Ganglion Cell-inner Plexiform Layer Thickness Measured by Cirrus High-definition Optical Coherence Tomography Enhances Glaucoma Diagnosis in Patients with Moderate or High Myopia

Abstract

Objective: To assess the diagnostic ability of Cirrus high-definition optical coherence tomography (HD-OCT) parameters in patients with moderate or high myopia for detecting glaucoma, and to compare the thickness of the macular ganglion cell-inner plexiform layer (GC-IPL) in glaucomatous and normal eyes in both types of myopia.Materials and Methods: This prospective study enrolled moderately (spherical equivalent -3.00 to -6.00 diopters) and highly (spherical equivalent ≤ -6.00 diopters) myopic patients without (controls) and with (study) glaucoma. Cirrus HD-OCT was used to determine the thickness of the peripapillary retinal nerve fiber layer (RNFL) and the GC-IPL. The area under the receiver operating characteristic curve was analyzed to evaluate the glaucoma detection capability of each Cirrus HD-OCT parameter.Results: Seventy eyes (31 moderate myopia, 39 high myopia) were included. The parameters with the best diagnostic ability were minimum GC-IPL, inferior RNFL and average RNFL thickness in moderately myopic eyes, and average RNFL, inferior RNFL and inferotemporal GC-IPL thickness in highly myopic eyes. All parameters were thinner in glaucomatous than in normal eyes in both groups.Conclusion: Although macular GC-IPL thickness demonstrated high ability to detect glaucoma in patients with moderate or high myopia, it should be used in combination with other structural imaging and functional assessments for diagnosing glaucoma.