Health

Risk of vision loss due to Glaucoma


Glaucoma can cause slow and insidious vision loss over many years; People at risk should have a comprehensive eye exam every 1-2 years.

Glaucoma is a group of eye diseases characterized by damage to the optic nerve, which can lead to irreversible vision loss.

MSc Pham Vu Huy Tung, Tam Anh General Hospital, said, damage to the optic nerve can occur when pressure in the eye increases. Usually, vision loss happens very slowly and can go unnoticed for a long time.

Those at risk should have a general eye exam, including intraocular pressure measurement and visual acuity testing. People with Glaucoma need lifelong treatment and monitoring with eye drops, possibly surgery.

According to Dr. Tung, subjects at risk of glaucoma include: people over 40 years old, having family members with the disease; nearsightedness or farsightedness; people with diabetes; people with high blood pressure; long-term corticosteroid users; previous eye injury or surgery.

The cause to the illness

Tung explained, Glaucoma occurs when an imbalance in the production and drainage of fluid in the eye (aqueous fluid) increases intraocular pressure to a level that is not good for the eyes. Normally, the fluid that nourishes the eye, is produced by the ciliary body behind the iris (in the posterior chamber) and passes through the pupil to the front of the eye (anterior chamber), where it exits the drains between the irises. and cornea (anterior chamber angle). The balance between production and drainage of aqueous humor keeps the aqueous humor flowing freely and prevents pressure in the eye from rising.

Glaucoma usually occurs in people over 60 years of age. Photo: Shutterstock.

With Glaucoma, the drainage channels become blocked or clogged. The aqueous humor cannot exit the eye even though new aqueous humor is being produced in the posterior chamber, causing increased pressure in the eye. When the pressure becomes higher than the optic nerve can bear, the optic nerve is damaged. This lesion is called Glaucoma.

Sometimes the intraocular pressure rises within the normal range but is still too high for the optic nerve to tolerate (called low pressure glaucoma or normal pressure glaucoma).

In most cases, the cause of glaucoma cannot be found, called primary glaucoma. When the cause of the disease is found, it is called secondary glaucoma. Causes of secondary glaucoma include infection, inflammation, tumor, large cataract, cataract surgery, medication, or other medical condition. These conditions prevent the aqueous humor from draining, leading to glaucoma and damage to the optic nerve.

Symptoms of Glaucoma

Dr. Tung said, Glaucoma is divided into two types: Open-angle Glaucoma and Closed-angle Glaucoma.

Open-angle glaucoma is painless. Both eyes are usually affected but not equally. The main symptom is the development of blind spots or patches of vision loss, over months to years. The blind spots slowly grow larger and merge together. Peripheral vision is usually lost first.

Patients may slip stairs, notice parts of words missing when reading, or have trouble driving. Vision loss happens so gradually that it often goes unnoticed until it is greatly reduced. Because central vision is often lost eventually, “tunnel vision” occurs, where the patient looks straight ahead perfectly but is blind in all other directions. If left untreated, tunnel vision is lost and completely blind.

In acute angle-closure glaucoma, the intraocular pressure rises rapidly and the patient often notices eye pain, severe headache, redness, blurred vision, rainbow halos around lights, and sudden loss of vision. They may also experience nausea and vomiting as a reaction to the glaucoma.

“Acute angle-closure glaucoma is considered an emergency because patients can lose vision as quickly as 2-3 hours after the onset of symptoms if the condition is left untreated,” said Dr. idea.

In chronic angle-closure glaucoma, the intraocular pressure rises slowly and symptoms often begin as in open-angle glaucoma. Some people may experience eye redness, irritability, blurred vision, or headaches while sleeping. According to Dr. Tung, people who have had open-angle glaucoma or closed-angle glaucoma in one eye are more likely to develop the disease in the other eye.

“Visibility loss from Glaucoma is permanent. But if Glaucoma is detected, appropriate treatment can prevent further vision loss. Glaucoma treatment is lifelong. Medications (usually in the form of eye drops) and surgery are used. Surgery is the main treatment for this disease. The type and severity of the disease determine the appropriate treatment,” said Dr. Tung.

Chau Vu

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