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Abstract #6389 Published in IGR 3-2
Role of frequency doubling perimetry in detecting neuro-ophthalmic visual field defects
Thomas D; Thomas R; Muliyil JP; George RAmerican Journal of Ophthalmology 2001; 131: 734-741
PURPOSE: To report the ability of frequency doubling perimetry (FDP) to detect 'neuro-ophthalmic' field defects, characterize them as hemianopic or quadrantanopic, and differentiate glaucomatous from 'other' neuro-ophthalmic field defects. METHODS: Sixty eyes of 30 normal subjects, 50 eyes of 29 patients with glaucomatous defects, and 138 eyes of 103 patients with 'typical' neuro-ophthalmic field defects underwent automated perimetry using the Swedish Interactive Threshold Algorithm and FDP. The sensitivity and specificity for identification of a field defect (FDP 20-5 and 20-1 screening tests), or to characterize hemianopia/quadrantanopia (full threshold test) were determined. Ability to discriminate glaucomatous defects was determined by comparing FDP full threshold test in glaucoma to pooled results of normal and neuro-ophthalmic groups. RESULTS: On FDP, a single point depressed to less than 1% probability had a sensitivity of 97.1% (20-5 test) and 95.7% (20-1 test) for detecting a neuro-ophthalmic visual field defect. The corresponding specificities were 95% using pooled results in normal subjects and patients with glaucoma and 'other' neuro-ophthalmic field defects. In 20-5 screening, a single abnormal point depressed to less than 2% probability level had a sensitivity of 98.6^ (specificity 85%). Two abnormal points in the 20-1 screening depressed to less than 1% probability level had a specificity of 100% (sensitivity 84.8%). In FDP 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 defect as glaucomatous were 86% and 74.7%. CONCLUSIONS: FDP is a sensitive and specific test for detecting 'neuro-ophthalmic' field defects. The presence of two abnormal points (20-1 screening program) 'rules in' the presence of a field defect. A normal 20-5 program (absence of a single abnormal point) almost 'rules out' a defect. FDP could not accurately categorize hemianopic, quadrantanopic, or glaucomatous defects.
Dr R. Thomas, Schell Eye Hospital, Department of Ophthalmology, Christian Medical College, Arni Road, Vellore 632001, Tamil Nadu, India. ravi@cmcvellore.ac.in
Classification:
6.6.3 Special methods (e.g. color, contrast, SWAP etc.) (Part of: 6 Clinical examination methods > 6.6 Visual field examination and other visual function tests)
