Military Target Identification After Wavefront-Guided and Wavefront-Optimized PRK

Stutzman, Richard

Military Target Identification After Wavefront-Guided and Wavefront-Optimized PRK

Sunday, April 27, 2014: 3:06 PM

Room 155 (Boston Convention and Exhibition Center)

Richard Stutzman, MD, Walter Reed National Military Medical Center, Bethesda, Maryland, USA

Rose Kristine C. Sia, MD, Warfighter Refractive Surgery and Research Center, Fort Belvoir, VA, USA

Denise S. Ryan, MS, Warfighter Refractive Surgery and Research Center, Falls Church, VA, USA

Tana Maurer, US Army RDECOM CERDEC NVESD, Fort Belvoir, VA, USA

Edward W. Trudo, MD, Storm Eye Institute, Charleston, SC, USA

Kraig S. Bower, MD, Wilmer Eye Institute, Lutherville, MD, USA

Narrative Responses:

Purpose
To determine the effect of WFG and WFO PRK on military task performance through psychophysical 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 is a prospective study of myopic patients randomized 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) postoperatively. Military task performance was evaluated preoperatively as well as 6 weeks and 6M postoperatively. Participants trained on the U.S. Army’s Recognition of Combat Vehicles (ROC-V) software, a training program to help soldiers identify thermal signatures of combat vehicles. Change in probability of vehicle identification (PID) for each observer pre- and 6M 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 6M, 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 6M, 55% of WFG observers increased preoperative PID by at least 10%; 9% decreased PID by more than 10%. At 6M, 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 underwent WFG PRK demonstrated improvement and an overall better performance on PID.