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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.

BACKGROUND AND OBJECTIVE: The goal of this study was to determine the anatomic outcome of traumatic retinal detachment (RD) from combat ocular trauma. MATERIALS AND METHODS: Retrospective study of patients sustaining a traumatic RD in Operation Iraqi Freedom and Operation Enduring Freedom who were evacuated to Walter Reed Army Medical Center from 2001 to 2011. The Fisher exact test, Wilcoxon rank sum test, and Agresti and Coull methods were used for analyses. RESULTS: There were 143 eyes of 134 patients in which a traumatic RD developed, of a total of 890 eyes of 652 patients in the Walter Reed Ocular Trauma Database. Based on our results, predictors for failure to reattach the retina include maculaoff status ( P = .0002), open-globe injury ( P = .03), proliferative vitreoretinopathy postoperatively ( P = .002), and presence of hyphema ( P = .02). Intraocular foreign body and time to initial retinal surgery did not increase risk for failure. Thirty-four percent (34%) of eyes failed to be reattached. CONCLUSIONS: Traumatic RD due to injury sustained in a combat zone resulted in poor prognosis, with 82.09% of eyes with RD having a best-corrected visual acuity worse than 20/200. The anatomic success of RD repair was shown to be 65.71%, likely owing to the severity of the injuries, concomitant systemic injuries, and delayed surgical intervention. [ Ophthalmic Surg Lasers Imaging Retina 2022;53:493–501.]

PURPOSE: To assess whether densitometry analysis appropriately monitors the development of haze in myopic patients after photorefractive keratectomy (PRK) when compared to subjective slit-lamp haze grade examinations, and whether sutureless cryo-preserved amniotic membrane reduced postoperative haze development when compared to the standard bandage contact lens. METHODS: In this retrospective cohort at the Center for Refractive Surgery, Walter Reed National Military Medical Center, a secondary analysis of prospectively collected data was performed. In the prospective study, participants underwent PRK for myopia. Postoperatively, a standard bandage contact lens was applied to the dominant eye and a sutureless cryo-preserved amniotic membrane graft to the nondominant eye. Participants were evaluated at 1, 3, and 6 months postoperatively for haze formation and corneal densitometry using slit-lamp biomicroscopy and Scheimpflug imaging, respectively. RESULTS: Densitometry measurements at 6 months postoperatively were positively and significantly associated with the presence or absence of haze as assessed by slit-lamp examination in 39 patients (78 eyes; age range: 21 to 44 years). Eyes with increased densitometry measurements had 2.3 to 3.4 times the odds ( P ⩽ .014) of having clinical haze on slit-lamp examination. Eyes with the amniotic membrane graft showed a positive correlation with increased corneal densitometry throughout most layers of the cornea. CONCLUSIONS: Densitometry analysis appears to be a useful tool to supplement slit-lamp examination in monitoring haze development after PRK. The amniotic membrane failed to show a reduction in corneal densitometry in myopic eyes after PRK. [ J Refract Surg . 2020;36(5):293–299.]

Introduction Traumatic brain injury (TBI) remains a significant source of disability for active duty service members in both deployed and training settings as well as those who have left active service. Service members with ocular trauma are at risk for a TBI and should be screened appropriately. Early detection results in treatment to minimize long-term sequelae which can often be debilitating. This study is the first to evaluate different combat-related ocular injuries and their associations with TBI. Materials and Methods A secondary analysis of existing data was conducted from a prospective study of patients who sustained combat ocular trauma (COT) during Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) between 2006 and 2020. Clinical data of a total of 88 participants were gathered and each case reviewed, including patient demographics, injury-related factors, history of TBI, and treatments rendered. All cases were then categorized to compare COT (n = 13) versus COT-T (Combat Ocular Trauma associated with TBI; n = 75). The Fisher’s exact test was completed for each category to assess for predictive factors of TBI within the ophthalmic trauma cohort. Odds ratios were calculated with their 95% CI. Results When compared to COT, COT-T was significantly associated with closed globe injuries (56%; OR 4.24, 95% CI 1.08-16.67), blast injuries (89.3%; OR 3.72, 95% CI 0.93-14.9), multiple surgeries (89%; OR 2.51, 95% CI 0.57-11.08), anterior segment injuries (69.3%; OR 1.41, 95% CI 0.42-4.79), optic nerve injuries (24%; OR 1.05, 95% CI 0.26-4.25), orbital fractures (48%; OR 2.08, 95% CI 0.59-7.34), enucleation (17.3%; OR 2.52, 95% CI 0.300-21.08), the use of eye protection (68.6%; OR 2.18, 95% CI 0.57-8.32), and the need to undergo plastic surgery (78.7%; OR 2.30, 95% CI 0.66-8.02). Significant factors associated with COT included penetrating injury (30.8%; OR 0.027, 95% CI 0.07-1.08), posterior segment injuries (92%; OR 0.264, 95% CI 0.032-2.17), bilateral injuries (76.9%; OR 0.678, 95% CI 0.17-2.69), and bilateral blindness (7.7%; OR 0.857, 95% CI 0.092-7.99). Conclusions Patients who have sustained combat-related ocular injuries, specifically blast injury, anterior segment injury, or an orbital fracture, were noted to be more likely to have also sustained a TBI. However, of the evaluated variables in predicting the co-occurrence of TBI, only closed globe injury was identified as statistically significant. Service members with injuries requiring multiple surgical procedures, reconstructive plastic surgery, or enucleation of an eye were also more likely to be diagnosed with a TBI, but these variables were not found to be predictive of TBI among ocular trauma patients. The presence of eye protection was not protective against TBI. Further studies are needed to find significant predictors of TBI in combat ocular trauma patients to assist in the early and accurate detection of TBI.

