What Are The Different Types of Glaucoma? Find Clear Answers

Ever wondered why your ophthalmologist keeps encouraging you to have “regular eye pressure checks,” especially after your 40s, even when your vision feels perfectly fine? The reason is “glaucoma”. Glaucoma is often silent until real damage has already occurred, and it doesn’t show up as just one condition; it comes in several distinct types, each with a different warning pattern, risk profile, and urgency level.

If you’ve searched “what are the different types of glaucoma,” you’re likely trying to understand which one applies to you, a parent, or a grandparent. This guide breaks down each type in plain language, so you know exactly what to watch for and when to act, not just what the textbook definition says.

A] Understanding Glaucoma Before Learning Its Types

Before exploring the different types, it’s important to understand what glaucoma actually is.

Your eyes continuously produce a clear fluid called aqueous humour, which nourishes the eye and normally drains through a tiny drainage system. When this drainage slows down or becomes blocked, high eye pressure may develop. Over time, this increased pressure can damage the optic nerve.

Now, what is the optic nerve? It is basically the structure responsible for carrying visual signals from your eyes to your brain. Once optic nerve fibres are damaged, the resulting vision loss cannot be restored.

One of the biggest challenges with glaucoma is that it usually develops without pain or noticeable symptoms in its early stages. In fact, it can develop even when your eye pressure falls within the normal range. That’s why routine eye examinations are so important, particularly when you are over 40, have diabetes, high myopia, or a family history of glaucoma.

At our eye hospital in Mumbai, we do comprehensive glaucoma screening to understand it in greater detail. You can also read our comprehensive guide on glaucoma diagnosis and treatment for a clearer picture.

B] The Core Types of Glaucoma Broken Down Simply

Every type of glaucoma damages the optic nerve; however, the reason it develops, how quickly it progresses, and the symptoms it causes can vary for each patient.

1. Open-Angle Glaucoma (The Most Common Type of Glaucoma)

Nearly 90% of all glaucoma cases worldwide are due to open-angle glaucoma. This is the most common type of glaucoma.

In this condition, the drainage angle stays open, but the drainage meshwork gradually loses its ability to drain fluid effectively. Just think of it as a kitchen sink that drains a little slower with time; the water still drains but not as fast as it used to. Similarly, fluid slowly builds up in the eye, increasing pressure and damaging the optic nerve over time.

The main concern with open-angle glaucoma is that it often has no warning signs. Most people do not understand, as the central vision remains unaffected, which gives clear vision, but peripheral vision slowly narrows. By the time vision changes become noticeable, optic nerve damage has already taken place.

Due to this silent progression, glaucoma is often called the “silent thief of sight.”

2. Angle-Closure Glaucoma (The Sudden Emergency)

Angle-closure glaucoma is unlike open-angle glaucoma; it develops rapidly.

Here, the drainage angle between the iris and cornea gets blocked, which builds up fluid in the eye and increases the pressure quickly, often within hours.

Typical angle-closure glaucoma symptoms include:

• Sudden, severe eye pain
• Blurred vision
• Intense headache
• Seeing rainbow-coloured halos around lights
• Redness of the eye
• Nausea or vomiting

Unlike open-angle glaucoma symptoms, these symptoms should never be ignored.

Angle-closure glaucoma is a medical emergency, and delaying treatment, even by a few hours, may result in permanent vision loss. Immediate evaluation by an ophthalmologist is essential.

3. Normal-Tension Glaucoma (When Eye Pressure Isn’t High)

In this type, the optic nerve can get damaged even when eye pressure is within the normal range. While there is no exact cause, reduced blood flow to the optic nerve and increased nerve sensitivity could be the reason.

Research suggests it’s disproportionately more common in Asian populations, including India, compared to Western populations, making it a particularly relevant type for local patients to be aware of, since a “normal” pressure reading alone doesn’t rule out risk. This highlights why routine eye screening should never be limited to pressure checks alone.

4. Secondary Glaucoma (Caused by Another Eye Condition)

Secondary glaucoma causes are a consequence of another underlying issue rather than occurring on its own. Common secondary glaucoma causes include:

• Uncontrolled diabetes
• Eye injuries or trauma
• Advanced or untreated cataracts
• Prolonged use of steroid eye drops
• Eye inflammation (uveitis)
• Certain eye surgeries

Because the trigger varies, treatment always starts with addressing the root cause alongside managing eye pressure.

