Is Glaucoma Hereditary?

Posted on January 23, 2020March 19, 2026 by Dr Shibal Bhartiya

Glaucoma is hereditary. This means that if someone in your family, especially a first degree relative, has glaucoma, your risk for developing glaucoma is definitely higher than the general population.

Types of Glaucoma: Open Angle, Closed Angle, Normal Tension, and More

Types of Glaucoma: Open Angle, Closed Angle, Normal Tension, and More, explained by Dr Shibal Bhartiya, glaucoma specialist in Gurgaon.

Glaucoma is not a single disease. It is a family of conditions, each with different causes, risk factors, and treatment approaches. What they share is a common outcome: damage to the optic nerve, leading to progressive and irreversible vision loss if untreated.

Understanding which type of glaucoma you have helps you ask better questions and follow your treatment plan with more confidence. This page explains the main types, from the most common to the less well known, written for patients rather than clinicians.

Dr Shibal Bhartiya is a fellowship-trained glaucoma specialist and Mayo Clinic Research Collaborator with over 25 years of experience. Her approach focuses on identifying risk before damage is irreversible, simplifying treatment decisions, and protecting vision long-term. Emphasis on early detection, risk assessment, and continuity of care. She is rated 5 stars across 1,500+ patient reviews on Google.

Not all glaucomas behave the same way, and the treatment that is right for open-angle glaucoma may be wrong for angle-closure or normal tension glaucoma. Getting the diagnosis right, and the type right, is where good glaucoma care begins.

If you are uncertain about your diagnosis, a structured second opinion can bring clarity.

THE TWO MAIN TYPES OF GLAUCOMA

Q1. What is the difference between open-angle and closed-angle glaucoma?

Most glaucomas fall into one of two broad categories, determined by the anatomy of the drainage angle of the eye.

Open-angle glaucoma is by far the more common type of glaucoma. The drainage angle is open and appears normal, but fluid drains too slowly, causing pressure to build gradually over months and years. It has no symptoms in the early stages. Patients typically lose peripheral vision first, and the brain compensates so well that many people do not notice the loss until the disease is advanced. This is why regular screening is essential, particularly for those with risk factors.

Closed-angle glaucoma occurs when the drainage angle is narrow or blocked, preventing fluid from draining. It can occur suddenly (acute angle closure) or gradually (chronic angle closure). The acute form is a medical emergency with symptoms including severe eye pain, redness, blurred vision, and nausea. The chronic form is subtler and may mimic open-angle glaucoma.

Note: The distinction between the two types of glaucoma (open and closed angle) is made using a test called gonioscopy. This single test shapes all subsequent treatment decisions.

CLOSED-ANGLE GLAUCOMA

Q2. I have been diagnosed with angle-closure glaucoma. What does that mean for me?

In angle-closure glaucoma, the iris (the coloured part of the eye) is too close to the drainage angle, narrowing or blocking it. When the angle closes, fluid cannot drain and eye pressure rises sharply.

The acute form causes a sudden, severe rise in pressure. Symptoms include a red, painful eye with blurred vision, coloured halos around lights, headache, and nausea. This is an eye emergency; seek immediate medical help if this happens.

The chronic form builds more slowly, with few symptoms other than occasional coloured halos and mild headaches. It can go undetected for years without a formal eye examination.

Treatment for angle-closure glaucoma starts with a laser procedure called laser peripheral iridotomy (LPI). This creates a small opening in the iris to provide an alternative drainage pathway. After LPI, some patients require no further treatment; others need long-term eye drops. Your doctor will monitor your pressure and angle anatomy over time.

Note: Family members of patients with angle-closure glaucoma have a higher risk of the same condition. Preventive laser iridotomy can be offered to at-risk relatives before any acute episode occurs.

NORMAL TENSION GLAUCOMA

Q3. My doctor says I have glaucoma, but my eye pressures are normal. How is that possible?

