Purchase this article with an account.
F Yu, F Topouzis, AL Coleman; Detection of Visual Field Loss with 76-Suprathreshold (76-ST) Visual Fields . Invest. Ophthalmol. Vis. Sci. 2002;43(13):2130.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: The 76 suprathreshold testing strategy on the Humphrey perimeter (76 -ST) has been used as a screening test in several population-based studies. We were interested in whether there was another way of defining visual field loss on the 76-ST than counting the number of points missed overall. Methods: In a population-based study of individuals 60 years or older, 88 consecutive subjects had 76-ST as the screening visual field test. Each subject then had a visual field using the Humphrey 30-2 Full Threshold testing strategy (30-2 FT). If this visual field was not within normal limits, at least one confirming visual field was done. The 30-2 FT was used as the gold standard, and a visual defect was defined as glaucomatous or non-glaucomatous according to the criteria used for the Ocular Hypertension Treatment Study. A visual field defect with the 76-ST was considered to be present when 1) at least one or more points were missing (not including points at the blind spot) or 2) at least 10% points were lost in the peripheral field. The peripheral field was defined as 12 points nasally, 12 points superiorly, 12 points inferiorly, and 14 points temporally. False positive and false negative rates were calculated. Results: 77 subjects (128 eyes) had both reliable 76-ST and 30-2 FT. 35 (27.3%) of the 128 eyes had a visual field defect on the 30-2 FT, and 5 (8.9%) eyes had a borderline defect. When visual field loss from the 76-ST was defined as missing at least one point (not including points at the blind spot), 52 eyes (40.6%) were considered to have visual field loss. There was a false positive rate of 38.5% (95% CI: 26.3%, 52.2%) and a false negative rate of 10.7% (95% CI: 5.4%, 19.7%). When a visual field defect was defined as at least 10% of the points being missed from the peripheral region, 30 eyes (24.4%) had visual field loss. The false positive rate was 23.3% (95% CI: 11.6%, 41.5%) and the false negative rate was 17.3% (95% CI: 11.1%, 26.1%). Conclusion: A more sophisticated method for defining visual field loss on the 76-ST decreased the false positive rate by more than 15% but increased the false negative rate by 6.6%. Since the 76-ST is a screening test, a lower false positive rate implies that fewer individuals will undergo additional testing to rule out glaucoma while more individuals with glaucomatous visual field loss will be missed because of the higher false negative rate.
This PDF is available to Subscribers Only