Glaucoma: causes, symptoms and treatments

Glaucoma is the leading cause of irreversible blindness in people over 60

It is estimated that there are currently over 67 million cases of glaucoma worldwide. The likelihood of having glaucoma increases with age. In fact, nearly 10% of people age 70 and over have glaucoma.

What causes glaucoma?

Glaucoma is a progressive disease caused by damage to the optic nerve. Although glaucoma is a disease most commonly found in middle-aged to elderly adults, the risk of getting glaucoma increases due to:

• Age – your risk of getting glaucoma increases as you age, especially beyond 60
• Ethnicity – Asians are more likely to suffer from angle-closure glaucoma than other ethnic groups. African Americans over 40 and Hispanics over age 60 are at increased risk for open-angle glaucoma.
• Family history of glaucoma
• Increased intraocular fluid pressure – Although this is an important risk factor, only half all Americans with glaucoma will show increased intraocular pressure when measured at random because eye pressure fluctuates constantly. Thus it's important to screen for glaucoma by taking many measurements of intraocular pressure over time to look for trends of elevated pressure.
• Severe nearsightedness or farsightedness
• Thin corneas
• Diabetes
• High blood pressure
• Chronic steroid use
• Prior eye injury

How to prevent glaucoma? 

While there are no ways to prevent glaucoma, you can take steps to lower your risk of developing the condition. These include:

• Regular Eye Exams: Regular eye exams are the best way to detect glaucoma early before it causes irreversible vision loss. Adults should have a comprehensive eye exam every 1-2 years or more often if recommended by their eye doctor.
• Exercise: Exercise and physical activity may help to reduce the risk of developing glaucoma by improving blood flow to the eyes and reducing intraocular pressure.
• Healthy Diet: Eating a healthy diet that's rich in fruits and vegetables and low in saturated and trans fats may help to lower the risk of developing glaucoma.
• Manage other health conditions: High blood pressure, diabetes, and cardiovascular disease are all risk factors for glaucoma. Managing these conditions through lifestyle changes and medications may help to lower your risk.
• Avoid Smoking: Smoking has been linked to an increased risk of glaucoma, so avoiding tobacco use is essential for eye health.

Types of glaucoma

Chronic (primary open-angle) glaucoma

This is the most common type of glaucoma in which ocular fluid drains too slowly, or is over-produced, causing pressure inside the eye to build up. It usually results from an aging under-functioning eye drainage system. That said, younger people can also get this form of glaucoma, although rarely.

Normal-tension glaucoma

This is a form of open-angle glaucoma where eye pressure is “within the normal range;” however, there is evidence of optic nerve damage. No one knows the exact reason for this, but it is thought that reduced blood flow to the optic nerve may play a role in normal-tension glaucoma.

Acute (angle-closure) glaucoma

Acute angle-closure glaucoma (also referred to as narrow-angle glaucoma) occurs when the drainage system within the eye suddenly becomes blocked, causing a rapid rise in eye pressure. Because this can result in blindness, it is an emergency requiring immediate urgent medical attention.

The onset of symptoms is immediate and can include blurred vision, severe headaches, eye pain, nausea, vomiting, or seeing rainbow-like halos around lights.

A non-emergent variation of this condition (known as chronic angle-closure glaucoma) may present gradually with mild symptoms; similar to open-angle glaucoma. Those of Asian and Native American descent are at higher risk for this type of glaucoma.

Secondary glaucoma

Secondary glaucoma may occur as the result of another eye disease or condition, such as diabetes, chronic steroid use, inflammation, injury, or a tumor. For example, uveitis is an inflammatory condition that can cause secondary glaucoma. 

What are the symptoms of glaucoma?

Unfortunately, half of the people with the disease are not aware that they have any eye health issues as there are typically no early warning signs. This is the reason glaucoma is commonly referred to as “Silent Thief of Sight”, because vision is preserved until late in the disease and when it is detected late, the irreversible and permanent damage has already occurred. This highlights the importance of regular eye exams, especially if there is a strong family history of glaucoma.

Glaucoma symptoms depend on the type of glaucoma and include:

Open-angle glaucoma symptoms

Patchy blind spots typically arise in the peripheral vision, often affecting both eyes. Patients with advanced disease experience tunnel vision with nearly complete loss of peripheral vision.

Acute angle-closure glaucoma symptoms

A sudden rapid increase in IOP results in severe eye pain, eye redness, blurred vision, and seeing colored halos around bright lights. Headache, nausea, and vomiting are common. This condition requires emergency medical attention in order to prevent blindness.

Chronic angle-closure glaucoma symptoms

Chronic angle-closure glaucoma is rarely symptomatic, making it difficult to diagnose. Some patients report short episodes of mild symptoms occurring in the evening and resolving by morning.

