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Abstract #6042 Published in IGR 2-2
False-negative responses in glaucoma perimetry: indicators of patient performance or test reliability?
Bengtsson B; Heijl AInvestigative Ophthalmology and Visual Science 2000; 41: 2201-2204
PURPOSE: To study whether false-negative answers in computerized glaucoma perimetry indicate the patient's ability to perform perimetry or test result reliability. METHODS: A retrospective evaluation was performed of visual field test results obtained with a perimetry program (Humphrey 30-2 Sita Standard; Humphrey Instruments, San Leandro, CA) in 70 consecutive patients with unilateral glaucomatous field loss. Frequencies of false-negative answers were compared between the two eyes of each patient and related to amount of visual field damage in the glaucomatous eyes using linear regression analysis. RESULTS: Frequencies of false-negative answers were higher in eyes with field loss. The intrapatient intereye difference was 6.6% on average (p < 0.0001). In seven subjects with false-negative frequency of 5% or more in both eyes, the mean difference was 12.7% between eyes. The differences in false-negative answers depended significantly on the amount of field loss in the glaucomatous eyes (p = 0.0003). Larger differences were seen in patients with advanced field loss in the affected eye. CONCLUSIONS: The increased frequencies of false-negative answers in eyes with field loss were strongly associated with field status. The higher false-negative frequencies in eyes with glaucomatous field loss compared with unaffected eyes may be explained by the increased variability in threshold values typically found in such eyes. False-negative answers in patients with glaucoma therefore represent eye rather than patient status.
Dr. B. Bengtsson, Department of Ophthalmology, Malm÷ University Hospital, Malm÷, Sweden. boel.bengtsson@oftal.mas.lu.se
Classification:
6.6.2 Automated (Part of: 6 Clinical examination methods > 6.6 Visual field examination and other visual function tests)
