Published: 18 Jun 2025

ICD9: 365.9      ICD10: H40.9      ICD11: 9C61

Glaucoma is a group of eye diseases that damage the optic nerve, which connects the eye to the brain.
This damage often results from abnormally high pressure inside the eye (intraocular pressure), though not always.

Here's a breakdown of key aspects of glaucoma:

Optic Nerve Damage: The defining characteristic of glaucoma is damage to the optic nerve. This nerve is crucial for transmitting visual information from the eye to the brain. As the nerve fibers deteriorate, blind spots develop in the field of vision.

Intraocular Pressure (IOP): While elevated IOP is a major risk factor, it's not the only cause.
High IOP: In many cases, glaucoma is associated with increased fluid pressure inside the eye. This pressure puts stress on the optic nerve, leading to damage.
Normal-Tension Glaucoma: Some people develop glaucoma with normal IOP. The exact cause is not fully understood, but factors like blood flow problems to the optic nerve may play a role.

Progressive Vision Loss: Glaucoma typically progresses slowly and painlessly at first. Many people are unaware they have the condition until significant vision loss has occurred. Peripheral (side) vision is usually affected first.

Types of Glaucoma:
Open-Angle Glaucoma: The most common type. The drainage angle (where fluid leaves the eye) remains open, but the fluid drains too slowly, causing pressure to build up.
Angle-Closure Glaucoma: The drainage angle becomes blocked, preventing fluid from leaving the eye. This can happen suddenly (acute) or gradually (chronic). Acute angle-closure glaucoma is a medical emergency.
Normal-Tension Glaucoma: Optic nerve damage occurs despite normal IOP.
Congenital Glaucoma: A rare condition present at birth due to improper development of the eye's drainage system.
Secondary Glaucoma: Glaucoma that develops as a result of another medical condition, such as eye injury, inflammation, or certain medications.

Risk Factors:
Age: The risk of glaucoma increases with age.
Family History: Having a family history of glaucoma increases your risk.
Race/Ethnicity: People of African descent, Hispanic descent, and Asian descent have a higher risk of certain types of glaucoma.
High Intraocular Pressure: Elevated IOP is a significant risk factor.
Myopia (Nearsightedness): Nearsighted individuals have a higher risk of open-angle glaucoma.
Diabetes: People with diabetes are at increased risk.
High Blood Pressure: Elevated blood pressure can be a risk factor.
Corticosteroid Use: Prolonged use of steroid medications, especially eye drops, can increase IOP and the risk of glaucoma.

Diagnosis: An eye doctor (ophthalmologist or optometrist) diagnoses glaucoma through a comprehensive eye exam, which may include:
Tonometry: Measuring IOP.
Ophthalmoscopy: Examining the optic nerve.
Gonioscopy: Examining the drainage angle.
Visual Field Testing: Checking for blind spots in your vision.
Optical Coherence Tomography (OCT): Imaging the optic nerve to assess its structure and thickness.

Treatment: The goal of glaucoma treatment is to lower IOP and prevent further optic nerve damage. Treatment options include:
Eye Drops: Medicated eye drops are the most common initial treatment to lower IOP.
Laser Surgery: Laser procedures can help improve fluid drainage. Examples include laser trabeculoplasty (for open-angle glaucoma) and laser iridotomy (for angle-closure glaucoma).
Microsurgery: Surgical procedures, such as trabeculectomy or glaucoma drainage devices (tubes), create new pathways for fluid to drain from the eye.
Minimally Invasive Glaucoma Surgery (MIGS): These procedures are less invasive than traditional glaucoma surgery and often have fewer complications.

Importance of Early Detection: Early detection and treatment of glaucoma are crucial to prevent or slow vision loss. Because glaucoma often has no symptoms in its early stages, regular eye exams are essential, especially for those at higher risk.

Irreversible Damage: Vision loss from glaucoma is generally irreversible. Therefore, ongoing management is necessary to prevent further damage.

In summary, glaucoma is a serious eye condition that can lead to blindness if left untreated. Regular eye exams are key to early detection and management. If you have any concerns about your vision or risk factors for glaucoma, consult with an eye doctor.