Small-incision lenticule extraction in the U.S. military: prospective study of visual and military task performance.

PURPOSE: To assess early visual outcomes and military task performance after small-incision lenticule extraction (SMILE) among U.S. military service members. SETTING: Warfighter Refractive Eye Surgery Program and Research Center and Night Vision and Electronic Sensors Directorate, Fort Belvoir, Virginia. DESIGN: Single-center, prospective, observational study. METHODS: The study was composed of active duty service members (n = 37) electing to undergo SMILE for myopia or myopic astigmatism. Testing performed preoperatively and at 1 month and 3 months postoperatively included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, wavefront aberrometry, low-contrast visual acuity (LCVA), contrast sensitivity, and vision-related questionnaire. 14 participants underwent rifle marksmanship with spectacle correction before and without correction at 6 to 8 weeks postoperatively. RESULTS: At 3 months postoperatively, the efficacy index was 0.96 and the safety index was 1.03. UDVA was ≥20/20 in 69 (96%) of eyes. LCVA change from baseline was significant under night vision condition. Eye problems contributed to 10% work and 20% activity impairments, both of which decreased to 0% (P = .001). The overall satisfaction rating for SMILE was high at 90.9 (95% CI, 85.3 to 96.5), and 95% of participants would be willing to undergo the procedure again. The median scores between preoperative and 6 to 8 weeks postoperative firing performance were comparable (34 vs 35, with and without correction, respectively; P = .247). CONCLUSIONS: After the early recovery period, SMILE seems to preserve quality of vision, which appears to facilitate the accomplishment of tasks related to their work as military service members as well as performing activities outside of work.

Correction to: Preliminary evaluation of the Vision PERformance (VIPER) simulator.

An amendment to this paper has been published and can be accessed via the original article.

Visual outcomes after SMILE from the first-year experience at a U.S. military refractive surgery center and comparison with PRK and LASIK outcomes.

PURPOSE: To assess the visual outcomes of small-incision lenticule extraction (SMILE) after the first year of treatments at a military refractive surgery center and compare with photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) outcomes during the same period. SETTING: Warfighter Refractive Eye Surgery Program and Research Center, Fort Belvoir, VA. DESIGN: Retrospective study. METHODS: Records of service members who underwent SMILE, PRK, or LASIK for myopia from March 2017 to February 2018 were reviewed. Preoperative and up to 6-month postoperative data were collected. Visual outcomes were compared between treatments. RESULTS: Of 563 treated eyes, 173 (30.7%) underwent SMILE, 304 (54.0%) PRK, and 86 (15.3%) LASIK. In comparing SMILE with PRK 1 month postoperatively, SMILE (145 eyes [87.9%]) attained uncorrected distance visual acuity (UDVA) ≥20/20 more vs PRK (214 eyes [73.8%]; P < .01). Similarly, SMILE (152 eyes [94.4%]) achieved more eyes with manifest spherical equivalent (MSE) within ±0.50 diopters (D) from intended target vs PRK (250 eyes [85.9%]; P = .01). None lost ≥1 line of corrected distance visual acuity in SMILE vs PRK (16 eyes [5.5%]; P < .01). Thereafter, there were no other significant differences except SMILE had 117 eyes (95.1%) vs PRK with 224 eyes (99.6%) achieving UDVA ≥20/20 at 3 months postoperatively (P = .01). In assessing SMILE vs LASIK, all parameters were comparable; however, 77 SMILE eyes (96.3%) had MSE within ±0.50 D from target vs 31 LASIK eyes (83.8%) at 6 months postoperatively (P = .02). CONCLUSIONS: The first year after SMILE treatments in a U.S. military center demonstrated early postoperative outcomes superior to PRK. SMILE seemed more predictable compared with LASIK.

Preliminary evaluation of the VIsion PERformance (VIPER) simulator.

BACKGROUND: This study evaluated the VIsion PERformance (VIPER) simulator's ability to assess the functional visual performance in warfighters conducting civilian and military tasks. METHODS: Thirty service members, aged 25-35 years old with a best corrected distance visual acuity (VA) better than or equal to 20/20 or logarithm of the minimum angle of resolution (logMAR) 0.00, were randomized to locate and identify road signs and mock improvised explosive devices (IEDs) under either daytime conditions or with infrared imagery, with (cc) and without (sc) wearing their habitual correction. Participants also underwent binocular uncorrected (UDVA) and corrected (CDVA) visual assessment, refraction, contrast sensitivity testing and wavefront aberrometry. RESULTS: The mean age was 28.47 years. The manifest spherical equivalent was - 3.16 ± 1.75 diopters (D), the UDVA in both eyes (OU) was logMAR 0.83 ± 0.47, and the CDVA OU was - 0.11 ± 0.06. For VIPER, the mean difference in the detection distance (DD) for road signs ccDD vs. scDD was 76.7 ± 52.8 m (P < 0.001). The average difference in identification distance (ID) ccID vs. scID was 13.9 ± 6.3 m (P < 0.001). The mean accuracies were 83.5 and 27.9% for cc and sc, respectively (P < 0.001). The regression analysis indicated that a 1.6 m change in the distance accounts for a 1% change in the accuracy (P = 0.002). Without correction, a 4.1 m change accounts for a 1% change in the accuracy (P < 0.001). The average IED ccDD was 29.9 ± 8.2 m, and that for scDD was 13.2 ± 13.6 m (P < 0.001). The average IED ccID was 32.2 ± 6.2 m and that for the scID was 7.4 ± 10.3 m (P < 0.001). The mean IED identification accuracy was 46.7 and 11.4% for cc and sc, respectively (P < 0.001). CONCLUSIONS: The preliminary results reflect VIPER's ability to assess functional visual performance when detecting and identifying signs and IEDs. Furthermore, VIPER is able to detect performance changes with and without correction.