Purpose: To compare the efficacy and accuracy of wavefront-guided (WFG) and wavefront-optimized (WFO) PRK and LASIK for the treatment of myopia with low to moderate astigmatism.Methods: In this prospective cohort study, 215 active duty military service members (430 eyes, mean spherical equivalent -3.61 ± 1.53 D) electing either PRK or LASIK were randomized to undergo WFG or WFO treatment. Up to 12 months, postoperative visual outcomes following surgeries were compared between 4 treatment groups: WFG PRK, WFG LASIK, WFO PRK, and WFO LASIK for myopia with 0.25 to 0.50 D astigmatism (≤ 0.50 D cyl subgroup) and ≥ 0.75 D astigmatism (≥ 0.75 D cyl subgroup). High and low contrast visual acuities were assessed and vector analysis was performed.Results: At 12 months postoperatively, the surgically induced astigmatism, magnitude of error, correction and flattening indices were significantly different between treatment groups (P values ≤ 0.001) in the ≤ 0.50 D cyl subgroup. In ≥ the 0.75 D cyl subgroup, there were no significant differences in vector analysis parameters except for the magnitude of error and correction index (P values ≤ 0.010). The treatment groups were comparable in terms of postoperative uncorrected distance visual acuity, manifest spherical equivalent, and best-corrected low contrast visual acuity.Conclusions: No treatment modality showed consistent superiority in correcting low to moderate astigmatism. Overall, both PRK and LASIK using either wavefront-guided or wavefront-optimized laser platforms were similarly effective and accurate in treating myopia with a low to moderate amount of astigmatism.

Purpose The purpose of this study was to assess visual and health-related quality of life (QOL) among U.S. military service members who sustained combat ocular trauma (COT) with or without associated traumatic brain injury (TBI). Methods This was a single-center, prospective observational study of U.S. service members (n = 88) with COT who were treated at Walter Reed National Military Medical Center. Participants completed the National Eye Institute Visual Function Questionnaire (VFQ-25) at enrollment and at follow-up (>1 year) and supplemental surveys: Neurobehavioral Symptom Inventory, the Medical Outcomes 36-item Short Form Survey (SF-36), and Mayo-Portland Adaptability Inventory. Results Initial and follow-up VFQ-25 showed a statistically significant increase in median scores for near activities (initial: 75.0, follow-up 83.3; P = .004) and peripheral vision (initial: 50.0, follow-up: 75.0; P = .009) and in composite scores (initial: 79.5, follow-up: 79.8; P = .022). Comparing those who did (n = 78) and did not (n = 8) have a TBI history, there were no significant differences in median change in VFQ-25 composite scores (with TBI: 2.3 vs. no TBI: 10.7; P = .179). Participants with a TBI history had a significantly lower median SF-36 General Health score (with TBI: 67.5 vs. no TBI: 92.5; P = .009) Conclusions Vision-related QOL of COT patients is generally good in the long term. However, those with both COT and a history of TBI conditions showed significantly worse functioning in several domains than those without TBI. As TBI is a common finding in COT, this association is an important factor impacting this population’s overall clinical presentation and daily functions.

Lipids in complex, protein-enriched films at air/liquid interfaces reduce surface tension. In the absence of this benefit, the light refracting and immunoprotective tear film on eyes would collapse. Premature collapse, coupled with chronic inflammation compromising visual acuity, is a hallmark of dry eye disease affecting 7 to 10% of individuals worldwide. Although collapse seems independent of mutation (unlike newborn lung alveoli), selective proteome and possible lipidome changes have been noted. These include elevated tissue transglutaminase and consequent inactivation through C-terminal cross-linking of the tear mitogen lacritin, leading to significant loss of lacritin monomer. Lacritin monomer restores homeostasis via autophagy and mitochondrial fusion and promotes basal tearing. Here, we discover that lacritin monomer C-terminal processing, inclusive of cysteine, serine, and metalloproteinase activity, generates cationic amphipathic α-helical proteoforms. Such proteoforms (using synthetic peptide surrogates) act like alveolar surfactant proteins to rapidly bind and stabilize the tear lipid layer. Immunodepletion of C- but not N-terminal proteoforms nor intact lacritin, from normal human tears promotes loss of stability akin to human dry eye tears. Stability of these and dry eye tears is rescuable with C- but not N-terminal proteoforms. Repeated topical application in rabbits reveals a proteoform turnover time of 7 to 33 h with gradual loss from human tear lipid that retains bioactivity without further processing. Thus, the processed C-terminus of lacritin that is deficient or absent in dry eye tears appears to play a key role in preventing tear film collapse and as a natural slow release mechanism that restores epithelial homeostasis.

