Correlations between the Michigan Retinal Degeneration Questionnaire and visual function parameters in patients with retinitis pigmentosa

Abstract

PurposeTo validate the use of best‐corrected visual acuity (BCVA), low‐luminance visual acuity (LLVA), low‐luminance deficit (LLD; the difference between BCVA and LLVA), mean macular sensitivity and fixation stability as parameters of vision‐related quality of life based on the novel Michigan Retinal Degeneration Questionnaire (MRDQ) in retinitis pigmentosa (RP) patients.MethodsIn this prospective cross sectional study, 30 patients with RP (47% female) were included with a median age of 41.0 years (interquartile range: 24.1–58.3 years). BCVA, LLVA and LLD were measured with Early Treatment Diabetic Retinopathy Study (ETDRS) charts. Mesopic microperimetry was performed to measure mean macular sensitivity and fixation stability. Patients completed a Dutch translation of the MRDQ which results in an experienced disability (Θ‐)score of seven domains. Spearman's rank correlation was used.ResultsBCVA correlated significantly to the MRDQ domain of central vision (r = 0.657; p < 0.001) and colour vision (r = 0.524; p = 0.003). Lower LLVA significantly correlated to higher experienced disability in the MRDQ domains for central vision (=0.550; p = 0.002) and contrast sensitivity (r = 0.502; p = 0.005). LLD was significantly correlated to the MRDQ domains of scotopic function (r = −0.484; p = 0.007) and mesopic peripheral function (r = −0.533; p = 0.002). Lower mean macular sensitivity was significantly associated with high experienced disability in all domains except for photosensitivity.ConclusionsThe majority of the MRDQ domains is strongly associated with visual function parameters. These findings show that visual function measurements, especially LLVA, LLD and mean macular sensitivity on microperimetry, reflect vision‐related quality of life and can be used as relevant outcome measures in clinical trials for RP.

Exploring self-reported visual function and vision-related anxiety in patients with RPGR-associated retinal degeneration

“…The MRDQ and MVAQ were developed using item response theory, factor analysis, and graded response models 3 , 13 . MRDQ measures the impact of visual impairment in daily tasks, containing 59 Likert-scaled question items across seven different dimensions: central vision, color vision, contrast sensitivity, scotopic function, photopic peripheral vision, mesopic peripheral vision, and photosensitivity 3 , 15 .…”

“…Retinitis pigmentosa (RP) encompasses a diverse group of inherited retinal disorders characterized initially by night blindness and visual field constriction due to the loss of rod photoreceptors 1 – 3 . As the disease progresses, cone photoreceptors deteriorate, typically resulting in the loss of color vision, contrast sensitivity, and central vision 1 – 3 .…”

“…Retinitis pigmentosa (RP) encompasses a diverse group of inherited retinal disorders characterized initially by night blindness and visual field constriction due to the loss of rod photoreceptors 1 – 3 . As the disease progresses, cone photoreceptors deteriorate, typically resulting in the loss of color vision, contrast sensitivity, and central vision 1 – 3 . Retinitis pigmentosa stands as the most prevalent inherited retinal disease (IRD) globally, affecting an estimated 1 in 4000 individuals, and X-linked retinitis pigmentosa (XLRP) accounts for 5–15% of all cases 2 , 4 .…”

“…X-linked RP imposes a particularly heavy humanistic, economic and emotional burden due to its early onset and rapid progression to blindness 12 . Patient-reported outcome (PRO) measures play a crucial role in assessing treatment efficacy and understanding its association with patient-perceived treatment benefits in a standardized manner 3 , 15 , 16 . These clinical outcome assessments convey the patient’s viewpoint on the disease’s impact on their life, and which aspects of visual dysfunction affect their emotional well-being 15 , 16 .…”

“…The Michigan Retinal Degeneration Questionnaire (MRDQ) and the Michigan Vision-related Anxiety Questionnaire (MVAQ) are two psychometrically validated PRO measures specifically developed for IRD patients, which were translated and linguistically validated for usage in Portuguese-speaking countries 17 . The MRDQ captures subjective disability across several domains representative of physiological visual function pathways 3 , 15 . Meanwhile, the MVAQ provides insight into vision-related anxiety, assessing the contributions of both cone and rod systems separately 16 .…”