Detection of colour vision changes in patients with systemic diseases that can affect the eye

Abstract

AbstractPurpose Changes in colour vision can provide the earliest signs of vision loss caused by either retinal or systemic disease (Expert Rev.Ophthalmol. 6(4):409‐420,2011). Both yellow‐blue (YB) and red‐green (RG) mechanisms are affected in acquired deficiency, but some diseases may cause different patterns of colour vision loss. Patients with different systemic diseases were examined to discover abnormal changes in colour vision using a newly developed, age‐corrected system for colour assessment.Methods 334 subjects (age range: 41 to 91years) were investigated. The subjects were classified as normal, hypertensive, diabetic, diabetic and hypertensive, idiopathic and other systemic conditions. RG and YB colour thresholds were measured monocularly in each eye using the Colour Assessment and Diagnosis (CAD) test.Results Subjects with early stage pathology were excluded using a number of criteria including the discovery of right / left eye asymmetric loss in colour sensitivity. Age‐corrected limits of normal colour vision were employed to detect significant changes in chromatic sensitivity. The results reveal significantly higher RG and YB thresholds in all groups (including the idiopathic and other systemic conditions group).Conclusion The use of age‐corrected normal limits of chromatic sensitivity makes it possible to detect reliably significant loss of colour vision in systemic disease. Loss of chromatic sensitivity that precedes retinopathy is present in every systemic condition examined. Further studies are needed to discover the extent to which the pattern of selective RG and YB losses can be attributed to specific diseases of the eye.