Refractive surgery should be avoided in patients who have high risk for ectasia
NEW YORK — Surgeons should avoid performing corneal refractive surgery on patients who are at high risk for developing ectasia and those with corneal abnormalities, according to a speaker here.
“There are two main areas you want to focus on in terms of when to avoid corneal refractive surgery. One is when the risk of ectasia is high. The other is when there are other abnormalities of the ocular media, typically cataract or dysfunctional lens, which might preclude good visual acuity or less than ideal patient satisfaction,” Parag A. Majmudar, MD, said at OSN New York 2017.
Surgeons can determine the patients who are at high risk for ectasia by looking at their intrinsic biomechanical properties and alterable biomechanical properties. Age is an often overlooked intrinsic biomechanical property that can predispose a patient to developing ectasia. Abnormal preoperative topography is an important identifiable risk factor as well, he said.
“The concept of PTA [percent tissue altered] is the most robust risk factor of ectasia after LASIK in patients with a normal topography. It’s more of an individualized measure of the biomechanical properties. It’s a look at the flap thickness and ablation depth, divided by the central corneal thickness. You’re getting an idea of how much of the tissue you are changing. Anything above 35% to 40% is thought to be a little bit of a higher risk for developing ectasia,” he said.
Not all corneas should be operated on, and surgeons should take all factors into consideration. There is a myriad of technology available that surgeons should utilize to help make better patient selection decisions, Majmudar said. – by Robert Linnehan
Majmudar PA. When should we avoid corneal refractive surgery? Presented at: OSN New York 2017; Oct. 20-22, 2017; New York.
Disclosure: Majmudar reports no relevant financial disclosures.