Glaucoma treatment 

While there is no cure for glaucoma, its progression can be slowed down through a variety of means. Treatment options are influenced by how advanced the disease is, as well as whether the patient is an appropriate candidate for a given treatment.

Treatment options fall into one of 3 categories:

1. Glaucoma medications

The most common treatment for glaucoma is eye drops (pills are also used, but as a temporary measure prior to surgery). The goal of these medications is to decrease intraocular pressure by either promoting drainage of excess eye fluid or by reducing eye fluid production.

Although medications are extremely effective in lowering eye pressure, they can come with a myriad of other issues such as intolerable side effects, difficulty applying eye drops, or adhering to the dosing schedule. Your doctor will advise you on the best medications to fit your particular needs and offer other alternatives if medications are not the best option.

2. Glaucoma surgery: Laser eye surgery for glaucoma

At Assil Gaur Eye Institute, we utilize a variety of lasers to treat both open and closed-angle glaucoma, tailoring our approach to each patient's particular need.

Types of laser surgery for glaucoma include:

Selective laser trabeculoplasty (SLT) for Glaucoma

SLT is used in the treatment of open-angle glaucoma in order to “stimulate” the eye's natural drainage pathway to work more efficiently in removing excess intraocular fluid. It uses a low energy laser to target specific (trabecular) cells and succeeds in lowering eye pressure in about 85% of patients. This procedure is painless, is done in 5 minutes, and has a fast recovery with no restrictions after it is performed.

Laser peripheral iridotomy (LPI) for Glaucoma

In closed-angle glaucoma, the angle located in the front inner corner of the eye between the iris (colored part of the eye) and cornea is too narrow. This blocks the site where ocular fluid must drain out of the eye. The LPI uses a laser to make a small opening in the iris, creating a second channel through which ocular fluid can flow to the front of the eye and out through the drainage system. This procedure has a success rate of 98% with a fast recovery and no restrictions after it is performed.

Transscleral cyclophotocoagulation for Glaucoma

Transscleral cyclophotocoagulation is used to treat open-angle glaucoma that has failed other surgical treatments in eyes with poor visual potential. A targeted laser beam is directed through the sclera (white part of your eye) to the ciliary body, which is the structure that produces intraocular fluid. The beam shrinks this structure in order to decrease its fluid production and thus lowers eye pressure.

3. Conventional microsurgery for Glaucoma

In certain circumstances, patients with early to moderate glaucoma benefit from conventional surgery, where the doctor makes an incision and works on the inner structures of your eye.

Infant or congenital glaucoma (meaning you are born with it) is primarily treated with surgery because the cause of the problem is a very distorted drainage system that requires delicate repair.

Types of conventional microsurgery for glaucoma include:

Minimally invasive glaucoma surgery (MIGS) 

At Assil Gaur Eye Institute, we go one step beyond conventional surgery and perform state of the art Minimally Invasive Glaucoma Surgery (MIGS) which uses microscopic instruments allowing for a smaller incision surgery. As a result, it provides a safer option to reduce eye pressure with the added benefit of a higher success rate and faster recovery time than conventional surgery.

The goal of MIGS procedures is to improve fluid drainage out of the eye, thus reducing elevated eye pressure that damages the optic nerve. MIGS procedures are often performed in combination with cataract surgery for the appropriate patients. The types of MIGS performed at the Assil Gaur Eye Institute include iStent, I Stent inject, OMNI 360, XEN gel stent, and Endocyclophotocoagulation.

OMNI® Glaucoma Treatment System

The FDA Approved OMNI® Glaucoma Treatment System is the next-generation Minimally Invasive glaucoma surgery. Developed by Sight Sciences, the OMNI 360 is the only device that combines two well-established minimally invasive glaucoma surgery (MIGS procedures) into one using a single device and a single clear corneal incision. The procedure is implant-free, allowing the eye’s natural drainage system to safely restore pressure.

Trabectome for Glaucoma

Trabectome is a procedure for open-angle glaucoma patients in which the doctor uses tiny instruments to remove a piece of the trabecular meshwork where intraocular fluid normally drains from, thereby widening the opening for intraocular fluid to exit the eye.

iStent for Glaucoma

iStent Is the smallest FDA approved device for use in the human body, measuring 1mm in length, like the tip of a ballpoint pen! It's a specially coated titanium tube that is inserted between the cornea and the lens to create a secondary channel for draining off intraocular fluid. This stent is used for a wide variety of glaucoma patients.

How is glaucoma diagnosed?

