32 research outputs found

    Clinical and Epidemiologic Research Case-Control Pilot Study of Soft Contact Lens Wearers With Corneal Infiltrative Events and Healthy Controls

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    PURPOSE. The purpose of this study was to assess risk factors associated with soft contact lens (SCL)-related corneal infiltrative events (CIEs). METHODS. This was a single-visit, case-control study conducted at five academic centers in North America. Cases were defined as current SCL wearers with a symptomatic CIE. For each case, three age-and sex-matched controls were enrolled. Subjects completed the Contact Lens Risk Survey (CLRS), a standardized scripted medical interview, supplied a recent health history, and underwent an ocular examination. Microbial culturing of the ocular surface, SCL, and lens storage case was conducted for all cases and one of the three matched controls. Univariate and multivariate logistic regression modeling were used to assess the risk of developing a CIE. RESULTS. Thirty cases and 90 controls 13 to 31 years of age completed the study. Corneal infiltrative event diagnosis included contact lens-associated red eye, infiltrative keratitis, and contact lens peripheral ulcer. Subjects with symptomatic CIEs were more likely to harbor substantial levels of gram-negative bioburden on the ocular surface and contact lens. Significant risk factors for developing a CIE were overnight wear of SCLs, use of multipurpose solution, rinsing SCLs with water, lens storage case older than 6 months, previous ''red eye'' event, use of ocular drops in the past week, and illness during the past week. CONCLUSIONS. This pilot study demonstrated feasibility of enrolling a representative pool of SCL wearers with an untreated, symptomatic CIE and assessing CIE risk factors by using standardized methods. A larger sample size is needed to determine relationships between patient-reported behaviors and exposures, microbial bioburden, and CIE development. Keywords: adverse events, contact lenses, corneal infiltrative events, microbial culturing A recent report from the US Centers for Disease Control and Prevention (CDC) called to light the substantial burden associated with contact lens-related complications. 1 The CDC report estimated that contact lens-related keratitis results in nearly 1 million doctor visits each year and carries an associated cost of $175 million. 1 This estimate does not include the additional ''costs'' to the patient such as pain or discomfort, missed school or work, and potential for permanent loss of vision. Approximately 37 million people in the United States currently wear contact lenses and, due to the increasing prevalence of myopia, more and younger patients are expected to begin wearing contact lenses to aid in its management

    A multi-ethnic genome-wide association study implicates collagen matrix integrity and cell differentiation pathways in keratoconus

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    Keratoconus is characterised by reduced rigidity of the cornea with distortion and focal thinning that causes blurred vision, however, the pathogenetic mechanisms are unknown. It can lead to severe visual morbidity in children and young adults and is a common indication for corneal transplantation worldwide. Here we report the first large scale genome-wide association study of keratoconus including 4,669 cases and 116,547 controls. We have identified significant association with 36 genomic loci that, for the first time, implicate both dysregulation of corneal collagen matrix integrity and cell differentiation pathways as primary disease-causing mechanisms. The results also suggest pleiotropy, with some disease mechanisms shared with other corneal diseases, such as Fuchs endothelial corneal dystrophy. The common variants associated with keratoconus explain 12.5% of the genetic variance, which shows potential for the future development of a diagnostic test to detect susceptibility to disease

    Random Survival Forests Analysis of Intraoperative Complications as Predictors of Descemet Stripping Automated Endothelial Keratoplasty Graft Failure in the Cornea Preservation Time Study

