Nationwide epidemiological approach to identify associations between keratoconus and immune-mediated diseases.

Background: The aetiology of keratoconus (KC) remains poorly understood. KC has typically been described as a non-inflammatory disorder of the cornea. Nonetheless, there is increasing presumptive evidence for the role of the immune system in the pathogenesis of KC.

Parameters Associated With Endothelial Cell Density Variability After Descemet Membrane Endothelial Keratoplasty.

Purpose: To evaluate which parameters may affect endothelial cell loss after Descemet membrane endothelial keratoplasty (DMEK) by comparing eyes in the low vs high quartile of endothelial cell loss over a follow-up period of 4 years.

Design: Retrospective cohort study.

Methods: Donor endothelial cell density (ECD) decline was evaluated for 351 eyes of 275 patients up to 4 years after DMEK for Fuchs endothelial corneal dystrophy (FECD).

Clinical Outcome of Rebubbling for Graft Detachment After Descemet Membrane Endothelial Keratoplasty.

Purpose: To assess the clinical outcome after successful rebubbling procedures for visually significant graft detachment after Descemet membrane endothelial keratoplasty (DMEK).

Methods: From a total of 760 consecutive DMEK surgeries, 41 eyes required rebubbling. Of those, 33 eyes of 31 patients were successful and were included in our retrospective outcome analysis study.

Two-Year Clinical Outcome of 500 Consecutive Cases Undergoing Descemet Membrane Endothelial Keratoplasty.

Purpose: To evaluate the clinical outcome of 500 consecutive cases up to 2 years after Descemet membrane endothelial keratoplasty (DMEK) and to assess which parameters may have influenced the clinical outcome.

Methods: From a group of 500 eyes (393 patients), which underwent DMEK for Fuchs endothelial corneal dystrophy (FECD), bullous keratopathy, failed corneal transplants and other indications, clinical outcomes [best-corrected visual acuity (BCVA), central endothelial cell density (ECD), and central corneal thickness] were evaluated before, and at 6, 12, and 24 months after DMEK and postoperative complications were documented.

Results: At 12 months postoperatively, 81% of eyes reached a BCVA of ≥20/25 (≥0.

Association Between Graft Storage Time and Donor Age With Endothelial Cell Density and Graft Adherence After Descemet Membrane Endothelial Keratoplasty.

Importance: After retrospectively evaluating the clinical outcome of 500 consecutive cases after Descemet membrane endothelial keratoplasty (DMEK), we extended the analysis in this study by assessing the effect of donor-related parameters on endothelial cell density (ECD) decline and detachment rate in this group.

Observations: This retrospective case series included 500 cases who had undergone DMEK from October 2007 to September 2012 at the Netherlands Institute for Innovative Ocular Surgery (NIIOS), Rotterdam, the Netherlands. Logistic regression analysis (n = 332 eyes) showed that donor age might be associated with a 3% increase in the risk for a detachment (odds ratio, 0.

Endothelial Survival After Descemet Membrane Endothelial Keratoplasty: Effect of Surgical Indication and Graft Adherence Status.

Importance: This study evaluates the longevity of Descemet membrane endothelial keratoplasty (DMEK) grafts in terms of endothelial survival and endothelial failure.

Objective: To determine endothelial survival and its association with the indication for surgery and/or partial graft detachment in DMEK.

Design, Setting, And Participants: Retrospective cross-sectional study of data collected from August 8, 2006, until June 17, 2015, at a tertiary referral center.

Association of Childhood Complex Trauma and Dissociation With Complex Posttraumatic Stress Disorder Symptoms in Adulthood.

This study replicates and extends prior research on the relationship of childhood complex trauma (CCT) and complex posttraumatic stress disorder (cPTSD) in adulthood, examining the role of psychoform and somatoform dissociation as a potential mediator. CCT, dissociation, and cPTSD were assessed in a large sample of adult psychiatric inpatients. Almost two thirds of participants reported having experienced CCT.

Prevalence of use of performance enhancing drugs by fitness centre members.

Studies on the use of performance enhancing drugs (PED) in fitness centres rely predominately on conventional survey methods using direct questioning. However, research indicates that direct questioning of sensitive information is characterized by under-reporting. The aim of the present study was to contrast direct questioning of different types of PED use by Dutch fitness centre members with results obtained with the Randomized Response Technique (RRT).

Dual imputation model for incomplete longitudinal data.

Missing values are a practical issue in the analysis of longitudinal data. Multiple imputation (MI) is a well-known likelihood-based method that has optimal properties in terms of efficiency and consistency if the imputation model is correctly specified. Doubly robust (DR) weighing-based methods protect against misspecification bias if one of the models, but not necessarily both, for the data or the mechanism leading to missing data is correct.

