The term glaucoma describes an eye disease that causes damage to the optic nerve. When this damage worsens over time, it can lead to permanent blindness.
According to WHO, glaucoma is the second leading cause of blindness in the world.
But early detection can prevent or slow the progression of vision loss.
Everyone is at risk of glaucoma. However, people over the age of 60 are at an increased risk.
In this article, we’re going to highlight what causes glaucoma. And glaucoma symptoms and the diagnosis and treatment options currently available.
But before that, we need to understand the role of the optic nerve in the progression of glaucoma.
What Is The Optic Nerve?
A crucial part of your vision is the optic nerve. It is responsible for sending signals from the retina (a thin tissue that receives light) to the brain. Your brain then uses these signals to create visual images.
When the optic nerve gets damaged, the connection between the retina and the brain is lost, leading to vision loss.
What Causes Glaucoma?
Elevated pressure inside the eye is one of the primary glaucoma causes.
You see, your eye constantly produces a liquid called aqueous humor. This liquid is responsible for keeping your eyes moist. But as new aqueous humor forms, the old amount drains out of your eyes through tiny channels, located at an area called the drainage angle of the eyes.
This process keeps the pressure inside your eyes stable.
Glaucoma is caused by the poor working of the drainage angle, leading to slow movement of the liquid.
It causes the pressure inside the eye to build up, which damages the optic nerve, ultimately leading to vision loss.
Types Of Glaucoma
There are 4 main glaucoma types:
- Open-Angle Glaucoma
Open-angle glaucoma or Primary Open-Angle Glaucoma (POAG) is the most common form of the condition. It affects more than 2 million individuals in the United States.
It occurs when the aqueous humor fails to leave through the channels, even though the drainage angle is open. It happens when the drainage angle becomes clogged with age. As a result, the pressure inside the eye starts building up, eventually damaging the optic nerve.
Open-Angle Glaucoma Symptoms: With POAG, there are no symptoms observed in the early stage. There is no vision impairment. But as it gets worse, there is a loss of peripheral vision.
- Angle-Closure Glaucoma
This form of glaucoma is not very prevalent.
In angle-closure glaucoma, the internal eye pressure suddenly increases. It is a medical emergency, so don’t take it lightly.
It occurs when a small part of the entire drainage angle closes up, leading to blockage of the drainage system.
Angle-closure glaucoma symptoms include:
- Redness of the eye
- Severe pain
- Blurred vision
- Seeing halos
- Secondary Glaucoma
Secondary glaucoma is another type of open-angle glaucoma. It appears when the internal eye pressure increases because of external factors like eye injury, cataracts, or eye tumors.
Secondary glaucoma occurs when an existing condition causes the internal eye pressure to rise enough to destroy the optic nerve.
The condition may appear suddenly or gradually. Fortunately, if glaucoma diagnosis occurs before any significant damage to the optic nerve, it can get resolved sooner.
Symptom: Peripheral vision loss is often the first symptom people notice, but when they do, it’s usually too late. Therefore, we suggest you get eye checkups done regularly for glaucoma cure to happen early.
- Congenital Glaucoma
This type of open-angle glaucoma is relatively rare and inherited. It occurs when the drainage area does not fully develop at birth. It increases eye pressure, resulting in damage to the optic nerve that can cause blindness.
Congenital Glaucoma symptoms include:
- Involuntary eye twitching
- Enlarged eye
- Excessive eye tearing
- Normal-Tension Glaucoma
When there is a decrease in the blood flow to the optic nerve, it leads to normal-tension glaucoma. It progressively damages the optic nerve despite internal eye pressure being normal.
Symptoms include blind spots in the field of vision and loss of peripheral vision.
How Is Glaucoma Diagnosed?
During routine eye exams, ophthalmologists examine patients for glaucoma. There are five glaucoma tests they might use to detect the condition.
- Tonometry Test
A tonometry glaucoma test measures the internal pressure of your eye. While performing this test, eye drops are applied to numb the eye. The doctor then uses a tonometer – a device to measure the pressure within the eye.
The normal pressure comes in the range of 10-20mm of Hg, while patients with glaucoma have pressures exceeding 20mm of Hg.
