Improved computerized perimetric threshold strategies

Perimetric threshold examination is the most important method for diagnosing and monitoring patients with glaucoma. Such examination, however, is time-consuming and often difficult for the elderly patients in whom glaucoma is prevalent. Shorter test strategies have been proposed, but unfortunately also with lower test quality. By using new computer-intense techniques for acquisition and processing of test data it was possible to reduce test time of perimetric threshold tests without decreasing quality in test results. The new SITA strategies were developed using such techniques to yield the same accuracy in test results as today’s traditional test strategies, the Humphrey Full Threshold and Fastpac strategies, while considerably reducing test time. Most development was performed using computer simulations. The SITA strategies were evaluated in comparison with traditional strategies in real-time measurements in both normal subjects and glaucoma patients. Test time was reduced by nearly 50% and reproducibility was at least as good as with the conventional strategies. Age normal sensitivity values were higher, and normal limits were narrower, i.e., in SITA fields shallower defects are needed to be recognized as significant loss. Both SITA strategies showed at least as good sensitivity and specificity as the Humphrey Full Threshold strategy when interpreting test results relative to age normal values and normal limits.