Annual glaucoma screening keeps ‘eye' on vision

By Glenna Picton

Detecting glaucoma early can prevent long-term damage to eyesight, so yearly screenings should become routine for everyone over the age of 40, advise ophthalmologists at Baylor College of Medicine.

"The biggest problem with glaucoma is that it's a silent disease – a 'sneak thief of sight,'" said Silvia Orengo-Nania, M.D., professor of ophthalmology in the Baylor Eye Clinic at BCM. "You could have visual damage occurring over time and not know it. Once damage occurs, it is irreversible and you will not be able to get any vision back that you have lost. This is why screening early is critical."

During the exam, the eyes are dilated and a doctor looks at the optic nerve (the nerve between your eye and brain that transmits visions signals) and measures the intraocular pressure (the fluid pressure inside the eye), Orengo-Nania explained.

Glaucoma usually occurs when increased pressure in the eye slowly destroys the optic nerve, damaging your ability to see, she said.

Leading cause of blindness

Glaucoma is roughly divided into two groups: open angle and closed angle. Open angle is the slow chronic form of the disease. Closed angle, seen less frequently, occurs suddenly and is painful, prompting patients and physician to take quick action.

Approximately 2 million people in the United States are visually impaired by glaucoma. It is one of the leading causes of blindness.

"It slowly gets rid of peripheral vision (or side vision). Then it begins to affect the center vision," said Orengo-Nania. "The slow progression is how people miss the early warning signs and eventually become sight-impaired and possibly blind. "

Nerve damage from glaucoma usually starts around age 40. By the time the decrease in vision affects quality of life, patients may be in their 60s, Orengo-Nania said.

Risk factors for disease

"Glaucoma tends to be a much more blinding and aggressive disease in African Americans. It's really important that this high-risk group get screened and treated properly early on," said Orengo-Nania.

Other risk factors include family history, prolonged steroid use, injury to the eye or head and advanced age.

"The older you are, the greater your risk of developing glaucoma," said Orengo-Nania. "This is mostly a disease of the elderly, but it can affect all age groups."

Treatment to slow progression

Treatment can help slow down, but not reverse, impaired vision, Orengo-Nania said.

"The treatment goals are to lower the eye pressure, which will halt the progression of the disease," said Orengo-Nania. "There is no cure but you could slow it down so much that the disease outlives you, preventing further damage."

Ophthalmologists begin with eye drops to lower pressure, Orengo-Nania said. If the drops are not effective, ophthalmologists may choose surgery (laser or incision) as the next method of treatment.

Research underway

Orengo-Nania and colleagues at the Baylor Eye Clinic are committed to advancing glaucoma research programs.

"We are involved in a variety of clinical trials studying new medications for the treatment of glaucoma," said Orengo-Nania. "In the laboratory, we are looking at new ways to prevent nerve damage from occurring and new methods for checking loss of visual field in order to pick up progression early and change treatment more effectively."

For more information on current glaucoma clinical trials at the Baylor Eye Clinic, contact Benita Slight at 713-798-4125 or bslight@bcm.edu or contact Cindy Dorenbach at 713-798-4037 or ctanz@bcm.edu.