Temporal summation measurements with the Octopus 1-2-3 perimeter.
Until recently, measurements of temporal summation required the construction of specialized instrumentation or the custom modification of an existing perimeter, which meant that such testing was unstandardized and relatively expensive. This precluded extensive use of this type of visual response testing, especially in a clinical setting. In an effort to change this situation, a personal computer (PC) program has been devised that makes use of a new interface for remote operation of the Octopus 1-2-3 automated perimeter. The program can be used to measure temporal summation at 1-5 locations in the visual field (0 degrees-30 degrees eccentricity) for 1-10 stimulus durations (5.6-999 ms) in the presence or absence of background illumination (10 cd/m2). Two auxiliary programs for analyzing the resulting data have been developed as well. Preliminary measurement trials were performed on four normal and two glaucomatous eyes at three test locations for ten stimulus durations in both the presence and the absence of background illumination. Ten examinations were carried out for each eye to reduce the effects of short-term fluctuations. The resulting temporal summation curves and the associated critical durations were similar to those found in the literature. No effect of disease on the critical duration was found (n = 2). With this program package, the effects of disease on temporal summation can now be tested using a commercially available instrument. To determine its clinical usefulness, though, investigations with larger populations will have to be made.
Funkhouser
A T
AT
Lindenhof Hospital, Bern, Switzerland.
Fankhauser
F
F
D002908:Chronic Disease; D003199:Computer Systems; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006801:Humans; D012984:Software; D014786:Vision Disorders / Q000503:physiopathology; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields / Q000502:physiology*