Glaucoma is a collection of eye disorders causing damage to the optic nerve, which transmits visual data from the eye to the brain. Optic nerve damage is usually linked to increased eye pressure, although glaucoma can also develop under standard pressure.
While glaucoma can affect individuals of any age, it is most common among older adults. In general, it is the main reason for blindness in people above 60 years.
Several types of glaucoma do not have any warning signs. Since the effect occurs so gradually, it makes it difficult to notice vision changes till the condition is advanced.
Regular eye tests, including eye pressure measurements, are highly essential. Early detection of glaucoma can help slow down or prevent vision loss. Also, if you have been diagnosed with the condition, you will require ongoing treatment or monitoring for a lifetime.
By Able Health I Medically reviewed by Dr. Alireza Estedlal
Page last reviewed: February 2024 I Next review due: February 2026
What is glaucoma?
Glaucoma occurs when fluid accumulation in the eye causes damage to the optic nerve. This could lead to permanent vision loss if untreated. Glaucoma is the second primary cause of blindness globally.
Treatments, which include eye drops, laser therapy, and surgery, help slow vision loss and preserve sight.
Types of glaucoma
The types of glaucoma include:
Open-angle glaucoma
This is the most prevalent form, which affects up to 90 percent of Americans with glaucoma. It develops due to the build-up of resistance in the drainage canals of the eyes. Drainage canals may seem open and working normally. But with time, fluid accumulates and increases pressure on the optic nerve. This type of glaucoma often goes undetected for years since it doesn’t cause any symptoms.
Closed-angle glaucoma
This type, which is also known as narrow-angle glaucoma or angleclosure, is rare and can develop abruptly (acute). When the angle between the iris and cornea becomes too narrow, closed-angle glaucoma occurs. It can happen due to changes in the pupil that cause rapid dilation, which obstructs the drainage canals, preventing aqueous fluid from exiting the eye and causing an increase in eye pressure. Symptoms such as headaches and eye pain may be severe and necessitate medical care right away.
Normal-tension glaucoma
At least 1 out of 3 individuals experience optic nerve damage even with normal or slightly elevated eye pressure. Healthcare specialists do not know the exact cause of this type of glaucoma. It is also referred to as normal-pressure or low-tension glaucoma and is more common in persons of Asian lineage or Asian Americans.
Congenital glaucoma
Sometimes, children are born with improperly formed drainage canals. Symptoms may be noticeable at birth or during the baby’s early childhood. Congenital glaucoma is also known as childhood, pediatric, or infantile glaucoma.
Who is at risk for glaucoma?
Age: The possibility of developing glaucoma significantly increases after 40 years, and people above the age of 60 are at a higher risk.
Genetics: Genes is a risk factor contributing to glaucoma, and having a family history of the condition increases the likelihood of developing it.
Race: Individuals of African, Asian, and Hispanic backgrounds are more likely to develop glaucoma.
Medical conditions: Disorders such as high blood pressure, diabetes, and nearsightedness can increase the possibility of developing glaucoma.
People with these risk factors should be cautious when it comes to their overall eye health and schedule regular eye examinations for early detection of glaucoma.
Common Symptoms of Glaucoma
Glaucoma symptoms can vary based on the type and phase of the condition.
Open-angle glaucoma
There are no symptoms during the early stages
Slowly, patchy blind spots in side vision or peripheral vision
Trouble seeing in central vision during the later stages
Acute angle-closure glaucoma
Severe headache
Intense eye pain
Blurry vision
Nausea or vomiting
Halos or tinted rings around lights
Eye redness
Normal-tension glaucoma
No symptoms during the early stages
Blurry vision occurs gradually
Loss of peripheral vision during the later stages
Glaucoma in children
In infants, there are cloudy or dull eyes, increased blinking and tears without crying
Blurry vision
Worsening nearsightedness
Headache
Pigmentary glaucoma
Halos around lights
Blurred vision during exercise
Steady loss of peripheral vision
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Glaucoma arises when the optic nerve sustains damage. As this nerve deteriorates slowly, blind spots form in vision. The exact cause of this damage is not entirely understood, but it is generally associated with increased eye pressure.
High pressure in the eye results from the collection of fluid flowing throughout the eye. The fluid is referred to as aqueous humor and normally drains through the trabecular meshwork, a tissue found at the angle at which the cornea and the iris connect. The cornea is crucial for vision since it allows light to get into the eye. If the eye produces excess fluid or the drainage system malfunctions, pressure within the eye can increase.
Open-angle glaucoma
This is the most common type of glaucoma. Normally, the drainage angle between the iris and cornea stays open. However, other areas of the drainage system malfunction, causing a slow, steady rise in eye pressure.
