Glaucoma is primarily related to increased pressure, known as intraocular pressure, in one or both eyes. This elevated pressure in the eyes can lead to damage of the optic nerve. There are also cases where glaucoma is not related to eye pressure and is attributed to other causes such as poor blood flow to the optic nerve.
What is Glaucoma?
It is a disease of the optic nerve. The optic nerve plays a crucial role in vision. It receives nerve impulses from the retina and then transmits these impulses to the brain, which in turn recognizes these electrical signals as vision.
Glaucoma typically causes progressive damage to the optic nerve that often sets out with a subtle loss of peripheral vision (side vision). Without treatment, as the disease progresses it can cause loss of the central vision and eventually blindness.
Types of Glaucoma
Open Angle Glaucoma: Also referred to as chronic glaucoma, this form of the disease does not exhibit other signs or symptoms except gradual loss of vision. In fact, the loss of vision can be so slow as to not provoke much thought, but in the end, it causes irreversible damage. This type of glaucoma is the most common to affect individuals.
Angle Closure Glaucoma: This type of the disease is also known as acute glaucoma. A clear fluid called the aqueous humor is continuously produced in the back of the eye. This fluid fills the front portion of the eye, leaving the eye through canals in the iris and cornea. Acute glaucoma occurs when the flow of this fluid is obstructed, causing a swift build-up of the fluid, and a consequent painful increase in eye pressure. This is an emergency and you must call your doctor immediately if you experience these symptoms: severe pain, blurred vision, and nausea.
Congenital Glaucoma: This is often a condition that children are born with and can be hereditary too. It presents itself as a defect in the angle of the eye, preventing normal fluid drainage. Symptoms include excessive tearing, cloudy eyes, and sensitivity to light.
Normal Tension Glaucoma: The cause for this type of glaucoma is not known as individuals may experience symptoms without an increase in eye pressure. The only causes that can be attributed to the condition are extreme sensitivity in the eye or lack of adequate blood flow to the optic nerve.
Secondary Glaucoma: This type of glaucoma is usually a side effect of accidents/ injuries or other eye conditions like cataracts or tumours. Other causes include certain types of medication, or in rare cases, eye surgery.
Symptoms of Glaucoma and Risk Factors
Common symptoms to look out for:
- Severe eye pain
- Nausea and vomiting
- Unexpected disturbances in vision
- Seeing coloured rings around lights
- Redness in the eye
Major risk factors for the disease include:
- Family history of glaucoma
- Over 45 years of age
- Prior history of increased intraocular pressure
- Decrease in corneal rigidity and thickness
- Near-sightedness or far-sightedness
- Any previous injury to the eye
- Use of steroids, either directly in the eye, or orally or injected