Eyeworld

46 Military target identification after wavefront-guided and wavefront-optimized PRK Richard Stutzman, MD, and colleagues Purpose: To determine the effect of WFG and WFO PRK on military task performance through psychophysi- cal testing. We attempted to measure the ability to detect and discriminate objects of military interest using thermal imagery as presented on a computer screen. Methods: This was a prospective study of myopic patients random- ized to undergo either WFG or WFO PRK. Subjective manifest refraction, uncorrected and corrected distance visual acuities (UDVA and CDVA) were determined preoperatively and at 1, 3, and 6 months (M) postopera- tively. Military task performance was evaluated preoperatively as well as 6 weeks and 6 M postoperatively. Participants were trained on the U.S. Army's Recognition of Combat Vehicles (ROC-V) software, a train- ing program to help soldiers identify thermal signatures of combat vehicles. Change in probability of vehicle identification (PID) for each observer pre- and 6 M postoperatively was one of the military tasks assessed. Results: Mean participant age was 29.2±5.7 years. The manifest spherical equivalent was –3.87±1.46 diopters (D). At 6 M, 100% WFG vs. 95.8% WFO achieved UDVA of ≥20/20 (p=0.48); 96.2% WFG vs. 92.3% WFO were ±0.50 D of emmetropia (p=0.99). At 6 M, 55% of WFG observers increased preoperative PID by at least 10%; 9% decreased PID by more than 10%. At 6 M, 25% of WFO observers increased preoperative PID by at least 10%; 12% decreased PID by more than 10%. Conclusion: Visual outcomes following WFG and WFO PRK are excellent and comparable to one another. Individuals who under- went WFG PRK demonstrated im- provement and an overall better performance on PID. Dr. Berdahl: The work by Dr. Stutzman and colleagues is fascinating because it uses military task performance as a vi- sually intense measure to discriminate small real world objects. Their goal is to compare wavefront-guided and wavefront-optimized PRK. What they found was that both wavefront-guided and wavefront-optimized PRK are tremendous procedures and that soldiers perform as good or better after having PRK as they did before. A couple of interesting observations include that the wavefront-guided group did better on military tasks than prior to surgery and that more than 95% of patients had an uncorrected visual acuity of 20/20 or better. Biomechanical changes pre- and post-flapless femto refractive procedure and femto-LASIK by assessment of corneal deformation response Moones F. Abdalla, MD, and colleagues Purpose: To evaluate and compare corneal deformation amplitude in patients prior to and following small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (femto-LASIK) using non-contact tonometer with visualization and measurement of the corneal deformation response to an air pulse with an ultra high-speed Scheimpflug camera. Methods: Prospective, comparative study, 20 patients, 40 eyes divided into 2 groups. Corneal deformation amplitude was recorded using (Corvis ST, Oculus, Arlington, Wash.) prior to and 3 months after corneal laser refractive surgery for myopia. Preoperative corneal defor- mation amplitude was correlated with age and preoperative central corneal thickness (CCT). Postopera- EW REFRACTIVE SURGERY 46 July 2014 Hot off the press: John Berdahl, MD, highlighted the best refractive papers at the "Hot Off the Press" session at the 2014 ASCRS•ASOA Symposium & Congress. The papers were chosen from the Best Paper of Session winners. Here are the abstracts from the studies, with his comments regarding selection. Dr. Berdahl highlights the best refractive papers at the "Hot Off the Press" session. Source: EyeWorld First in a series of 5 presentations 43-47 Refractive_EW July 2014-DL2_Layout 1 6/30/14 8:45 AM Page 46

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