Ask the Flight Surgeon / By CPT Albert J. Lee, MD: Q:Are Soldiers on flight status allowed to have corrective eye surgery like LASIK or PRK? If so, what are the differences among the types of surgeries?
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FS: Corneal refractive surgery is becoming widely accepted in the aviation community. Currently U.S. Army Aeromedical Activity (USAAMA or AAMA) waives three types of corneal refractive surgery – LASIK, LASEK, and PRK. For Soldiers already on flight status, careful planning that involves the command and medical provider is needed to ensure the mission is not affected and the Soldier has enough time to recover from surgery. Anyone who plans to get on flight status in the future should ensure all medical documentation of eye exams, before and after the surgery, are available for the flight surgeon to review.
Three major types of refractive error are common. Nearsightedness (myopia) patients are able to see objects close to eyes and farsightedness (hyperopia) patients are able to see objects far from the eyes. Astigmatism is when refraction varies at different parts of the eye and vision is blurry regardless of the distance. This can occur with either nearsightedness or farsightedness. The traditional method of correcting vision is through glasses or contact lenses. These devices provide an additional layer of refraction allowing the light, after it passes through the corrective lens, to focus on the retina and produce clear vision.
What is corneal refractive surgery? How does it work?
The eye is responsible for receiving light and projecting it onto the retina in the back of the eye. The cornea, a ½ millimeter thick layer of tissue, along with the lens is responsible for focusing this light. When the refraction is not quite right, the light focuses in front or behind the retina, causing blurry vision. All corneal refractive surgery uses a series of laser beams to reshape the cornea by “shaving” it. By reshaping the cornea, the light is redirected to the proper focal length producing a clear image.
Different surgical techniques are used and the differences are based on the way the surgeon gets down to the corneal layer. LASIK (Laser-assisted in situ keratomileusis) is where the surgeon cuts a flap of the top layer of the cornea then uses the laser to reshape the cornea. The flap is then replaced back on the same spot after the surgery. LASEK (laser epithelial keratomileusis) uses a technique of weakening the top layer of cornea with an alcohol solution then pushing it to the side. PRK (photorefractive keratectomy) is where the surgeon uses a brush or other devices to remove the top layer of the cornea. Once the surgery is done, a bandage contact lens is applied to the eye.
All these methods are considered routine and have a low risk of negative outcomes but the risk is not zero. Some common side effects associated with all these procedures include night vision difficulties due to glare and dry eyes. The flap created for LASIK might not heal all the way causing it to dislodge spontaneously. Operational concerns like rotor wash is also a concern for dislodging this flap if it has not healed correctly. PRK usually has a longer recovery period, as the cornea needs to regenerate the top layer. This leaves a large defect in the protective layer of the cornea which increases the risk of infection.
Corneal refractive surgery is considered an effective intervention for vision correction. After the surgery, patients can expect 90-99% chance of achieving 20/40 and 57-79% chance of achieving 20/20 or better. Most patients are satisfied with the outcome of the surgery.
Before getting the surgery, active duty personnel must receive an authorization from their chain of command. Commanders should be advised that the Soldier will need a minimum of 6-12 weeks of recovery period. AAMA requires minimum of three months (for initial applicants), or 6 weeks (for current aviation personnel) of recovery after surgery. At least two normal post-surgery eye exams, one month apart, are required. To get back on flight status or to apply for flight status after surgery, a Corneal Refractive Surgery Information Worksheet needs to be filled out by a medical provider and submitted to a flight surgeon.
If you are thinking about getting the corneal refractive surgery done, consult your flight surgeon. He or she will be able to give you all the documents needed for the commander’s approval, and the corneal refraction surgery worksheet.
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CPT (Dr.) Albert Lee is a flight surgeon at the U.S. Army School of Aviation Medicine, Fort Rucker, AL. He is currently going through an aerospace medicine residency, specializing in aerospace and occupational medicine.