Glaucoma: risk factors, eye tests and treatment options, a review

Glaucoma often causes no symptoms in its early stages, so a person can have it without knowing. This article explains what glaucoma is, who is at higher risk, how it is found and how it is managed, using information from the NHS, the US National Eye Institute and the CDC.

1. Introduction

Glaucoma is a group of eye diseases that damage the optic nerve. The optic nerve is the nerve that connects the eye to the brain ^{[1, 2]}. Without early diagnosis and treatment, glaucoma can lead to loss of sight, and in some cases blindness ^{[1, 2]}. The CDC describes it as the second leading cause of blindness worldwide ^[3].

Doctors describe several types. Primary glaucoma is the most common and usually develops slowly over many years. Open-angle glaucoma is the most common form in the United States. Angle-closure glaucoma is less common and can cause sudden, severe symptoms. Secondary glaucoma is caused by another condition or an eye injury, and a rare type, called childhood or congenital glaucoma, affects young children ^{[1, 2]}.

2. Causes and risk factors

Glaucoma is usually linked to a build-up of pressure inside the eye. This happens when the fluid in the eye does not drain properly, and the pressure then damages the optic nerve ^[1]. Some people have nerve damage even when their eye pressure is in the normal range, and high eye pressure does not always lead to glaucoma. The exact cause of the common types is not fully understood ^{[1, 2]}.

You are more likely to have glaucoma if ^{[1, 2, 3]}:

• You are over 50 (the NHS) or over 60 (the CDC)
• A parent, brother or sister has glaucoma
• You are of Black African, Caribbean or Asian background (the NHS); the CDC says Black people over 40 are at higher risk
• You have diabetes, short-sightedness or long-sightedness

The CDC reports that people with diabetes are about twice as likely to develop glaucoma as people without it ^[3]. Anyone can develop glaucoma, so people who feel well still need eye checks.

3. Signs and symptoms

Open-angle glaucoma usually has no early symptoms. The CDC and the National Eye Institute say about half of people with it do not know they have it ^{[2, 3]}. It usually affects both eyes, though one may be worse ^[1]. Sight is lost slowly, normally starting with side (peripheral) vision, and later the centre of vision can be affected ^{[2, 3]}.

Angle-closure glaucoma can come on suddenly. Warning signs include ^{[1, 2]}:

• Intense eye pain
• A red eye and tenderness around the eye
• Blurred vision and seeing rainbow-coloured rings around lights
• Headache, feeling sick or being sick

4. Diagnosis and tests

Glaucoma is usually found during a routine eye test, often before any symptoms appear ^[1]. The only way to confirm it is a comprehensive dilated eye exam, where drops widen the pupil. The doctor also measures eye pressure and uses a visual field test to check side vision. The exam is simple and painless ^{[2, 4]}. If glaucoma is suspected, the NHS says you will be referred to an ophthalmologist, a doctor who specialises in eyes ^[1].

The NHS advises an eye test at least every two years, and more often for people at higher risk ^[1]. The National Eye Institute suggests an exam every one to two years for people over 60, for African American people over 40 and for those with a family history of glaucoma ^[4].

5. Treatment and management

Treatment cannot reverse damage that has already happened, but it can slow or stop further loss of sight ^{[1, 2]}. The aim is to lower eye pressure. Your eye doctor will advise which treatment is right for you. The options described are ^{[1, 2, 3]}:

• Prescription eye drops, the most common treatment, which lower eye pressure and protect the optic nerve
• Oral medicine in some cases
• Laser treatment, a simple procedure done in the office that helps fluid drain from the eye
• Surgery, with several types of operation, if other treatments are not enough

Follow-up visits are important so the doctor can check that the treatment is working, and the NHS discourages missing them ^[1]. Take your prescribed medicine as directed and tell your doctor about any side effects ^{[2, 3]}. If vision loss makes daily tasks hard, ask about low vision services and aids ^[2]. The NHS says support groups and lifestyle changes may help people living with glaucoma ^[1].

6. Prevention and self-care

There is no known way to prevent the common types of glaucoma, which is why regular eye exams matter for early detection ^[2]. The CDC suggests healthy habits that also protect general health: keep a healthy weight, control blood pressure, stay physically active and do not smoke ^[3]. Because glaucoma can run in families, encourage close relatives to have their eyes checked ^{[2, 3]}.

7. When to see a doctor

See your doctor or optician if you have any worry about your sight ^[1]. Book regular eye exams even if your vision seems fine. Sudden symptoms such as severe eye pain, a red eye, blurred vision, rainbow rings around lights, headache or vomiting need emergency care. The NHS advises not to drive yourself, and to bring the medicines you take ^[1].

In an emergency, call your local emergency number (112 in India, 911 in the United States).

8. Conclusion

Glaucoma often gives no warning, so eye exams are the main way to catch it early. Treatment lowers eye pressure and can protect the sight you still have, but it cannot undo damage. Know your family history, attend follow-up visits and take prescribed treatment as your eye doctor directs.