Velhagen Pflügertrident pseudoisochromatic plates in screening congenital red-green vision defects

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 1 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 Pflugertrident test is easy to use when screening of preschool-aged children is needed.

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Velhagen Pflügertrident pseudoisochromatic plates in screening congenital red-green vision defects

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This study was supported by Finnish Eye Foundation

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Offprint requests to: M. Mantyjärvi