angol - magyar Orvosi Orvosi: Műszerek testing statistics

"Severe central visual field loss is
considered a threat to fixation when it affects two of the four test points closest to the point of fixation so that the measured sensitivity is ten decibels or less on the Numeric Test Plot. 
If a point has been retested, that is, a value appears in brackets below the original value, the retest value must not be ten decibels or less on the Numeric Test Plot, regardless of the initial value. "