This is understandably confusing. Between 10 and 25 percent of people with glaucoma have eye pressures that fall within the normal range (below 21 mmHg). This is called normal tension glaucoma (NTG), or low tension glaucoma.

The exact cause is not fully understood. Two leading theories are that the optic nerve is unusually sensitive to pressure and sustains damage even at pressures that would be harmless in most people, or that the blood supply to the optic nerve is compromised, making it vulnerable to damage independent of pressure. Of all the types of glaucoma, this is perhaps the most confusing for patients.

Conditions associated with normal tension glaucoma include:

Japanese ancestry (NTG is significantly more common in East Asian populations)
A family history of normal tension glaucoma
Migraines and vasospastic disorders such as Raynaud’s disease
Sleep apnoea
Alzheimer’s disease

Treatment still focuses on lowering eye pressure, like all other types of glaucoma. Even when eye pressure is within the normal range to start with, clinical trials have shown this slows progression. Eye drops, laser, or surgery may be used depending on the rate of progression and individual risk factors.

Note: Normal tension glaucoma often progresses more slowly than high-pressure glaucoma, but regular monitoring is still essential. Missing follow-up appointments is the most common reason for avoidable vision loss.

OCULAR HYPERTENSION

Q4. My eye pressures are high but my doctor says I do not have glaucoma. What is ocular hypertension?

If your eye pressure is above the normal range but your optic nerve and visual field show no signs of damage, you have ocular hypertension (OHT). It is not glaucoma, but it is a significant risk factor for developing glaucoma.

Not everyone with high eye pressure will develop glaucoma. Your individual risk depends on your age, ethnicity, family history, and corneal thickness (thicker corneas can give falsely high pressure readings).

Your doctor will weigh your risk profile before deciding whether to treat. Options include eye drops or selective laser trabeculoplasty (SLT). In lower-risk patients, careful monitoring without treatment is often appropriate, since all glaucoma medications carry some side effect burden.

Whether or not you receive treatment, regular eye checks are essential. The goal is to detect any optic nerve or visual field changes before significant vision is lost. Knowing your risk early is one of the best things you can do for your vision.

GLAUCOMA SUSPECT

Q5. My doctor says I am a glaucoma suspect. My tests were normal. Why do I still need annual monitoring?

A glaucoma suspect is someone whose optic nerve appearance raises concern, even when eye pressure and visual field tests are currently normal.

The most common reason is a larger than average cup-to-disc ratio (the proportion of the optic nerve head occupied by the central cup). A ratio above 0.5, or a difference of 20 percent or more between the two eyes, warrants closer monitoring. Other reasons include borderline eye pressures or a strong family history of glaucoma.

This does not mean you have glaucoma. It means your doctor wants a baseline record to compare against over time. If the optic nerve or visual field changes, that change can be detected early and treatment started before significant vision is lost.

Most glaucoma suspects are asked to return for annual or biannual testing. Once several years of stable results have been recorded, the interval between visits may be extended.

Note: The value of being labelled a glaucoma suspect is that it keeps you in the system. Early detection is the single most powerful tool for preventing glaucoma blindness.

SECONDARY GLAUCOMA

Q6. What is secondary glaucoma, and what causes it?

Secondary glaucoma is glaucoma caused by another identifiable condition or event, rather than arising on its own. It is managed in the same way as primary glaucoma (eye drops, laser, or surgery), but the underlying cause must also be addressed.