Incidence of irregular astigmatism eligible for contact lens fitting after Descemet membrane endothelial keratoplasty.

Purpose: To evaluate the incidence and causes of anterior corneal surface irregularities after successful Descemet membrane endothelial keratoplasty (DMEK) and the efficacy of contact lens fitting in these cases.

Setting: Tertiary referral center.

Design: Retrospective study of prospectively collected data.

Outcomes of Descemet membrane endothelial keratoplasty in phakic eyes.

Purpose: To determine the clinical outcomes of isolated Descemet membrane transplantation (ie, Descemet membrane endothelial keratoplasty [DMEK]) in phakic eyes.

Setting: Tertiary referral center.

Design: Cohort study.

Towards an evidence-based treatment model for cognitive behavioral interventions focusing on chronic fatigue syndrome.

Objective: The purpose of the present study was to develop a treatment model for cognitive behavioral interventions focusing on chronic fatigue syndrome (CFS) based on the model of perpetuating factors introduced by Vercoulen et al. [Journal of Psychosomatic Research 1998;45:507-17].

Methods: For this purpose, we reanalyzed the data of a previously conducted randomized controlled trial in which a low intensity cognitive behavioral intervention was compared to a waiting list control group.

Prevention and management of graft detachment in descemet membrane endothelial keratoplasty.

Objective: To describe the prevention and management of various types of graft detachment after Descemet membrane endothelial keratoplasty.

Methods: In 150 consecutive eyes that underwent Descemet membrane endothelial keratoplasty, the incidence and type of graft detachment were studied at 1, 3, 6, 9, 12, and 24 months after surgery in a nonrandomized, prospective clinical study at a tertiary referral center. Four groups of detachments were identified: a partial detachment of one-third or less of the graft surface area (n = 16; group 1); a partial detachment of more than one-third of the graft surface area (n = 8; group 2); a graft positioned upside down (n = 4; group 3); and a free-floating Descemet roll in the host anterior chamber (n = 8; group 4).

Refractive change and stability after Descemet membrane endothelial keratoplasty. Effect of corneal dehydration-induced hyperopic shift on intraocular lens power calculation.

Purpose: To determine the refractive change and stability of the transplanted cornea after Descemet membrane endothelial keratoplasty (DMEK) through a 3.0 mm clear corneal incision.

Setting: Tertiary referral center.

Efficacy of descemet membrane endothelial keratoplasty: clinical outcome of 200 consecutive cases after a learning curve of 25 cases.

Objective: To evaluate Descemet membrane endothelial keratoplasty for management of corneal endothelial disorders.

Methods: Descemet membrane endothelial keratoplasty was performed in 200 patients with Fuchs endothelial dystrophy or bullous keratopathy. Best-corrected visual acuity, subjective and objective refractive outcome and stability, and endothelial cell density were evaluated at 1, 3, and 6 months postoperatively, and intraoperative and postoperative complications were documented.

Patterns of corneal endothelialization and corneal clearance after descemet membrane endothelial keratoplasty for fuchs endothelial dystrophy.

Purpose: To describe various endothelial migration healing patterns after Descemet membrane endothelial keratoplasty (DMEK), and to determine the contribution of the donor and host endothelium in the clearance of a transplanted cornea.

Design: Nonrandomized, prospective clinical study.

Methods: In a total of 150 consecutive eyes that underwent DMEK (ie, transplantation of an isolated Descemet graft, for Fuchs endothelial dystrophy), re-endothelialization patterns were studied.

Feature selection in feature network models: finding predictive subsets of features with the Positive Lasso.

A set of features is the basis for the network representation of proximity data achieved by feature network models (FNMs). Features are binary variables that characterize the objects in an experiment, with some measure of proximity as response variable. Sometimes features are provided by theory and play an important role in the construction of the experimental conditions.

Estimating standard errors in feature network models.

Feature network models are graphical structures that represent proximity data in a discrete space while using the same formalism that is the basis of least squares methods employed in multidimensional scaling. Existing methods to derive a network model from empirical data only give the best-fitting network and yield no standard errors for the parameter estimates. The additivity properties of networks make it possible to consider the model as a univariate (multiple) linear regression problem with positivity restrictions on the parameters.

Effects of Group Size and Lack of Sphericity on the Recovery of Clusters in K-means Cluster Analysis.

K-means cluster analysis is known for its tendency to produce spherical and equally sized clusters. To assess the magnitude of these effects, a simulation study was conducted, in which populations were created with varying departures from sphericity and group sizes. An analysis of the recovery of clusters in the samples taken from these populations showed a significant effect of lack of sphericity and group size.