Role of frequency doubling perimetry in detecting neuro-ophthalmic visual field defects

PURPOSE: To report the ability of frequency doubling perimetry to detect "n euro-ophthalmic" held defects, characterize them as hemianopic or quadranta nopic, and differentiate glaucomatous from "other" neuro-ophthalmic field d efects. METHODS: Sixty eyes of 30 normal subjects, 50 eyes of 29 patients with glau comatous defects, and 138 eyes of 103 patients with "typical" neuro-ophthal mic field defects underwent automated perimetry using the Swedish interacti ve Threshold Algorithm and frequency doubling perimetry. The sensitivity an d specificity for identification of a field defect (frequency doubling peri metry 20-5 and 20-1 screening tests), or to characterize hemianopia/quadran tanopia (full threshold test) were determined. Ability to discriminate glau comatous defects was determined by comparing frequency doubling perimetry f ull threshold test in glaucoma to pooled results of normal and neuro-ophtha lmic groups. RESULTS: On frequency doubling perimetry, a single point depressed to less than 1% probability had a sensitivity of 97.1% (20-5 test) and 95.1% (20-1 test) for detecting a neuro-ophthalmic visual field defect. The correspondi ng specificities were 95% using pooled results in normal subjects and patie nts with glaucoma and "other" neuro-ophthalmic field defects. In 20-5 screening a single abnormal point depressed to less than 2% probabi lity level had a sensitivity of 98.6% (specificity 85%). Two abnormal point s in the 20-1 screening depressed to less than 1% probability level had a s pecificity of 100% (sensitivity 84.8%). In frequency doubling perimetry full threshold, sensitivity and specificity for detection of hemianopia were 86.8% and 83.2%; for quadrantanopia they were 79.2% and 38.6%, The sensitivity and specificity for categorizing a de fect as glaucomatous were 86% and 74.7%. CONCLUSIONS: Frequency doubling perimetry is a sensitive and specific test for detecting "neuro-ophthalmic" field defects. The presence of two abnorma l points (20-1 screening program) "rules in" the presence of a held defect. A normal 20-5 program (absence of a single abnormal point) almost "rules o ut" a defect. Frequency doubling perimetry could not accurately categorize hemianopic, quadrantanopic, or glaucomatous defects, (Am J Ophthalmol 2001; 131:734-741, (C) 2001 by Elsevier Science Inc, All rights reserved.).