5. Congenital Glaucoma (The Rare Childhood Form)

Congenital glaucoma in babies is rare but serious. It develops when a child is born with an improperly developed drainage system. Parents should look out for symptoms such as:

• Excessive tearing
• Sensitivity to light
• Cloudy or enlarged eyes
• Frequent eye rubbing

Because infants cannot describe vision problems, recognising these signs early is essential. Prompt diagnosis and treatment by a paediatric ophthalmologist offer the best chance of preserving healthy vision and supporting normal visual development.

C] Are You At Risk? Identifying the Red Flags

Glaucoma can affect anyone; you may be at higher risk if you fall into any of these categories:

• Age 40 and above: risk rises steadily with each decade
• Family history of glaucoma: especially a parent or sibling with the condition
• High myopia (severe nearsightedness): linked to structural changes that raise risk
• Diabetes or hypertension: both affect blood flow and fluid dynamics in the eye
• Long-term corticosteroid use: via eye drops, inhalers, or oral medication

If two or more of these apply to you, a dedicated glaucoma screening, not just a routine vision test, should be on your calendar this year.

D] Treatment Options & Expert Glaucoma Care at Arohi Eye Hospital

Getting your glaucoma diagnosis doesn’t mean you are destined to have glaucoma. In fact, early detection helps start treatment early and prevent further damage, allowing patients to maintain useful vision for life.

Glaucoma treatment is never one-size-fits-all; it’s tailored to the specific type of glaucoma you have, how advanced it is, and how your eyes respond to initial therapy.

1. Eye Drops

Prescribing eye drops is often the very first treatment for open-angle glaucoma. They reduce the eye’s fluid production or improve drainage to lower eye pressure.

2. Laser Treatment

Laser procedures become the next option when medications alone are not enough. Here are the options for laser treatment:

• Selective Laser Trabeculoplasty (SLT) improves drainage in open-angle glaucoma.
• Laser Peripheral Iridotomy (LPI) creates a tiny opening in the iris to relieve pressure in angle-closure glaucoma and is often performed urgently.

3. Surgical Treatment

When glaucoma progression continues despite medications and laser treatment, surgery may be necessary. The procedure depends on your condition.

• Trabeculectomy
• Glaucoma drainage implants
• Minimally Invasive Glaucoma Surgery (MIGS)

At Arohi Eye Hospital, every treatment decision starts with an accurate diagnosis, which is why identifying your specific type of glaucoma isn’t just academic information.

It’s the foundation of your entire treatment plan.

Conclusion

Glaucoma isn’t a single disease; it’s a group of conditions that affect the optic nerve in different ways. While open-angle glaucoma progresses silently, angle-closure glaucoma requires immediate medical attention, and other forms may develop even with normal eye pressure. Understanding these differences helps you recognise risk factors and appreciate why early diagnosis is so important.

Remember, vision lost to glaucoma cannot be restored, but vision that hasn’t been lost yet can often be protected for life with the right treatment plan. If you fall into any risk category discussed here, don’t wait for symptoms to appear; book a comprehensive glaucoma screening today.

Frequently Asked Questions

1. What are the different types of glaucoma?

The main types include open-angle, angle-closure, normal-tension, secondary and congenital glaucoma. Each one behaves differently and requires its own approach to management.

2. Which type of glaucoma is the most common?

Open-angle glaucoma is the most common type of glaucoma. It makes up nearly 90 percent of all cases.

3. What are the early signs of glaucoma?

Early on, there are often no clear signs. Later, you may notice fading side vision, more difficulty driving at night or, in sudden cases, blurry vision along with pain and halos around lights.

4. Which type of glaucoma is the most dangerous?

Acute angle-closure glaucoma moves the fastest. Pressure can rise sharply and cause serious damage within hours if it is not treated immediately.

5. Can glaucoma develop without high eye pressure?

Yes. Normal-tension glaucoma damages the optic nerve even when pressure readings stay normal. That is why a full eye examination matters more than a pressure check alone.