Threshold perimetry and the diagnosis of glaucoma

Visual field examinations are one of the commonest, presumably most sensitive practical indices of optic nerve dysfunction in glaucoma. Given the difficulties in training and retaining good technicians, and presumed vagaries of the Goldmann-type isopter examination technique, interest has turned to computer-controlled automated suprathreshold and threshold static perimetry. Despite the enthusiasm for these approaches, we lack rigorous tests of their value, criteria of abnormality and progressive deterioration, and even normal standards. These important issues are now being addressed. In the interim ophthalmologists must be cautious in their use and interpretation.