Glaucoma
A group of eye conditions that damage the optic nerve, the pathway that connects the eye to the brain and allows us to see.
Understanding Glaucoma
Glaucoma is a group of progressive eye conditions that damage the optic nerve, which carries visual information from the retina to the brain. Although glaucoma is not primarily a retinal condition, it is a major cause of irreversible vision loss.
Glaucoma is often associated with increased pressure inside the eye (intraocular pressure), which can damage the optic nerve over time. However, optic nerve damage can also occur when eye pressure is within the normal range.
Vision loss often begins with peripheral (side) vision and may progress gradually without noticeable symptoms in the early stages. As damage advances, it can affect a person’s ability to see and navigate their surroundings. Vision loss caused by glaucoma is generally permanent, making early detection and appropriate treatment essential.
There are several types of glaucoma:
- Primary Open-Angle Glaucoma (POAG): The most common form, which usually develops gradually as fluid drainage from the eye becomes less efficient.
- Angle-Closure Glaucoma: Occurs when the drainage angle becomes blocked, causing a rapid rise in eye pressure. Acute angle-closure glaucoma is a medical emergency.
- Normal-Tension Glaucoma: Optic nerve damage occurs despite eye pressure remaining within the normal range.
- Secondary Glaucoma: Develops as a result of another eye condition, medical condition, medication or injury.
- Congenital or Childhood Glaucoma: Rare forms that affect infants and children.
Regular eye examinations can help detect glaucoma before significant vision loss occurs. Although existing optic nerve damage cannot usually be reversed, treatment can help reduce the risk of further damage and preserve remaining vision.
Retina International recognises the importance of understanding all conditions that affect vision and supports access to information, research and communities that help people affected by vision loss.

~76 million
people worldwide live with glaucoma
~50%
may not know they have it
1 in 2
could experience significant vision loss without appropriate detection and management
How Glaucoma can affect vision
Possible symptoms, particularly in more advanced disease, include:
- Loss of peripheral vision
- Difficulty seeing in low light
- Difficulty adjusting between light and dark environments
- Blurred vision
- Reduced visual field
- Eye pain, headache, nausea, or sudden vision changes in acute angle-closure glaucoma
Sudden symptoms such as severe eye pain, redness, nausea, or rapid vision loss require urgent medical attention.
Identifying Glaucoma
Eye Pressure Measurement (Tonometry)
Measures the pressure inside the eye.
Optic Nerve Examination
Allows clinicians to assess changes to the optic nerve.
Visual Field Testing
Measures areas of vision that may have been affected.
Optical Coherence Tomography (OCT)
Provides detailed images of the optic nerve and retinal nerve fibre layer.
Gonioscopy
Examines the drainage angle of the eye to determine the type of glaucoma.
Supporting individuals living with glaucoma
Eye Drops
Medications can reduce eye pressure by:
- Reducing fluid production
- Improving fluid drainage
Laser Treatment
Laser procedures may improve fluid drainage or reduce fluid production.
Surgery
Surgical options may be considered when other treatments are not sufficient.
Examples include:
- Trabeculectomy
- Glaucoma drainage devices
- Minimally invasive glaucoma surgery (MIGS)
Regular monitoring is essential to assess whether treatment is controlling disease progression.
Adapting to diagnosis
Living with glaucoma often involves ongoing management and regular eye care.
People affected may benefit from:
- Attending scheduled eye appointments
- Taking medications as prescribed
- Understanding changes in vision
- Using low-vision support services where needed
- Making adaptations to maintain independence
Because glaucoma can affect peripheral vision, some people may experience challenges with:
- Mobility
- Driving
- Navigating unfamiliar environments
- Reading and daily activities
Support from healthcare professionals and patient communities can help people adapt and maintain quality of life.

Advancing the future of glaucoma treatment
Early Detection
Researchers are developing improved imaging technologies and artificial intelligence tools to identify glaucoma changes earlier.
Personalised Treatment
Studies are exploring how genetic, clinical, and imaging information can help tailor treatment approaches.
Neuroprotection
Research is investigating ways to protect optic nerve cells from damage.
Regenerative Approaches
Future research aims to explore whether damaged optic nerve pathways can be repaired or restored.
Information and community support
Take the Next Step
A diagnosis of glaucoma can raise questions about treatment, monitoring, and maintaining independence.
Support may include:
- Eye care professionals
- Vision rehabilitation services
- Low-vision resources
- Patient organisations
- Educational materials
Retina International’s global community connects people affected by vision loss with information, support networks, and opportunities to engage with research and advocacy.
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