Combining spectral domain optical coherence tomography of retinal nerve fiber layer and noncontact tonometry in mass glaucoma screening during the World Glaucoma Week

Abstract

This study reports the combination of noncontact tonometry and spectral domain optical coherence tomography (SD-OCT) in mass glaucoma screening in the Lebanese population. This cross-sectional study included Lebanese individuals who participated in a glaucoma screening campaign in March 2018 and March 2019 for World Glaucoma Week. Intraocular pressure (IOP) was measured by noncontact tonometry. Optic nerve head (ONH) and retinal nerve fiber layer (RNFL) scans were obtained using SD-OCT. Glaucoma suspects were defined as individuals having an IOP above 21mmHg in at least one eye and/or RNFL thinning in either the superior or the inferior quadrant. Among the 1116 individuals who were examined, 15.5% were found to be glaucoma suspects based upon their IOP readings, 15.5% based on OCT, and 3.0% based on both criteria combined. The mean vertical and horizontal disc diameter was 1.75±0.23mm and 1.57±0.22mm, respectively. Eyes that were suspects by OCT with normal IOP had thinner corneas when compared to eyes with normal OCT and high IOP (512.25μm vs. 559.12μm, P<0.0001). SD-OCT can be an easy and relatively fast component of mass glaucoma screening in addition to IOP measurement. Further studies are needed to establish this combination as a valid glaucoma screening method.