A glaucoma is a group of eye illnesses that damage the optic nerve. Glaucoma is the second leading cause of blindness worldwide after cataracts. Though there is no cure, treatment and regular checkups to stop or slow down its progression. Read below to learn more about how to prevent glaucoma and potentially save your sight.
Glaucoma is a term used to describe a group of eye disorders damaging the optic nerve, which is a bundle of nerve fibers responsible for transmitting visual information from the eye’s retina to the brain for interpretation.
Normally, a fluid called aqueous humor is produced constantly in the front part of the eye. The fluid helps to nourish the eyes and maintain the eyes’ shape. This fluid is drained away through the drainage channels, called the trabecular meshwork, at the drainage angle where the iris and cornea meet. If the channels are blocked or if excessive fluid is produced, then the pressure inside the eye (intraocular pressure, IOP) rises and damages the optic nerve, possibly leading to vision loss.
Although this mechanism is likely to be the reason for glaucoma, however, the exact cause of glaucoma is not clearly understood yet. In fact, glaucoma can also develop with normal intraocular pressure. This subtype is named low-tension or normal-tension glaucoma.
There are many types of glaucomas which are mainly classified as either open-angle glaucoma (chronic) or angle-closure glaucoma (chronic or acute). Glaucoma can be primary or secondary, primary glaucoma refers to glaucoma without a known cause whereas secondary glaucoma refers to any glaucoma due to an identifiable cause, such as medical conditions (e.g. cataracts), medicines, injuries, tumors, etc. Major types of glaucoma include:
Though open-angle glaucoma is very common, many people do not notice any signs or symptoms until it progresses gradually to result in vision loss. That’s why glaucoma is called the “silent thief of sight”. For that reason, it is vitally important to take regular eye examinations with your ophthalmologist to prevent vision loss.
Signs and symptoms of open-angle glaucoma develop slowly, and you may not notice them until the later stages. As it progresses, the following glaucoma symptoms become obvious:
Acute angle-closure glaucoma (AACG):
Acute angle-closure glaucoma is a medical emergency and can give rise to more severe signs and symptoms suddenly. You should seek medical help immediately if you experience the following glaucoma symptoms:
Glaucoma can affect anyone, but certain groups are at higher risk and need to be checked more frequently by an ophthalmologist. Risk factors of glaucoma include:
In order to screen or diagnose glaucoma, your ophthalmologist will take your complete medical history and perform a comprehensive eye examination. The following examinations and tests can be done to diagnose glaucoma:
There is no cure for glaucoma and vision loss cannot be reversed, but it can be treated in several ways to slow down the disease progression and prevent further damage. The main treatment for glaucoma is medication (eye drops). If it fails, your doctor may recommend laser therapy and surgery.
Medication is used to lower intraocular pressure (IOP) as a means to reduce the progression of visual field loss. Treatment can either increase the outflow of aqueous humor or decrease the production of aqueous humor. Based on your response and severity, more than one of the following eye drops may be prescribed:
If medication is not effective or tolerable, laser therapy is an alternative treatment option for glaucoma. It aims to help aqueous humor drain from the eyes. There are several types of laser treatments, including:
If medication and laser therapy do not relieve glaucoma’s conditions, several surgical procedures can be recommended:
Although glaucoma can be treated to relieve its signs and symptoms, there is no way to cure or prevent it yet. Therefore, it is crucial to take comprehensive eye examinations regularly to catch glaucoma as early as possible to prevent its progression and vision loss.
According to the American Academy of Ophthalmology, adults are recommended to get a complete eye examination at age 40. You should discuss with your ophthalmologist how often you should undergo an eye test, especially if you are at high risk of glaucoma because of diabetes, high blood pressure or a family history of eye disease. Find an ophthalmologist in Hong Kong here.
If you suffer from open-angle glaucoma, you may not notice any symptoms at first. As it progresses, you will start to see small blind spots in your peripheral vision and gradually experience tunnel vision. At that point, complete vision loss can occur if glaucoma is untreated.
If you have glaucoma, your eye pressure (intraocular pressure) is typically abnormally high and can damage your optic nerve, which is responsible for transmitting visual information to the brain. When most of the optic nerve is damaged, permanent vision loss follows.
Glaucoma is incurable and vision loss cannot be reversed, however, glaucoma can be managed with various treatments, such as eye drops, laser and surgery. The goal of therapy is to slow down the disease progression and prevent further damage by lowering intraocular pressure. Therefore, it is important to have regular eye examinations to catch glaucoma at an early stage.
Dr. Marcus Marcet is a Specialist in Ophthalmology in Hong Kong and a Diplomate of the American Board of Ophthalmology. Dr. Marcet's particular area of interest is in conditions of the eyelid and oculoplastic surgery.
This article was independently written by Healthy Matters. It is informative only and not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be relied upon for specific medical advice.
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