Abstract
Abstract: :
Purpose:To determine the repeatability and progression of pattern deviation (PD) plot p–values on full threshold standard automated perimetry (SAP–FT) given their proximity to baseline defective PD locations. Methods:48 patients with ≥ 2 abnormal SAPs were identified with progressive glaucomatous optic neuropathy as evidenced by consensus, masked review of color stereophoto series. Their first and last SAP–FT tests were analyzed: 1) Abnormal PD locations were defined as p < .05 in the first test. 2) For a single patient, a Cartesian coordinate system was fixed to the PD plot choosing an arbitrary abnormal location in the first test as the origin, and describing all locations by their Euclidian distance. 3) A matrix was used to record whether each distance's p–value remained abnormal, worsened, remained normal, or became normal. 4) A new abnormal location in the first test was chosen as the origin, and all locations were re–described by distances. 5) Steps 3 and 4 were repeated until all abnormal locations served as the origin. 6) The distances were binned 1–10, 11–20, 21–30, 31–40, and 41–50 degrees 7) Steps 2 through 6 were repeated for all patients and the percentage of progressing points within each bin were determined. Results:Mean (± SD) length of follow–up was 5.09 ± 2.68 years. The percentage of locations progressing increased with proximity to already existing defects: 20%, 16%, 12%, 11%, and 9% from the most to the least proximal bins. The least and most proximal bins were significantly different (X2(1) = 4.74, p = 0.029). Conclusions:The distributions show a trend towards more progression in locations close to initially abnormal locations. These findings will assist us in our project to further develop SCotoma–Oriented PErimetry (SCOPE), an algorithm for individualized follow–up on visual fields.
Keywords: perimetry • visual fields