Abstract
Abstract: :
Purpose:The debilitating nature of untreated diabetic retinopathy promotes the need for cost–effective screening methods. Stereomacular color fundus photographs and fluorescein angiography are difficult to obtain and relatively expensive tools for diabetic screening. Non–stereo fundus imaging is easier to obtain but have limitations in establishing macular edema. There is evidence that tritan color vision is diminished in patients with diabetic maculopathy, but testing with traditional methods such as the FM100 hue and Farnsworth–Lanthony D–15 test are cumbersome and labor intensive. This study assesses the ability of an automated, digital color contrast sensitivity program in investigating diabetic maculopathy. Method: One hundred fifty consecutive known diabetic patients were recruited for this study. Visual acuities were assessed followed by color contrast sensitivity testing of each eye using the diabetic module of ChromaTest, a software program analyzing the age–corrected tritan and protan color contrast thresholds. Each test for both eyes lasted for about 5 minutes. Dilated fundoscopy with slit lamp biomicroscopy was then performed to confirm the staging of diabetic maculopathy according to the Early Treatment Diabetic Retinopathy Study for each patient. Results: Three hundred eyes were included in the study. Average LogMar visual acuity was 0.21 (Snellen equvialent 20/32). Twenty two eyes were shown to have clinically significant macular edema (CSME) and one hundred fifteen eyes with previously untreated non–proliferative diabetic retinopathy (NPDR) on fundus biomicroscopy. Non–parametric student t–test analysis showed statistical significance for difference of color contrast thresholds (ie. Tritan – Protan Color Contrast Thresholds) between CSME and NPDR eyes (p=0.042). Conclusion: The ChromaTest is a simple, relatively cheap, easy to use, and quick test for color contrast sensitivity in diabetic maculopathy. As it can potentially distinguish between sight threatening diabetic maculopathy with CSME from NPDR, it might be useful as a second level screening tool for those units using non–stereo fundus imaging for diabetic retinopathy screening.
Keywords: diabetic retinopathy • color vision • macula/fovea