Competitive athletes’ visual demands are much more specific than those of our typical patients. Athletes are regularly subjected to extreme heat or cold, rain, wind, snow, perspiration and physical contact––all while traveling at a high rate of speed and/or focusing on rapidly moving objects.
Even more challenging, many athletes are expected to adapt to dynamic lighting conditions seamlessly, as many baseball, football and soccer players start a game in the late afternoon in the direct sunlight and finish playing in artificial light under a nighttime sky. When combined, these factors create endless potential for vision-related problems.
Here, we’ll review the primary reasons why your athletic patients likely will ask you if laser vision correction (LVC) is right for them. Additionally, we’ll discuss a host of individual pre- and postoperative considerations that you will have to address.
Athletes Want LVC
|A golfer presented with decreased vision and light sensitivity one day after rubbing his eye. He underwent LASIK 13 months earlier. Notice the significant inflammation located at the LASIK flap interface.
LVC is becoming increasingly more common in athletes. Many athletes prefer laser treatments to other forms of vision correction for a host of reasons, including:
• Superior postoperative visual acuity, which is necessary for faster reaction time and optimum depth perception.
• Spectacles and contact lenses (regardless of aspheric design) may reduce contrast sensitivity under different lighting conditions.1
• Training and competition often takes place in extreme environments. Resultant perspiration and the use of protective headgear can make spectacle wear virtually impossible.
• A greater likelihood for contact lens intolerance caused by a decreased blink rate, disruption of the natural tear film secondary to increased perspiration, and excessive tear evaporation resulting from prolonged exposure to extreme weather conditions.
One question that we are often asked: “Does the type of LVC matter for certain athletes?” Although there is no definitive answer, there are different benefits to certain procedures.
The postoperative differences for various laser procedures range from safety concerns and postoperative recovery times to in-game performance issues. Contrast sensitivity is one of our most influential postoperative variables, and can be considered a more sensitive assessment of visual function than even visual acuity. For this reason, we place considerable emphasis on the correction of higher-order aberrations (HOA). And, no matter what, we will address each patient’s specific visual demands with respect to the sports he or she participates in when determining the optimal refractive procedure.
Primary Considerations for LVC
Without question, eye care clinicians must consider the potential ocular safety (or lack thereof) associated with a particular sport. Obviously, some athletes have a much higher incidence of eye injuries than others. For example, basketball players routinely experience ocular injuries that involve finger- and fingernail-related corneal trauma. This type of injury can become considerably more serious if associated with corneal flap complications. Other athletes, such as volleyball players, usually suffer blunt trauma to the entire orbit, which poses much less of a specific corneal concern.
Here’s a review of some of the most important considerations we must account for when recommending LVC to athletes:
• Flap stability. Traditional microkeratome-cut corneal flaps generally are relatively stable. But, with the advent of the femtosecond-created flaps, our concerns of long-term stability largely have been alleviated. With sufficient healing time, we do not consider blunt trauma to the facial area (e.g., secondary to boxing) or major concussive forces (e.g., secondary to football) to be deterrents for creating laser-assisted flaps.
Also, femtosecond-created flaps have been shown to yield better contrast sensitivity, a faster visual recovery and improved quality of vision compared to mechanically- created flaps.2
Extensive testing has confirmed the stability of femtosecond-created corneal flaps.3 So, we do not consider the flap a variable in the surgical decision process unless there is a significant risk of digital trauma to the eye. One study indicated that the amount of blunt force needed to dislodge a laser-cut flap typically was enough to dislocate the lens and cause iris separation from its sclera/ciliary attachment.3 This suggests that flap dislocation is a rare, relatively minor problem, considering the excessive force the athlete would have to encounter.
|After one week of aggressive topical corticosteroid therapy, the golfer’s interface inflammation was almost completely resolved.
Additionally, laser-cut flaps were shown to be stable following testing with variably angled, direct air streams in excess of 400mph.3 Although, flap stability was shown to be the same at both days one and nine postoperatively, we still err on the side of caution (one week) before permitting our athletes to resume contact sports.
• Recovery time. Although individuals who undergo either custom surface ablation or LASIK with femtosecond-cut flaps exhibit similar postoperative results at the three- to six-month follow-up, studies show a much faster recovery of optimum vision in patients with laser-created flaps.4 For athletes who currently are in season or cannot sacrifice a prolonged off-season visual recovery period, LASIK with femtosecond-cut corneal flaps is a much better option than surface ablation.
• Type of sport. The two major sports in which we consider flap integrity to be of fundamental concern are basketball and wrestling. Basketball players and wrestlers have a disproportionately high incidence of digital cornea insult, and mechanical trauma to the flap can negatively impact the chance for good visual recovery.
Furthermore, the growing popularity of mixed martial arts and ultimate fighting has kept our concerns about finger-related eye trauma fairly high. For these athletes, we will not create a corneal flap of any kind.
Additionally, we often choose not to create a flap in swimmers. Instead, we recommend surface ablation procedures. Why? Because swimming goggles often exhibit constant pressure on the globe when worn, as well as create a vacuum suction during both application and removal––both of which could dislodge the flap.
• Existing refractive error. Although some studies have shown similar postoperative uncorrected visual acuity between conventional and wavefront-guided LASIK (wLASIK) in patients with existing refractive error, these reports also show that wavefront-guided treatments have produced significantly better outcomes for contrast sensitivity and glare under mesopic conditions, as well as fewer subjective complaints.5 Some of the accuracy is due to flap architecture (e.g., femtosecond-created flaps have a planar configuration whereas microkeratome-cut flaps are meniscus-shaped and may produce some unwanted optical power).
