The Earliest Visual Field Defects In Mid-Chiasmal Compression

Analysis of visual field records from 254 personally examined pituitary adenoma patients allowed identification of the earliest visual field defect attributable to mid-chiasmal compression. This took the form of a bitemporal foreshortening of central isopters, not extending beyond 15 degrees of eccentricity, usually somewhat more pronounced above, often lacking a clear vertical step, and often asymmetrical between the eyes. These defects seemed to be more difficult to detect in static profiles.