Purpose: The aim of this study was to evaluate the psychometric properties of the Keratoconus Outcomes Research Questionnaire (KORQ) in patients enrolled in the Save Sight Keratoconus Registry. Methods: A cross-sectional study was conducted utilizing prospectively collected web-based registry data. The psychometric properties of the KORQ were assessed using both classical test theory and Rasch analysis. Andrich group rating scale variant of the Rasch analysis was conducted using Winsteps software, Version 3.92.1. Results: The KORQ was completed by 189 patients with keratoconus (men, 67.7%; white, 69.8%; median age 29 years; better eye median values: visual acuity, 75 LogMAR letters; Kmax, 51.3 D; K2, 46.5 D; thinnest pachymetry, 485 μm). Cronbach's α for the “Activity Limitation” and “Symptoms” scales were 0.95 and 0.91, respectively, with both scales free from floor or ceiling effects. On Rasch analysis, the category thresholds were ordered and well-spaced for both scales. The Activity Limitation scale had excellent psychometric properties including person separation index (3.6), unidimensionality (variance explained, 65.4%), fit statistics (<1.3 MnSq), and measurement range (3.6 logits). Similarly, the Symptoms scale had satisfactory psychometric properties including person separation index (2.5), unidimensionality (variance explained, 54.3%), fit statistics (<1.30 MnSq except for 1 item), and measurement range (2.0 logits). Both scales were well targeted to the population and free of differential item functioning. Conclusions: The KORQ is a psychometrically robust patient-reported outcome measure for evaluating quality of life parameters in keratoconus. It enables routine collection and monitoring of meaningful patient-reported outcome data in clinical settings, including registries.

The purpose of this study was to review published data on donor characteristics and the influence on preoperative Descemet membrane endothelial keratoplasty (DMEK) preparation and intraoperative graft manipulation.Methods: A systematic review of PubMed, EMBASE, OVID MEDLINE, and EBSCOhost was conducted up to April 2020. Studies were screened and predefined data criteria extracted. Eleven studies were found to meet the inclusion criteria.Results: Research regarding donor characteristics and the relationship to DMEK graft preparation and intraoperative graft manipulation was found to be limited because of the overall low-quality data. However, there was a trend of evidence supporting donor diabetes increasing the risk of graft tearing and consequent preparation failure and younger donors producing tighter scrolls complicating intraoperative graft unfolding.Conclusions: Further research into the area is warranted to better understand how donor characteristics impact preoperative DMEK graft preparation and intraoperative graft manipulation.

Purpose:The aim of this study was to evaluate the quality-of-life (QoL) status in keratoconus severity subgroups using the Keratoconus Outcomes Research Questionnaire (KORQ) and to determine the relationship between the QoL scores and the standard clinical variables.Methods:A cross-sectional study was conducted using prospective, web-based Save Sight Keratoconus Registry data. Rasch analysis was conducted on the KORQ data using the Andrich Rating Scale Model. Comparative analysis included Welch t test and 1-way ANOVA. Associations between visual acuity, corneal curvature, and minimum corneal thickness with KORQ scores were evaluated with Pearson correlation and multiple regression adjusted for age and sex.Results:The KORQ was completed by 542 patients with keratoconus (male, 67.7%; mean age, 31.6 years). Keratoconus severity, based on Kmax, was mild [<48 diopter (D)], moderate (48–55 D), and severe (>55 D) in 26.3%, 45.0%, and 28.7% of patients, respectively. Activity limitation (AL) and symptoms (SY) scales of the KORQ had robust psychometric properties including well-functioning response categories, unidimensionality, excellent measurement precision, and satisfactory fit statistics. In a group-wise analysis, the female patients had significantly lower AL and SY scores. Similarly, the severe keratoconus group had the worst AL and SY scores. Contact lens wearers had worse KORQ scores than the spectacles wearers. Overall, statistically significant but weak correlations between KORQ scores and visual acuity and corneal curvature (Kmax and K2) (Pearson r, 0.11–0.35) were observed. The correlations for SY were weaker than for AL scores.Conclusions:Female sex, contact lens wear, reduced visual acuity, and higher disease severity were associated with worse AL and SY scores in keratoconus. Although the correlations between clinical and QoL scores were statistically significant, the low magnitudes suggested a complex relationship between clinical parameters and patient-reported outcomes.