENT

This can help with some types of glaucoma. It works by helping the fluid in your eye drain, which can help lower the pressure of your eye.

SURGERY

If glaucoma medicines and laser treatment have not helped to treat your glaucoma, your doctor may recommend surgery. There are few types of surgery that can help lower the pressure in your eye;

⦁ Trabeculectomy

⦁ Glaucoma implant surgery

⦁ Minimally Invasive Glaucoma Surgery

PREVENTION

There is no known way to prevent glaucoma, but early detection and treatment can improve your chance of preventing vision loss. It is therefore important to have regular eye examination from the age of 40 years and older.

Glaucoma is the second leading cause of blindness. Even though, it cannot be prevented but if detected early, you can prevent vision loss. Constant eye examination is necessary for this step. Today March 9, 2023 as the WORLD GLAUCOMA DAY, be informed and share with your loved ones even your enemies, haha. Thanks for asking

REFERENCES

1. Tim Newman (January 21, 2021) What is Glaucoma published by Medical News Today.

2. Kimberly Holland (March 31, 2017) Glaucoma published by Healthline.

3. Kierstan Boyd (December 06, 2022) Glaucoma published by American Academy of ophthalmology.

4. Glaucoma published by National Eye Institute.