Angle-closure glaucoma
This occurs when the iris bulges entirely or partially, hence blocking the drainage angle. Because of this, fluid cannot flow through the eye, leading to increased pressure. Angle-closure glaucoma can develop abruptly or gradually.
Normal-tension glaucoma
The actual reason behind optic nerve damage, even with normal eye pressure, is unknown. However, the possible causes include a sensitive optic nerve or reduced blood flow. Limited blood supply may be due to the accumulation of fatty deposits within the arteries (atherosclerosis) or conditions damaging circulation.
Glaucoma in children
Children can be born with glaucoma or experience it within the first few years of their life. An injury, obstructed drainage, or underlying health problems can damage the optic nerve.
Pigmentary glaucoma
With pigmentary glaucoma, pigment granules from the iris flake off and obstruct or slow down fluid drainage. Sometimes, activities like jogging can stir up these granules. These results in pigment granule deposits on the tissues found at the angle at which the cornea and iris meet. The deposits, on the other hand, lead to increased pressure.
Glaucoma is hereditary and usually runs in families. Scientists have linked certain genes in some people to elevated eye pressure as well as optic nerve damage.
Risk factors
Glaucoma can cause vision damage even before the symptoms become noticeable. Therefore, it is important to be aware of associated risk factors, which include:
Certain health problems, including diabetes, high blood pressure, migraines, or sickle cell anemia
Thin corneas in the center
severe nearsightedness or farsightedness
Eye injury or particular kinds of eye surgeries
Long-term use of corticosteroid drugs, particularly eye drops
Individuals who have drainage angles that are narrowed are also at a high risk of developing angle-closure glaucoma.
How is Glaucoma Diagnosed?
To diagnose glaucoma, the doctor will start by reviewing your medical history and performing a thorough eye examination. Other diagnostic tests they might also conduct include:
Tonometry to measure intraocular pressure
Dilated eye exam and imaging tests to check for optic nerve damage
Visual field test to look for parts of vision loss
Pachymetry to measure corneal thickness
Gonioscopy to inspect the drainage angle
Glaucoma Treatment Options
The damage that results from glaucoma is irreversible. However, treatment and frequent check-ups are essential in slowing down or preventing vision loss, particularly if the disease is detected early.
Glaucoma treatment aims to lower intraocular pressure. The available options are prescription eye drops, laser treatments, oral medications, surgical procedures, or a combination of choices.
Eyedrops
The treatment of glaucoma generally begins with prescription eye drops. While some drops lower eye pressure by boosting fluid drainage from the eye, others reduce the amount of fluid the eye produces. Based on how minimal the eye pressure should be, the doctor may prescribe several eye drops.
Common prescription eye drop medications include:
Prostaglandins: The drugs increase fluid outflow from the eye, reducing eye pressure. Examples of prostaglandins are latanoprost (Xalatan), tafluprost (Zioptan), travoprost (Travatan Z), bimatoprost (Lumigan), and latanoprostenebunod (Vyzulta).
The potential side effects may include darkening of the iris, mild eye redness and stinging, darkening of the eyelashes or eyelid skin pigment, and blurry eyesight. This category of medication is prescribed for use once every day.
Beta blockers: These work by reducing fluid production in the eye and lowering eye pressure. Common beta blockers include betaxolol (Betoptic S) and Timolol (Betimol, Istalol, Timoptic).
Side effects that may be associated with these drugs are slowed heart rhythm, difficulty breathing, low blood pressure, impotence, and exhaustion. This group of medications may be prescribed for use once or twice every day, based on the condition.
Alpha-adrenergic agonists: These eyedrops help minimize fluid production circulating all over the inside of the eye. Furthermore, they are helpful in increasing fluid outflow in the eye. Drugs in this category are apraclonidine (Iopidine) and brimonidine (Alphagan P, Qoliana).
Some potential side effects are high blood pressure, irregular heart pulse, tiredness, red, itchy or swollen eyes, and dry mouth. Doctors usually prescribe alpha-adrenergic agonists for use twice a day and sometimes three times daily.
Carbonic anhydrase inhibitors: These help lower fluid production in the eye. Medications in this class include brinzolamide (Azopt) and dorzolamide. Side effects that can occur include frequent urination, metallic taste and tingling in fingers and toes. Carbonic anhydrase inhibitors are prescribed for use twice a day and sometimes three times daily.
Rho kinase inhibitor: This eyedrop helps reduce eye pressure by inhibiting rho kinase enzymes that increase fluid in the eye. An example is netarsudil (Rhopressa), which is prescribed for use once per day. Eye discomfort and redness are the possible side effects.
