Fastpac visual field screening

Abstract

In epidemiology, screening for visual field defects has traditionally been expensive, time consuming and laborious. To achieve cost-and time effective visual field screening, a faster algorithm has been developed for the Humphrey perimeter called Fastpac, which is designed to achieve threshold perimetry in two-thirds the time of the standard algorithm.We compared Fastpac and conventional full-threshold 24-2 fields obtained in 39 eyes of 36 participants. We divided the participants' fields into normal (14) and glaucomatous (25) visual field groups, and compared the test times, number of questions asked and statistical parameters generated for each field for Fastpac as compared to the standard algorithm.Then we divided the participants' fields into Fastpac and standard fields and again compared the test times, number of questions and statistical parameters.Finally we asked trained observers to judge the fields as being normal or abnormal, in a masked fashion, and found a high degreee of agreement between the fields generated by Fastpac and standard.Fastpac offers accurate full-threshold screening in two-thirds the time of the conventional algorithm and would be very useful for large scale prevalence studies in ophthalmic epidemiology.