Evaluation of the Friedmann Visual Field Analyser Mark II. Part 2. Results from a population with induced visual field defects.

The Friedmann Visual Field Analyser Mark II is evaluated with a group of 301 normal eyes, 155 of which had an induced visual field defect. Measures of sensitivity and specificity are calculated from these data by criteria similar to those used by other researchers. The inadequacies of using pass/fail criteria in the clinical situation are discussed, and a solution is proposed in which each field response is scored and the score compared with those from normal and defective populations. An example is given of how this form of analysis could be incorporated into the clinical situation.