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.

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.]

Introduction Simulation training in medical education provides the ability to teach valuable surgical skills in an environment free of risk to patients. Surgical simulation in ophthalmology continues to evolve as new technologies advance, though widespread use in ophthalmology outside of cataract surgery simulation is lacking. Here, we present a study into the efficacy of surgical simulation for eyelid laceration repair when compared with standard tissue-based instruction. Materials and Methods The study included 43 ophthalmology residents and 16 staff ophthalmologists from the Ocular Trauma Surgery Laboratory (OTSL) at the Uniformed Services University of the Health Sciences (USUHS). After initial evaluation on their ability to repair marginal eyelid lacerations on a porcine eye, residents were randomized to receive training in marginal eyelid repair technique from faculty preceptors using either traditional porcine tissue or the Ocular and Craniofacial Trauma Treatment Training System (Medical Device and Simulation Laboratory). They were then reevaluated after training. Participating staff also underwent initial evaluation, self-guided training, and post-training evaluation. Outcome measures included successful repair of laceration, number of sutures required to close a 10-mm wound, time required to repair, and the following graded on a scale of 1–4 (1—poor, 2—fair, 3—good, 4—excellent): tarsal plate reconstruction and margin approximation. Results Among residents, improved scores in marginal approximation were noted after training when comparing scores both within the simulator-trained group (pre-training score: 2.0, post-training score: 3.0; p = 0.03) and between the simulator (SIM) and live tissue (LIVE) groups (SIM: 3.0, LIVE: 2.0 p = 0.03). Neither residents nor staff demonstrated significant differences between SIM versus LIVE in other metrics evaluated. Response in a post-study survey was favorable to simulator training, with 79% noting the simulator was helpful in teaching skills, and 83% noting they would use the simulator again. Conclusion Simulator technology for teaching marginal eyelid laceration repair appears to be noninferior to traditional tissue-based instruction. Additionally, it appears to be superior when evaluating the ability to approximate the eyelid margin appropriately. Simulators are safe and ethical alternatives to tissue-based instruction, and are favorably received among trainees, and therefore warrant additional investigation and development for ophthalmic surgical training.

To describe the visual outlook and quality of life of service members after combat ocular trauma.In a single-center, prospective observational study of service members sustaining ocular trauma, participants underwent a series of ocular examinations and noninvasive tests, including the National Eye Institute Visual Functioning Questionnaire (VFQ-25).Of the 165 enrolled participants, 137 completed the VFQ-25. The mean VFQ-25 composite score was 74.4 ± 20.7 (range: 1.4-100). Among 118 participants with visual acuity assessment, 92% had best corrected visual acuity (BCVA) of 20/20 or better in at least one eye. Among participants with severe vision loss (BCVA ≤20/200), there was no statistically significant difference in self-reported general health compared to those without severe vision loss (p = 0.17). However, there was a significantly lower visual quality of life reported in the composite score and all of the 11 subscales of the VFQ-25.While this study provides evidence that combat ocular trauma is associated with a lower visual quality of life, limitations include the relatively small sample size and the limited documentation of the use of eye protection at time of injury among participants.

Purpose To evaluate the effect of sutureless cryopreserved amniotic membrane (Prokera) on corneal wound healing after photorefractive keratectomy (PRK). Setting Center for Refractive Surgery, Walter Reed Army Medical Center, Washington, DC, USA. Design Prospective nonrandomized control trial. Methods Patients had PRK for myopia with or without astigmatism. A 20% ethanol solution was used to create a standard 9.0 mm epithelial defect followed by photoablation with the Allegretto Wave Eye-Q 400 Hz laser. After surgery, a high-oxygen-transmissible bandage contact lens (Acuvue Oasys) was applied on the dominant eye and cryopreserved amniotic membrane on the nondominant eye. The postoperative regimen was otherwise identical for both eyes. Postoperatively, patients were evaluated daily until complete corneal reepithelialization occurred in both eyes and then at 2 weeks and 1, 3, 6, and 12 months. Reepithelialization was assessed daily with slitlamp examination, fluorescein staining, and photography. Secondary outcome measures included adverse effects, ocular comfort, visual outcomes, and corneal haze. Results Forty patients were enrolled. The amniotic membrane graft sped corneal reepithelialization 1 day after PRK but was not better than the bandage contact lens in hastening complete reepithelialization of the cornea. Visual outcomes, corneal clarity, and optical quality of the cornea were comparable between the amniotic membrane graft eyes and bandage contact lens eyes. Conclusion Although the amniotic membrane graft was reasonably well tolerated with few significant adverse effects, the role of amniotic membrane in modulating wound healing after PRK remains speculative. Financial Disclosure None of the authors has a financial or proprietary interest in any material or method mentioned.

