•Dr Priscilia Imade
WHAT IS OCULAR HYPERTENSION?
Ocular hypertension means that the fluid pressure inside your eye (intraocular pressure or IOP) is higher than the normal range, which is usually between 10-21 mmHg. When your eye pressure goes above 21 mmHg, you are said to have ocular hypertension.
• It is NOT a disease on its own but an important risk factor for glaucoma.
• Ocular hypertension does not damage the optic nerve or affect your vision directly, but it increases your risk of developing glaucoma over time.
• It is often silent, meaning there are no symptoms like pain or redness. That’s why many people only discover they have high eye pressure during a routine eye examination.
WHAT IS GLAUCOMA?
Glaucoma is a group of eye diseases where increased intraocular pressure (or other factors) causes damage to the optic nerve, the part of the eye that carries visual signals to the brain.
• Glaucoma is one of the leading causes of irreversible blindness worldwide.
• The condition often develops slowly and may not show noticeable symptoms in the early stages. This is why it is sometimes called the “silent thief of sight.”
• Without treatment, glaucoma can gradually cause peripheral (side) vision loss and as it worsens, it can affect central vision too.
TYPES OF GLAUCOMA
1. Open-Angle Glaucoma (POAG):
• The most common type.
• The drainage angle where fluid leaves the eye appears open, but the trabecular meshwork (drainage tissue) becomes less efficient.
• Progresses slowly over time and is painless.
2. Angle-Closure Glaucoma (ACG):
• The drainage angle suddenly becomes blocked, causing a rapid rise in eye pressure.
• Can present with severe eye pain, headaches, halos around lights, nausea and blurred vision.
• Considered a medical emergency.
3. Normal-Tension Glaucoma:
• Occurs when optic nerve damage happens despite normal eye pressure.
• Believed to be linked to poor blood flow or increased optic nerve sensitivity.
HOW ARE THEY CONNECTED?
• Ocular hypertension is a warning sign and a risk factor for glaucoma. However, not everyone with ocular hypertension will develop glaucoma.
• Some patients with normal IOP can still develop glaucoma (normal-tension glaucoma), which suggests that optic nerve health and blood flow are also involved.
• Regular monitoring is key because glaucoma damage is permanent but preventable with early detection.
WHAT CAUSES HIGH EYE PRESSURE?
• Reduced drainage of aqueous humor through the trabecular meshwork.
• Overproduction of aqueous humor.
• Use of steroids (eye drops, oral or systemic steroids).
• Eye injuries or trauma.
• Genetic factors as glaucoma often runs in families.
• Thin cornea (central corneal thickness) may increase glaucoma risk even with moderately raised IOP.
DIAGNOSIS:
Eye doctors use several tests to check for ocular hypertension or glaucoma:
• Tonometry: Measures eye pressure.
• Gonioscopy: Examines the drainage angle inside the eye.
• Ophthalmoscopy/BIO: Looks at the optic nerve for damage.
• Visual Field Test: Checks for blind spots in your side vision.
• OCT Scan: A high-resolution scan that shows the thickness of the optic nerve fibers.
TREATMENT:
• For ocular hypertension some people may only need regular monitoring, while others might benefit from medicated eye drops to lower eye pressure if they are at higher risk (e.g., family history, thin cornea).
• For glaucoma, treatment is essential to protect vision. The goal is to lower eye pressure and prevent further nerve damage. Treatment options include:
1. Medicated eye drops (most common).
2. Laser therapy such as laser trabeculoplasty.
3. Surgery, such as trabeculectomy or drainage implants, in severe or uncontrolled cases.
CONCLUSION:
• Ocular hypertension is like an early warning sign. It gives you the opportunity to take preventive steps to avoid glaucoma.
• Glaucoma is irreversible but manageable when caught early.
• Many people lose vision from glaucoma because they don’t get regular eye exams.
• Early detection and treatment can save your sight and preserve your quality of life.
If you are over 40, have a family history of glaucoma, are of African descent (which is a risk factor), make sure you get a comprehensive eye examination at least once every year.
*Dr Priscilia Imade is CEO, Modern Eye Clinic, Lagos. E-mail: moderneyecliniclagos@gmail.com
Another edition of the column returns on Monday in The Frontier.
