Eyeworld

50 | EYEWORLD | MAY 2020 R RESEARCH HIGHLIGHT EFRACTIVE Contact Moshirfar: cornea2020@me.com by Maxine Lipner Senior Contributing Writer J ust because a patient has a cardiac device implanted doesn't preclude safe refractive surgery, said Majid Moshirfar, MD, noting some newer devices shield the implant with a mag- net. When Dr. Moshirfar and fellow in- vestigators studied a group of patients who had not disclosed their implants prior to refractive surgery, they found no related issues. 1 The idea for the study came from the recognition that some cardiac implant patients had already been inadvertently treated with the excimer laser. Dr. Moshirfar found that occa- sionally, refractive patients would come back and later disclose they had a cardiac condition that warranted an implant. "They actually had [a cardiac implant] when I did their LASIK and nothing happened," he said. In this retrospective analysis, investigators identified 13 patients who underwent refractive surgery from 1997–2014. Cardiologists who Dr. Moshirfar consulted were not concerned that the devices would be affected by the excimer laser but did warn him that if the implant shocked the patient during the refractive sur- gery, he/she may jump up from the jolt. They also told Dr. Moshirfar that newer devices have an option to disable them temporarily if there is concern about something like that happening. This involves placing a special magnet on the chest where the pacemaker is located. "If you put this magnet on, the defibrillator is not going to fire, even if the patient goes into some form of arrhythmia," Dr. Moshirfar said. Current dilemma This leaves ophthalmologists with a dilemma. "As a physician you have to ask yourself which is more important: for you to deactivate the defibrillator so that the surgery can go smooth- ly or for you not to put the magnet on," Dr. Moshirfar said. Based on his 13 cases in the study, Dr. Moshirfar doesn't think there is a risk of the patient having a 20-second excimer laser ablation getting a sudden shock from the pacemaker device. Even if the patient does trip the pacemaker during the surgery, modern eye trackers provide a safety net. The excimer treatment will stop if resulting movement is too great, avoiding treat- ment decentration, he explained. Forewarn patients Before knowingly operating on a patient with an implantable cardiac device, Dr. Moshirfar stressed the importance of telling them about what could happen, even if the risk is very low. "It's important to discuss this with the patient and the cardiologist, and document in the chart that this crossed your mind," he said. "You made the decision that the interference of the pacemaker on your laser and your laser on this pacemaker is quite negligible, with a risk so low that you don't think it's necessary to demagne- tize the device on the patient's chest." Vigilance should be higher if the patient is having LASIK and SMILE vs. PRK, Dr. Moshirfar said, because LASIK and SMILE are slightly longer procedures. With any of these patients, it's more than just the eye involved. "The take-home message is you're not just the eye doctor, you're a doctor of the whole body," Dr. Moshirfar said. This means talking to the patient about their medical history and potentially asking questions about their heart rhythm. Those who have older pace- makers are likely older patients. This may mean drilling down on how often their implant fires. "That's when you need to have a consult with the cardiologist, and you may even go as far as having the patient have an EKG monitor during the surgery," he said. Going forward, Dr. Moshirfar said he is optimistic that newer, leadless pacemakers with greater immunity to electromagnetic fields will make even these minor concerns a moot point. Are implantable cardiac devices a refractive surgery contraindication? About the doctor Majid Moshirfar, MD Professor of ophthalmology University of Utah John A. Moran Eye Center Salt Lake City, Utah Reference 1. Shah TJ, et al. Safety of the excimer laser in LASIK and PRK for patients with implantable cardiac devices: our clinical experience in the past two decades. J Ophthalmol Vis Res. 2019;14:530–531. Relevant disclosures Moshirfar: None

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