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.]

Purpose To evaluate dry-eye manifestations after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) and determine the incidence and predictive factors of chronic dry eye using a set of dry-eye criteria. Setting Walter Reed Army Medical Center, Washington, DC, USA. Design Prospective, non-randomized clinical study. Methods Dry-eye evaluation was performed before and after surgery. Main outcome measures included dry-eye manifestations, incidence, and predictive factors of chronic dry eye. Results This study comprised 143 active-duty U.S. Army personnel, ages 29.9 ± 5.2 years, with myopia or myopic astigmatism (manifest spherical equivalent −3.83 ± 1.96 diopters) having PRK or LASIK. Schirmer scores, corneal sensitivity, ocular surface staining, surface regularity index, and responses to dry-eye questionnaire significantly changed over time after PRK. After LASIK, significant changes were observed in tear breakup time, corneal sensitivity, ocular surface staining, and responses to questionnaire. Twelve months postoperatively, 5.0% of PRK and 0.8% of LASIK participants developed chronic dry eye. Regression analysis showed that pre-operatively lower Schirmer score will significantly influence development of chronic dry eye after PRK, whereas preoperatively, lower Schirmer score or higher ocular surface staining score will significantly influence the occurrence of chronic dry eye after LASIK. Conclusions Chronic dry eye was uncommon after PRK and LASIK. Ocular surface and tear-film characteristics during pre-operative examination might help to predict chronic dry-eye development in PRK and LASIK. Financial Disclosure The authors have no financial interest in any product, drug, instrument, or equipment discussed in this manuscript.

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 .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.

Antimicrobial peptides are important as the first line of innate defense, through their tendency to disrupt bacterial membranes or intracellular pathways and potentially as the next generation of antibiotics. How they protect wet epithelia is not entirely clear, with most individually inactive under physiological conditions and many preferentially targeting Gram-positive bacteria. Tears covering the surface of the eye are bactericidal for Gram-positive and -negative bacteria. Here we narrow much of the bactericidal activity to a latent C-terminal fragment in the prosecretory mitogen lacritin and report that the mechanism combines membrane permeabilization with rapid metabolic changes, including reduced levels of dephosphocoenzyme A, spermidine, putrescine, and phosphatidylethanolamines and elevated alanine, leucine, phenylalanine, tryptophan, proline, glycine, lysine, serine, glutamate, cadaverine, and pyrophosphate. Thus, death by metabolic stress parallels cellular attempts to survive. Cleavage-dependent appearance of the C-terminal cationic amphipathic α-helix is inducible within hours by Staphylococcus epidermidis and slowly by another mechanism, in a chymotrypsin- or leupeptin protease-inhibitable manner. Although bactericidal at low micromolar levels, within a biphasic 1-10 nM dose optimum, the same domain is mitogenic and cytoprotective for epithelia via a syndecan-1 targeting mechanism dependent on heparanase. Thus, the C terminus of lacritin is multifunctional by dose and proteolytic processing and appears to play a key role in the innate protection of the eye, with wider potential benefit elsewhere as lacritin flows from exocrine secretory cells.

To compare visual performance, marksmanship performance, and threshold target identification following wavefront-guided (WFG) versus wavefront-optimized (WFO) photorefractive keratectomy (PRK).In this prospective, randomized clinical trial, active duty U.S. military Soldiers, age 21 or over, electing to undergo PRK were randomized to undergo WFG (n = 27) or WFO (n = 27) PRK for myopia or myopic astigmatism. Binocular visual performance was assessed preoperatively and 1, 3, and 6 months postoperatively: Super Vision Test high contrast, Super Vision Test contrast sensitivity (CS), and 25% contrast acuity with night vision goggle filter. CS function was generated testing at five spatial frequencies. Marksmanship performance in low light conditions was evaluated in a firing tunnel. Target detection and identification performance was tested for probability of identification of varying target sets and probability of detection of humans in cluttered environments.Visual performance, CS function, marksmanship, and threshold target identification demonstrated no statistically significant differences over time between the two treatments. Exploratory regression analysis of firing range tasks at 6 months showed no significant differences or correlations between procedures. Regression analysis of vehicle and handheld probability of identification showed a significant association with pretreatment performance.Both WFG and WFO PRK results translate to excellent and comparable visual and military performance.

Nighttime military operations include challenges encountered in daylight but also introduce unique visual and cognitive demands characteristic of a low-light environment. Because the majority of human sensory input is visual, and successful performance of military tasks is largely dependent on visual performance, it is critical for personnel operating in settings with reduced visual capability to maximize the abilities and strategies they retain. While military image intensification devices (e.g., night vision goggles, NVGs) significantly enhance visual performance, equipment can malfunction, batteries expire, and mission-specific combat loads may preclude utilization of all available aids. Hence the availability of optical aids should not undermine the importance of optimally corrected unaided night vision. This chapter discusses some of the important factors contributing to night vision and their influence on performance on commonly encountered tasks during military operations.