Miotic or cholinergic agents: These drugs work by increasing fluid outflow from the eye and are available as pilocarpine (IsoptoCarpine). The possible side effects are headache, smaller pupils, eye ache, blurry or dim vision, and nearsightedness. Usually, this category of medication is prescribed for use up to four times daily. Due to the possible side effects and frequent usage, they are less commonly recommended.
Given that some eye drops can be absorbed into the bloodstream, one can have side effects not related to the eyes. So, to reduce absorption, you should close your eyes for at least 1-2 minutes after using the drops. Also, try pressing lightly the corners of the eyes around the nose to shut off the tear duct for 1-2 minutes. After that, wipe any excess drops from the eyelids.
If multiple eye drops are prescribed or you are required to use artificial tears, ensure that you pause at least 5 minutes between applying different drops.
Oral medications
If using eye drops does not lower your eye pressure to the intended level, your eye doctor can prescribe oral medications, typically carbonic anhydrase inhibitors. The potential side effects are frequent urination, depression, tingling in the fingers and toes, stomach upset, or kidney stones.
Surgery and other therapies
Additional treatment options for glaucoma are surgery and laser therapy. These techniques might assist with fluid drainage in the eye and reduction of eye pressure:
Laser therapy: For people who are intolerant to eye drops, laser trabeculoplasty is an option. It’s also recommended if the medication doesn’t slow glaucoma progression. Sometimes, the doctor can suggest laser treatment before applying eye drops.
This procedure, which is performed in your eye specialist’s office, uses a small laser to enhance the fluid drain of the tissue positioned at the angle where the iris and cornea join. The full effects of laser therapy may take a few weeks to be noticeable.
Filtering surgery: This procedure, which is known as trabeculectomy, involves creating an opening in the sclera (the white part of the eye). The surgery provides an additional pathway for fluid to exit the eye.
Drainage tubes: The surgeon performs this procedure by inserting a small tube into the eye to help drain extra fluid and reduce eye pressure.
Minimally invasive glaucoma surgery (MIGS): This procedure helps lower eye pressure while requiring less postoperative care. It also has minimal risk compared to trabeculectomy or drainage tools. These treatments are usually combined with cataract surgery. Since there are various MIGS techniques, your eye doctor will advise you on the most suitable one.
After surgery, follow-up examinations with your eye doctor are essential. You may also need additional treatments if your eye pressure starts rising again or other changes arise in the eye.
Treating acute angle-closure glaucoma
Acute angle-closure glaucoma is often a medical emergency requiring immediate treatment to lower eye pressure. Treatment typically involves medications as well as laser or surgical therapies.
Laser peripheral iridotomy is a procedure that may be recommended. It involves creating a tiny hole in the iris with a laser to enable fluid to flow through it. This opens the drainage angle of the eye and reduces pressure.
Prevention
Taking the necessary steps can aid the detection and management of glaucoma while in the early stages. This might also help prevent vision loss and slow down its progression.
The prevention measures to consider are:
Getting regular eye tests: Comprehensive frequent eye exams are helpful in detecting glaucoma early before major damages arise. The American Academy of Ophthalmology suggests an eye test every 5 to 10 years for those below the age of 40, every 2 to 4 years for people who are 40 to 54 years old, every 1 to 3 years for those who are 55 to 64 years old, and every 1 to 2 years for persons above the age of 65.
Furthermore, if you are at higher risk of developing glaucoma, more regular screenings are necessary. Therefore, you should consult your healthcare provider for a personalized screening schedule.
Knowing the eye health history of your family: Glaucoma often runs in families. So, if you have a family history of the disease, then you may require more regular screenings.
Wearing eye protection: Severe eye injuries could result in glaucoma. It’s thus important to use eye protection when playing sports or working with power toolsto prevent injuries.
Regularly taking prescribed eye drops: Glaucoma eye drops may be effective in reducing the possibility of increased eye pressure progressing to glaucoma. Use these drops as directed by your doctor, even if you do not have any symptoms.
Coping with Glaucoma: Support Groups, Counseling, and Adaptive Devices
It can be physically and emotionally challenging to live with glaucoma. Therefore, it’s essential for people with the disorder to find emotional assistance and associate with others who are experiencing similar problems. Support counseling can help people express their concerns, ask questions, and develop coping strategies.
Additionally, adaptive equipment could assist glaucoma patients in maintaining their independence and standard of living. Talking timepieces, magnifiers, and large-print materials are examples of these devices. It is also essential for occupational therapists or low-vision professionals to determine which adaptive devices are most suited for each patient’s needs.
People with glaucoma can as well get information and help from resources like the Glaucoma Research Foundation and local vision programs.
In general, emotional assistance, adaptive equipment, and other resources are necessary for those living with glaucoma to cope and maintain their independence and quality of life. People can also preserve their eyesight and overall wellness by getting medical help if they are exhibiting signs or are at risk of developing glaucoma.
