What is glaucoma?

Glaucoma is a disease that damages the eye’s optic nerve and causes loss of peripheral vision. It usually happens when fluid builds up in the front part of the eye. That extra fluid increases the pressure in the eye, damaging the optic nerve. Glaucoma is the second leading cause of blindness in the U.S. and the leading cause of preventable blindness. In fact, roughly half of the 3 million Americans who have glaucoma do not realize they are affected by the disease due to the absence of warning signs. But blindness from glaucoma can often be prevented with early treatment, and glaucoma can easily be detected during a complete eye exam by an ophthalmologist. Dr. Cohn is a glaucoma specialist, and exclusively studied and treated glaucoma patients during a year-long glaucoma fellowship.

What are the symptoms?

The most common type of glaucoma, the "open angle" type, often has NO SYMPTOMS until central vision is lost in the most advanced stages of the disease. Unfortunately, patients most often walk around with glaucoma and don’t even know they have it. That is why routine eye exams from an ophthalmologist are so important. Most patients are unaware that the pressure in their eyes may be elevated.

"Acute angle closure glaucoma," a much less common variety, usually presents with a red, painful eye with blurred vision, nausea, and headache. Angle closure is an ocular emergency that requires prompt treatment by an ophthalmologist.

How is glaucoma diagnosed?

Glaucoma is diagnosed during a routine ophthalmic exam. The optic nerve is observed for damage. The pressure inside the eye is measured easily in the office. Patients usually undergo a visual field test if the doctor is suspicious of possible glaucoma. This 20-300 minute test involves having the patient push a button every time he/she sees a small light flash on different parts of a viewing screen. This produces a sensitive map of areas where peripheral vision may be fading without the patient’s knowledge.  A screening pressure check is not sufficient to diagnose glaucoma.  Patients with "normal tension" glaucoma may have optic nerve damage with normal eye pressure. 

What are the possible treatments?

Treatment often begins with eyedrops designed to lower the intraocular pressure. It has long been felt that reducing the pressure in the eye helps to slow optic nerve damage.

When eye drops alone fail to control the eye pressure, Dr. Cohn commonly chooses to perform Selective Laser Trabeculoplasty (SLT), a brief in-office laser procedure, in which small laser spots are applied to the drainage canals to help stimulate the drain to work better. This laser may be periodically repeated to re-stimulate the drain if the effect starts to wane with time. SLT is performed in the office and takes less than 5 minutes. Patients are comfortable through the entire procedure. 

Surgical intervention is usually reserved for patients who have failed laser treatment and have worsening glaucoma despite several medications. When fluid can’t escape from the eye and the eye pressure has become persistently elevated, surgery is performed to allow fluid to escape from the eye. This can be performed either with a drainage flap made in the white of the eye, or a silicone drainage tube that drains fluid to a plate on the outer wall of the eye. Either technique has a 80-90% success rate.

For our patients that need cataract surgery and also have glaucoma, a MIGS (minimally invasive glaucoma surgery) procedure may be useful. The MIGS procedure involves implanting a small drainage device at the same time as cataract surgery, to help improve outflow from the eye. Dr. Cohn has found these to work quite successfully in many of his patients. Dr. Cohn, a fellowship-trained glaucoma specialist, has performed thousands of successful glaucoma surgeries in Orlando over the last two decades.