Background: When evaluating vision, it is important to assess not just the ability to read letters on a vision chart, but also how well one sees in real life scenarios. As part of the Warfighter Refractive Eye Surgery Program (WRESP), visual outcomes are assessed before and after refractive surgery. A Warfighter’s ability to read signs and detect and identify objects is crucial, not only when deployed in a military setting, but also in their civilian lives. Objective: VIPER, a VIsion PERformance simulator was envisioned as actual video-based simulated driving to test warfighters’ functional vision under realistic conditions. Designed to use interactive video image controlled environments at daytime, dusk, night, and with thermal imaging vision, it simulates the experience of viewing and identifying road signs and other objects while driving. We hypothesize that VIPER will facilitate efficient and quantifiable assessment of changes in vision and measurement of functional military performance. Study Design: Video images were recorded on an isolated 1.1 mile stretch of road with separate target sets of six simulated road signs and six objects of military interest, separately. The video footage were integrated with customdesigned C++ based software that presented the simulated drive to an observer on a computer monitor at 10, 20 or 30 miles/hour. VIPER permits the observer to indicate when a target is seen and when it is identified. Distances at which the observer recognizes and identifies targets are automatically logged. Errors in recognition and identification are also recorded. This first report describes VIPER's development and a preliminary study to establish a baseline for its performance. In the study, nine soldiers viewed simulations at 10 miles/hour and 30 miles/hour, run in randomized order for each participant seated at 36 inches from the monitor. Relevance: Ultimately, patients are interested in how their vision will affect their ability to perform daily activities. In the military context, in addition to reading road signs, this includes vision with night sensors and identification of objects of military interest. Once completed and validated, VIPER will be used to evaluate functional performance before and after refractive surgery. Results: This initial study was to prove the principle, and its results at the time of this publication were very preliminary. Nine Soldiers viewed visible-day and IR-day VIPER simulations with civilian and military targets, separately, at 10 and 30 miles/hour. Analyses were performed separately for visible and IR, and also aggregated. Only the civilian targets are discussed in this report. At 10 miles/hour, the population detected civilian road signs at an aggregated average of 90.11 ± 64.20 m, and identified them at 26.93 ± 22.27m. At 30 miles/hour, the corresponding distances were 103.03 ± 58.81 and 26.26 ± 8.55, respectively. Conclusion: This preliminary report proves the principle and suggests that VIPER could be a useful clinical tool in longitudinal assessment of functional vision in warfighters.

To determine whether patients without dry eye preoperatively have an altered conjunctival goblet cell density and mucin secretion postoperatively and to explore what factors affect changes in goblet cell density and mucin secretion.The former Walter Reed Army Medical Center, Washington, DC, USA.Prospective nonrandomized clinical study.Impression cytology was used to determine conjunctival goblet cell density before and 1 week, 1 month, and 3 months after photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK). The McMonnies questionnaire, Schirmer test, tear breakup time, corneal sensitivity, rose bengal staining, and computerized videokeratoscopy were also performed to assess tear-film and ocular-surface health.The ratio of goblet cell to total cells changed postoperatively from baseline in both groups (P .001). The most significant change was a median 29% decrease 1 month postoperatively. However, there were no significant differences between groups over time (P = .772). The ratio of filled goblet cell to total goblet cell did not change significantly over the same time period (P = .128), and there were no significant differences between the PRK group and the LASIK group over time (P = .282).Patients without apparent dry eye had an altered conjunctival goblet cell population after PRK or LASIK. The conjunctival goblet cell population tended to decrease in the early postoperative period after either surgery and was most affected by preoperative goblet cell density. The changes in the tear film and ocular surface did not seem to affect goblet cell mucin secretion after either procedure.None of the authors has a financial or proprietary interest in any material or method mentioned.

Background Retreatments are sometimes necessary to correct residual or induced refractive errors following refractive surgery. Many different combinations of primary treatment methods and retreatment techniques have been studied, however, few studies have investigated wavefront-optimized (WFO) technology for retreatment following primary refractive surgery. This study aimed to report the outcomes of WFO photorefractive keratectomy (PRK) retreatments of refractive error following previous laser refractive surgery with PRK, laser in situ keratomileusis (LASIK), or laser-assisted subepithelial keratectomy (LASEK). Methods We reviewed records of patients who underwent WFO PRK retreatments using the Allegretto Wave Eye-Q 400 Hz Excimer Laser System (Alcon Surgical) between January 2008 and April 2011 at Walter Reed Army Medical Center and Madigan Army Medical Center. Outcomes were recorded in terms of uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent (MRSE), corrected distance visual acuity (CDVA), and complications at 1 month (M), 3 M, and 6 M post-op. Results Seventy-eight patients (120 eyes) underwent WFO PRK retreatment during the study period. Primary surgery was surface ablation in 87 eyes (78 PRK, 9 LASEK) and LASIK in 33 eyes. The mean spherical equivalent before retreatment was −0.79 ± 0.94 D (−3.00 to 1.88 D). UDVA was ≥ 20/20 in 69 eyes (60.0 %) at 1 M, 54 eyes (71.1 %) at 3 M, and 27 eyes (73.0 %) at 6 M follow-up. MRSE was within ±0.50 D of emmetropia in 78 eyes (67.8 %) at 1 M, 59 eyes (77.6 %) at 3 M, and 25 eyes (67.6 %) at 6 M follow-up. CDVA was maintained within ±1 line of pre-op in 113 of 115 eyes (98.3 %) at 1 M, 74 of 76 eyes (97.4 %) at 3 M, and 37 eyes (100 %) at 6 M follow-up. Conclusion Although follow-up was limited beyond 3 M, WFO PRK retreatments in patients with residual refractive error may be a safe and effective procedure. Further studies are necessary to determine the long-term safety and stability of outcomes.

