Comparison of the Frequency Doubling Technology screening algorithm and the Humphrey 24-2 SITA-FAST in a large eye screening

Purpose: To compare the Frequency Doubling Technology (FDT) C20‐1 screening algorithm and the Humphrey Field Analyser II (HFA) 24−2 SITA‐FAST in a large eye screening. Methods: In a non‐randomized, prospective, free eye screening, the FDT Screening Protocol (C20‐1 Screening Algorithm) was administered to 574 attendees (422 men and 152 women, average age 64, range 17−89 years) of the 1998 Veterans of Foreign Wars (VFW) Convention in San Antonio, Texas. Individuals who failed the FDT (two or more misses out of 17 locations) immediately underwent white‐on‐white threshold visual field perimetry (HFA 24‐2, SITA‐FAST). Humphrey visual field analysis included STATPAC and masked evaluations by three glaucoma specialists. Results: Approximately one‐tenth of the VFW conference attendees voluntarily presented themselves for screening. Among these 574 volunteers, 69 (12%) failed the FDT and underwent HFA analysis. Eighty‐one per cent (56/69) of these FDT failures had abnormal HFA Glaucoma Hemifield Tests. Eighty‐eight per cent (61/69) were judged to have nerve fibre type visual field loss on HFA by at least two of three masked examiners. A positive correlation existed between the number of FDT locations missed and the HFA mean deviation (r = 0.5, P = 0.0001). A similar association was observed when FDT and HFA results were analysed by quadrant (r = 0.5, P