Progression & Causes

Glaucoma is a series of diseases that result in damage to the optic nerves and eventual loss of vision. Glaucoma can affect anyone from newborn infants to the elderly. It is estimated that 3 million Americans have glaucoma. During this time, most people will NOT experience any symptoms. If left untreated, it can affect the vision and ultimately lead to permanent blindness. Glaucoma usually develops slowly over a period of years, but some rare forms can develop over hours. Inside the eye, a clear fluid called the acqeous humor, is produced to nourish the structures within the eye. Normally, this fluid leaves the eye through a drainage system called the trabecular meshwork located in the angle of the eye. In glaucoma, this fluid fails to drain at a normal rate and the intraocular pressure (IOP) rises. When the pressure in the eye is too high (this varies from person to person) this damages the optic nerve, which is responsible for sending visual images from the eye to the brain. When the nerve cells die, permanent damage occurs.

Glaucoma is detected through a complete eye examination. Early on, there are no symptoms. Vision stays normal and there is no pain. Over time and without treatment, people with glaucoma will experience a loss of peripheral vision, followed by a loss of central vision. Eventually without treatment, blindness can result.

Types of Glaucoma

PRIMARY OPEN ANGLE

This is the most common type of glaucoma. In these cases, the drainage area inside the eye (the angle) remains open, but internal changes develop for unknown reasons. This causes the fluid to drain too slowly out of the eye. As the fluid builds up, the pressure inside the eye gradually rises.

ACUTE ANGLE CLOSURE

This is a rare form of glaucoma where the drainage angle suddenly becomes blocked or narrows. As the pressure inside the eye rises, blurred vision, severe pain, and occasionally nausea and vomiting can result. This is an ocular emergency. Prompt laser treatment may help resolve this problem.

OTHER TYPES OF GLAUCOMA

Congenital glaucoma, narrow angle glaucoma, chronic angle closure glaucoma, and other types exist.

Treatment

Once glaucoma has been diagnosed, treatment should begin as soon as possible to help minimize the risk of permanent vision loss. Glaucoma is not cured, but in most cases it can be controlled. Treatment focuses on relieving any symptoms that may be present and preventing further damage from occurring. The vast majority of patients can be treated successfully with eye drops. Since glaucoma is a progressive disease, eye drops may need to be added or changed to maintain proper control of the pressure in the eyes. It is critical to use the drops daily as directed, and to have routine follow up eye examinations and testing with your eye doctor. Occasionally, if eye drops are not adequately controlling a patient’s glaucoma, other treatment options include the following below.
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Selective Laser Trabeculoplasty (SLT)

This is done for patients with open angle glaucoma. The laser is focused on the trabecular mesh-work and it stretches open the drainage area of the eye (the angle) to allow more fluid to drain from the eye and therefore lower the eye pressure. This is a highly effective procedure, but usually needs to be repeated every four or five years.

Endocyclophotocoagulation (ECP)

Uses a special laser and fiber optic system to treat areas inside the eye (ciliary processes). This procedure decreases the amount of fluid produced inside the eye and thereby lowers the pressure inside the eye. Typically, this surgery is done in combination with cataract surgery.

Laser Peripheral Iridotomy (LPI)

LPI is used to equalize the pressure between the front and the back of the eye preventing a pressure imbalance from damaging the optic nerve. This treatment requires making a very small hole in the iris (the colored part of the eye), allowing the eye’s natural fluid to easily flow from the back to the front of the eye. This is done for patients with narrow or closed angles.

Trabeculectomy (Filtering Microsurgery)

This is for patients who have not been helped by eye drops or lasers. A new drainage passage is created by making a small hole and flap in the sclera (the white wall of the eye) and creating a collection pouch for the ocular fluids.

Tube Shunt Surgery

This is usually reserved for severe glaucoma cases. This is a complex surgery and requires several follow up visits and may require possible adjustments following surgery. A thin, flexible tube (shunt) is inserted into the eye. This shunt is connected to a pouch that collects the intra-ocular fluid. By completely bypassing the obstructed drainage system of the eye, it can lead to dramatically lower the eye pressures. Most patients can reduce or eliminate their need for glaucoma drops. This is the most effective way to lower a person’s eye pressure, but it also has the highest number of complications.

iStent Surgery

The iStent Trabecular Micro-Bypass stent is a new surgical therapy for mild to moderate glaucoma that is designed to improve fluid outflow in the eye to safely lower eye pressure. This may reduce or eliminate the need for glaucoma medications. iStent is the smallest medical device ever approved by the FDA and is placed in your eye during cataract surgery. It is so small, you won’t be able to see or feel it after surgery but it will be continuously working to help reduce your eye pressure.