Color Vision Loss Progression in IRD Patients: Retinal Structural Changes Correlations, and a Novel Color Discrimination Test for Extreme Low Vision Patients
This prospective, observational investigation seeks to delineate the interplay between chromatic vision deficits and both functional visual outcomes and anatomical retinal biomarkers in individuals affected by Inherited Retinal Dystrophies (IRDs). The study will recruit approximately 200 subjects, encompassing a heterogeneous population of IRD patients-spanning a range of genotypes and clinical severities-as well as control participants devoid of retinal pathology. All enrolled individuals will undergo a standardized battery of evaluations, including quantitative color vision assessment, best-corrected visual acuity (BCVA) determination, and advanced multimodal retinal imaging. The principal aim is to characterize the relationship between impairments in color discrimination and morphologic disruptions within the outer retinal layers, with particular emphasis on the continuity and reflectivity of the ellipsoid zone (EZ)-historically referred to as the inner segment/outer segment (IS/OS) junction-assessed through spectral-domain optical coherence tomography (SD-OCT). Further, the study will explore associations between chromatic perceptual deficits and underlying genetic mutations, mutation patterns specific to IRD subtypes, and the influence of patient age on the severity and progression of color vision loss. A key secondary objective is the clinical appraisal and validation of a novel diagnostic modality, the Moji Low-Vision Color Discrimination Test (Moji Test), which is specifically engineered to quantify residual color perception in individuals with advanced central visual impairment. The test's discriminatory capacity will be benchmarked against established color vision testing paradigms to assess its reliability, clinical sensitivity, and suitability for implementation in populations with severe visual acuity reduction. By incorporating a genetically and phenotypically diverse IRD cohort, the study is designed to enable granular, stratified analyses that will refine the understanding of structural-functional correlations in hereditary retinal disease. The inclusion of a control group with preserved retinal architecture and normal color vision function will provide essential normative baselines for comparative evaluation and statistical inference.
⁃ Color Perception and Communication Ability Participants must have the ability to verbally identify or describe colors and test stimuli. This requires adequate cognitive and communicative capacity to understand instructions and respond appropriately during color vision testing.
⁃ Diagnosis of Inherited Retinal Dystrophy (IRD Group Only) Participants assigned to the IRD group must have a confirmed clinical diagnosis of an inherited retinal dystrophy
⁃ No Evidence of Inherited Retinal Disease (Control Group Only)
‣ Participants in the control group must have:
• No known history or clinical evidence of inherited retinal degeneration
• Normal retinal health or only non-retinal ocular conditions not affecting retinal function (e.g., mild cataract, corrected refractive error)
• Normal or expected-normal color vision