Glaucoma

Q: What is glaucoma?

A: Glaucoma is a group of eye diseases that can cause damage to the optic nerve, and is one of the most common causes of blindness. It often occurs when there is an increased intraocular pressure (IOP, or pressure inside the eye) which can lead to optic nerve damage and vision loss. However, not all glaucoma cases are associated with elevated IOP, and other factors may contribute to the condition.

Q: What are the main types of glaucoma?

A: There are several types of glaucoma, but the two most common ones are (1) open-angle glaucoma and (2) angle-closure glaucoma:

Open-Angle Glaucoma — this is the most common type of glaucoma. It develops slowly over time as the drainage angle in the eye becomes less efficient, leading to a gradual increase in intraocular pressure. People with open-angle glaucoma may not experience symptoms until the disease is in advanced stages, which is why it’s often referred to as the “silent thief of sight.”

Angle-Closure Glaucoma — this type of glaucoma occurs when the drainage angle in the eye becomes blocked, leading to a severe increase in intraocular pressure. Angle-closure glaucoma is sometimes accompanied by noticeable symptoms, such as eye pain, redness, headaches and vision disturbances.

Q: How is glaucoma treated?

A: The management of glaucoma typically involves a combination of the following approaches:

Medications — eye drops or oral medications are often prescribed to lower intraocular pressure. These medications can help reduce the risk of further optic nerve damage. It’s important to use these medications as directed by your ophthalmologist.

Laser Therapy — some types of glaucoma may be treated with laser procedures, such as selective laser trabeculoplasty (SLT) or laser peripheral iridotomy (LPI). These procedures aim to improve the drainage of fluid in the eye.

Surgery — surgical interventions like trabeculectomy or lens extraction surgery may be necessary in cases where medications and laser therapy are not effective in controlling intraocular pressure.

Regular Eye Examinations — early detection is crucial in managing glaucoma. Regular eye exams can help identify the disease in its early stages, allowing for prompt intervention.

Lifestyle Modifications — some lifestyle changes, like maintaining a healthy diet, exercising regularly, and managing other health conditions like diabetes, can contribute to better glaucoma management.

It’s important to note that glaucoma management is a lifelong process, as there is no cure for the condition. The goal is to preserve remaining vision, slow down the progression of the disease, and prevent further damage to the optic nerve. Therefore, individuals diagnosed with glaucoma should work closely with their ophthalmologist to develop a personalized treatment plan and adhere to it to maintain good eye health. Regular follow-up visits and monitoring are essential for successful glaucoma management.

Q: What is chronic angle-closure glaucoma?

A: Chronic angle-closure glaucoma is one of a group of eye diseases characterised by increased intraocular pressure (IOP) that can lead to damage to the optic nerve and potential vision loss. It is one of the two main types of angle-closure glaucoma, with the other being acute angle-closure.

In chronic angle-closure glaucoma, the angle of the eye’s drainage system gradually narrows over time. This angle refers to the area where the cornea and iris meet, and it plays a crucial role in allowing aqueous humor (the clear fluid in the eye) to drain properly. When this angle becomes progressively blocked or narrowed, it can impede the drainage of aqueous humor from the eye, leading to an increase in intraocular pressure.

The gradual increase in intraocular pressure can damage the optic nerve, which is responsible for transmitting visual information from the eye to the brain. As the optic nerve is damaged, it can result in a loss of peripheral vision, and if left untreated, it can lead to permanent vision loss.

Symptoms of chronic angle-closure glaucoma can be subtle or absent in the early stages, making regular eye exams important for its detection. Treatment typically involves the use of medications to lower intraocular pressure, laser therapy to improve the drainage angle, or sometimes surgery to create a new drainage pathway for aqueous humor.

It’s important for individuals at risk of developing chronic angle-closure glaucoma, such as those with a family history of the condition, to have regular eye check-ups and consult with an eye care specialist for early diagnosis and management. If you suspect you have any form of glaucoma or experience symptoms like blurred vision, halos around lights, eye pain, or changes in your vision, you should seek immediate medical attention.

Q: What is acute angle-closure?

A: Acute angle-closure is a medical emergency that occurs when the drainage angle within the eye becomes blocked or obstructed by the iris. This leads to a sudden and significant increase in intraocular pressure (IOP), which can damage the optic nerve and cause vision loss if left untreated.

The front part of the eye contains a clear fluid called aqueous humor, which nourishes the cornea and lens. This fluid is produced in the ciliary body and drains out of the eye through a tiny space between the iris (the coloured part of the eye) and the cornea. This drainage angle is essential for maintaining the normal pressure within the eye.

Acute angle-closure occurs when the drainage angle becomes blocked or narrowed, due to a large natural lens that sits too far forwards in the eye, and forward displacement of the iris. This can happen suddenly, causing a rapid increase in IOP.

Angle-closure glaucoma typically presents with sudden and severe symptoms, including:

• Severe eye pain
• Blurred or hazy vision
• Headache
• Halos or rainbow-colored rings around lights
• Nausea and vomiting
• Redness of the eye

Acute angle-closure is a medical emergency and requires immediate treatment to lower the intraocular pressure and relieve symptoms.  Treatment options include:

Medications — the first line of treatment is usually medications to lower intraocular pressure. These may include oral carbonic anhydrase inhibitors, topical beta-blockers, alpha agonists, and prostaglandin analogs.

Laser Therapy — laser peripheral iridotomy (LPI) is performed to create a small hole in the peripheral iris. This hole allows the aqueous humor to flow freely, relieving the angle closure. Laser treatment is highly effective at preventing acute angle-closure.

Surgery — in cases where laser therapy is not possible or unsuccessful, surgical intervention may be necessary. Procedures such as clear lens extraction may be considered to improve the drainage of aqueous humor.

Follow-Up — after the acute phase of angle-closure is treated, ongoing monitoring and management are essential to prevent further episodes and protect the patient’s vision. Patients with angle-closure glaucoma may require long-term use of glaucoma medications and regular follow-up with an ophthalmologist.

It’s important to recognise the symptoms of angle-closure glaucoma and seek immediate medical attention if you or someone you know experiences them. Early intervention is crucial to prevent permanent vision loss associated with this condition.