Glaucoma is the leading cause of permanent blindness worldwide and the second leading cause of permanent blindness in the United States. It is estimated that three million people in the United States suffer from glaucoma, a number that is expected to increase to 6.3 million over the next 30 years. Although glaucoma is more common in adults over 60, it can develop at any age. Although there is currently no cure for glaucoma, vision loss can be slowed or stopped if the disease is diagnosed and treated early.
What is glaucoma?
Glaucoma is a group of disorders that damage the optic nerve in the eye, which carries visual signals from the retina to the brain, allowing us to see. In glaucoma, the optic nerve is slowly damaged, causing progressive loss of vision and permanent blindness. Because damage occurs slowly, it is often symptomless and goes unnoticed until it is too late. As it progresses, glaucoma can lead to a poor quality of life, an increased risk of falls, reduced mobility, and difficulty driving.
Glaucoma is often associated with increased pressure inside the eye. Healthy eyes produce a fluid called watery, which crosses and leaves the eye. In glaucoma, this process does not work properly, resulting in increased eye pressure and damage to the optic nerve. The two main types of glaucoma – open-angle glaucoma and narrow-angle glaucoma – are determined by the structure of the drainage path at the front of the eye (called the angle), through which flows the aqueous fluid.
In open-angle glaucoma, the angle appears open, but a number of factors – including drainage issues – lead to poor pressure regulation. This form of glaucoma can occur at both high and normal eye pressures (normal tension glaucoma). Both subtypes can cause vision loss and damage to the optic nerve.
In narrow-angle glaucoma, the angle is narrow and the resulting structural problems can lead to abrupt closure of the drainage path, leading to a sudden increase in eye pressure. This condition is known as acute angle closure. Although relatively rare, acute narrow-angle glaucoma is an eye emergency and requires immediate treatment with drugs, laser, or surgery, as it can lead to rapid and irreversible blindness. Closed-angle glaucoma also exists in a chronic form where the increase in eye pressure occurs more slowly, often without symptoms, but still requires evaluation and treatment.
Who is at risk of developing glaucoma?
Glaucoma is a complex disease, and although many associated genes have been identified, the underlying causes are still unclear.
However, a number of important risk factors have been identified, including
- over 60 (40 for African Americans)
- a first-degree relative with glaucoma
- African-American or Hispanic descent
- Offspring from East and Southeast Asia (for narrow-angle glaucoma)
- history of eye trauma or multiple eye surgeries
- chronic eye diseases, such as eye disease linked to diabetes
- very short-sighted or clairvoyant
- the use of steroid drugs.
What are the symptoms of glaucoma?
Most people with glaucoma, especially those with open angle glaucoma or normal tension glaucoma, may have no or very few symptoms for years. It is probably not surprising that about 50% of glaucoma cases go undiagnosed, highlighting the need regular eye exams, from 40 years old. An eye care professional will be able to spot signs of glaucoma before you can, and prompt intervention is essential to prevent disease progression and vision loss.
The first signs of glaucoma include difficulty with low contrast and some loss of peripheral vision. At more advanced stages, patients develop loss of their visual field, or blind spots, which eventually progress to central vision loss.
Acute angle-closure glaucoma causes symptoms of pain, blurred vision, and nausea, and is a medical emergency.
What treatment options are available?
Although there is currently no cure for glaucoma, prompt treatment can help slow or stop the progression of vision loss. Depending on many factors, including your age and the type and severity of your glaucoma, treatment may include medication and / or surgery to reduce eye pressure.
Medicines include pressure lowering eye drops that work to increase fluid drainage or decrease fluid production. The laser is sometimes used to increase drainage (in the angle) or to make an opening in the iris, or colored part of the eye, in narrow-angle glaucoma. Various surgical techniques can be used to create an alternate route for draining fluids into the eye, which is called filter surgery and tube bypass surgery. Recent surgical innovations called minimally invasive glaucoma surgery, or MIGS, increase fluid drainage using microscopic-sized implantable stents and shunts.
The future of glaucoma care
Glaucoma research continues to improve our understanding of the causes of the disease and to develop more targeted and personalized treatments. There are subtypes of glaucoma, beyond the main categories described here, which many believe will benefit from different treatments. In the future, genetic testing may play a role in estimating an individual’s risk of developing glaucoma over time. In addition, treatments to stop the loss of nerve cells (from the retina and optic nerve) called neuroprotection are showing promise. Researchers are studying new drugs, drug delivery systems, and innovations to make surgery safer and more efficient.
Early detection is essential
If you are worried about glaucoma, and especially if you have a family history, the best approach is to see your ophthalmologist regularly. Every adult should have a basic eye exam at age 40even if your vision is normal. Vision loss from glaucoma can be minimized with treatment, so early detection is essential.