Glaucoma
What is glaucoma?
Glaucoma is a group of eye diseases that damage the optic nerve, which carries visual information from the eye to the brain. It is often associated with increased eye pressure, although glaucoma can also occur with normal eye pressure. Once optic nerve damage occurs, vision loss is permanent and cannot be reversed. Because it often develops without noticeable symptoms, glaucoma is known as the “Silent Thief of Sight.”
What causes glaucoma?
- Blockage or reduced drainage of aqueous humour (eye fluid)
- Increased eye pressure
- Progressive optic nerve damage
- In some cases, glaucoma occurs despite normal eye pressure
Common symptoms
- No symptoms in the early stages
- Gradual loss of side (peripheral) vision
- Difficulty seeing objects to the side
- Trouble reading fine print
- Difficulty driving, especially at night
- Tunnel vision in advanced stages
Types of glaucoma
1. Primary open-angle glaucoma (POAG)
- The most common type
- Develops slowly over years
- Painless
- No early symptoms
- Progressive vision loss
2. Angle-closure glaucoma
- Occurs when the drainage angle becomes blocked
- Severe eye pain
- Red eye
- Sudden blurred vision
- Coloured halos around lights
- Severe headache
- Nausea and vomiting
- Requires immediate medical attention
3. Congenital glaucoma
- Present in infants due to abnormal drainage system development
- Excessive tearing
- Sensitivity to light
- Enlarged eyes
- Cloudy cornea
- Early surgery can help preserve vision
4. Secondary glaucoma
May occur due to
- Eye injury
- Long-term steroid use
- Eye inflammation (uveitis)
- Diabetic eye disease
- Previous eye surgery
- Certain medications
Risk factors
- Age above 40 years
- Family history of glaucoma
- High eye pressure
- Diabetes
- High myopia (high minus power)
- Long-term steroid use
- Previous eye injury
- Certain retinal, corneal, or inflammatory eye diseases
When should you get your eyes checked?
- Every 1–2 years after age 40
- Earlier, if you have risk factors
- Regularly, if you have a family history of glaucoma
- Immediately, if symptoms of acute glaucoma develop
How is glaucoma diagnosed?
A comprehensive eye examination may include
- Eye pressure measurement (Tonometry)
- Corneal thickness measurement
- Optic nerve evaluation
- Gonioscopy (drainage angle assessment)
- Visual field testing
- OCT (Optical Coherence Tomography) scan
Treatment
Vision already lost from glaucoma cannot be restored. Treatment aims to lower eye pressure, prevent further optic nerve damage, and preserve remaining vision.
Eye drops
- Reduce fluid production
- Improve fluid drainage
- Must be used regularly as prescribed
Laser treatment
- Laser Peripheral Iridotomy (LPI)
- Selective Laser Trabeculoplasty (SLT)
Surgery
- Trabeculectomy
- Minimally Invasive Glaucoma Surgery (MIGS)
- Glaucoma drainage devices
Regular follow-up is essential
Even when vision seems stable:
- Eye pressure can change
- Optic nerve damage may continue
- Treatment may need adjustment
Living with glaucoma
- Use medications regularly
- Attend scheduled eye appointments
- Control diabetes and blood pressure
- Inform your doctor about all medications
- Discuss any side effects of treatment
- Wear protective eyewear when needed
- Encourage family members to undergo glaucoma screening
Key message
Glaucoma can cause irreversible vision loss and blindness if left untreated. However, early detection, timely treatment, and regular follow-up can help preserve vision for life.
Detect early. Treat early. Preserve vision for life.