Lacritin proteoforms prevent tear film collapse and maintain epithelial homeostasis.

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.

A cleavage-potentiated fragment of tear lacritin is bactericidal.

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.

Polymorphism in THBS1 gene is associated with post-refractive surgery chronic ocular surface inflammation.

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-1ß (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.

The U.S. Army Surface Ablation Study: comparison of PRK, MMC-PRK, and LASEK in moderate to high myopia.

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.

Visual outcomes after Epi-LASIK and PRK for low and moderate myopia.

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<.001), and 12 months (75.9% vs 61.9%, 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.

Alcohol versus brush PRK: visual outcomes and adverse effects.

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.

Risk Factors for Failure of Final Anatomic Surgical Reattachment in Retinal Detachments From Combat Ocular Trauma.

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.].

Correlative Factors for Traumatic Brain Injury in Combat Ocular Trauma.

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.

The Impact of Combat Ocular Trauma and Traumatic Brain Injury on Vision- and Health-Related Quality of Life Among U.S. Military Casualties.

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.

Visual and IOP outcomes after PRK in pigment dispersion syndrome.

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

Comparison of Simulation-Based versus Cadaveric-Tissue-Based Ocular Trauma Training on Novice Ophthalmologists: Repair of Corneal Laceration Model.

Purpose The aim of this study was to evaluate whether the simulated tissue models may be used in place of animal-based model for corneal laceration repair for surgical skills acquisition. Design Prospective randomized controlled trial. Participants Seventy-nine military and civilian 2nd- and 3rd-year ophthalmology residents and 16 staff ophthalmologists participating in the Tri-Service Ocular Trauma Skills Laboratory at the Uniformed Services University (Bethesda, MD). Methods Resident ophthalmologists underwent preliminary evaluation of their ability to close a 5-mm linear, full-thickness corneal laceration involving the visual axis. They then were randomized to undergo 90 to 120 minutes of either simulator-based (SIM) or swine cadaveric-tissue-based (CADAVER) corneal laceration repair. The same evaluation was performed post training. On a more limited basis, the study was repeated for attending ophthalmologists to act as a pilot for future analysis and test efficacy for "refresher" training. Main Outcome Measures Successful wound closure with secondary outcomes of suture length, tension, depth, and orientation, as graded by attending ophthalmologists. Results No significant difference in CADAVER versus SIM groups in the primary outcome of watertight wound closure of the corneal laceration. CADAVER group performed better than SIM group for certain metrics (suture depth, p = 0.009; length, p = 0.003; and tension, p = 0.043) that are associated with poor wound closure and increased amount of induced corneal astigmatism. For attending ophthalmologists, six of the eight in each group (SIM and CADAVER) retained or improved their skills. Conclusions For resident ophthalmologists, SIM training is sufficient for achieving the primary outcome of watertight wound closure. However, CADAVER training is superior for wound metrics for the ideal closure. For attending ophthalmologists, SIM training may be useful for retention of skills.

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.

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.

Assessment of Corneal Haze After PRK and the Effect of Sutureless Amniotic Membrane Graft by Corneal Densitometry.

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.].

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.

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: Visual and Military Task Performance.

PURPOSE: To compare visual performance, marksmanship performance, and threshold target identification following wavefront-guided (WFG) versus wavefront-optimized (WFO) photorefractive keratectomy (PRK). METHODS: 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. RESULTS: 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. CONCLUSIONS: Both WFG and WFO PRK results translate to excellent and comparable visual and military performance.

Self-Reported Visual Quality of Life After Combat Ocular Trauma.

OBJECTIVES: To describe the visual outlook and quality of life of service members after combat ocular trauma. METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.