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    A new analytic method can evaluate factors of interest associated with graft failure after Descemet stripping automated endothelial keratoplasty (DSAEK) or more generally in any ophthalmic surgical setting with a time-to-event outcome. To reanalyze types of intraoperative complications associated with DSAEK graft failure in the Cornea Preservation Time Study using random survival forests. This cohort study, initially conceived in April 2019, used a prediction model to conduct a post hoc secondary analysis of data collected in a multicenter, double-masked, randomized clinical trial. Forty US clinical sites with 70 surgeons participated, with donor corneas provided by 23 US eye banks. The study included 1090 participants, representing 1330 eyes, undergoing DSAEK for Fuchs dystrophy (1255 eyes [94.4%]) or pseudophakic or aphakic corneal edema (75 eyes [5.6%]). Enrollment occurred between April 16, 2012, and February 20, 2014, and follow-up ended June 5, 2017. Statistical analysis was performed from July 10, 2019, to May 29, 2020. Descemet stripping automated endothelial keratoplasty with random assignment of a donor cornea with preservation time of 7 days or less or 8 to 14 days. Ranked variable importance for intraoperative complications among 50 donor, recipient, and eye bank variables and restricted mean survival time through 47 months (1434 days) after DSAEK were examined. Random survival forests, a nonparametric method (with less restrictive model assumptions) that is far more flexible in its ability to model nonlinear effects and interactions, was used to analyze the data. This study included 1090 participants (663 women [60.8%]; median age, 70 years [range, 42-90 years]), representing 1330 eyes. Random survival forests ranked a DSAEK intraoperative complication as the third most predictive factor of graft failure, after surgeon and eye bank, in the final model with 5 predictors. In the first 47 months after DSAEK, the estimated mean difference in restricted mean survival time for grafts that experienced a DSAEK intraoperative complication vs those that did not was -227 days (99% CI, -352 to -70 days) based on the final RSF model. These findings, while post hoc, support the hypothesis that random survival forests allow for an improved analytic approach for identifying factors predictive of graft failure and for obtaining adjusted graft survival estimates. Random survival forests offer the opportunity to guide the development of future population-based cohort ophthalmic surgical studies, establishing definitive factors for procedural success

    Phototherapy-related ophthalmologic disorders

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    Phototherapy is an effective treatment option for a variety of dermatologic disorders, and the list of indications for its use continues to grow with advances in technology and our understanding of disease processes. Commonly used types of phototherapy include PUVA, broadband UVB, narrowband UVB, photodynamic therapy, and intense pulsed light therapy. Each therapeutic modality can have adverse acute and chronic effects on periocular and ocular structures, including the conjunctiva, cornea, crystalline lens, and retina. There are many types of protective eyewear options available, including goggles and contact lenses that can be used to prevent damage to ocular structures during phototherapy, particularly if eyelid closure is incomplete

    A Murine Model of Contact Lens–Associated Fusarium Keratitis

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    The 2006 outbreak of contact lens–associated Fusarium keratitis resulted in more than 300 cases in the United States in which a commercial lens care product was implicated. In the current study, Fusarium grown as biofilm on silicone hydrogel lenses induced keratitis in a murine model and severity of disease and survival of the organisms were dependent on MyD88, IL-1R1, and TLR4

    Repeatability of Corneal Topography Measurement in Keratoconus with the TMS-1

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    Purpose. The purpose of this study was to report the test–retest variability of simulated indices derived from the TMS-1 topography instrument (Tomey Technology, Waltham, MA) in keratoconus subjects enrolled in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study. Methods. Four images were taken at an initial visit and at a repeat visit several weeks later. From these images, 17 indices were simulated from published formulas. Mixed-model analysis was used on test–retest data from the TMS-1 videokeratography instrument during the baseline year. This analysis yields estimates of within- and between-visit variability. Results. Repeatability analysis revealed that within-visit standard errors were 1.0 to 5.9 times greater in keratoconus eyes than in normal controls when two images were analyzed from each visit. These values changed only slightly when more images were used. The ratio of between-visit standard errors of the indices were nearly equally greater than normal controls for (0.9 – 4.6 and 0.9 – 4.3) two images per eye and all images per eye, respectively. Conclusions. These results suggest that the repeatability of simulated indices derived from TMS-1 topography in keratoconus subjects is poorer than in normal controls
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