where is the macula represented in Meyers loop?
where x is the height of the spared region. Subtracting this from the normal quadrant area will give us an estimate of the amount of field lost for that isopter, which we then express as a proportion of the normal quadrant area for that isopter. Third, for six fields with more complex borders we performed a manual calculation of the area affected. We used the same formula to determine the area of each 10° arc (i.e. 20 30° eccentricity, 30 40°) lying within a given isopter. For each arc we then estimated the percentage loss, using the radial degree markers as guidelines, and multiplied by arc area to give the area of loss in that arc. These areas were then summed for all arcs and divided by total quadrant area to give the proportionate area loss for that isopter. After calculating the proportion of area loss for each isopter, we averaged these for all available isopters to yield the fraction of the upper quadrant lost in each eye. A value of 1 indicates complete quadrantanopia and a val
