Effects of astigmatism on the Humphrey Matrix perimeter.

PURPOSE To evaluate the influence of astigmatism in terms of its amount and direction on the results of Humphrey Matrix perimetry. METHODS A total of 31 healthy volunteers from hospital staff were consecutively recruited to undergo repeat testing with Humphrey Matrix 24-2 full threshold program with various induced simple myopic astigmatism. All subjects had previous experience (at least twice) with Matrix testing. To produce simple myopic astigmatism, a 0 diopter (D), +1 D, or +2 D cylindrical lens was added and inserted in the 180 degrees direction and in the 90 degrees direction after complete correction of distance vision. The influences of astigmatism were evaluated in terms of the mean deviation (MD), pattern standard deviation (PSD), and test duration (TD). RESULTS A significant difference was observed only in the MD from five sessions. The MD in cases of 2 D inverse astigmatism was significantly lower than that in the absence of astigmatism. CONCLUSIONS In patients with inverse myopic astigmatism of > or =2 D, the influences of astigmatism on the visual field should be taken into consideration when the results of Humphrey Matrix perimetry are evaluated.