Background: We have developed an improved pediatric vision screener (PVS) that\ncan reliably detect central fixation, eye alignment and focus. The instrument identifies\nrisk factors for amblyopia, namely eye misalignment and defocus.\nMethods: The device uses the birefringence of the human fovea (the most sensitive\npart of the retina). The optics have been reported in more detail previously. The present\narticle focuses on the electronics and the analysis algorithms used. The objective of this\nstudy was to optimize the analog design, data acquisition, noise suppression techniques,\nthe classification algorithms and the decision making thresholds, as well as to\nvalidate the performance of the research instrument on an initial group of young test\nsubjectsââ?¬â?18 patients with known vision abnormalities (eight male and 10 female),\nages 4ââ?¬â??25 (only one above 18) and 19 controls with proven lack of vision issues. Four\nstatistical methods were used to derive decision making thresholds that would best\nseparate patients with abnormalities from controls. Sensitivity and specificity were\ncalculated for each method, and the most suitable one was selected.\nResults: Both the central fixation and the focus detection criteria worked robustly and\nallowed reliable separation between normal test subjects and symptomatic subjects.\nThe sensitivity of the instrument was 100 % for both central fixation and focus detection.\nThe specificity was 100 % for central fixation and 89.5 % for focus detection. The\noverall sensitivity was 100 % and the overall specificity was 94.7 %.\nConclusions: Despite the relatively small initial sample size, we believe that the PVS\ninstrument design, the analysis methods employed, and the device as a whole, will\nprove valuable for mass screening of children.
Loading....