July 2016

 

COVER FEATURE

 

Refractive surgery in military personnel and first responders

Careful consideration of military refractive surgery results


by Maxine Lipner EyeWorld Senior Contributing Writer

 
 

The Navys approach to refractive surgery has been highly systematic, evidence-based, and operationally focused. Elizabeth Hofmeister, MD

 
LASIK procedure

LASIK procedure being performed. The flap has been created and the patient is under the excimer laser.

The LASIK flap has been retracted

The LASIK flap has been retracted, patient fixation has been confirmed, and the photoablation is about to proceed.

Captain and doctor Marine Capt. Michael Oginsky was the first Naval aviator to undergo wavefront-guided LASIK with the femtosecond laser.

Dr. examines captain eyesDr. Schallhorn examines Capt. Oginskys eyes before he undergoes LASIK.

Source (all): Steven Schallhorn, MD

Study results on refractive surgery in the military have been pivotal in establishing acceptance for refractive surgical procedures

For those in the military, excellent vision can mean the difference between life and death, said Elizabeth Hofmeister, MD, captain, Navy Medical Center, San Diego. In her experience with those on the front lines of the Navy and Marine Corp, keen sight can be crucial. We have pilots landing on aircraft carriers at night, a sniper whos trying to take aim at some small, distant target, or a lookout on a ship trying to identify something on the horizon, Dr. Hofmeister said. If they dont have excellent vision, they could make the wrong choice, and it could end up with someone being hurt or killed. Study results honing in on refractive surgery in the military have been pivotal in garnering acceptance for refractive surgical procedures in this population.

Military studies

David Tanzer, MD, chief medical officer and divisional vice president for global medical affairs, Abbott Medical Optics, Abbott Park, Illinois, who is retired from the military, said that the peer-reviewed literature is overwhelmingly favorable toward refractive surgery in the military. There are numerous papers that have been published on refractive surgery, he said. PRK, LASIK, and implantable collamer lenses or phakic intraocular lenses are all refractive surgical procedures that have been studied and performed safely and effectively in military personnel. One pivotal refractive military study was a LASIK trial published in the Journal of Cataract & Refractive Surgery, involving U.S. Naval aviators.1 This showed a high level of safety and effectiveness in terms of the uncorrected visual acuity, reported Dr. Tanzer, who was the lead author. Dr. Hofmeister, who also took part in the study, views the excellent visual outcomes and high patient satisfaction as unprecedented. Our uncorrected visual acuity was 20/20 or better in 98.3% of the patients who were treated for myopia or myopia with astigmatism and 95.7% of those who were treated for hyperopia, she said, adding that many people gained lines of best corrected visual acuity, 95.9% said that LASIK helped their effectiveness as Naval aviators, and 99.6% would recommend the same treatment to other pilots.

Dr. Tanzer thinks the fact that so many would be willing to recommend the procedure to others is particularly striking. These were anonymous questionnaires, so one would think that if they had any reservations about the results, they would not be as likely to recommend the procedure to a fellow Naval aviator, he said. He added that in this study of 330 Naval aviators, only 1 was equivocal about recommending the procedure to a fellow aviator. The aviator in question was older and was corrected for distance visual acuity in both eyes, since monovision is not done in the military. That older aviator required some reading glasses to read up close, which is something that is disclosed in informed consent, Dr. Tanzer said. Because of that occurrence, he wasnt as likely to recommend the treatment to a fellow Naval aviator. This is 1 of many refractive studies that the Navy has undertaken. The Navys approach to refractive surgery has been highly systematic, evidence-based, and operationally focused, according to Dr. Hofmeister. She added that the idea has been to look at how such surgeries affect the performance of Navy and Marine Corps personnel doing their jobs. We implemented PRK and then later LASIK in a careful and safe way, Dr. Hofmeister said. She said this was thanks to the efforts of 2 retired captains, Steven Schallhorn, MD, and Frank Butler, MD. Both were Navy ophthalmologists who had firsthand experience with the operational Navy. Because of that awareness, they understood that visual outcomes are much more than 20/20 acuity alone. They wanted to make sure that people could still see well in low-contrast situations, that they would be OK at high altitude or with low-oxygen tensions, and they wanted to make sure that the LASIK flap could not be easily dislocated in an ejection situation, she said. Dr. Tanzer likewise credits Drs. Schallhorn and Butler with starting the discussion about the pros and cons of refractive surgical procedures in the military versus wearing glasses and contact lenses in an operational environment. Those conversations resulted in overwhelming support by the military community for refractive surgery, he said. They clearly saw the values of their fighting force not wearing glasses or contact lenses in that operational environment. They provided funding for research that was done first in the Navy and then in the Army and the Air Force to prove safety and effectiveness of refractive surgery as it transitioned from conventional ablations to more sophisticated wavefront-guided ablations and LASIK as it moved from mechanical microkeratomes to femtosecond lasers, he explained.

