OBJECTIVE: To evaluate the effectiveness of associating diagnostic tests for the detection of patients with glaucoma. METHOD: Forty-six eyes with cup/disc ratio >0.4 or disc asymmetry >0.2 were submitted to aplanation tonometry and automated static perimetry (screening and full threshold). The full threshold was adopted as gold standard for glaucoma diagnosis. RESULTS: The positive predictive value (pretest probability) of disc parameters was 34.8%. The sensitivity, specificity, positive and negative likelihood ratios of screening perimetry were respectively 75%, 93%, 10.7 and 0.27. Using a cutoff of 20 mmHg the sensitivity, specificity, positive and negative likelihood ratios of tonometry were respectively 19%, 90%, 1.9 and 0.9. An abnormal screening test changes the probability of having a pathologic full threshold from 34.8% to 85% and a normal one changes this probability to 12%. The results of tonometry in changing the probability of having a pathologic full threshold were 34.8% to 50% when the test was positive (IOP>20 mmHg) and 34.8 to 32% when the test was negative (IOP<20 mmHg). CONCLUSION: The results in identifying subjects with glaucoma are better when disc parameters are associated with screening visual field than with tonometry.
Glaucoma; Tonometry; Perimetry; Blindness; Optic disc; Macular degeneration; Vision screening
