Evaluation of FASTPAC: a new strategy for threshold estimation with the Humphrey Field Analyser

Abstract

A new strategy for threshold estimation, FASTPAC, has been introduced for the Humphrey Field Analyser with the aim of improving the efficiency of visual field examination without loss of accuracy. FASTPAC was compared to the standard 4-2 double staircase strategy in 98 normal volunteers (age 23-83 years). One eye of each subject was examined with both strategies on two visits using Program 30-2. The order of strategy was randomised. FASTPAC examination time was 43% faster than the standard algorithm, but the mean sensitivities were similar. Short-term fluctuation was 24% higher with FASTPAC (P < 0.001). Most parameters were adversely affected by increasing age. FASTPAC offers a valid alternative to the standard strategy in the examination of suspected normal fields and should always be considered as an alternative to the threshold-related screening strategies. The performance of the algorithm in the identification of field loss and in areas of reduced sensitivity awaits further study.