Purpose
The automation of confrontation perimetry requires the recording and analysis of the behavioral responses of the subject. The purpose of this study was to evaluate the feasibility of detecting these responses by the analysis of video recordings performed during the exams.
Methods
The study involved the analysis of 12 visual field results which were part of the assessment of infants with neuro-ophthalmology disorders. Infants’ ages ranged from 12 to 60 months (median value 42).<br /> The visual fields were performed binocularly on a MonCvONE full field computerized perimeter (Metrovision, Perenchies). With the mouse interface the operator controlled the presentation of tests (Goldmann V-4) first at the center of the screen to attract attention then in the periphery. The operator interpreted the subject’s behavior from the video of the head and noted if an orientation response was present. The same protocol was repeated along 12 meridians.<br /> The first part of the study, a second experienced operator re-evaluated the subject’s responses by analyzing “off line” the videos recorded throughout the exams (the stimulus was displayed in overlay with the video).<br /> In a second part of the study, the operator determined if the pupils could be detected and be used as a clue for response detection.
Results
For the evaluation of orientation responses, there was an excellent agreement (better than 95 percent) between the 2 operators.<br /> Over a total of 170 recorded responses, 112 (65 percent) allowed a detection of the pupil movement. The pupil response was not detected reliably in most cases of large nystagmus, or when the test was presented in the lower visual field (due to masking by the eye lids) or when the orientation response involved a large cephalic movement.
Conclusions
Computerized confrontation perimetry can improve the evaluation of the visual field in young infants. However, in a large percentage of clinical cases, experienced operators are needed not only to interact with the young subjects but also for the interpretation of orientation responses.