Effect of dichoptic adaptation on frequency-doubling perimetry

Abstract

BACKGROUND: In frequency-doubling technology (FDT) perimetry, the second eye tested has reduced sensitivity. We investigated the cause of this sensitivity reduction. METHODS: Contrast sensitivity was measured for frequency doubling (0.25 cpd, 25 Hz) and nonflickering (4 cpd) gratings, arranged similarly to the targets in the FDT perimeter (Welch Allyn, Skaneateles Falls, NY, and Humphrey Instruments, San Leandro, CA). Various test orders were examined. RESULTS: Frequency-doubling (FD) sensitivity was reduced (0.15 log) in the second eye. A similar reduction occurred when first and second eye gratings were oriented orthogonally, suggesting that dichoptic contrast adaptation was not the cause...