WHAT IS GLAUCOMA? Types, Symptoms, Causes, Diagnosis, Treatment

Glaucoma is a group of eye disorders that lead to progressive damage to the optic nerve. It is characterized by loss of nerve tissue that results in vision loss. People with glaucoma can lose nerve tissue, resulting in vision loss.
The optic nerve is a bundle of about a million individual nerve fibers that transmits the visual signals from the eye to the brain. In the most common form of glaucoma, open-angle glaucoma, the fluid pressure inside the eye increases. This increase in pressure may cause progressive damage to the optic nerve and loss of nerve fibers. Advanced glaucoma may even lead to blindness. Not everyone with high eye pressure will develop glaucoma, and some people with normal eye pressure will develop glaucoma. When the pressure inside a person’s eye is too high for a particular optic nerve, whatever that pressure measurement may be, glaucoma will develop. Glaucoma often occurs in people over age 40, although an infant (congenital) form of glaucoma exists. People with a family history of glaucoma, African Americans over the age of 40 and Hispanics over the age of 60 have an increased risk of developing glaucoma. Other risk factors include thinner corneas, chronic eye inflammation and taking medications that increase the pressure in the eyes.

Open-angle glaucoma, the most prevalent type, develops slowly without symptoms. Before serious vision loss, many people are unaware they have the illness. Glaucoma initially affects peripheral or side vision but can cause central vision loss. Glaucoma can cause blindness in both eyes if untreated.

Acute angle-closure glaucoma, a rarer variety, arises suddenly due to eye pressure increases. It can cause severe eye pain, nausea, redness, halos or colorful rings surrounding lights, and blurred vision. See your optometrist promptly for this critical condition that can cause significant vision loss. Glaucoma is unpreventable. However, early diagnosis and treatment can control it. Medicine or surgery can slow or stop eyesight loss. The vision lost to glaucoma cannot be recovered. Individuals at risk glaucoma should get an annual dilated eye exam depending on your condition, your doctor may recommend more frequent exams.

Causes and Types Glaucoma

There are many theories about the causes of glaucoma, but the exact cause is unknown. Although the disease is usually associated with an increase in fluid pressure inside the eye, other theories include a lack of adequate blood supply to the nerve.

Types of glaucoma

Open-angle glaucoma
Angle-closure glaucoma
Normal-tension or low-tension glaucoma

The following are the different types of glaucoma and their potential causes:

Open-angle glaucoma

This is the most common form of glaucoma. Damage to the optic nerve is slow and painless. Those affected can lose a large portion of vision before they notice any vision problems. One theory about its development is that the eye’s drainage system becomes inefficient over time. This leads to an increased amount of fluid and a gradual buildup of pressure within the eye. Another theory about the cause of this type of glaucoma is that there is poor blood flow (perfusion) to the optic nerve. Other theories also exist.

Angle-closure glaucoma

This type of glaucoma, also called closed-angle glaucoma or narrow-angle glaucoma, is a less common form of the disease. It is a medical emergency that can cause vision loss within a day of its onset. It occurs when the drainage angle in the eye (formed by the cornea and the iris) closes or becomes blocked. Many people who develop this type of glaucoma have a very narrow drainage angle. With age, the lens in the eye becomes larger, pushing the iris forward and narrowing the space between the iris and the cornea. As this angle narrows, the fluid in the eye is blocked from the drainage system. Therefore the fluid builds up and eye pressure increases. Angle-closure glaucoma can be chronic (progressing gradually) or acute (appearing suddenly). The acute form occurs when the iris completely blocks fluid drainage. When people with a narrow drainage angle have their pupils dilated, the angle may close and cause a sudden increase in eye pressure. Although an acute attack often affects only one eye, the other eye may be at risk of an attack as well.

Normal-tension or low-tension glaucoma

This type of glaucoma results from an injury or another eye disease. It may be caused by a variety of medical conditions, medications, physical injuries, and eye abnormalities. Infrequently, eye surgery can lead to low-tension glaucoma.

In this form of glaucoma, eye pressure remains within the “normal” range, but the optic nerve is damaged nevertheless. It is not known why this happens. Possibly, people with low-tension glaucoma have an abnormally sensitive optic nerve. Or they may have a reduced blood supply to the optic nerve caused by a condition such as atherosclerosis, a hardening of the arteries. Under these circumstances, even normal pressure on the optic nerve can cause damage.

Risk Factors of Glaucoma

The following factors can increase the risk of developing glaucoma:

Some people have a higher than normal risk of getting glaucoma. This includes:

• Eye injuries that are caused by physical trauma. Eye pressure can be immediately elevated as a consequence of severe trauma, such as being struck in the eye.
• The presence of glaucoma in the family. The likelihood of having glaucoma is increased when there is a history of the disease in one’s family.
• Medical conditions. According to the findings of a few studies, the likelihood of acquiring glaucoma is elevated in those who have diabetes, high blood pressure, and heart disease.
• Risk factors that are related to the eyes. There are several characteristics of the eye architecture that indicate an increased chance of developing glaucoma. These characteristics include thinner corneas and sensitivity of the optic nerve.
• Glaucoma is a condition that is substantially more likely to affect African Americans than it is Caucasians, and African Americans are also significantly more likely to experience permanent visual loss. Glaucoma with angle closure is more likely to occur in people of Asian heritage and Native Alaskans.
• Individuals who are over the age of sixty are at a higher risk for the condition. However, after the age of 40, African Americans are at a greater risk than other people.

Talk with an ophthalmologist about your risk for getting glaucoma. People with more than one of these risk factors have an even higher risk of glaucoma.

Symptoms of Glaucoma

Some folks have high eye pressure but no injury. These “glaucoma suspects” are at higher risk of developing it. Despite normal eye pressure, some are glaucoma suspects. For instance, their ophthalmologist may identify an optic nerve issue. Many glaucoma suspects have no symptoms. Glaucoma suspects must be closely monitored by their ophthalmologists. An ophthalmologist can monitor changes and treat if necessary.

Diagnosis of Glaucoma

Eye exams that are comprehensive are the only method that can definitively diagnose glaucoma. For the purpose of detecting glaucoma, a screening that merely examines the patient’s ocular pressure is insufficient.

Within the course of a glaucoma examination, your ophthalmologist will:

• Take a reading of your eye pressure.
• Your eye’s drainage angle should be examined.
• Check for any signs of injury to your optic nerve.
• Examine your vision on the sides (periphery).
• You can either take a picture of your optic nerve or have it measured on a computer.
• Find out how thick your cornea is by measuring it.

Treatment of Glaucoma

Treatment for glaucoma is focused at lowering the pressure that is present in the eye. Using eye drops that require a prescription on a consistent basis is the most prevalent and frequently the initial treatment. Systemic medicines, laser therapy, or other surgical procedures can be necessary in certain circumstances. Eyesight can be preserved via early diagnosis and ongoing therapy for glaucoma, despite the fact that there is currently no cure for the disease. A variety of medical procedures, including medication, surgery, laser surgery, conventional surgery, and drainage implants, are utilized in the therapy process.

Prevention of Glaucoma

Glaucoma is incurable. Glaucoma patients must need lifelong treatment. Compliance with eye medications and eye exams is vital because the illness can advance or change without warning. Treatment may need to be changed frequently. Controlling eye pressure helps prevent optic nerve injury and vision loss. Your optometrist may lower eye pressure to prevent optic nerve damage. This level, called the target pressure, is likely a range. Target pressure varies by person based on damage and other factors. Target pressure may vary. New glaucoma drugs are constantly being developed. Controlling glaucoma with early detection, treatment, and monitoring helps prevent vision loss.