March 2011

 

REFRACTIVE SURGERY

 

Stressing over striae


by Maxine Lipner Senior EyeWorld Contributing Editor
 

 

How one practitioner handled the longest case

When it comes to flap striae, just because a certain length of time has passed does not mean that patients are out of the woods, according to Roxana Ursea, M.D., assistant professor of ophthalmology, and director, cornea and refractive surgery division, University of Arizona, Tucson. In the November 2010 issue of the Journal of Refractive Surgery, Dr. Ursea reported on a case of traumatic flap striae, which occurred a record 6 years after LASIK.

The case involved a 28-year-old patient who was referred to Dr. Ursea by a colleague. "The patient had trauma and poor vision and was referred to me for evaluation," Dr. Ursea said. "Seven years prior to his presentation, he had LASIK for myopia and astigmatismin fact, he was initially seen as a post-trauma patient with microhyphema." At that point the flap striae were not yet detected. While the patient was put on anti-inflammatory drops and his hyphema cleared up, his vision did not improve much. It was then that the patient was referred for a second opinion to Dr. Ursea, who is a corneal specialist. At that point, Dr. Ursea detected the striae and proceeded to treat these. "Initially I tried a conservative approach with a lot of lubrication," Dr. Ursea said. "There was no improvement, and after talking to the patient he agreed to have the flap lifted and irrigated and then repositioned." Dr. Ursea found that she had remarkably little trouble accomplishing this. The patient's vision then returned to 20/20. "Looking back at the literature, it was the longest interval of time after the initial refractive surgery procedure that there was an occurrence of flap striae," Dr. Ursea said.

Smoothing techniques

This was one of many different approaches that could have been taken. "There are a lot of approaches that were described before," Dr. Ursea said. "Some involve using artificial tears, some involve lifting the flap and irrigating with a hyposaline solution." In some cases a hypothermic spatula is tried. "A spatula is warmed up to try to smooth the striae in the flap," Dr. Ursea said. Likewise, others use a Caro iron to warm up and smooth the tissue. Yet another tact is repeated stretching followed by smoothing.

Dr. Ursea bases her chosen technique on whether or not vision is affected. "I tend to lift the flap and find that it's better to lift it sooner rather than later if the vision is affected," she said. "This is better visualized by the red reflex so that when I do a retinoscopy I can actually see the striaeI know that the vision is affected." Another modality Dr. Ursea sometimes uses is sodium fluorescein at the slit lamp. She finds this to be a more sensitive method for detecting striae. Usually Dr. Ursea then lifts and hydrates the flap and stretches it manually.

Perpetual weakness

Dr. Ursea hopes that practitioners come away with the understanding that this can happen at any time down the lineat no point are they safe. "The lesson is related to the sealing of the flap the first time because surgeons think that as time passes, they are safe and there is no problem," she said. "But in all of the reports previously and also in this particular case, the message is that if there is trauma, the flap dislocates because it is never actually 100% healed like an intact cornea that has not undergone this procedure."

Looking at the histopathology it appears to Dr. Ursea that the strength of the post-LASIK cornea is better in the periphery of the flap than in the center. "The healing in the center is not so good because there are no bridging collagen fibers," Dr. Ursea said. "It takes about 6 months for that primitive scarring to occur." When it does, the collagen in the flap margins tends to be stronger. Dr. Ursea stressed that LASIK is not for everyone, which she urges practitioners to keep in mind. "Depending on the lifestyle and hobbies of the patient, you might think twice about what kind of procedure to perform because this can happen at a very late stage and many years after the procedure," she said. "Let's say that the patient does active sports or is in the military or police enforcement where there is a chance that something may happenyou might prefer a surface procedure rather than a flap."

Editors' note: Dr. Ursea has no financial interests related to her comments.

Contact information

Ursea: rursea@eyes.arizona.edu

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