- Perimetry Glaucoma Test
It is also known as visual field testing. The objective of this test is to look straight ahead at a light spot appearing in different parts of your peripheral vision.
Perimetry test measures your side vision and central vision. A visual field test is usually conducted one to two times a year after the glaucoma diagnosis. This helps determine if any changes have occurred in your vision since.
This glaucoma test checks the health of the optic nerve. The doctor adds eyedrops to your eyes to examine the color and shape of the optic nerve.
The doctor then uses a device to magnify the optic nerve to observe any changes.
A pachymetry test measures the thickness of the cornea (a thin tissue covering your eye). It is effective because corneal thickness can influence eye pressure readings.
During this test, the doctor places a small device in front of the eye to measure the corneal thickness.
It is painless, simple, and only takes a few minutes to perform.
This test visualizes the drainage angles of the eye. It measures the drainage area and angle of the eye.
The doctor places a specialized contact lens on the eye that tells the doctor whether the drainage angle is open or closed.
How Is Glaucoma Treated?
Glaucoma treatment either improves the fluid flow from the eye or reduces its production.
- Glaucoma Eye Drops –
Glaucoma Eye Drops can be any of the mentioned compounds:
- Prostaglandin analogs
Prostaglandins are hormone-like substances having a wide range of functions throughout the body. These drops work to increase the drainage of fluid from the eye.
- Adrenergic agonists
They reduce the production of fluid by the eye and increase its drainage.
- Carbonic anhydrase inhibitors
These glaucoma medicines reduce the production of fluid in the eye.
- Parasympathomimetic agents
They work by Increasing the aqueous outflow from the eye.
- Osmotic agents
They treat sudden (acute) forms of glaucoma where the eye pressure remains high.
- Rho-kinase inhibitor
This glaucoma medicine lowers eye pressure by suppressing the rho kinase enzymes responsible for the fluid increase.
- Miotic or cholinergic agents
These increase the outflow of fluid from your eye.
- Glaucoma Laser Treatment –
- Laser cyclo-ablation
This procedure is for patients with severe glaucoma with poor visual potential. It involves applying a laser to the part of the eye that makes the aqueous fluid. This therapy destroys the cells that make the fluid and reduces the eye pressure.
- Laser trabeculoplasty
Usually, it takes two sessions, separated by weeks or months. After the glaucoma treatment, the drainage channels tend to unclog again after two years.
- Laser iridotomy
It involves making a hole in the colored part of the eye (iris) to allow fluid to drain in the eyes with narrow or closed angles.
- Glaucoma laser surgery
- Trabeculoplasty – This glaucoma surgery is for people who have open-angle glaucoma.
- Iridotomy – This procedure is for people who have angle-closure glaucoma. The ophthalmologist uses a laser to create a tiny hole in the iris. The hole helps fluid flow to the drainage angle.
- Trabeculectomy – This glaucoma treatment includes creating a tiny flap in the outer layer of the eye to help with fluid drainage.
- Using glaucoma drainage devices – During this treatment, the surgeon implants a tiny drainage tube in the eye. The glaucoma drainage implant sends the fluid to an area specified for collection which the surgeon creates beneath the white part of the eye.
- Cataract surgery – This glaucoma surgery involves the removal of the natural eye lens. Removing the eye lens with cataract surgery creates more space for fluid to leave the eye.
Frequently Asked Questions
- Is glaucoma hereditary?
Open-angle Glaucoma is genetic. If anyone in your family has open-angle glaucoma, you’re very likely to get it.
- Can glaucoma be cured?
It is not possible to restore the entire vision lost because of glaucoma. But timely diagnosis can help manage the situation. Glaucoma Eye drops and laser glaucoma treatments can assist with that.
- Is glaucoma painful?
People with glaucoma rarely experience any pain.
- Is it necessary to see my eye doctor regularly?
Whether you have glaucoma or not, it is necessary to visit your eye doctor for regular checkups.
Now you know about glaucoma causes, symptoms, and treatment.
Even though Glaucoma is not preventable, an expert doctor can help detect it early. Regular checkups with an ophthalmologist can help you start the treatment as soon as possible and slow the progression of vision loss.
If you notice any of the symptoms, it is advisable to visit your doctor as early as possible.
Comment below if you have any questions.