By Dr Andile Pieterson & Dr Ayanda Mthembu (TwinsOnEyes) — Optometrists
Glaucoma is one of the leading causes of irreversible blindness worldwide. Often called the “silent thief of sight,” it develops slowly and usually without noticeable symptoms in its early stages. By the time vision changes are detected permanent damage may already have occurred. Understanding glaucoma its causes, symptoms and treatment options is essential for protecting long-term vision and maintaining quality of life.
What Is Glaucoma?
Glaucoma refers to a group of eye conditions that damage the optic nerve the structure responsible for carrying visual information from the eye to the brain. This damage is most commonly linked to increased pressure inside the eye known as intraocular pressure (IOP), although glaucoma can also occur when eye pressure is within normal limits.
The eye continuously produces a clear fluid called aqueous humor. This fluid nourishes the eye and helps maintain its shape. Normally it drains through a specialized drainage system at the front of the eye. When drainage is reduced or blocked fluid builds up increasing eye pressure. Over time this pressure damages the delicate fibers of the optic nerve leading to gradual and permanent vision loss. Types of Glaucoma
The two most common forms are primary open-angle glaucoma and angle-closure glaucoma.
Primary Open-Angle Glaucoma This is the most common type. The drainage angle remains open but fluid drains too slowly causing a gradual rise in eye pressure. Vision loss usually begins with peripheral vision and progresses inward. Because it develops slowly and painlessly many people are unaware they have it until the condition is advanced.
Angle-Closure Glaucoma This less common but more severe type occurs when the drainage angle suddenly becomes blocked. Eye pressure rises rapidly, leading to severe eye pain, blurred vision, headache, nausea, redness, and seeing halos around lights. Angle-closure glaucoma is a medical emergency requiring immediate treatment to prevent permanent vision loss.
Other forms include congenital glaucoma in infants and secondary glaucoma caused by injury, inflammation, diabetes, or long-term steroid use.
Risk Factors While anyone can develop glaucoma, certain factors increase the risk: • Age over 40, with higher risk after 60 • Family history of glaucoma • Elevated intraocular pressure • Diabetes or high blood pressure • Previous eye injuries • Long-term steroid use • African ancestry, which carries a higher risk for some types
In South Africa, where access to routine eye care may differ between communities awareness and regular screenings are especially important. Many individuals seek help only once symptoms appear but by then damage may already be significant.
Symptoms
Symptoms depend on the type of glaucoma.
Open-angle glaucoma often has no early warning signs. Peripheral vision gradually decreases creating blind spots that may go unnoticed. As the disease progresses central vision may also be affected. Angle-closure glaucoma causes sudden symptoms, including: • Severe eye pain • Redness • Blurred vision • Headache • Nausea and vomiting • Halos around lights
Because early stages are often symptom-free comprehensive eye examinations remain the only reliable way to detect glaucoma early.
Diagnosis
Glaucoma is diagnosed through a thorough eye examination performed by an optometrist or ophthalmologist. Tests may include: • Tonometry to measure eye pressure • Ophthalmoscopy to examine the optic nerve • Visual field testing to assess peripheral vision • Pachymetry to measure corneal thickness • Gonioscopy to evaluate the drainage angle Early detection is crucial as optic nerve damage cannot be reversed. Treatment focuses on preventing further progression and preserving remaining vision.
Treatment Options
Although there is no cure for glaucoma treatment can effectively slow or stop further vision loss by lowering eye pressure.
Eye Drops: Prescription eye drops are usually the first line of treatment. They either reduce fluid production or improve drainage. Consistency is critical as missed doses can allow pressure to rise.
Oral Medications: In some cases tablets may be prescribed to further reduce eye pressure.
Laser Therapy: Laser procedures can improve fluid drainage or decrease fluid production. These treatments are typically quick and performed in a clinical setting.
Surgery: If medications and laser therapy are insufficient surgery may be necessary to create a new drainage pathway.
Treatment is often lifelong, and regular follow-up visits are essential to monitor eye pressure and optic nerve health.
Living with Glaucoma
A glaucoma diagnosis can feel overwhelming but with proper care most people maintain useful vision throughout their lives. Adhering to treatment and attending routine check-ups significantly reduces the risk of severe vision loss.
Healthy lifestyle habits may support overall eye health, including regular physical activity, maintaining healthy blood pressure and blood sugar levels, avoiding smoking, and eating a balanced diet rich in leafy greens. Support from family and healthcare providers helps individuals adjust to any changes in vision and maintain independence.
Prevention and Awareness
While glaucoma cannot always be prevented, early detection makes a significant difference. Regular/ Routine eye examinations, especially for individuals over 40 or those with risk factors is recommended every 12-18 months. Pearls of wisdom: Glaucoma is a thief of sight. It develops slowly and painlessly and by the time vision changes are noticed damage may already be permanent. Do not wait for symptoms. Protect your sight with regular eye examinations. An eye test can save more than your vision, it can protect your quality of life.