Question 7: How are fixation losses determined and what is the most common reason for high fixation losses?

Question 7: How are fixation losses determined and what is the most common reason for high fixation losses?

Fixation losses. Not all fixation losses represent true loss of fixation. The perimeter first quickly locates the blind spot and then projects an occasional maximum stimulus into it. If the patient responds to the stimulus, a shift in the blind spot and fixation has occurred, and the machine records a fixation loss. A high number of fixation losses may thus indicate that the center of the blind spot was slightly mislocated. A high false-positive rate will give a high fixation loss rate as well.