Analysis of Glaucomatous Changes of the Macula Using Optical Coherence Tomography

Abstract

In glaucoma, progressive retinal nerve fibre loss can be measured in the peripapillary and macular regions using optical coherence tomography (OCT). The goal of this study was to evaluate the impact of glaucoma on all measureable retinal layers using the spectral domain OCT (SD-OCT). SD-OCT scans using automated retinal layer segmentation were performed in both eyes of primary open-angle glaucoma patients with strictly monocular absolute visual field scotoma in the central 10° of their visual field. The same measurements were performed in one eye per person in a healthy age-matched control group. The mean thickness of all retinal layers in the central 24 × 24° of the macular region was compared between groups. SD-OCT scans were performed in 24 eyes of 12 glaucoma patients (10 female, 2 male) with a mean age of 72.3 ± 8.1 years and in 12 eyes of 12 healthy controls (9 female, 3male) with a mean age of 66,0 ± 7,6 years. Statistically significant thickness differences between the glaucomatous and the healthy eyes could be demonstrated for the retinal nerve fibre layer, the ganglion cell layer, the inner plexiform layer and the complete retinal thickness, with lower mean thicknesses in the glaucoma group. Using SD-OCT, single retinal layers of the macular region can be scanned and measured automatically. In glaucoma, a decrease in thickness of the inner retinal layers containing ganglion cells and their axons or dendrites could be demonstrated compared to healthy eyes. No corresponding difference in thickness could be found for the outer retinal layers using SD-OCT measurements.