False-Negative Responses in Glaucoma Perimetry: Indicators of Patient Performance or Test Reliability?

• Published in: Investigative ophthalmology & visual science Vol. 41; no. 8; pp. 2201 - 2204
• Main Authors: Bengtsson, Boel, Heijl, Anders
• Format: Journal Article
• Language: English
• Published: Rockville, MD ARVO 01.07.2000; Association for Research in Vision and Ophtalmology
• Subjects: Adult; Aged; Aged, 80 and over; Biological and medical sciences; False Negative Reactions; Female; Glaucoma - diagnosis; Glaucoma and intraocular pressure; Humans; Male; Medical sciences; Middle Aged; Ophthalmology; Predictive Value of Tests; Reproducibility of Results; Retrospective Studies; Visual Field Tests - standards; Visual Fields; Performance evaluation; Human; Visual field; Deficiency; Variability; Perimetry; Test reliability; Eye disease; Visual field disease; False negative; Glaucoma (eye); Reliability; Performance; Computer aid; Threshold
• ISSN: 0146-0404; 1552-5783

To study whether false-negative answers in computerized glaucoma perimetry indicate the patient's ability to perform perimetry or test result reliability. 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. 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. 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.