The ChromaTest, a digital color contrast sensitivity analyzer, for diabetic maculopathy: a pilot study

Roger Wong , Jaheed Khan , Temi Adewoyin , Sobha Sivaprasad , Geoffrey B Arden and Victor Chong

Retinal Research Unit, Ophthalmology Department, King's College Hospital NHS Trust, Denmark Hill, London SE5 9RS, UK

author email corresponding author email

BMC Ophthalmology 2008, 8:15doi:10.1186/1471-2415-8-15


Published:	17 August 2008

Abstract

Background

To assess the ability of the Chromatest in investigating diabetic maculopathy.

Method

Patients with Type 2 diabetes and no concurrent ocular pathology or previous laser photocoagulation were recruited. Visual acuities were assessed followed by colour contrast sensitivity testing of each eye using Chromatest. Dilated fundoscopy with slit lamp biomicroscopy with 78 D lens was then performed to confirm the stage of diabetic retinopathy according to the Early Treatment Diabetic Retinopathy Study.

Results

150 eyes in 150 patients were recruited into this study. 35 eyes with no previous laser photocoagulation were shown to have clinically significant macular oedema (CSMO) and 115 eyes with untreated non-proliferative diabetic retinopathy (NPDR) on fundus biomicroscopy. Statistical significant difference was found between CSMO and NPDR eyes for protan colour contrast threshold (p = 0.01). Statistical significance was found between CSMO and NPDR eyes for tritan colour contrast threshold (p = 0.0002). Sensitivity and specificity for screening of CSMO using pass-fail criterion for age matched TCCT results achieved 71% (95% confidence interval: 53–85%) and 70% (95% confidence interval: 60–78%), respectively. However, threshold levels were derived using the same data set for both training and testing the effectiveness since this was the first study of NPDR using the Chromatest

Conclusion

The ChromaTest is a simple, cheap, easy to use, and quick test for colour contrast sensitivity. This study did not achieve results to justify use of the Chromatest for screening, but it reinforced the changes seen in tritan colour vision in diabetic retinopathy.