The detection of glaucomatous visual field defects by oculo-kinetic perimetry: which points are best for screening?

Oculo-kinetic perimetry (OKP) uses the patient's ocular movements to position a test stimulus in the visual field. By virtue of its simplicity and low cost, this test could be useful in the screening of glaucoma. The general purpose OKP chart, however, which tests 100 points in the central 25 degrees field, is too time-consuming for this purpose, taking approximately 4-7 minutes per eye. Accordingly, this study was performed to identify the points most likely to detect patients with glaucoma. Fifty-one eyes with glaucomatous visual field defects and 51 non-glaucomatous eyes of age matched individuals were tested by conventional and oculo-kinetic perimetry. At least one of only six points were missed by 82.4% of glaucomatous eyes and by 9.8% of nonglaucomatous eyes. These results, although falling short of the ideal efficiency, are comparable with data published by other research groups using computerised equipment and suggest that, with further development, a specialised OKP chart testing only a small number of points might be valuable in screening for glaucoma.