Contrast Sensitivity After Wavefront-Guided and Wavefront-Optimized PRK and LASIK for Myopia and Myopic Astigmatism.

PURPOSE: To compare contrast sensitivity among participants undergoing wavefront-guided or wavefront-optimized photorefractive keratectomy (PRK) or LASIK for the treatment of myopia or myopic astigmatism 12 months after surgery. METHODS: In a prospective, randomized clinical trial, 215 participants with myopia ranging from -0.50 to -7.25 diopters (D) and less than -3.50 D of manifest astigmatism electing to undergo either LASIK or PRK were randomized to receive wavefront-guided or wavefront-optimized treatment. Corrected Super Vision Test (Precision Vision, La Salle, IL) high contrast and small letter contrast sensitivity, uncorrected postoperative contrast sensitivity function, and uncorrected and corrected distance visual acuity were measured preoperatively and at 1, 3, 6, and 12 months postoperatively. RESULTS: There was a significant difference within each of the four groups over time when measuring high contrast visual acuity (P < .001) and small letter contrast sensitivity (P < .001), with the most significant decrease occurring 1 month postoperatively. However, there were no significant differences when comparing the four groups for high contrast sensitivity (P = .22) or small letter contrast sensitivity (P = .06). The area under the logarithm of contrast sensitivity function did not differ significantly over time (P = .09) or between groups (P = .16). A pairwise comparison of preoperative to 12-month CDVA showed a significant improvement in all groups (P < .017). The change in CDVA was also significantly different between groups as determined by one-way analysis of variance (P = .003). CONCLUSIONS: Wavefront-guided and wavefront-optimized PRK and LASIK procedures maintained high contrast, small letter contrast sensitivity, and contrast sensitivity function 12 months postoperatively. Although the recovery period for visual performance was longer for PRK versus LASIK, there was no significant difference in treatment type or treatment profile at 12 months postoperatively. [J Refract Surg. 2018;34(9):590-596.].

Vision-Related Quality of Life and Perception of Military Readiness and Capabilities Following Refractive Surgery Among Active Duty U.S. Military Service Members.

PURPOSE: To assess vision-related quality of life and military readiness and capabilities among active duty U.S. military service members undergoing refractive surgery. METHODS: In this prospective, single-center, observational study, active duty U.S. military service members electing to undergo refractive surgery were asked to complete a military performance questionnaire and the National Eye Institute Refractive Error Quality of Life Instrument (NEI RQL-42) preoperatively and at 6 months postoperatively. On the military performance questionnaire, participants rated (1 = very bad to 5 = very good) how they felt their vision affected their military readiness and capabilities after refractive surgery. RESULTS: Among 360 participants at 6 months postoperatively, the overall mean military performance score increased from 3.6 ± 0.8 to 4.8 ± 0.3, a change of 1.2, with 91.7% of the participants indicating an overall improvement in readiness and capability (P < .001). Scores measuring overall individual readiness, contribution to unit's mission, use of night vision goggles, function at night, weapons sighting ability, employment of personal masks, weather extreme environmental conditions, and optical support were significantly higher postoperatively (P < .001). For the NEI RQL-42, scores were significantly higher postoperatively for the subscales clarity of vision, expectations, near vision, far vision, diurnal fluctuations, activity limit, glare, dependence on correction, worry, appearance, and satisfaction with correction (all P < .001), but not for symptoms after refractive surgery (P = .403). CONCLUSIONS: Refractive surgery significantly improves military readiness and capabilities and vision-related quality of life of active duty U.S. military service members with refractive error. [J Refract Surg. 2018;34(9):597-603.].

Wavefront-guided versus wavefront-optimized photorefractive keratectomy: Clinical outcomes and patient satisfaction.

PURPOSE: To compare visual outcomes following Visx Star S4 Customvue wavefront-guided and Allegretto Wave Eye-Q 400 Hz wavefront-optimized photorefractive keratectomy (PRK). SETTING: Warfighter Refractive Eye Surgery Program and Research Center, Fort Belvoir, Virginia, and Walter Reed National Military Medical Center, Bethesda, Maryland, USA. DESIGN: Prospective randomized clinical trial. METHODS: Active-duty United States military soldiers were randomized to have wavefront-guided (Visx Star S4 Customvue) or wavefront-optimized PRK. Participants were followed up to 12 months postoperatively. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and manifest spherical equivalent (SE). Secondary outcome measures included refractive astigmatism, higher-order aberrations (HOAs), contrast sensitivity, subjective visual complaints, and patient satisfaction. RESULTS: The study evaluated 108 soldiers (mean age 30.3 years ± 6.3 [SD]; mean manifest SE -3.51 ± 1.63 D). At 12 months postoperatively, achieved UDVA, CDVA, manifest SE, and refractive astigmatism were comparable between wavefront-guided and wavefront-optimized groups (P > .213). Spherical aberration and total HOAs significantly increased from baseline in both groups (P < .006). The change in coma, trefoil, spherical aberration, and total HOAs (P > .254) were comparable between groups. There were fewer losses of photopic low-contrast visual acuity (LCVA) at 5% contrast after wavefront-guided compared to wavefront-optimized treatment (P = .003). There was no significant difference between treatment groups in visual symptoms, overall vision expectation, and satisfaction (P > .075). CONCLUSION: Wavefront-guided treatment offered a small advantage in photopic LCVA. Refractive outcomes, HOAs, self-reported visual difficulties, overall vision expectation, and satisfaction were otherwise comparable between wavefront-guided and wavefront-optimized treatments. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.