title: A portable visual acuity device used in diabetic retinal screening.
abstract: OBJECTIVE
  To correlate visual acuity measured with the Optec 800 to the gold-standard Early Treatment Diabetic Retinopathy Study (ETDRS) chart.
  
  
  METHODS
  Prospective, cross-sectional study.
  
  
  METHODS
  Forty patients of the Vanderbilt Eye Institute agreed to undergo visual acuity testing. Five patients were excluded because of enucleation or functional blindness of one or both eyes. Two patients were excluded because of poor cooperation during testing. Patients were randomized to one of the two methods and participated in visual acuity testing in a forced-choice manner. The sequence was repeated with the alternate instrument. A total-correct score was calculated for each data set.
  
  
  RESULTS
  There was no statistically significant difference in scores between the two methods (P(1) = .153, P(2) = .307.) Other factors such as gender, age, and instrument testing order did not affect performance. Age was inversely correlated with total correct score.
  
  
  CONCLUSIONS
  In this small cohort, the Optec 800 (Chicago, Illinois, USA) and the ETDRS chart recorded similar visual acuity measurements.
authors.affiliation: Vanderbilt University Medical Center, Department of Ophthalmology and Visual Sciences Nashville, Tennessee, USA. lori.kehler@vanderbilt.edu
authors.forename: Lori Ann F
authors.initials: LF
authors.lastname: Kehler
authors.forename: K Bradley
authors.initials: KB
authors.lastname: Kehler
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Merin
authors.forename: James C
authors.initials: JC
authors.lastname: Tsai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018592:Cross-Over Studies; D003930:Diabetic Retinopathy / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014786:Vision Disorders / Q000175:diagnosis* / Q000503:physiopathology; D015351:Vision Screening / Q000295:instrumentation*; D014792:Visual Acuity