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.

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.

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.

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.].

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.

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.].

Goblet cell response after photorefractive keratectomy and laser in situ keratomileusis.

PURPOSE: 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. SETTING: The former Walter Reed Army Medical Center, Washington, DC, USA. DESIGN: Prospective nonrandomized clinical study. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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. FINANCIAL DISCLOSURE: None of the authors has a financial or proprietary interest in any material or method mentioned.

Sutureless cryopreserved amniotic membrane graft and wound healing after photorefractive keratectomy.

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.

Wavefront-optimized surface retreatments of refractive error following previous laser refractive surgery: a retrospective study.

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.

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.

Chronic dry eye in photorefractive keratectomy and laser in situ keratomileusis: Manifestations, incidence, and predictive factors.

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.

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.

Residency training in refractive surgery.

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.

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.

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.

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

Photorefractive keratectomy in posterior polymorphous dystrophy with vesicular and band subtypes.

PURPOSE: To evaluate the safety and efficacy of photorefractive keratectomy (PRK) in patients with posterior polymorphous dystrophy (PPMD) with vesicular and band subtypes. SETTING: Walter Reed Center for Refractive Surgery, Washington, DC, USA. DESIGN: Case series. METHODS: The records of patients with PPMD who had PRK between January 2002 and May 2009 were reviewed. Data for analysis included sex, age, ablation depth, residual stromal bed thickness, manifest spherical equivalent, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, central corneal thickness (CCT), endothelial cell density (ECD), intraocular pressure (IOP), and complications. Preoperative and postoperative results were compared using the Wilcoxon signed-rank test, with P < .05 considered significant. RESULTS: Fourteen eyes of 7 men (mean age 29.1 years ± 9.1 [SD]; range 21 to 42 years) with at least a 6-month follow-up were reviewed. At the final follow-up (mean 19.5 months; range 6.3 to 58.3 months), all eyes had a UDVA of 20/15 and all eyes were within ± 0.50 diopter of emmetropia. The CDVA was unchanged from preoperatively in 71.4% of eyes and improved by 1 line in 28.6%. There were no significant complications. The IOP did not change significantly over the follow-up (P = .272). At the final visit, the mean ECD (2795.3 ± 366.0 cells/mm(2)) was unchanged from baseline (2809.1 ± 338.3 cells/mm(2)) (P = .114). CONCLUSIONS: Photorefractive keratectomy in PPMD patients with vesicular and band subtypes resulted in excellent visual outcomes and a low incidence of adverse effects. Endothelial cell densities did not change significantly in the early postoperative period. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.