What is glaucoma?
Glaucoma is the common name for a group of diseases that result in damage to the optic nerve and loss of vision. Glaucoma is generally a preventable form of vision loss and can be cured if detected early. Unfortunately, about 10% of people who receive proper treatment nevertheless still lose their vision. Glaucoma often has no obvious signs or symptoms before vision loss begins. The best way to protect yourself is to have regular eye exams along with a special glaucoma screening.
Causes of glaucoma
In most cases, optic nerve damage in glaucoma is caused by increased intraocular pressure, in which the pressure of fluid inside the eye increases, resulting in compression and damage to the optic nerve. Intraocular pressure increases when the fluids produced in the eye lose their ability to leave the eye through their normal pathway, known as the open angle between the iris and the cornea. They accumulate in the eye, leading to an increase in pressure. However, in cases of glaucoma with normal pressure, the cause of optic nerve damage is not always clear.
Risk factors for glaucoma
Glaucoma is the second most common cause of blindness in the world. Because the signs and symptoms of glaucoma are often subtle, it is known as the ‘silent thief of sight’. Everyone is advised to have regular glaucoma screenings as part of a comprehensive eye exam, especially if one or more glaucoma risk factors are present.
Glaucoma risk factors vary depending on the type of glaucoma.
Primary open-angle glaucoma
Primary open-angle glaucoma, in which the open angle becomes blocked over time, is the most common form of glaucoma. Risk factors for open-angle glaucoma include:
- Age. Individuals over the age of 60 are six times more likely to have glaucoma.
- Family history. If other members of your family have glaucoma, your risk increases four to nine times.
- Medications. Steroids can increase your risk of open-angle glaucoma by 40 per cent.
- Health conditions. High blood pressure can increase your risk of open-angle glaucoma.
Glaucoma risk factors vary depending on the type of glaucoma.
Closed-angle glaucoma
Closed-angle glaucoma, also known as acute-angle glaucoma, occurs when the iris protrudes over the angle, blocking the drainage channels. This leads to a rapid and dangerous rise in intraocular pressure. Risk factors for closed-angle glaucoma include
- Sight. If you have farsightedness, your risk is increased.
- Age. Your risk of closed-angle glaucoma increases with age.
- Gender. Women are at increased risk.
Secondary glaucoma
Secondary glaucoma, in which the open angle is obstructed due to damage to the eye, inflammation, malignancy, cataract or diabetes, can occur due to one of the following causes:
- Injury to the eye. Both blunt and penetrating trauma to the eye can lead to secondary glaucoma.
- Health conditions. Diabetes and cataracts can increase the risk of secondary glaucoma.
- Gender and skin colour. Light-skinned women are at risk for a certain type of secondary glaucoma.
- Medications. Certain medications may increase the risk of open-angle or closed-angle glaucoma secondary to glaucoma.
Protect your eyesight
Even if you are not exposed to any of the risk factors, you can still develop glaucoma. Getting glaucoma screenings is recommended.
Treatment of glaucoma
Glaucoma treatment can prevent severe vision loss if the disease is diagnosed early enough. Treatment options include:
- Glaucoma drops
- Surgery
- Selective laser trabeculoplasty (SLT)
Glaucoma requires lifelong treatment and monitoring. If you have been prescribed glaucoma medication, you need to take it according to your doctor’s instructions. Glaucoma DOES have signs – it can be diagnosed before you experience any symptoms. Symptoms are subjective and may or may not be understood by your doctor. Signs are objective and understood by the doctor, but may or may not be noticed by the patient.
