Age-related Changes of Macular Ganglion Cell-inner Plexiform Layer Thickness in Korean Elderly Subjects

Purpose: We sought to establish normative ranges of the ganglion cell-inner plexiform layer (GCIPL) thickness using spectral-domain optical coherence tomography in Korean elderly individuals and to identify factors that influence GCIPL thickness. Methods: We conducted a retrospective, observational study of 114 healthy subjects (75 years old or older) who underwentcomprehensive ophthalmic examinations at a single institution. GCIPL thickness was measured with the Cirrus spectral-domainoptical coherence tomography system and automatic segmentation. Subjects were divided into two age groups: thoseyounger than 80 years and those 80 years or older, respectively. A cross-sectional analysis was adopted to evaluate associationsof GCIPL thickness with sex, age, intraocular pressure, optic disc rim area, axial length, spherical equivalent (SE) refractiveerrors, astigmatism, and body mass index. Results: The average and minimum GCIPL thicknesses were 80.3 ± 5.6 μm and 76.3 ± 5.9 μm, respectively. The GCIPL thicknesswas significantly lower in the older group than in the younger group in the inferior, inferonasal, and inferotemporal segments(all p < 0.01). A thinner average GCIPL thickness was strongly associated with increasing age (β = -2.87, p = 0.021) andthinner circumpapillary retinal nerve fiber layer thickness (β = 2.87, p < 0.001) in all segments. Conclusions: GCIPL thickness decreased with age globally and in all segments, even after 75 years of age. Thinner GCIPL wasassociated with older age and thinner circumpapillary retinal nerve fiber layer. Age-related changes should be consideredwhen using GCIPL thickness to assess glaucoma and other optic neuropathies characterized by retinal ganglion cell loss.