Background and Objective A smooth corneal surface prior to laser ablation is important in order to achieve a favorable refractive outcome. In this study, we compare PRK outcomes following two commonly used methods of epithelial debridement: Amoils epithelial scrubber (brush) versus 20% ethanol (alcohol). Study Design/Patients and Methods We reviewed records of patients who underwent wavefront-optimized PRK for myopia or myopic astigmatism between January 2008 and June 2010. Two treatment groups (brush vs. alcohol) were compared in terms of uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent (MRSE), corrected distance visual acuity (CDVA), and complications at postoperative months 1, 3, 6, and 12. Results One thousand five hundred ninety-three eyes of 804 patients underwent PRK during the study period: 828 brush-treated eyes and 765 alcohol-treated eyes. At 6 months postoperatively UDVA was ≥20/20 in 94.7% of brush-treated eyes versus 94.4% of alcohol-treated eyes (P = 0.907). At 1 month a higher percentage of brush-treated eyes maintained or gained one or more lines CDVA compared to alcohol-treated eyes (P = 0.007), but there were no other differences in UDVA, MRSE, or CDVA at any point postoperatively. At 1 month 75.4% of brush-treated eyes versus 70.4% of alcohol-treated eyes were free of complications (P = 0.032), and there were fewer brush-treated eyes with corneal haze (4.0% vs. 6.9%, P = 0.012) and dry eye (8.9% vs. 14.4%, P = 0.001). Although corneal haze was slightly more frequent in the alcohol group, most was trace and not significant. Conclusions Although alcohol-assisted PRK had more minor complications in the early postoperative period, including corneal haze and dry eye, results for both groups beyond 1 month were comparable. Lasers Surg. Med. 44: 475–481, 2012. © Wiley Periodicals, Inc.

PURPOSE: To evaluate visual outcomes following epi-LASIK compared to photorefractive keratectomy (PRK). METHODS: Of a total 294 patients aged ≥21 years, 145 (290 eyes) underwent epi-LASIK and 149 (298 eyes) underwent PRK for low to moderate myopia or myopic astigmatism. Epi-LASIK was performed with the Amadeus II epikeratome (Abbott Medical Optics) and PRK with the Amoils rotary epithelial brush (Innovative Excimer Solutions). All ablations were performed using the same excimer laser system. Outcome measures included intraoperative complications, corneal reepithelialization, postoperative pain, uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent (MRSE), corrected distance visual acuity (CDVA), corneal haze, and quality of vision. RESULTS: Mean preoperative MRSE was −2.97±1.19 diopters (D) for epi-LASIK versus −2.95±1.06 D for PRK. Complete reepithelialization was achieved by postoperative day 4 in 46.9% of epi-LASIK eyes versus 92.4% of PRK eyes, with superior UDVA at postoperative day 1 in the PRK group ( P =.002). Using Fisher exact test, a significantly higher percentage of epi-LASIK eyes compared to PRK eyes achieved 20/15 or better at 1 month (25.8% vs 17.8%, P =.031), 3 months (62.3% vs 49.3%, P =.004), 6 months (77.1% vs 57.9%, P P =.002). A change in MRSE >0.50 D occurred in 8.4% of epi-LASIK eyes within the 3- and 12-month interval versus 17.7% of PRK eyes ( P =.04). No differences were noted between the two procedures in CDVA or clinically significant haze. CONCLUSIONS: Epi-LASIK showed superior refractive efficacy and stability but required more time for wound healing, resulting in inferior early visual outcomes and a tendency to overcorrect higher refractive errors compared to PRK. Both treatments were safe and comparable in terms of pain and haze formation.

