A study has demonstrated that colour contrast sensitivity differences exist in patients with early to advanced age-related macular degeneration, which makes colour contrast sensitivity testing a useful clinical adjunctive tool when identifying AMD and detecting disease severity.
The study, published in BMJ Open Ophthalmology, enrolled 85 participants (a total of 144 eyes) from multiple clinical practices. Participants were divided into three groups: the control group comprising 57 healthy eyes, the nonexudative AMD (NE-AMD) group comprising 45 eyes and the exudative AMD (E-AMD) group, comprising 42 eyes.
As a base-line, they recorded monocular bestcorrected visual acuity for each eye at 40 cm with 100% black contrast. This was compared against the number of letters correctly identified (out of 10) for various colour presentations (red, green, blue and yellow) and at decreasing contrast levels (100%, 75%, 50% and 25%), using the King-Devick Variable Colour Contrast Sensitivity Chart. The researchers reported worse visual performance under various colour contrast settings in E-AMD patients compared with healthy controls and NE-AMD patients. Colour contrast performance using blue and yellow differentiated more advanced stages of disease in E-AMD from earlier NE-AMD disease. Blue and black colour contrast performance more accurately identified the E-AMD group from healthy controls and the NE-AMD group.
They concluded that colour contrast, particularly with black, blue and yellow, is impaired in E-AMD suggesting the potential for colour contrast measures to serve as an adjunctive clinical tool in identifying subtle altered visual function as well as the potential for detecting disease severity.
- Ittiara Shaun, Hariprasad Anya S, Messner Leonard V, Tresley David J, Leong Danielle, Schechet Sidney A. Use of the King- Devick Variable Color Contrast Sensitivity Chart to differentiate stages of age-related macular degeneration. BMJ Open Ophthalmology. bmjophth.bmj.com/content/5/1/e000451