Pterygium surgery trends and pearls

Complicated cataract cases

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Pterygium surgery trends and pearls
by Vanessa Caceres EyeWorld Contributing Editor



Pterygium is a common problem that, if managed incorrectly, can lead to a more significant clinical condition post-op. A recurrent pterygium is a different disease than a primary pterygium. Recurrences are more inflamed, progress more rapidly, lead to more conjunctival scarring, are more difficult to surgically remove, and are more likely to lead to loss of vision. Therefore surgeons need to use an operative technique that first and foremost reduces the recurrence rate and leads to the best outcome. Clinical trials have definitively shown that the bare sclera technique has a very high recurrence rate (25-90%) and should never be used as the sole procedure. Excision with some adjunct therapy is the treatment of choice. Surgeons have many options available to them and have to make surgical decisions that they feel are the correct options for the particular lesion and patient. Conjunctival graft, amniotic membrane, mitomycin C, and sutures vs. tissue glue are some of the choices available. To help sort out these issues, I have asked three experienced corneal surgeons, David Verdier, M.D., Chris Rapuano, M.D., and Rick Palmon, M.D., to give us their views on the surgical management of pterygium.

Edward J. Holland, M.D., cornea editor




A patient with pterygium Source: Rick Palmon, M.D.

Traditional approach with modern modifications earns kudos

When it comes to pterygium surgery, many surgeons think that a tried-and-true approach with free conjunctival autografts is the best way to prevent recurrences.

"I've been using the same techniques that I started to use when I finished my fellowship in 1984," said David D. Verdier, M.D., Verdier Eye Center, Grand Rapids, Mich. "Someone had published a study on conjunctival autografts decreasing the incidence of recurrence. I made a point from then on to excise the pterygium to bare sclera and replace the area where the pterygium was with a conjunctival autograft, usually harvested from the superior conjunctiva of the patient. This is still the gold standard, in my opinion," he said.

Although the introduction of amniotic membrane grafts several years ago initially caused surgeons to switch to the use of those over conjunctival autografts, many found that the recurrence rate with amniotic grafts was higher, said Christopher J. Rapuano, M.D., professor of ophthalmology, Jefferson Medical College, Thomas Jefferson University, and co-director, Cornea Service, Wills Eye Institute, both in Philadelphia. Although amniotic membrane grafts serve a purpose in select cases, many surgeons subsequently returned to the use of conjunctival autografts, he said.

"When amniotic membrane grafts came out, I used them a lot, and I found my recurrence rates were higher," said Rick Palmon, M.D., Southwest Florida Eye Care, Fort Myers. Like Dr. Verdier, Drs. Rapuano and Palmon primarily use conjunctival autografts once the pterygium is removed. "I used to initially do a sliding conjunctival graft and free up some of the conjunctiva above and below, but my recurrence rate was higher than switching to the full free conjunctival graft, where I take healthy tissue from the superior temporal quadrant and bring that down. Since then, my recurrence rate has dropped significantly," said Dr. Palmon.

Fibrin glue, post-op trends
One advance that these specialists praise is the introduction of fibrin glue over the use of sutures in pterygium surgery.

"The tissue glue is helpful, and the eyes are quieter," said Dr. Palmon, who sees aggressive pterygiums in his sun-soaked, farm-heavy area of the country. "The comfort level for patients is significantly better. With sutures, as they'd dissolve, there would be associated inflammation and that increased the chance of recurrence. I don't see that now," he said.

"I used to suture, but now I use fibrin glue," said Dr. Verdier. "People balk at fibrin glue because it's significantly more expensive, but sutures are not cheap, either. When you add in patient comfort, the bottom line is that tissue glue is the way to go."

"I used to use eight to 10 sutures, but now that I'm using fibrin glue, I'm down to two to three sutures," Dr. Rapuano said. "Some doctors are not using any sutures at all"—something that Dr. Rapuano would not usually feel comfortable doing.

