UMMC Performing Groundbreaking Glaucoma Surgery

After years with few new surgical options to treat glaucoma — the second leading cause of blindness worldwide — ophthalmologists at University of Maryland Medical Center are leading a new frontier in managing the common eye condition, performing a novel, minimally invasive procedure expected to transform glaucoma into
a surgically curable disease.

The University of Maryland was the first in the State offering iStent surgery, implanting the speck-sized metallic shunt in several dozen glaucoma patients since last spring. The smallest medical device thus far to be embedded in the human body, iStent is inserted into the Schlemm’s canal — a circular channel that normally drains inner-eye fluid — to ease dangerously high eye pressure.

About 4,000 people have undergone the procedure nationwide since its FDA approval in 2012. UM ophthalmologists Lily Im, M.D., and Osamah J. Saeedi, M.D., are among the very few practitioners in the state currently performing the surgery, which is done in conjunction with cataract removal.

“In the world of glaucoma, we’re on the cusp of a huge change in the way we treat this disease,” says Dr. Im, director of the Glaucoma Service and an assistant professor of ophthalmology at University of Maryland School of Medicine. “With the advent of a whole new class of minimally invasive glaucoma surgery —
known as MIGS — I hope traditional glaucoma surgery will go the way of the dinosaurs. It’s exciting to be on the cutting edge and to be the first in Maryland to offer this treatment.”


Glaucoma is an increasing global menace, forecasted to affect 78 million patients worldwide by 2020. The United States has an estimated 2.2 million cases of open-angle glaucoma, the most common form of the disease, with more than 88,000 of the estimated 3 million patients in 2020 predicted to go blind.

Open-angle glaucoma occurs when the eye’s drainage canals gradually become clogged, dangerously raising pressure inside the eyes. Because vision loss resulting from glaucoma is irreversible, physicians seek to control the condition’s progression by prescribing medications such as eye drops or pills to regulate inner-eye pressure or lessen fluid production.

When medications fail or lead to intolerable side effects, ophthalmologists may turn to traditional glaucoma surgery, which creates a passage in the sclera (the white part of the eye) for excess eye fluid drainage. But neither eye drops nor traditional surgery are close to ideal, Dr. Im explains. Eye drops, in particular, are a deceptively simple solution but require constant vigilance, becoming a difficult regimen to maintain.

“Eye drops have a lot of side effects,” she says. “There are a lot of preservatives in them — you’re putting chemicals in your eye. Eye drops are easy to forget, and compliance is a huge issue. People don’t want to walk around with red, dry eyes.

“Avoiding traditional glaucoma surgery is the goal,” Dr. Im adds. “The earlier we can catch glaucoma and the more aggressive we are at treating it in its beginning stages, the more we can prevent progression and traditional surgery, which has a higher failure rate — upwards of 50% — over the lifetime of the surgery.”


Unlike traditional glaucoma surgery, the iStent procedure is far less invasive and doesn’t create a new bypass for eye drainage. Instead, the minimally invasive operation — just one of several emerging MIGS in the pipeline — uses the eye’s existing drainage system.

In a healthy eye, the clear fluid known as aqueous humor, which fills the space between the cornea and lens, drains from natural pathways that include the Schlemm’s canal. The iStent device, approximately the size of the year stamped on the head of a penny, is inserted into the canal with the help of a pre-loaded, single-use surgical tool using a magnifier. Only topical anesthesia is needed.

“It looks like a piece of lint,” Dr. Im says of the iStent shunt. “You’re operating under a microscope and you have to have steady hands. It’s a very delicate procedure. It’s very high magnification, the most magnified procedure we do.”

As the first available “micro-bypass stent” for glaucoma treatment, iStent is only FDA-approved to be performed for mild or moderate cases of open-angle glaucoma during simultaneous cataract removal. Dr. Im says this requirement makes sense, since it’s almost impossible to implant the iStent device without touching the eye’s lens, creating a cataract in the process. Most people over age 70 — who also comprise the majority of glaucoma patients — happen to be
affected by cataracts, she says.

About 3.5 million cataract procedures are done in the United States each year, with about 20% of those patients also on at least one medication for ocular hypertension, or higher-than-normal pressure inside the eyes.

“Every week I’m doing two or three of these surgeries now,” Dr. Im says. “It’s part of our standard armamentarium now.”


The rise of the this new procedure at UMMC coincides with the explosive growth of the Department of Ophthalmology and Visual Sciences, which is chaired by Bennie H. Jeng, M.D., and encompasses nearly two dozen faculty members. The University of Maryland School of Medicine has the distinction of establishing the first department for diseases of the eye in the United States in 1873.

In addition to bringing many more faculty members on board in recent years, the department’s services continue to grow at satellite locations including an expanded practice in Owings Mills. Plans are underway to open additional practices in 2015 in Towson, Waterloo and Glen Burnie, Dr. Im notes.

The iStent surgery sets UMMC apart from all other Maryland institutions offering eye care, a distinction Dr. Im says is attributable to their willingness within this ophthalmology department to embrace new technologies.

“The iStent procedure requires extremely careful hand-eye coordination — it’s very unique in the way you approach the eye,” she says. “I think it shows that we’re really a dynamic department … and willing to go out of the normal comfort zone.”

To make an appointment with University of Maryland Eye Associates, please call 667-214-1111.