Major decisions regarding life and death are routinely made on the modern battlefield, where visual function of the individual soldier can be of critical importance in the decision-making process. Glasses in the combat environment have considerable disadvantages: degradation of short term visual performance can occur as dust and sweat accumulate on lenses during a mission or patrol; long term visual performance can diminish as lenses become increasingly scratched and pitted; during periods of intense physical trauma, glasses can be knocked off the soldier’s face and lost or broken. Although refractive surgery offers certain benefits on the battlefield when compared to wearing glasses, it is not without potential disadvantages. As a byproduct of refractive surgery, elevated optical aberrations can be induced, causing decreases in contrast sensitivity and increases in the symptoms of glare, halos, and starbursts. Typically, these symptoms occur under low light level conditions, the same conditions under which most military operations are initiated. With the advent of wavefront aberrometry, we are now seeing correction not only of myopia and astigmatism but of other, smaller optical aberrations that can cause the above symptoms. In collaboration with the Warfighter Refractive Eye Surgery Program and Research Center (WRESP-RC) at Fort Belvoir and Walter Reed National Military Medical Center (WRNMMC), the overall objective of this study is to determine the impact of wavefront guided (WFG) versus wavefront-optimized (WFO) photorefractive keratectomy (PRK) on military task visual performance. Psychophysical perception testing was conducted before and after surgery to measure each participant’s performance regarding target detection and identification using thermal imagery. The results are presented here.

PURPOSE: To compare visual outcomes following photorefractive keratectomy (PRK), PRK with mitomycin C (MMC-PRK), and LASEK in moderate and high myopia in military personnel. METHODS: This prospective, randomized contralateral eye study included 167 patients 21 years or older with manifest spherical equivalent −5.99 ± 1.40 diopters (D) (range: −3.88 to −9.38 D) randomized to either MMC-PRK or LASEK treatment in their dominant eye and conventional PRK without MMC in the fellow eye. All procedures were performed using the LADARVision 4000 Excimer Laser System (Alcon Surgical Inc., Ft. Worth, TX). High- and low-contrast visual acuities, manifest refraction, endothelial cell count, and corneal haze were evaluated up to 12 months postoperatively. RESULTS: At 12 months postoperatively, visual outcomes were comparable among the treatment groups. Corneal haze of any grade was less common in MMC-PRK compared to PRK at 1 month (21.4% vs 31.0%; P < .01) and 3 months (12.8% vs 35.9%; P = .03) postoperatively; it was also less common in MMC-PRK compared to LASEK at 1 month (21.4% vs 55.9%; P < .01), 3 months (12.8% vs 42.4%; P < .01), and 6 months (12.2% vs 36.4%; P = .03) postoperatively. Haze rate (grade 0.5 or higher) was comparable between LASEK and PRK. Clinically significant haze (grade 2 or higher) developed after PRK (4 eyes) and LASEK (2 eyes), but not after MMC-PRK. CONCLUSIONS: MMC-PRK showed some benefits in minimizing corneal haze formation. One year after surgery, there was no discernible difference in the postoperative refractive outcomes among the three methods. [ J Refract Surg. 2014;30(4):256–264.]

Purpose To determine the association of single nucleotide polymorphisms (SNPs) of the thrombospondin 1 ( THBS1) gene with development of chronic ocular surface inflammation (keratoconjunctivitis) after refractive surgery. Design Retrospective cohort study. Participants Active duty U.S. Army soldiers (n = 143) who opted for refractive surgery. Methods Conjunctival impression cytology samples collected from participants before the surgery were used to harvest DNA for genotyping 5 THBS1 SNPs (rs1478604, rs2228262, rs2292305, rs2228262, and rs3743125) using the Sequenom iPLEX Gold platform (Sequenom, San Diego, CA). Samples collected after surgery were used to harvest RNA for gene expression analysis by real-time polymerase chain reaction (PCR). Participants were followed for 1 year after surgery to monitor the status of keratoconjunctivitis. Main Outcome Measures Genetic basis of the development of chronic keratoconjunctivitis after refractive surgery. Results Carriers of minor alleles of 3 SNPs each were found to be more susceptible to developing chronic keratoconjunctivitis (rs1478604: odds ratio [OR], 2.5; 95% confidence interval [CI], 1.41–4.47; P = 2.5×10 −3 ; rs2228262 and rs2292305: OR, 1.9; 95% CI, 1.05–3.51; P = 4.8×10 −2 ). Carriers of the rs1478604 minor allele expressed significantly reduced levels of thrombospondin 1 (TSP1) ( P = 0.042) and increased levels of an inflammatory cytokine associated with keratoconjunctivitis, interleukin-1β ( P = 0.025), in their ocular surface epithelial cells compared with homozygous major allele controls. Conclusions Genetic variation in the THBS1 gene that results in decreased expression of the encoded glycoprotein TSP1 in ocular surface epithelial cells significantly increases the susceptibility to develop chronic ocular surface inflammation after refractive surgery. Further investigation of THBS1 SNPs in a larger sample size is warranted.

Purpose. To evaluate the use of ocular imaging to enhance management and diagnosis of war-related anterior segment ocular injuries.Methods. This study was a prospective observational case series from an ongoing IRB-approved combat ocular trauma tracking study. Subjects with anterior segment ocular injury were imaged, when possible, using anterior segment optical coherence tomography (AS-OCT), confocal microscopy (CM), and slit lamp biomicroscopy.Results. Images captured from participants with combat ocular trauma on different systems provided comprehensive and alternate views of anterior segment injury to investigators.Conclusion. In combat-related trauma of the anterior segment, adjunct image acquisition enhances slit lamp examination and enables real timeIn vivoobservation of the cornea facilitating injury characterization, progression, and management.