Dr. Tanzer was lead investigator for a microkeratome comparison study that proved increased safety and efficacy of the femtosecond laser for creating flaps compared to 3 different mechanical microkeratomes. This study was presented but not published. It mirrored what is in the peer-reviewed literature, he said. It showed that the femtosecond laser created a more reproducible flap and provided better visual acuities after LASIK than we could achieve with a mechanical microkeratome. That allowed the military to invest in femtosecond lasers for LASIK in all of its Navy refractive surgery centers. This also resulted in a significant shift from PRK to LASIK for those undergoing refractive procedures. Prior to that, surface ablations were all that we were doing, Dr. Tanzer said, adding that this changed when they figured out that they were able to combine safety, efficacy, and a more rapid return to duty with femtosecond LASIK.

Functional vision is key

Dr. Tanzer said that functional vision is paramount for the military. The Army is very keen on doing studies looking at functional visual acuity in their personnel. They have a sophisticated night simulator where they look at target detection and identification in a military- specific scenario at night, he said. Theyre looking at the ability to detect targets and accurately identify targets in a military scenario after LASIK and PRK done in various ways. The Air Force is developing a sophisticated flight simulator to examine visual performance in an aviation-specific environment looking at peripheral vision, pursuit vision, etc. in a dynamic simulator following refractive surgery, Dr. Tanzer said. With the aid of such simulators, it has been reported that individuals who were treated with LASIK or PRK were as good as or better at properly detecting and identifying the target in a night combat environment after surgery compared to when they wore glasses or contacts, Dr. Tanzer said. The technology being used for refractive surgery is state of the art, Dr. Hofmeister said. We have 6 Navy centers, and all the centers have the latest generation excimer lasers, and were using the most advanced ablation profiles that are available on those platforms, she said, adding that this includes wavefront-guided excimer ablations or wavefront-optimized excimer ablations, depending on the platform. Many of the centers have access to 2 different excimer lasers. That broadens the opportunities and applicability of the laser because each laser has slightly different FDA approvals and different refractive ranges that they can treat, Dr. Hofmeister said. Femtosecond lasers are also available at all Navy centers to make flaps.

We also have access to phakic intraocular lenses for select patients, Dr. Hofmeister said. However, this is not a first-line treatment because it carries a much different set of risks than surface ablation or LASIK. Still, for those who arent eligible for PRK or LASIK because they have such high myopia and their corneas arent quite thick enough, phakic intraocular lenses are a good option, she finds.

The only restriction in our population is that patients who are in Naval aviation cannot have a phakic intraocular lens. All of the other warfare specialties allow for that, Dr. Hofmeister noted. The reasoning here has less to do with medical concerns than the fact that there are plenty of excellent Naval aviation candidates available.

Refractive surgery in the military has opened many doors. In the 1980s, Dr. Hofmeister said myopia alone was enough to quash the hopes of many who had seen the movie Top Gun and wanted to pursue their aspirations. Now that playing field is leveled, Dr. Hofmeister said. People can have refractive surgery and still be a pilot. Dr. Tanzer is likewise enthusiastic about how far things have come, and he credits the admirals, generals, and other military leaders. They have been, for the most part, strongly supportive of refractive surgery being conducted in their hospitals, and that has resulted in an overwhelmingly successful program in all 3 services, he said. I think were close to having performed 1 million procedures to date since the startup of these programs.

Military refractive surgery article summaryReference

1. Tanzer DJ, et al. Laser in situ keratomileusis in United States Naval aviators. J Cataract Refract Surg. 2013;39:104758.

Editors note: Dr. Hofmeister has no financial interests related to her comments. Dr. Tanzer has financial interests with Abbott Medical Optics.

Contact information

Hofmeister
: elizabeth.m.hofmeister.mil@mail.mil
Tanzer: David.Tanzer@abbott.com

Related articles:

Reflections on refractive surgery in the military by Eric Donnenfeld, MD, EyeWorld chief medical editor

Refractive surgery in the military changed the lives of troops by Liz Hillman EyeWorld Staff Writer

Refractive surgery and patient selection in the military by Ellen Stodola EyeWorld Senior Staff Writer

Refractive surgery options within the Army

Tools for post-refractive surgery eyes by Louise Gagnon EyeWorld Contributing Writer

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