Understanding the importance of contrast sensitivity to visual performance in athletes, we always recommend wavefront-guided treatments––if possible.
• Enhancement procedures. Assuming that there are no physiological contraindications, we will enhance an athlete based on best-corrected visual acuity and symptoms. This includes very small residual refractive error. Understanding the necessity of exceptional vision, we are more likely to enhance a very small residual refractive error in an athlete than in a normal patient.
To illustrate this point, our medical director, Steven Dell, M.D., recently performed an enhancement procedure on a Major League Baseball player. The athlete had an uncorrected visual acuity of 20/20- O.S. This was important to address because he bats right-handed, which means that flawless visual acuity in his left eye is essential for hitting the ball. In a typical patient, the risk/reward ratio would not justify an enhancement procedure for 20/20- visual acuity. But, in this particular case, the enhancement was justified and the patient was extremely satisfied.
We usually use wavefront-guided surface ablations to enhance our athletes (although this is technically off-label). Wavefront-guided enhancements have been shown to reduce HOAs and improve low contrast sensitivity, whereas conventional enhancements have been shown to increase HOAs and decrease high contrast sensitivity.6,7
• Postoperative dry eye. As always, significant preoperative dry eye is a contraindication to LVC, but postoperative dry eye often is unavoidable. Because dry eye can increase HOAs––partially negating some of the benefits of wavefront-guided treatments––we treat any postoperative dry eye very aggressively.8,9 This includes identifying any sign or symptoms of mild dry eye during the preoperative work-up, and then starting any necessary treatments from weeks to months in advance.
Our threshold for deficient tear volume or mild blepharitis is very low. Low tear volume may be treated with artificial tears (with or without punctal occlusion) or topical cyclosporine eye drops. There is mounting evidence that nutritional therapy may increase tear production and quality, so this is a routine suggestion of ours.10 Although moderate to severe blepharitis is a contraindication for refractive surgery, patients with mild belpharitis are operated on routinely. While mild blepharitis ultimately carries the same risks of more severe cases, we are genuinely concerned about the athlete’s visual performance as well.
|LVC in ‘Airborne Athletes’
|Previously, LASIK had not been authorized for aviators in the U.S. Navy and U.S. Air Force because of concerns regarding postoperative vision quality. A pivotal study conducted by Steven Schallhorn, M.D., and associates indicated that patients who had femtosecond-cut flap wLASIK for myopia correction experienced significantly better visual performance while driving at night than those who underwent non-wLASIK with mechanical keratome-cut corneal flaps.12 These result were instrumental in the U.S. military’s decision to permit wLASIK in aviators and astronauts.12
The U.S. military and NASA have conducted extensive research on pilots in extreme conditions. Parameters studied included postoperative contrast sensitivity, visual acuity, return to flight time, postoperative flight performance, hypoxia and high-altitude flap stability. The researchers noted that, in all parameters studied, wLASIK with femtosecond laser-created flaps proved to be equal or superior to any other form of vision correction studied.13 With this extensive body of research, our clinicians are now comfortable recommending the aforementioned treatment option to all pilots that we treat.
At this time, every branch of the U.S. military permits custom wLASIK with a laser-created flap for its pilots. The only exception is that Navy pilots (and prospective pilots) must agree to enter a study before undergoing the procedure.
Poor or altered meibum production will lead to early tear film break-up time (TFBUT), evaporative dry eye and loss of surface tension that is required to maintain optimum tear meniscus. Preoperative treatment options for blepharitis include oral tetracycline analogues, topical macrolide antibiotic drops, topical combination steroid/antibiotic drops and nutritional support. We are cautious about the use of warm compresses and lid scrubs during both the preoperative and acute postoperative phases, because heat and mechanical stimulation can exacerbate inflammation. Instead, we may use warm compresses and lid scrubs for long-term blepharitis management after the surgery.
When the tear film evaporates, it does so in a non-uniform fashion (which is evident upon watching TFBUT with fluorescein staining). This is important to understand, considering that the largest index of refractive change in the human eye occurs at the air/tear film interface.11 So, this process can have a significant impact on any athlete’s ability to perceive images clearly.
With thinner corneal flaps and shallower ablation depths, surgeons no longer sever as many corneal nerves as they used to. This has yielded far fewer cases of persistent dry eye in athletes. Nonetheless, a large armamentarium of treatment options is required before considering refractive surgery on an elite, professional athlete.
In addition to more aggressive therapies, artificial tears and omega-3 fatty acids are mainstays of our preoperative treatment that we often continue for several months into the postoperative period. There is also mounting speculative research that supplementation with macular carotenoids may have a beneficial effect on vision following laser surgery. There has yet to be repeatable and well-controlled data to support this hypothesis, but we are very interested in the future results.
At this time, the only two laser vision procedures that our practice offers athletes are wavefront-guided surface ablation and femtosecond-created flap wLASIK. We believe that these two procedures give our athletes the best possible postoperative vision as well as the fewest potential complications. Due to decreased recovery time and improved patient safety, we perform significantly more wLASIK procedures than surface ablations on our athletes.
In general, however, you must pay particular attention to both preoperative and postoperative dry eye concerns. Do not forget to educate athletes on the importance of artificial tear use during the postoperative period. Also, be sure to inform athletes that enhancement procedures may be more common due to their specific visual requirements.
Dr. Cunningham is the director of research and optometry at Dell Laser Consultants, in Austin, Texas.
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