The most common secondary types of glaucoma include:

Pseudoexfoliation glaucoma: A protein-like material deposits on the lens and drainage structures of the eye, blocking outflow. This is one of the most common secondary glaucomas in India and tends to cause higher pressures and faster progression than primary open-angle glaucoma. It requires close monitoring and often more aggressive treatment.
Pigmentary glaucoma: Pigment granules shed from the back of the iris clog the drainage angle. It typically affects younger, myopic (short-sighted) patients and is often missed because these patients are not in the standard high-risk age group for glaucoma screening.
Steroid-induced glaucoma: Long-term use of steroid eye drops, nasal sprays, skin creams, or oral steroids can raise eye pressure in susceptible individuals. If you are on any form of steroid medication for any condition, ask your doctor whether your eye pressure has been checked.
Traumatic glaucoma: An injury to the eye can damage the drainage angle and cause pressure to rise, sometimes years after the original injury. Any history of significant eye trauma should be disclosed to your eye doctor.
Neovascular glaucoma: New, abnormal blood vessels grow over the drainage angle, blocking outflow. It is most commonly associated with poorly controlled diabetes and retinal vein occlusion. It is one of the more difficult types to manage and often requires surgery.

Note: If you have a systemic condition such as diabetes, or are on long-term steroid medication, make sure your eye doctor is aware. These are glaucoma risk factors that are often overlooked.

CONGENITAL AND CHILDHOOD GLAUCOMA

Q7. My child has been diagnosed with glaucoma. How is that possible, and what should I expect?

Glaucoma can affect any age group, though it is most common in adults over 40. In children, the most common cause is a structural defect in the drainage angle that is present from birth; this is called congenital glaucoma or primary infantile glaucoma.

Signs that parents typically notice first include:

Cloudy or hazy eyes
Unusual sensitivity to light; the child may turn away from bright light or bury their face
Excessive tearing
Eyes that appear larger than normal (because raised pressure causes the infant eye to expand)

Eye drops may be started initially to control pressure, but surgery is almost always required for congenital glaucoma. Early surgical intervention gives the best chance of preserving good vision throughout the child’s life.

Some children also have a co-existing cataract or other eye abnormality that needs to be managed alongside the glaucoma. Glasses, patching therapy for amblyopia (lazy eye), and follow-up surgeries may all be part of the long-term plan.

Children with glaucoma can lead fully independent lives. Even where some vision has been lost, tailored rehabilitation and visual aids allow children to participate in all age-appropriate activities. As a parent, remaining engaged with the care team and encouraging the child’s independence are the most important things you can do.

Note: Congenital glaucoma is rare. If your child has been diagnosed, seek care from a specialist with specific paediatric glaucoma experience. Early and consistent follow-up is critical.

Read the research articles

This article was written by Dr Shibal Bhartiya, fellowship-trained glaucoma specialist and Mayo Clinic Research Collaborator, Clinical Director at Marengo Asia Hospitals, Gurugram, known for ethical, patient-centred glaucoma care and independent glaucoma second opinions. This article was edited in April 2026.

She has published peer-reviewed research on glaucoma management, examining how treatment decisions should balance medical evidence, patient preferences, and long-term vision outcomes.

As Editor-in-Chief of Clinical and Experimental Vision and Eye Research and Executive Editor of the Journal of Current Glaucoma Practice (Pubmed Indexed, official journal of the International Society of Glaucoma Surgery), Dr Shibal Bhartiya brings editorial and research depth to every clinical decision. Her 200+ publications, including 90+ PubMed-indexed publications and 28 edited textbooks span glaucoma biology, surgical outcomes, health equity, and emerging diagnostics.

Available on Pubmed and Google Scholar

Dr Shibal Bhartiya
Glaucoma • Second Opinion • Advanced Care

www.drshibalbhartiya.com
+91 88826 38735

Patient reviews Google Business Profile

Upload your reports for a structured review.

Glaucoma Diagnosis in Gurgaon

Glaucoma Diagnosis in Gurgaon: What to expect

Glaucoma steals vision silently. Most patients feel no pain and notice no changes, until significant nerve damage has already occurred.

Early diagnosis changes everything. In, Gurgaon, Dr. Shibal Bhartiya offers a complete glaucoma diagnostic workup using advanced imaging and functional testing.

If you have a family history of glaucoma, are over 40, or have been told your eye pressure is high, this page explains exactly what your evaluation involves.

