title: Classification of Farnsworth-Munsell 100-hue test results in the early treatment diabetic retinopathy study.
abstract: OBJECTIVE
  To classify and describe clinically meaningful classes of color vision defects using pretreatment Farnsworth-Munsell 100-hue results from the Early Treatment Diabetic Retinopathy Study (ETDRS) patients using standard statistical techniques.
  
  
  METHODS
  The ETDRS was a randomized trial investigating retinal photocoagulation and oral aspirin in diabetic retinopathy.
  
  
  METHODS
  Farnsworth-Munsell (FM) 100-hue test was successfully administered before initiation of study treatment in each eye of 2701 of the 3711 ETDRS patients. Test results were converted into a Fourier series, classified by cluster analysis in the deferred-treatment group of eyes, and verified in the immediate-treatment group of eyes as separate samples.
  
  
  RESULTS
  Cluster analysis uncovered thirteen distinct patterns. Pattern A (51% or 1366 of the eyes) showed unimpaired hue discrimination and was comprised of younger patients with no or little macular edema. Pattern B eyes (10% or 262) showed generalized impairment of hue discrimination with no main axis defect. Patterns C (C1, C2, C3), comprising 26% (or 698) of the eyes, showed increasing severity of the yellow-blue diabetic retinopathy defect, associated with increasing mean age and increasing macular edema severity. Patterns D (D1, D2), comprising 6% (or 164) of the eyes, were similar to the C patterns but showed a stronger yellow-blue defect. Patterns E (E1, E2, E3), or approximately 2% (or 38) of the eyes and predominantly male, exhibited the expected pattern for congenital protan defect. Patterns F, G, and H, approximately 6% (or 153) of the eyes, showed distinct patterns of one-sided axes. The nomenclature is arbitrary.
  
  
  CONCLUSIONS
  Cluster analysis of FM 100-hue test results has found 13 patterns of impaired hue discrimination, helpful in understanding color vision defects in diabetes mellitus.
authors.affiliation: Maryland Medical Research Institute, 600 Wyndhurst Avenue, Baltimore, MD 21210, USA. fbarton@mmri.org
authors.forename: Franca B
authors.initials: FB
authors.lastname: Barton
authors.forename: Donald S
authors.initials: DS
authors.lastname: Fong
authors.forename: Genell L
authors.initials: GL
authors.lastname: Knatterud
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D016000:Cluster Analysis; D003119:Color Perception Tests / Q000145:classification*; D003117:Color Vision Defects / Q000145:classification* / Q000628:therapy; D003131:Combined Modality Therapy; D003930:Diabetic Retinopathy / Q000145:classification* / Q000628:therapy; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D017075:Laser Coagulation; D008297:Male; D008875:Middle Aged
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin