Glaucoma follow-up when converting from long to short perimetric threshold tests.

OBJECTIVES: To study the influence of test length in automated perimetry follow-up of glaucomatous eyes and, particularly, to determine if it is possible to usefully interpret test results obtained using a testing algorithm shorter than that used for baseline testing. METHODS: Automated perimetry findings were retrospectively evaluated in 31 patients with glaucoma for whom multiple Humphrey 30-2 tests were available on the Full Threshold strategy and the SITA Standard strategy. RESULTS: Variability around the mean deviation regression lines was smaller with SITA than with the Full Threshold strategy. Mean deviation values with SITA averaged about 1 dB less severe. Although localized scotomas measured in decibels were deeper on the Full Threshold strategy, number of significantly depressed points on total deviation and pattern deviation probability plot analyses did not differ significantly between the 2 strategies. CONCLUSIONS: The SITA strategy showed test-retest consistency that was at least as good as that of the Full Threshold strategy. The 2 strategies produced similar results when analyzed relative to their respective normal significance limits. Generally, it is appropriate to establish a new baseline when converting from one perimetric algorithm to another. When necessary, however, results may be usefully compared if such comparisons are based on total and pattern deviation probability maps rather than on decibel values.

Automated light- and dark-adapted perimetry for evaluating retinitis pigmentosa.

Visual fields and dark-adapted thresholds, essential measurements of visual function in patients with retinitis pigmentosa (RP), are usually performed manually. The authors have modified a computerized perimeter to perform automated light- and dark-adapted static perimetry across the visual field of RP patients. Results permit assessment of the level of visual disability in the light and dark and also help define subtypes of RP.

Clinical evaluation of the Humphrey automatic refractor.

A new automatic objective refractor was used on healthy adults. In the absence of cycloplegic drugs, spherocylindrical objective refractions performed with the instrument provided 20/20 acuity 96% as often as with standard subjective techniques. No instrument-induced accommodations effects were seen. One hundred percent of instrument spherical findings were repeatable within 0.50 diopters; all cylindrical findings were repeatable within 0.37 D. This result represents a higher level of repeatability than that reported for standard subjective refraction under clinical conditions. In the absence of cycloplegic drugs, the correlation coefficient between the instrument's findings and standard subjective spherical findings was .97 v .98 between two practitioners' subjective refractions. The average difference between cylindrical findings of the instrument and those of an experienced practitioner was 0.04 D larger than the average difference seen between two practitioners using subjective techniques.