Different types of glaucoma

Glaucoma is a group of eye conditions that damage the optic nerve, crucial for good vision. This damage is often caused by abnormally high pressure in the eye. Glaucoma is one of the leading causes of blindness for people over the age of 60. It can occur at any age but is more common in older adults. The most common types of glaucoma are open-angle glaucoma and angle-closure glaucoma.

Types of Glaucoma

1. Open-Angle Glaucoma (Chronic Glaucoma)

   • Description: This is the most common type of glaucoma. It occurs when the drainage angle formed by the cornea and iris remains open, but the trabecular meshwork is partially blocked. This leads to a gradual increase in eye pressure.
   • Symptoms: Often, there are no symptoms until significant vision loss occurs. Peripheral vision is usually affected first, followed by central vision.
   • Risk Factors: Age, family history, ethnicity (more common in African Americans), and conditions such as diabetes and hypertension.

2. Angle-Closure Glaucoma (Acute Glaucoma)

   • Description: This type occurs when the iris bulges forward to narrow or block the drainage angle formed by the cornea and iris. As a result, fluid cannot circulate through the eye and pressure increases rapidly.
   • Symptoms: Sudden onset of severe eye pain, headache, nausea, vomiting, blurred vision, and halos around lights.
   • Risk Factors: Age, hyperopia (farsightedness), Asian descent, and a family history of angle-closure glaucoma.

3. Normal-Tension Glaucoma

   • Description: In this type, optic nerve damage occurs even though the intraocular pressure (IOP) is within the normal range. The exact cause is not well understood but is thought to be related to a sensitive optic nerve or reduced blood flow to the optic nerve.
   • Symptoms: Similar to open-angle glaucoma, with gradual vision loss.
   • Risk Factors: Family history, cardiovascular disease, and Japanese ancestry.

4. Secondary Glaucoma

   • Description: This type occurs as a result of another medical condition or eye injury. Conditions such as uveitis, steroid use, eye trauma, and neovascular glaucoma can cause increased eye pressure and optic nerve damage.
   • Symptoms: Vary depending on the underlying cause but generally include increased eye pressure and vision changes.
   • Risk Factors: Depends on the underlying condition causing the glaucoma.

5. Congenital Glaucoma

   • Description: This is a rare type that occurs in infants and young children due to abnormal development of the eye's drainage system before birth. It can be hereditary.
   • Symptoms: Signs include enlarged eyes, cloudiness of the cornea, excessive tearing, and sensitivity to light.
   • Risk Factors: Genetic mutations and family history.

Management and Treatment

Early detection through regular eye exams is crucial for preventing vision loss from glaucoma. Treatments may include:

• Medications: Eye drops or oral medications to reduce eye pressure.
• Laser Therapy: Procedures such as laser trabeculoplasty for open-angle glaucoma and laser iridotomy for angle-closure glaucoma.
• Surgery: Techniques like trabeculectomy or the placement of drainage implants to improve fluid drainage.

By managing eye pressure and monitoring changes, the progression of glaucoma can be slowed, preserving vision.