Why Early Glaucoma Detection Matters

Vision lost to glaucoma cannot come back. But when you catch it early, treatment halts further damage. That is why a thorough diagnostic evaluation is essential, not optional.

Early detection matters most if you have:

A parent, sibling, or child with glaucoma (family history)
Eye pressure above the normal range
Thin corneas are a known risk factor
Diabetes, high myopia, or a history of eye injury
Age over 40, especially with South Asian ancestry

💡 Research shows that South Asians have a higher risk of angle-closure glaucoma. A screening examination can identify this risk before any symptoms appear.

7 Tests Used to Diagnose Glaucoma

Dr. Bhartiya uses a structured, evidence-based protocol. Each test answers a different question about the health of your optic nerve and visual system.

1. Intraocular Pressure (IOP) Measurement

High eye pressure is the most well-known glaucoma risk factor. Dr. Bhartiya measures IOP using Goldmann applanation tonometry, the gold-standard technique.

Normal IOP: 10–21 mmHg. Readings above this range trigger further evaluation. However, some patients develop glaucoma at normal pressures (normal-tension glaucoma), so IOP alone is never enough.

The test is quick and painless. It takes less than a minute per eye.

💡 IOP fluctuates through the day. Dr. Bhartiya may check your pressure at different times if she suspects normal-tension glaucoma.

2. OCT- Optic Nerve and RNFL Imaging

Optical Coherence Tomography (OCT) is the most important advance in modern glaucoma diagnosis. It gives Dr. Bhartiya a detailed cross-sectional scan of your optic nerve and retinal nerve fibre layer (RNFL).

OCT detects structural nerve damage up to 6 years before visual field loss becomes visible. This makes it the cornerstone of early detection.

OCT measures:

RNFL thickness, thinning here signals glaucoma damage
Optic nerve head parameters, including the cup-to-disc ratio
Ganglion cell complex, a sensitive early marker of nerve loss

The scan is non-contact, takes about 5 minutes, and requires no eye drops in most cases.

💡 Dr. Bhartiya’s research background in optic nerve imaging means she reads OCT results with particular depth, looking beyond the machine’s colour codes and interpreting the raw data.

3. Visual Field Testing (Perimetry)

Glaucoma damages peripheral vision first. A visual field test maps exactly which parts of your vision are affected, and how severely. You sit in front of a dome-shaped screen and press a button each time you see a light flash. The test takes 5–7 minutes per eye.

Visual field testing answers three questions:

Is there functional vision loss, and where?
How fast is the damage progressing?
Is current treatment working?

Results compare against age-matched norms. Serial testing over time is especially important, a single test shows the current state; repeated tests reveal the trend.

💡 Reliable results require full concentration. Bhartiya’s team explains the test carefully so your first attempt is accurate. But if there are too many false positives or negatives, they will request a repeat!

4. Corneal Pachymetry

Pachymetry measures the thickness of your cornea. This single measurement significantly changes how Dr. Bhartiya interprets your eye pressure.

Here is why. IOP measurements are affected by corneal thickness. A thin cornea makes pressure read falsely low. A thick cornea makes it read falsely high.

Average corneal thickness: ~545 microns. Corneas below 500 microns carry a significantly higher risk of glaucoma progression, even when IOP appears normal.

The test is painless and takes under 2 minutes. A small probe touches the cornea gently after numbing drops.

💡 Pachymetry is especially important if glaucoma is progressing despite treatment, and for patients with borderline IOP readings.

5. Gonioscopy: Examining the Drainage Angle

Gonioscopy is the only way to directly examine the drainage angle of the eye, where fluid exits. This examination determines whether your glaucoma is open-angle or angle-closure. That distinction drives every treatment decision.

Dr. Bhartiya places a specialised mirrored lens gently on your eye (after numbing drops) to visualise structures that are otherwise invisible.

