Automated Optic Nerve Head Hemoglobin Measurements versus General Ophthalmologists Evaluation to Differentiate Glaucomatous from Large Physiological Cupping: A Diagnostic Performance Comparative Study.

Abstract

The aim of this study is to compare the diagnostic performance in differentiating patients with glaucoma from those with presumed large physiological optic disc cupping (LPC), using optic nerve head hemoglobin levels (ONH Hb), as a screening method, versus the evaluation of general ophthalmologists. Twenty general ophthalmologists evaluated PowerPoint images of 40 patients with glaucoma and 40 presenting LPC. Presentation of patient's exams were distributed as follows: Group 1 (GI): color retinography (CR), Group 2 (GII): CR + visual field (VF), Group 3 (GIII): CR + optical coherence tomography (OCT), Group 4 (GIV): CR + VF + OCT. The Laguna ONhE software was used to estimate ONH Hb based on CR. Main outcomes were the comparison of sensitivity and accuracy between general ophthalmologists' evaluation and the glaucoma discriminant function (GDF) index from Laguna ONhE and also the agreement between examiners (Kappa statistics). Laguna ONhE GDF index demonstrated higher sensitivity values (GI- 90%; GII-90%; GIII-100%; GIV-100%) comparing to all groups (GI-59%; GII-86.5%; GIII-86.5%; GIV-68.5%). In GI, in which it was observed the worst accuracy result (64.8%), we found 75% for GDF. In GII, the accuracy was 81.3% and we found 55% for GDF. The highest agreement was in GII (Kappa=0.63; 95% CI=0.53-0.72), and the lowest in GI (Kappa=0.30; 95% CI=0.20-0.39). Laguna ONhE software, a low-cost and non-invasive method, showed good sensitivity and great utility as a screening method in differentiating patients with glaucoma from those with LPC, compared with evaluation of general ophthalmologists.