Introduction
Glaucoma is an ophthalmic condition in which the optic nerve (cranial nerve II) is damaged. Glaucoma is a general term which refers to a group of eye disorders which cause damage to the optic nerve. It can lead to loss of vision.
Key Data & Insights
Facts about Glaucoma
- It is a common age-related condition.
- It is approximated that 3 million Americans are affected by glaucoma.
- After cataracts, glaucoma is the second leading cause of blindness worldwide.
Understanding Causes
What are the causes of glaucoma?
- Glaucoma can occur without any specific cause, but many factors can play roles in its development.
- One of the factors is intraocular pressure (IOP).
- In glaucoma, aqueous humor builds up in the eye leading to elevated eye pressure which can damage the optic nerve and cause glaucoma.
Associated Risk Factors
What are the risk factors for glaucoma?
- There are several factors that can contribute to development of glaucoma.
- Among them are:
- Diabetes. Diabetic patients are twice as likely to get glaucoma when compared with non-diabetic patients.
- Family history of glaucoma.
- High blood pressure and very low blood pressure.
- Chronic use of corticosteroids.
- Previous eye injury or surgery.
- Myopia (nearsightedness) for open-angle glaucoma.
- Hyperopia (farsightedness) for closed-angle glaucoma.
Types
What are the types of glaucoma?
The following are the types of glaucoma:
- Open-angle glaucoma.
- Closed-angle glaucoma.
- Normal-tension glaucoma.
- Congenital glaucoma.
Open-angle glaucoma
- Open-angle glaucoma is the most common type of glaucoma.
- It affects up to 90% of Americans.
- It can go unnoticed for several years as many people do not present with symptoms.
- It occurs when there is build of resistance in the drainage canals of the eyes. These drainage canals seem to be open and performing normal function. As the fluid builds up in the eye (usually over months or years), it puts pressure on the cranial nerve II.
Closed-angle glaucoma
- Closed-angle glaucoma is rare and acute.
- It is also known as:
- Narrow-angle glaucoma.
- Angle-closure glaucoma.
- It can occur when:
- The angle between iris and cornea is too narrow.
- There is quick pupillary dilatation.
- Symptoms can include:
- Headaches.
- Eye pain
- It requires immediate medical attention.
Normal-tension glaucoma
- It is also referred to as:
- Normal-pressure glaucoma.
- Low-tension glaucoma.
- It is more common among Asians and Asian Americans.
- In normal-tension glaucoma, the eye pressure is normal or not very high and yet there is optic nerve damage.
Congenital glaucoma
- It is also referred to as:
- Childhood glaucoma.
- Infantile glaucoma.
- Paediatric glaucoma.
- Congenital glaucoma in babies whose drainage canals did not form well during pregnancy.
Symptoms & Clinical Diagnosis
General symptoms;
- Red eyes.
- Blurred vision.
- Nausea and vomiting.
- Headache.
- Pressure or pain in the eye.
- Rainbow-colored halos around lights.
Diagnostic Methods
How is glaucoma diagnosed?
- Damage done to optic nerve due to glaucoma is irreversible.
- Earlier detection and treatment can help to prevent blindness.
- Tests performed to check for glaucoma:
- Dilated eye examination.
- Visual acuity test.
- Visual field test.
- Genioscopy.
- Optical coherence tomography (OCT).
- Tonometry(ocular pressure test).
- Pachymetry.
Management & Treatment Options
Can glaucoma be cured?
- No, glaucoma does not have a definitive cure.
- The target is usually to stop symptoms and disease progression.
- Treatment can slow down any further loss of vision, but it does not restore lost vision.
Strategies for treatment
Treatment strategies include:
- Eye drops.
- Laser therapy.
- Surgery.
Complications & Challenges
Visual impairment (blindness). Untreated glaucoma can lead to faster development of permanent vision loss or blindness.
Strategies for Prevention
How can we prevent glaucoma?
- Routine eye check-ups.
- Glaucoma testing every:
- 1-3 years after age 35 for people who are at high risk.
- 2-4 years before age 40.
- 1-3 years between ages 40-54 years.
- 1-2 years for those aged between 55-64.
- 6-12 months after age 65.