Long- and Short-term Variability of Automated Perimetry Results in Patients With Optic Neuritis and Healthy Subjects

Abstract

To measure the short-and long-term variability of automated perimetry in patients with optic neuritis and normal subjects. Design: Prospective case-control design of patients with recovered optic neuritis with intraday and interday repetitions to obtain robust variability measurements. Entry criteria included a corrected pattern SD that was worse than the normal 5% probability level and a mean deviation worse than −3 dB but better than −20 dB. Five Humphrey 30-2 full threshold tests were administered during a 7-hour period (1 test every 2 hours) on the same day and at the same periods on 5 separate days. Subjects: Seventeen patients with recovered optic neuritis and 10 healthy subjects of similar age. Main Outcome Measures: Short-term variability and long-term variability for global visual field data. Results: Patients with optic neuritis demonstrated variations in visual field sensitivity that were outside the entire range of variability for normal controls. These variations occurred for multiple tests performed on the same day at specific times and for tests performed at specific times on different days. There were no consistent patterns of sensitivity changes that could be attributed to time of day. The most dramatic fluctuations occurred in a patient whose visual fields varied from normal to a hemianopic defect from one week to another and from a partial quadrant loss to a hemianopic defect at different times on the same day. Seven of the patients with optic neuritis also demonstrated intermittent vertical step defects. Conclusions: Patients with resolved optic neuritis can have large variations in visual field results on different days and at different times on the same day. The variations affect both the severity and the pattern of visual field loss and do not appear to be consistent across patients. These data indicate that care must be taken when automated visual field results in patients with optic neuritis are interpreted. Distinguishing systematic changes in sensitivity from variability requires more than a comparison of the current visual field with the most recent previous visual field.

Variability in Isopter Position and Fatigue during Semi-Automated Kinetic Perimetry

“…Although glaucoma patients were overall more experienced in visual field testing than other patients, we do not suspect that a learning effect could have counterbalanced the fatigue effect. Similarly, intratest variability (short-term fluctuations) of static perimetry has been reported to be larger in patients with glaucoma [2] and in optic neuritis [4] .…”

Criteria for early detection of temporal hemianopia in asymptomatic pituitary tumor

“…Other explanations were thought to be due to statokinetic dissociation 8 and testing procedure of automated perimetry. 9 The Humphrey Field Analyzer threshold program (central 30-2) determines primary points in each visual field quadrant first. The primary points threshold is used for the initial value of the eight neighboring points surrounding the primary points and finally could affect the values in the entire quadrant.…”

Test?retest reliability of the multifocal electroretinogram and Humphrey visual fields in patients with retinitis pigmentosa

“…Wall et al [24] examined the reliability of Humphrey thresholds in 10 control subjects five times in the same day; five additional subjects were tested five times at one-week intervals. These authors reported differences in mean deviations across visits.…”

“…The average threshold for a 30-year-old control subject is 31 dB (calculated using the output of a Humphrey Field Analyzer Model 750). From these values, we calculated that the average mean deviation in the Wall et al [24] study was 10% of the mean threshold value, with a range from 6% to 13%.…”

“…The reliability of some clinical measures previously has been quantified in control subjects and in patients with RP [18][19][20][21][22][23]. However, the reliability of Humphrey visual fields and mfERGs has been quantified predominately in control subjects [21][22][23][24]. Given the potential importance of these local measures, we quantified the inter-visit reliability of Humphrey visual field thresholds and mfERG amplitudes and implicit times in a group of patients with RP.…”