Reliability of Automated Perimetric Tests

To the Editor.  —Nelson-Quigg et al¹ have suggested that technician involvement during automated perimetric testing is crucial to the reliability of test results. We agree with this sentiment entirely. They also suggest that one reason their patients had fewer false-positive and false-negative responses than ours² was the difference in technician involvement between the two studies. As with their study, ours is part of a careful, prospective investigation of visual loss in ocular hypertension and early glaucoma. The technician constantly monitored the patient responses. For those who had difficulty fixating or staying awake, the test was stopped and restarted after a rest period. The fact that fixation losses were quite similar in their patients and ours suggests that technician involvement is unlikely to explain why their group had fewer false-positive and false-negative responses than ours.It is possible that patients may "learn" over time with regard to reliability measures.