title: The ChromaTest, a digital color contrast sensitivity analyzer, for diabetic maculopathy: a pilot study.
abstract: BACKGROUND
  To assess the ability of the Chromatest in investigating diabetic maculopathy.
  
  
  METHODS
  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
  
  
  CONCLUSIONS
  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.
authors.affiliation: Ophthalmology Department, Retinal Research Unit, King's College Hospital NHS Trust, Denmark Hill, London, UK. drrogerwong@gmail.com
authors.forename: Roger
authors.initials: R
authors.lastname: Wong
authors.forename: Jaheed
authors.initials: J
authors.lastname: Khan
authors.forename: Temi
authors.initials: T
authors.lastname: Adewoyin
authors.forename: Sobha
authors.initials: S
authors.lastname: Sivaprasad
authors.forename: Geoffrey B
authors.initials: GB
authors.lastname: Arden
authors.forename: Victor
authors.initials: V
authors.lastname: Chong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001331:Automation; D003118:Color Perception; D015350:Contrast Sensitivity; D003930:Diabetic Retinopathy / Q000175:diagnosis* / Q000503:physiopathology*; D003936:Diagnosis, Computer-Assisted; D005654:Fundus Oculi; D006801:Humans; D008269:Macular Edema / Q000175:diagnosis* / Q000503:physiopathology*; D008875:Middle Aged; D010865:Pilot Projects; D012680:Sensitivity and Specificity; D015351:Vision Screening / Q000379:methods* / Q000592:standards; D014792:Visual Acuity