To determine the predictive value of frequency-doubling threshold perimetry for glaucoma in a population-based study.
The Beijing Eye Study, a population-based study on subjects 40 years or older, included an ophthalmic examination with fundus photography and frequency-doubling threshold perimetry. Glaucoma was defined by a glaucomatous optic disc appearance.
The study population consisted of 4349 subjects (8615 eyes). Among 207 glaucomatous eyes (2.4%), 74 (35.7%) did not show any abnormality on frequency-doubling threshold perimetry, suggesting a diagnostic sensitivity of 64.3%. In the total study population, a visual field defect was found in 905 eyes (10.5%). In 133 (14.7%) of these eyes, a glaucomatous appearance of the optic disc was detected, and 772 eyes (85.3%) had a nonglaucomatous optic disc appearance (either normal or with nonglaucomatous optic nerve damage, retinal disease, corneal disease, or cataract). For 450 eyes (49.7%) with a visual field defect, the cause of the perimetric defect was not detected.
In a population-based study, frequency-doubling threshold perimetry has a sensitivity of about 64% to detect glaucoma. If the result is abnormal, the probability of glaucoma is about 15%. When results of frequency-doubling threshold perimetry are abnormal, the cause of the visual field defect may not be detectable in 50% of subjects.