Expert tips for surgically managing corneal perforations

One of the most memorable patients ever to walk into the office of Sonal Tuli, MD, had a fishhook protruding from his eye, which he held open with his fingers.

It is the kind of injury that gives even seasoned ophthalmologists pause. “People don’t want to deal with it,” Dr. Tuli said. “They don’t have the training, and it scares them.”

In her talk at the 2015 American Academy of Ophthalmology meeting, Dr. Tuli, who specializes in management of perforated corneal ulcers at the University of Florida in Gainesville, Florida, offered tips for plugging the holes. “We see a lot of it here,” she said.

Unlike lacerations, perforations often involve tissue loss, complicating the treatment, she said. The cornea does not have a blood supply, so it does not heal as rapidly as other tissues.

“What I’m talking about is a hole in the eye,” she said. “Now you have aqueous leaking out and infection tracking back in. It’s potentially eye-threatening.” Gluing, grafting, or a corneal transplant can usually save the eye, she said.

Understanding the mechanism of an injury can provide some guidance about treating it. A variety of unfortunate events can cause perforations, she said. In addition to fish hooks, projectiles can also make holes. Sometimes, physicians cause them in the process of trying to remove a foreign body or in the course of refractive surgery.

More often, keratitis causes the ulcers when fungi or bacteria, particularly Pseudomonas, invade the tissue. “Usually bacteria can’t do it by themselves unless there’s some trauma, even though it’s minor,” Dr. Tuli said. “It could be rubbing your eye really hard.”

Where and how this happens

Pseudomonas ulcer. Photo courtesy of Sonal Tuli, MDEstimates of the incidence of corneal ulcers seen in ophthalmology patients range from 1 in 1,000 to 1 in 10,000, she said.

They are more common in warm humid places where bacteria and fungi grow more quickly. She said that explains why so many find their way to her Florida practice.

“We definitely see tenfold more in the South,” she said. She often sees patients whose infections start with contaminated contact lenses. These ulcerations often cause significant tissue loss resulting in corneal perforations.

Neurotrophic keratitis, peripheral ulcer keratitis, and Rosacea-related blepharokeratitis can lead to similar damage. In addition, pellucid marginal degeneration, Terrien’s marginal degeneration, keratoglobus, and Peters anomaly can also be the causes.

As the eye becomes inflamed in response to breakdown of the epithelium, leukocytes produce proteases that cause tissue lysis.

“The basic principle is that these are substances that chew up the cornea,” Dr. Tuli said. “They can be produced by bacteria, by our own leukocytes that are recruited to the eye to fight the infection, or could be produced by autoimmune processes.”

Diseases such as rheumatoid arthritis can lead to cornea ulcers, she explained, because inflammatory mediators may emerge from the hairpin bends of limbal blood vessels in the eye, attacking tissues there much as they do in joints.

Signs to look for

As one sign that an ulcer may have resulted from an autoimmune process, Dr. Tuli recommended looking for a shelf of epithelium “almost like an excavation.” Infectious ulcers by contrast “look more like a bowl,” she said.

Autoimmune ulcers tend to be peripheral, whereas infectious ulcers are more likely to be central, since blood vessels at the periphery of the cornea can provide better protection from infection.

Whatever causes the initial insult, resulting stromal tissue loss can lead to a desemetocele. Minor trauma or straining can then rupture the desemetocele.

Clinicians may want to treat the underlying cause of the ulcer, for example using such protease inhibitors as tetracylines and vitamin C, or in the case of a bacterial infection, with topical and systemic antibiotics. Vitamin C benefits white blood migration and helps tetracycline to inhibit proteases, Dr. Tuli said. Steroid drops can suppress the inflammation.

“If it’s autoimmune, you need to suppress the immune system,” she said. “So typically we’ll put them on high-dose steroids and send them to a rheumatologist to put them on systemic immunosuppressants.”

If the cause is trauma, and the tissue loss is mostly linear and minimal, the clinician can attempt primary closure with sutures. However, this approach involves a high risk of leaks and gapes and can result in significant postoperative astigmatism.

“You’ll have to crank the sutures down,” Dr. Tuli explained. “That could cause the cornea to buckle and change shape. Sometimes when you take the stitches out, it does recover, but often if there is any tissue loss at all, it’s permanent.”

What to do

Pinpoint perforations may seal spontaneously under a tamponade. Aqueous suppressants can help. “A lot of people use glaucoma medications to reduce the pressure, allowing the hole to close,” Dr. Tuli said.

An off-the-shelf extended-wear contact lens works best as a tamponade, Dr. Tuli said. She doesn’t use pressure patches because they make the eye more warm and humid. With pressure patches, it is not possible to see whether the hole is healing, and the patient cannot give any information about how vision is affected.

Sometimes, the iris prolapses through the perforation. If the clinician encounters this phenomenon within 24 hours of the injury, it may be possible to reposition the iris, tamponade the perforation with an air bubble, and apply glue.

If the iris has prolapsed for a longer period of time, repositioning the iris raises the risk of dragging infection or epithelial cells from the surface deeper into the eye. If fluid is leaking from around the iris, Dr. Tuli recommends applying glue and a plastic drape circle.

If there is no leakage, there is usually a fibrin layer overlying the iris, and it may heal without intervention.

When does it need a specialist?

General ophthalmologists may be able to treat peripheral perforations less than 2-3 mm in diameter on their own. Gluing may work as a definitive procedure for these holes, Dr. Tuli said. She recommends cyanoacrylate glue. “You essentially want to plug the hole to allow the tissues to heal underneath,” she said.

Another option, especially useful in neurotrophic ulcers, is a pedicle conjunctival flap, which may allow fibrovascular tissue to cover the area, providing serum and growth factors.

Pleated or multilayer-amniotic membranes can be sutured or glued over the perforation as a third option.

For central perforations of this size, on the other hand, Dr. Tuli uses glue or amniotic tissue as a temporizing measure. “A small perforation in the center of the cornea won’t heal very well,” she said. “There are no blood vessels to provide fibrovascular scar tissue.” For these holes, corneal transplants are generally the definitive treatment, she said, and general ophthalmologists will usually want to refer these cases to specialists.

Likewise, perforations larger than 3 mm generally also require emergent corneal transplantation, and are best treated by an expert, Dr. Tuli said.

Sonal Tuli, MD

E: stuli@ufl.edu

This article was adapted from Dr. Tuli’s presentation at the 2015 meeting of the American Academy of Ophthalmology. Dr. Tuli did not indicate a financial interest in the subject matter.