Crowding of the peripheral nasal isopters in glaucoma.

We studied 300 visual fields of 153 consecutive patients who had glaucoma or increased intraocular pressures. All the visual fields were plotted with the same technique on a Goldmann perimeter. Crowding of the peripheral nasal isopters was said to be present when the nasal isopter, outlined with the peripheral threshold target, was less than 55 degrees from fixation and within 5 degrees of the nasal isopter plotted with the V4e (largest, most intense) target. This finding was detected in 65 visual fields; in 12 of these it was the only abnormality. Crowding of the peripheral nasal isopters is important in the early detection of glaucoma; the V4e target, or equivalent, is useful in examining the nasal periphery in screening protocols for glaucoma.