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Objective We sought to construct and validate a patient-reported outcome measure for screening and monitoring vision-related anxiety in patients with inherited retinal degenerations. Design Item-response theory and graded response modeling to quantitatively validate questionnaire items generated from qualitative interviews and patient feedback. Methods Patients at the Kellogg Eye Center (University of Michigan, Ann Arbor, Michigan, USA) with a clinical diagnosis of an inherited retinal degeneration (n = 128) participated in an interviewer-administered questionnaire. The questionnaire consisted of 166 items, 26 of which pertained to concepts of “worry” and “anxiety.” The subset of vision-related anxiety questions was analyzed by a graded response model using the Cai Metropolis–Hastings Robbins–Monro algorithm in the R software mirt package. Item reduction was performed based on item fit, item information, and item discriminability. To assess test–retest variability, 25 participants completed the questionnaire a second time 4 to 16 days later. Results The final questionnaire consisted of 14 items divided into 2 unidimensional domains: rod function anxiety and cone function anxiety. The questionnaire exhibited convergent validity with the Patient Health Questionnaire for symptoms of depression and anxiety. This vision-related anxiety questionnaire has high marginal reliability (0.81 for rod-function anxiety, 0.83 for cone-function anxiety) and exhibits minimal test–retest variability (ρ = 0.81 [0.64-0.91] for rod-function anxiety and ρ = 0.83 [0.68-0.92] for cone-function anxiety). Conclusions The Michigan Vision-Related Anxiety Questionnaire is a psychometrically validated 14-item patient-reported outcome measure to be used as a psychosocial screening and monitoring tool for patients with inherited retinal degenerations. It can be used in therapeutic clinical trials for measuring the benefit of an investigational therapy on a patient's vision-related anxiety.

Purpose To create a psychometrically validated patient-reported outcome measure for inherited retinal degenerations. Design Qualitative and quantitative patient-reported outcome (PROs) questionnaire development using item response theory validation. Methods One hundred twenty-eight patients with a diagnosis of an inherited retinal degeneration at the Kellogg Eye Center (University of Michigan) were recruited and administered a 166-item questionnaire comprising 7 expert-defined domains. The questionnaire was re-administered 4-16 days later to a subset of 25 participants to assess test-retest variability. Graded response models were fit by Cai's Metropolis-Hastings Robbins-Monro algorithm using the R (version 3.6.3) package mirt. Model data were fit to assess questionnaire dimensionality, to estimate item information, and to score participants. Poorly functioning items were removed, and the model was refit to create the final questionnaire. Results The psychometrically validated PROs measure was reduced to a 59-item questionnaire measuring 7 unidimesnional domains: central vision, color vision, contrast sensitivity, scotopic function, photopic peripheral vision, mesopic peripheral vision, and photosensitivity. A total of 39 items were removed because of poor factor loading, low item information, poor person-ability differentiation, or high item-level interdependence. This novel questionnaire produces a reliable domain score for person ability that does not show significant test-retest variability across repeated administration. Conclusions The final PRO questionnaire, known as the Michigan Retinal Degeneration Questionnaire, is psychometrically validated and available for use in the evaluation of patients with inherited retinal degenerations.

Background Patients with retinal diseases frequently complain of poor visual function even when visual acuity is relatively unaffected. This clinical finding has been attributed to deficits in contrast sensitivity (CS). The purpose of our study was to evaluate the CS in patients with clinical and genetic diagnosis of inherited retinal degeneration (IRD) and relatively preserved visual acuity. Methods Seventeen patients (30 eyes) with IRD and visual acuity of 20/40 or better, and 18 controls (18 eyes) without any ocular condition underwent slit lamp examination, visual acuity testing via standard Snellen chart testing, CS testing via the Quick Contrast Sensitivity Function (QCSF), and Spectral Domain Optical Coherence Tomography (SD-OCT). CS were measured at 1.0, 1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree (cpd). T tests with general estimated equations were used to compare CS between groups. Wald chi square followed by pairwise comparisons was used to compare CS between multiple groups. Results We included 12 patients with rod-cone dystrophy (RCD), 3 patients with Stargardt disease (STGD) and 2 patients with Best disease. Patients with IRD had significantly worse CS than controls (p