title: Velhagen Pfügertrident pseudoisochromatic plates in screening congenital red-green vision defects.
abstract: Red-green colour vision defects were screened in a group of 425 trade school students using Velhagen Pflügertrident pseudoisochromatic plates. Thereafter, the students were examined with the Nagel anomaloscope. Of the 425 students, 31 (7.3%) were found to be colour defectives. Deuteranomalous defects were found in 4.9% of cases; deuteranopic defects, in 0.2%; and protanomalous defects, in 2.1%. There were no protanopic students in the study group. The Velhagen plates found 19 of the 31 defectives (sensitivity, 61.3%); none of the students with normal colour vision were suspected of being colour defectives (specificity, 100%). The sensitivity of the Velhagen plates is not as high as that of other pseudoisochromatic tests. However, the Velhagen Pflügertrident test is easy to use when screening of pre-school-aged children is needed.
authors.affiliation: Department of Ophthalmology, University of Kuopio, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Mäntyjärvi
mesh_terms: D000293:Adolescent; D000328:Adult; D003119:Color Perception Tests / Q000379:methods; D003117:Color Vision Defects / Q000151:congenital* / Q000175:diagnosis / Q000453:epidemiology; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008297:Male; D015995:Prevalence; D015351:Vision Screening