SITA visual field testing in children

Purpose: The Swedish Interactive Thresholding Algorithm (SITA) is a new tes ting strategy for the Humphrey perimeter. The standard SITA algorithm short ens test time in adults without increasing variability, but its usefulness for detecting field defects in children has not been investigated. Methods: We evaluated 92 standard SITA 24-2 visual fields of children, most of whom had various types of optic neuropathies (pediatric idiopathic intracranial hypertension, homonymous defects, bitemporal defects, papilledema from bra in tumors), and compared them with 49 full threshold 24-2 fields obtained i n similar patients. We evaluated outcome measures of foveal threshold, mean defect, pattern standard deviation, false-negative and false-positive rate s, and test time. Five children (9 eyes) had both SITA and full threshold t esting (FTT). Results: The SITA decreased test time by over 50% compared wi th FTT (12.6 +/- 3.0 minutes vs 6.6 +/- 1.6 minutes [P <.00001]). When pati ents with field defects were eliminated, the pattern standard deviation was lower with SITA than FTT (P <.002), indicating lower intratest variability of SITA in subjects with normal fields. No detectable difference was obser ved in the other outcome measures. Subjective analysis of gray-scale fields in patients who underwent testing with the use of both strategies showed m arked similarities. Conclusions: SITA shortens test time significantly comp ared with FTT and does so without jeopardizing interpretability. SITA has l ess intratest variability than RT and therefore should be better for detect ing and following defects. Caution is advised when following a visual field defect unless the same strategy is used for each evaluation. Switching str ategies in the absence of a stable field defect is not recommended.