Gonioscopy reveals:

Open-angle glaucoma: the drainage angle is open but not working efficiently
Angle-closure glaucoma: the angle is narrow or blocked, often needing laser treatment
Secondary causes: such as steroid use, pigment dispersion, pseudoexfoliation, or neovascularisation

💡 Many patients in India have narrow drainage angles without knowing it. Gonioscopy at your first visit can prevent a potentially blinding acute angle-closure attack.

6. Diurnal IOP Monitoring and the Water Drinking Test

Eye pressure is not constant. It fluctuates throughout the day and night, typically peaking around 4 AM and varying by as much as 6–8 mmHg over 24 hours. A single pressure reading in clinic captures only one moment in that cycle.

This matters because peak IOP, not average IOP, is what damages the optic nerve. A patient whose pressure appears well-controlled at a morning clinic visit may have dangerously high peaks overnight.

24-hour IOP monitoring records pressure every two hours over a full day and night. It is the most comprehensive method but is cumbersome and expensive. It is reserved for complex cases where standard clinic measurements are insufficient.

The Water Drinking Test is a practical alternative. Eye pressure is measured at baseline, then you drink approximately 10 ml per kg body weight of water over five minutes. Pressure is then recorded every 15 minutes for one hour. The test gives a reasonable estimate of peak IOP, pressure fluctuation, and how quickly your eye recovers to baseline.

If a water drinking test has been scheduled, carry a one-litre bottle of water. There are no other specific preparations.

💡 Dr Bhartiya has published peer-reviewed research on 24-hour IOP monitoring, target IOP, and continuous pressure recording in glaucoma patients. This is an area of active clinical research at this practice.

7. Optic Disc Photography

A high-resolution photograph of your optic nerve is taken and stored in your record. This image becomes one of the most important documents in your long-term glaucoma care.

The reason is straightforward. Glaucoma causes slow, progressive changes to the optic disc — changes that are often difficult to detect at any single visit. A photograph taken today gives your doctor a precise baseline to compare against at every future visit. Subtle changes that would otherwise go unnoticed become visible when images from different years are placed side by side.

Disc photography requires no drops in most cases. You sit in front of a fundus camera, look at a fixation target, and a bright flash takes the image. It takes under two minutes.

💡 Serial disc photography over years is one of the most powerful tools for detecting glaucoma progression — and one of the most underused in routine practice.

What to Expect at Your Glaucoma Evaluation

A complete glaucoma workup takes approximately 60–90 minutes. Here is the sequence:

Brief history: symptoms, family history, current medications
Visual acuity and refraction
IOP measurement (both eyes)
Pachymetry
Gonioscopy
Dilated fundus examination and optic nerve evaluation
OCT imaging
Visual field testing (where indicated)
Detailed consultation: results, diagnosis, and treatment options

Dilation drops may be used during the examination. Your vision may be blurred for 3–4 hours afterwards. Plan not to drive yourself home.

Seeking a Second Opinion on Glaucoma?

Many patients come to Dr. Bhartiya after receiving a diagnosis elsewhere, unsure whether they need surgery, or concerned about a treatment recommendation.

A second opinion review includes a full re-evaluation of all existing tests, a fresh examination, and an honest, unhurried discussion of your options. Dr. Bhartiya brings her research expertise to every such case.

💡 Bring all previous reports, OCT scans, visual field printouts, and prescription history. The more information you bring, the more specific the guidance.

Book Your Glaucoma Diagnosis in Gurgaon

Do not wait for symptoms. Glaucoma gives no warning until significant damage is done.

Book a comprehensive glaucoma evaluation with Dr. Shibal Bhartiya at Gurgaon.

📞 Call or WhatsApp: +91 8882638735

🔗 Also read: Glaucoma Surgery in Gurgaon | Glaucoma Second Opinion | About Dr. Shibal Bhartiya

Frequently Asked Questions

Is glaucoma diagnosis painful?

No. All five tests are painless. IOP measurement, OCT, and visual field testing involve no contact with the eye. Pachymetry and gonioscopy use numbing drops first, so you feel minimal discomfort.

How often should I get screened?

