Effect of Patient Experience on the Results of Automated Perimetry in Glaucoma Suspect Patients

The first four Octopus-automated visual field examinations of 29 patients with elevated intraocular pressure but apparently normal optic discs and Goldmann visual fields were studied for the presence of a learning effect on the visual field parameters of mean sensitivity, number of disturbed test locations, total field loss, and short-term fluctuation. A learning effect, if present, would manifest itself as an improvement in the visual field as patients become more experienced with the test. There was no apparent effect of patient experience on the mean sensitivity of the whole visual fields or the mean sensitivity of the test locations within 20 degrees of fixation. There was a significant (P = 0.012) increase in mean sensitivity for the test locations outside 20 degrees of fixation. There were significant (P less than 0.01) improvements in short-term fluctuation, total loss, and number of disturbed points between the first and second visual field examinations. The results indicated that there was a learning effect between the first and second automated visual field in glaucoma suspect patients who had previous experience with manual perimetry. It was not, however, very large in most patients and seems to be present in the peripheral portions of the visual field only. In most cases, it was not necessary to obtain more than two "baseline" examinations unless a patient demonstrated unusually high short-term fluctuation or had visual field defects inconsistent with the remainder of their clinical examination.