Glaucoma can be diagnosed through a comprehensive eye exam with several tests and procedures. These may include:

• Tonometry: This test measures the pressure inside your eye (intraocular pressure).
• Visual field test: This test checks for any loss of peripheral (side) vision, a common sign of glaucoma.
• Optical coherence tomography (OCT): This test uses light waves to create a detailed image of the optic nerve and can detect any changes or damage to the nerve fibers.
• Dilated eye exam: During this exam, your ophthalmologist will use eye drops to widen your pupils and examine the inside of your eye, including the optic nerve and retina.
• Gonioscopy: This test uses a unique lens to examine the drainage angle of the eye, which can help determine if there is a risk for angle-closure glaucoma.

Glaucoma FAQs

Is glaucoma hereditary? 

The most common type, called primary open-angle glaucoma (POAG), can have a genetic component. Not everyone who has a genetic predisposition to glaucoma will develop the condition. Other factors, such as age, race, and overall health, also play a role in the development of glaucoma.

What does glaucoma vision look like?

Glaucoma can cause gradual and permanent vision loss, starting with the peripheral (side) vision and then affecting the central vision.

As the condition progresses, you may begin to experience the following symptoms:

• Loss of peripheral vision: The loss of peripheral vision is often one of the first signs of glaucoma. You may notice that your visual field is gradually decreasing or you're having trouble seeing objects to the side.
• Tunnel vision: As the loss of peripheral vision worsens, you may experience tunnel vision, where you can only see objects directly in front of you.
• Halos around lights: Some people with glaucoma may see halos or bright circles around lights, particularly at night.
• Blurred vision: Glaucoma can cause blurred or hazy vision, particularly in the early stages.
• Difficulty adjusting to low light levels: Glaucoma can make it more challenging to see in low light levels, such as when driving at night. 

Does glaucoma cause blindness?

Yes, glaucoma can cause blindness if it is not detected and treated early. Glaucoma is a leading cause of irreversible blindness worldwide. It is estimated that up to 10% of people with glaucoma who receive appropriate treatment still experience vision loss. If left untreated or if treatment is delayed, glaucoma can lead to complete blindness.

Is glaucoma painful?

In general, glaucoma itself is not painful. And because it often has no symptoms in its early stages, it can be very challenging to diagnose glaucoma early. However, some forms of glaucoma can cause discomfort, particularly when intraocular pressure is elevated.

Is glaucoma cancer?

No, glaucoma is not a type of cancer. Glaucoma is a group of eye diseases that damage the optic nerve, which is the nerve that carries visual information from the eye to the brain. This damage is usually caused by increased pressure within the eye, known as intraocular pressure.

Can glaucoma cause headaches?

Glaucoma can cause headaches through increased eye pressure, a common symptom of the disease. This increased pressure can lead to eye pain and discomfort, which may result in headaches. It's important to note that not all people with glaucoma experience increased eye pressure, and even if they do, it may not necessarily cause headaches.

Can glaucoma be reversed?

Unfortunately, there is currently no cure for glaucoma, and the damage to the optic nerve caused by the disease cannot be reversed. However, with early diagnosis and appropriate treatment, it is often possible to slow or halt the progression of the disease and prevent further damage to the optic nerve.

Does diabetes cause glaucoma?

While diabetes does not cause glaucoma, it is a risk factor for developing the disease. This is because high blood sugar levels associated with diabetes can damage blood vessels in the eye, leading to changes in the optic nerve and an increased risk of glaucoma.

Does glaucoma affect both eyes?

Glaucoma can affect one or both eyes. However, it's important to note that having glaucoma in one eye also increases the risk of developing the condition in the other eye. This is because the risk factors for glaucoma, such as high intraocular pressure, tend to be similar in both eyes.

In some cases, glaucoma may be more severe in one eye than the other, and the progression of the disease may differ between the two eyes. This can lead to differences in vision between the two eyes.

How successful is glaucoma surgery?

The success rate of glaucoma surgery depends on several factors, including the type of surgery, the severity of glaucoma, and the individual patient's response to the surgery. In general, however, glaucoma surgery can effectively lower intraocular pressure (IOP) and slow or halt the progression of the disease. 

Can cataracts cause glaucoma?

While cataracts themselves do not cause glaucoma, the two conditions can be linked in several ways:

• Some risk factors for cataracts and glaucoma, such as age and family history, are the same.
• Some types of glaucoma, such as angle-closure glaucoma, can be caused by a blockage in the eye’s drainage system. In some cases, a severe cataract can cause a blockage in this system, increasing the risk of angle-closure glaucoma.
• Cataract surgery is a standard procedure that involves removing the eye’s cloudy natural lens and replacing it with an artificial lens. While cataract surgery does not cause glaucoma, some studies have suggested that certain types of glaucoma may be more likely to develop or progress.