If you have risk factors — family history, high eye pressure, thin corneas, or age over 40 — annual screening is advisable. For diagnosed patients, Dr. Bhartiya sets a personalised review schedule based on disease stage and stability.

My eye pressure is normal. Can I still have glaucoma?

Yes. Normal-tension glaucoma is well-recognised and common in Asian populations. Dr. Bhartiya evaluates optic nerve structure and visual function alongside IOP — because pressure alone does not tell the whole story.

Can glaucoma be detected before symptoms appear?

Yes, and this is the entire point of a diagnostic evaluation. OCT detects structural nerve damage years before you notice any visual change. Early detection is the single most important factor in protecting your long-term vision.

What is the difference between open-angle and angle-closure glaucoma?

Open-angle glaucoma develops slowly and painlessly as drainage channels lose efficiency over time. Angle-closure glaucoma occurs when the drainage angle narrows or blocks — it can cause sudden pain, redness, and rapid vision loss. Gonioscopy distinguishes between the two and guides treatment.

How long does the full diagnostic evaluation take?

Approximately 60–90 minutes for a first-visit comprehensive workup. Follow-up visits for monitoring are usually shorter, 30–45 minutes.

How should I prepare for my glaucoma tests?

No specific preparation is needed. A few things will help:

Read a little about glaucoma beforehand and write down any questions you want to ask. Get a good night’s sleep before your visual field test, fatigue significantly affects results. Have a light meal before you arrive, as some tests take time. Continue all previously prescribed medications unless told otherwise.

If a water drinking test has been scheduled, carry a one-litre bottle of water. If dilation has been planned, arrange for someone to drive you home, your vision may be blurred for 3–4 hours after dilating drops. Bring something to read while you wait. Glaucoma investigations are painless, but they are time-consuming.

I have been advised gonioscopy. What does it involve?

Gonioscopy is used to examine the drainage angle of your eye, the area where fluid exits. It determines whether your glaucoma is open-angle or angle-closure, which drives every treatment decision.

Your doctor will apply numbing drops first, so the procedure is painless. A small mirrored lens is then placed gently on the eye. You will be asked to look in a specific direction while the doctor examines the angle with the slit lamp. The room lights are usually dimmed for better visibility.

Most people tolerate gonioscopy well. Occasionally, the procedure stimulates the vagus nerve and causes brief dizziness, this passes quickly. The whole examination takes a few minutes.

The visual field test sounds difficult. Any tips?

It is one of the harder tests to do well, but a few things help.

You will sit in front of a dome-shaped screen and press a button each time you see a flash of light. Keep looking at the central fixation light throughout, do not track the flashes. Press the button even if you are only partially sure you saw something.

Pace yourself. If you feel fatigued, tell the operator and take a break. If your eyes feel dry, blink or use your lubricant drops before continuing. Do not rush, pressing quickly to finish the test produces unreliable results and may mean you need to repeat it.

There is a learning curve. Your doctor may ask you to repeat the test at a subsequent visit, this is normal and not a cause for concern.

How is eye pressure measured?

The standard method is Goldmann applanation tonometry. Your doctor applies numbing drops and a small amount of orange dye, then brings a probe into gentle contact with the cornea. The test is painless and takes under a minute per eye.

Some clinics use a non-contact tonometer, the air-puff machine, which requires no drops and no contact. Both methods are accurate when performed correctly.

How does the doctor examine my optic nerve?

The optic nerve sits at the back of the eye and cannot be seen without special equipment. Your doctor will use one of two methods: an ophthalmoscope (a handheld light and lens), or a high-powered lens at the slit lamp. Dilating drops are often used to widen the pupil and allow a clearer view.

What the doctor looks for is the size and shape of the optic cup relative to the disc (the cup-to-disc ratio), the colour and rim tissue of the nerve, and any asymmetry between the two eyes. These findings, combined with OCT and visual field data, form the basis of diagnosis.

Read the research articles