Color Vision in Blue Cone Monochromacy: Outcome Measures for a Clinical Trial

Purpose: Blue cone monochromacy (BCM) is an X-linked retinopathy due to mutations in the OPN1LW/OPN1MW gene cluster. Symptoms include reduced visual acuity and disturbed color vision. We studied BCM color vision to determine outcome measures for future clinical trials.Methods: Patients with BCM and normal-vision participants were examined with Farnsworth-Munsell (FM) arrangement tests and the Color Assessment and Diagno-sis (CAD) test. A retrospective case series in 36 patients with BCM (ages 6-70) was performed with the FM D-15 test. A subset of six patients also had Roth-28 Hue and CAD tests.Results: All patients with BCM had abnormal results for D-15, Roth-28, and CAD tests. With D-15, there was protan-deutan confusion and no bimodal tendency. Roth-28 results reinforced that finding. There was symmetry in color vision metrics between the two eyes and coherence between sessions with the arrangement tests and CAD. Severe abnormalities in red-green sensitivity with CAD were expected. Unexpected were differ-ent levels of yellow-blue results with two patterns of abnormal thresholds: moderate elevation in two younger patients and severe elevation in four patients >= 35 years. Coeffi-cients of repeatability and intersession means were tabulated for all test modalities.Conclusions: Given understanding of advantages, disadvantages, and complexities of interpretation of results, both an arrangement test and CAD should be useful monitors of color vision through a clinical trial in BCM.Translational Relevance: Our pilot studies in BCM of arrangement and CAD tests indicated both were clinically feasible and interpretable in the context of this cone gene disease.

Automated summary

The purpose of this study was to determine outcome measures for future clinical trials in Blue cone monochromacy (BCM) by studying BCM color vision. The results showed that both the Farnsworth-Munsell arrangement test and the Color Assessment and Diagnosis (CAD) test were useful monitors of color vision through a clinical trial in BCM. The study also identified different levels of yellow-blue results and severe abnormalities in red-green sensitivity in BCM patients.