Comparison of glaucoma patients referred by glaucoma screening versus referral from primary eye clinic

PURPOSE: To investigate whether mass glaucoma screening relative to opportunistic case finding at a primary eye clinic is helpful for early detection of glaucoma. METHODS: Subjects referred by glaucoma screening (by non-contact tonometry and non-mydriatic fundus photography; group A, n = 220) and from a primary eye clinic (group B, n = 327) were retrospectively recruited. The positive predictive value (PPV) for glaucoma and the rate of glaucoma awareness were compared. Also, for the newly diagnosed glaucoma (‘definite glaucoma’) patients, the demographics and structural and functional severities of glaucoma were compared. RESULTS: The PPV for definite glaucoma was 25.5% for group A and 52.4% for group B. The rate of false-positive for ‘glaucoma referral to tertiary hospital’ was significantly higher for group A than for group B (38.6 vs. 18.3%, P < 0.001). Among the definite-glaucoma patients (group A: n = 56; group B: n = 182), the proportion of glaucoma awareness was significantly higher in group B (69.2%) than in group A (8.9%, P < 0.001). The mean deviation (MD) of visual field (VF) was significantly higher in group A than in group B (–3.08 ± 3.99 vs. –6.70 ± 7.29 dB, P(adjusted) = 0.040), and the inferior and inferotemporal ganglion cell-inner plexiform layer (GCIPL) thicknesses tended to be greater in group A than in group B, with marginal significance (P(adjusted) < 0.10). CONCLUSIONS: Glaucoma screening can be helpful for early detection of glaucoma. However, improvement of the screening strategy is needed in order to enhance its specificity for glaucoma.