Purpose To evaluate resident refractive surgery caseload and surgical outcomes in an academic medical center. Setting Walter Reed Army Medical Center, Washington, DC, USA. Design Comparative case study. Methods Keratorefractive procedures performed by residents at the Walter Reed Center for Refractive Surgery between 2002 and 2010 were reviewed. Outcomes of surgeries performed by the graduating classes of 2008 to 2010 were compared with those of cases performed by staff. The uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent, corrected distance visual acuity (CDVA), and complications were analyzed. Results Between 2002 and June 2010, residents performed 1566 procedures (1414 photorefractive keratectomy [PRK], 152 laser in situ keratomileusis), for a mean of 20.2 procedures from 2002 to 2004, 51.6 from 2005 to 2007, and 99.9 from 2008 to 2010. Outcomes analysis was performed on 333 resident eyes and 977 staff eyes treated between 2008 and June 2010. Six months postoperatively, 96.1% of resident-treated eyes and 94.6% of staff-treated eyes had a UDVA 20/20 or better (P=.312) and 61.3% and 64.3%, respectively, had a UDVA 20/15 or better (P=.324). The percentage of eyes within ±0.50 diopter of emmetropia at 6 months was 94.0% for residents and 91.1% for staff (P=.105). The postoperative CDVA was within 2 lines of preoperative baseline in all resident cases and 99.8% of staff cases (P=.999). Conclusions Resident experience grew steadily over the period studied. Overall safety and efficacy of resident-performed surgery, albeit mainly PRK based, matched that of fellowship-trained refractive surgeons. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

PURPOSE: To report the results of photorefractive keratectomy (PRK) in patients with pigment dispersion syndrome. METHODS: The pre- and postoperative records of patients with pigment dispersion syndrome who underwent PRK between January 2002 and March 2009 were reviewed. Data for analysis included gender, age, ablation depth, surgical complications, manifest refraction spherical equivalent, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), intraocular pressure (IOP), central corneal thickness (CCT), cup-to-disc (c/d) ratio, and postoperative complications. RESULTS: Thirty-seven eyes of 19 patients (17 men and 2 women) with a mean age of 37.5±6.9 years were included for review. At final follow-up, mean 404.1±119.5 days postoperative, UDVA was 20/15 or better in 67.6%, 20/20 or better in 91.9%, and 20/25 or better in 100% of eyes; 94.6% of eyes were within 0.50 diopters (D) and 100% were within 1.00 D of emmetropia. Corrected distance visual acuity was unchanged from preoperative in 73% and improved by one line in 27% of eyes. No eye lost 1 or more lines of CDVA. When corrected for change in CCT and curvature, mean postoperative IOP was elevated from baseline (16.7±3.8 mmHg) at 1 month (18.1±4.9 mmHg, P =.044) but unchanged at any other time postoperatively. Two (11%) of 19 patients were steroid responders, requiring a single topical agent until completing the course of steroids. No significant change was noted in mean c/d ratio from baseline (0.35±0.12) to final postoperative (0.35±0.13, P =.99). CONCLUSIONS: Although PRK in patients with pigment dispersion syndrome resulted in excellent UDVA, retention of CDVA, and low incidence of adverse effects 1 to 2 years after surgery, long-term safety and efficacy outcomes of PRK in this cohort remain speculative.

Several small proteomic studies suggest that the prosecretory tear protein lacritin may be selectively downregulated in dry eye syndrome and in blepharitis, yet little information is available about normal baseline levels. This study assessed lacritin levels in tears from healthy individuals and addressed whether they differ according to sex, age, or time of day.Rabbit antibodies against lacritin N-terminal peptide EDASSDSTGADPAQEAGTS (Pep Lac N-Term) were generated and characterized against human recombinant lacritin and N-65 truncation mutant. Basal tears were collected from 66 healthy individuals ranging in age from 18 to 52 years, and at four times during one 24-hour period from 34 other individuals. Lacritin levels were then analyzed by ELISA and Western blotting.Anti-Pep Lac N-Term bound lacritin, but not truncation mutant N-65 that lacks the N-terminal antigenic site. Tear lacritin levels followed a normal distribution with a mean of 4.2 ± 1.17 ng/100 ng total tear protein. Levels differed little by age or sex, and decreased slightly between 4 and 8 hours in a 24-hour cycle. Tear-blocking effects were minimal, as suggested by spiking of tears with recombinant lacritin.Anti-Pep Lac N-Term-detectable lacritin comprises ~4.2 ng/100 ng total tear protein in healthy individuals, with no significant differences between males and females or among individuals between 18 and 52 years old. Levels decrease slightly in the late afternoon. These findings provide a baseline for future immunodiagnostic studies of lacritin in dry eye and other ocular diseases.