International Ophthalmology 8:55-58 (1985) 9 Dr W. Junk Publishers. Dordrecht. Printedin the Netherlands Comparing continuous and stepwise luminance variation in static campimetry using the Grignolo-Tagliasco-Zingirian projection campimeter Paolo Capris, Giuseppe Spinelli & Mario Zingirian Genova, Italy Keywords: static perimetry, continuous luminance variation, stepwise luminance variation, temporal sum- mation, visual field examination Abstract In traditional static perimetry the remarkable precision achieved, resulting mainly from the lack of temporal factors related to latency, largely makes up for the relatively long time required to perform the test. Conversely, the increase in speed of the test and in the information content of the visual field charts counteract the lower precision attained with kinetic perimetry. If the influence of the latency time on responses could be kept at a low value, then adopting a static strategy, based on a continuous rather than discrete target luminance variation for threshold detection, could be justified. For this purpose a luminance variation time sequence designed to reproduce the conditions of the traditional static perimetric test was chosen. The test was performed on the Grignolo-Tagliasco-Zingirian projection campimeter, after compar- ing its clinical performance with the Goldmann perimeter. These two methods - one based on continuous variation, the other based on discrete target luminance variation- were compared using a 14-subject sample. We conclude that the presentation strategy based on continuous luminance variation can be regarded as a valid alternative to the traditional method. Introduction In traditional static perimetry the remarkable pre- cision achieved, resulting mainly from the lack of temporal factors related to latency, largely makes up for the relatively long time required to perform the test. Conversely, in reference to the kinetic method, the increase in speed of the test and in information content of the visual field charts is counteracted by lower precision due to response dependence on latency time (1-4). If this dependence could be reduced, thus retain- ing general precision, then adopting a static strat- egy based on a continuous rather than discrete luminance variation could be justified. We there- fore sought to verify this hypothesis, comparing the values of the photopic static threshold obtained using the method of continuously increasing lumi- nance limits with the values obtained using the traditional method - characterized by discrete lu- minance increase. There are two main reasons for not considering the first method. The first objection results from the possible influence of subject latency, while the second reason, a technical one, stems from the difficulty of implementing a continuous target- background contrast regulation device, with log- arithmic display, using the same light source. The latter difficulties, however, have been over- come using the Grignolo-Tagliasco-Zingirian pro- jection campimeter (5, 6) after suitable modifica- tions, and the influence of the latency time on