Glaucoma is a leading cause visual impairment in the US, and can affect patients of all ages, many of who do not experience any symptoms and may not be aware that they have the disease. Glaucoma actually refers to a group of diseases that cause damage to the optic nerve as a result of increased pressure within the eye. It can also be caused by a severe eye infection, injury, blocked blood vessels or inflammatory conditions of the eye.
Healthy Optic Nerve
Optic Nerve with Glaucoma
Types of Glaucoma
There are two main types of glaucoma, open-angle and closed-angle. Open-angle glaucoma is the most common type of glaucoma and results when fluid in the eye does not drain properly through the normal drainage channels, known as the trabecular meshwork. Open angle glaucoma usually occurs gradually and slowly, and is dangerous because it often does not cause symptoms until it is extremely advanced. Closed-angle glaucoma typically results from buildup of pressure in the eye behind the iris, preventing normal fluid circulation through the eye. Closed-angle glaucoma can occur suddenly, which is a medical emergency and requires prompt treatment to prevent blindness.
Many patients do not experience any symptoms during the early stages of glaucoma, as there is often no pain or discomfort and the vision loss can be subtle and gradual. This makes it difficult for many patients to know if they have the disease, and to tell if it is controlled by treatment. As glaucoma progresses, patients may experience a loss of peripheral or side vision, but when this becomes noticeable it usually means the disease is very advanced.
While some patients may experience symptoms from glaucoma as the disease progresses, others do not learn they have the condition until they undergo a complete eye exam. Eye doctors are trained to detect warning signs of glaucoma during an examination. Although measurement of the eye pressure is part of a glaucoma evaluation, it is not enough to determine whether or not there is glaucoma. There are several different tests that may be used to help diagnose and monitor glaucoma, including tests of the peripheral vision (visual field testing), thickness of the cornea (pachymetry), and three-dimensional imaging of the optic nerve layers (OCT-optical coherence tomography imaging).
Once glaucoma has been diagnosed, treatment is essential to reduce the risk of progressive vision loss. There is no cure for glaucoma, but it can be controlled and vision loss can usually be prevented. Treatment options for glaucoma focus on reducing the eye pressure, and includes eye drops, laser surgery or microsurgery. The best treatment for your individual case depends on the type and severity of the disease, and should be discussed with your doctor.
Eye drops are usually effective in reducing the eye pressure. Side effects can include redness, stinging, irritation or blurry vision, but are usually fairly minor. However, drops must be taken regularly, following directions, and continued indefinitely.
Laser surgery for glaucoma can be performed to open the trabecular meshwork, or relieve fluid blockage within the eye, or slow down fluid production. These laser procedures include laser trabeculoplasty, iridotomy or cyclophotocoagulation.
A new category of glaucoma procedures known as Minimally Invasive Glaucoma Surgery, or MIGS, is now available with a variety of instruments and devices that can help improve drainage of the eye. As the name implies, these less-invasive procedures can lower the pressure, with less risk and faster recovery than traditional glaucoma surgery. MIGS procedures include the iStent, canaloplasty, goniotomy, and a variety of new devices such as the Cypass and XEN stents. Coastal Eye has extensive experience with MIGS technologies, and commonly offers this technology to patients undergoing cataract surgery, or who just wish to reduce their dependence on constant drop use.
Traditional invasive glaucoma surgeries include various tube shunts such as the Baerveldt and Ahmed tubes, and the gold standard glaucoma surgery known as trabeculectomy. In trabeculectomy, a new drain is created under a protective ‘trap door’ in the white of the eye, providing continuous drainage and pressure control. Generally reserved for moderate to severe glaucoma that is no longer controlled with medications, trabeculectomy can be performed alone, or in combination with cataract surgery.