Post-operatively, Dr. Rapuano prescribed a tapering course of Tobradex (tobramycin and dexamethasone, Alcon, Forth Worth, Texas) over several weeks. Dr. Palmon treats inflammation rapidly to avoid the risk of infection or pterygium recurrence. If the eye gets red or inflamed, he will start the patient back on topical steroids. If that does not elicit a response in the eye, he will give an injection of 5-fluorouracil to quiet the area. "Once the pterygium starts to grow back, you're behind the curve, and it's harder to prevent it from coming back," he said.

Dr. Verdier uses pressure patching for 24-36 hours. If the patient has dry eye, he aims to keep the eye well-preserved with nonpreserved tears to avoid more scarring.

To MMC or not to MMC?
Considering mitomycin C (MMC)'s potential long-term effects on patients, the surgeons interviewed for this article generally favor a conservative role for the use of MMC during pterygium surgery. Because of the aggressiveness of pterygiums that Dr. Palmon treats, particularly in farmworkers, fishermen, and golf pros or attendants, he will sometimes use MMC. However, he is careful not to leave any bare sclera because of the risk of scleral thinning or melting. "If someone has a large nasal and temporal pterygium from both sides or one that involves the visual axis, that plays a role in how aggressive I am," Dr. Palmon said.

"Unless I was operating on a severe recurring pterygium, I wouldn't use mitomycin C," Dr. Verdier said. "It may depend on your population, but I've only had one recurrence in my career. I don't see as severe pterygiums as people do in the Sunbelt."

Although Dr. Rapuano generally does not use MMC, he will use it if he is treating a recurrent case.

Instead of intraoperative use, some surgeons prescribe MMC 0.02% four times a day for 7-14 days post-op to reduce recurrences, Dr. Verdier said.

Unusual cases
Not all cases qualify for typical pterygium surgery. Dr. Verdier is more cautious if he is suspicious of squamous cell carcinoma. "I just saw a pterygium that I thought could be squamous cell carcinoma. I'm going to do a biopsy before I remove it. I don't want to take it off without first seeing if it's cancerous," he said.

Other unusual cases would be patients with filtering blebs from glaucoma or other glaucoma-related issues. In these patients or in those with large pterygiums, where you would have to remove more tissue than you'd feel comfortable with, using an amniotic membrane might be a better choice, Dr. Verdier said. Surgeons are reviewing research that is investigating vascular endothelial growth factor inhibitors such as Avastin (bevacizumab, Genentech, South San Francisco) or Lucentis (ranibizumab, Genentech) injected or used topically to prevent recurrences, Dr. Palmon said. Published results so far have been mixed, he said.

Surgical pearls
If you're looking to perfect your pterygium technique, consider the following tips from Drs. Palmon, Rapuano, and Verdier: • Make sure to excise all of the inflamed tissue, not just the portion over the cornea, Dr. Palmon said.

• Do not leave any bare sclera if you use MMC, Dr. Palmon said. • Don't get too extensive in your removal efforts, Dr. Verdier said. Although you naturally want to remove the pterygium, he said he once caused double vision in a patient by going too far back with the dissection. "Once you get past the posterior to the rhexus muscles, especially if you go further back into orbital fat, you run an increased risk of scarring that can interfere with eye mobility," he said. "I get good or better results by not going 3-5 mm back from the limbus."

• Use a diamond burr to smooth out the cornea, Dr. Rapuano recommended. "I believe the smoother the cornea and limbus, the less chance there is of recurrence," he said.

• For similar reasons, Dr. Verdier recommends the use of a spatula or 64 Beaver blade parallel to the cornea but not cutting into the cornea. "You end up with smooth biologic tissue membrane. It's much better than if you just try and cut in."

Editors' note: The doctors interviewed have no financial interests related to this article.


Contact information
Palmon: 239-768-0006, rpalmon@swfleye.com
Rapuano: 215-928-3180, cjrapuano@willseye.org
Verdier: 616-949-2001, daverdier@aol.com





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