Automated pupil perimetry. Pupil field mapping in patients and normal subjects.
The authors developed an automated method of pupil perimetry by linking an infrared video pupillometer to a Humphrey Field Analyzer. Software was developed to automatically analyze the pupil responses to focal light stimuli and display the results graphically. All 76 locations of Humphrey program 30-2 could be tested twice within 5.5 minutes and the relative sensitivity of the field was determined by comparing the amplitude of pupil constriction or latency time at each stimulus location. The mean pupil responses within annular areas at 3 degrees, 9 degrees, 15 degrees, 21 degrees, and 27 degrees were shown to be linearly related to log stimulus intensity over a 15 dB range under low level mesopic conditions (3.15 asb bowl background). In normal subjects, the superior temporal quadrant usually had the greatest mean pupillomotor response and the inferior nasal quadrant had the least. Pupil responses in the temporal field were larger than corresponding locations in the nasal field. Patients with visual field defects who underwent testing by pupil perimetry showed pupillary deficits in the same location within the field, providing evidence that pupil perimetry may be a useful, objective means of assessing visual field function.