Comparison of visual field defects in the low-tension glaucomas with those in the high-tension glaucomas

We compared the visual fields of 79 eyes (48 patients) with low-tension glaucoma (intraocular pressure less than 21 mm Hg) to the visual fields of 106 eyes (74 patients) with high-tension glaucoma (intraocular pressure greater than 30 mm Hg). Both groups had similar amounts of total field loss as determined by computerized threshold perimetry. Scotomas in the low-tension group had a steeper slope (P less than .001), were significantly closer to fixation (P less than .001), and had greater depth (P less than .001) than those in the high-tension group. These findings suggested that more than one causative factor is important in the production of optic nerve damage in glaucoma.