PURPOSE: To compare the use of visual field and/or optical coherence tomography (OCT) combined with color retinography by non-glaucoma specialists for differentiating glaucoma from physiological cupping.
METHODS: Eighty patients with glaucoma or physiological cupping (40 of each) were randomized according to the examination used (GI: color retinography, GII: color retinography + visual field, GIII: color retinography + optical coherence tomography, GIV: color retinography + visual field + optical coherence tomography). Twenty non-specialist ophthalmologists diagnosed glaucoma from PowerPoint slide images, without direct patient examination.
RESULTS: Inter-examiner agreement was good for GII (ĸ: 0.63; 95%CI, 0.53-0.72), moderate for GIII (ĸ: 0.58; 95%CI, 0.48-0.68) and GIV (ĸ: 0.41; 95%CI, 0.31-0.51), and low for GI (ĸ: 0.30; 95%CI, 0.20-0.39) (p<0.001). Diagnostic accuracy was higher in GIII (15.8 ± 1.82) than GI (12.95 ± 1.46, p<0.001) and higher in GII (16.25 ± 2.02) than GI and GIV (14.10 ± 2.24) (both p<0.001). For glaucoma patients only, diagnostic accuracy in GII and GIII was superior to that in GI and GIV (both p<0.001). Sensitivity and specificity were 59% and 70.5% in GI; 86.5% and 76% in GII, 86.5% and 71.5% in GIII; and 68.5% and 72.5% in GIV, respectively. Accuracy was highest in GII (81.3% [95%CI, 77.1-84.8]), followed by GIII (79% [95%CI, 74.7-82.7]), GIV (70,5% [95%CI, 65.9-74.8]), and GI (64.8% [95%CI, 60.0-69.3]).
CONCLUSIONS: Non-glaucoma specialists could not differentiate glaucoma from increased physiological cupping when using color retinography assessment alone. Diagnostic accuracy and inter-rater agreement improved significantly with the addition of visual field or optical coherence tomography. However, the use of both modalities did not improve sensitivity/specificity.
Keywords: Glaucoma; Tomography, optical coherence; Visual field tests; Optic disk; Observer variation