The Influence of Age on Retinal and Optic Nerve Microcirculation in Normal Subjects

ABSTRACT

Perfusion disorder of the optic nerve head has been thought to be one of the risk factors glaucoma and studies on optic nerve perfusion have been performed recently. Heidelberg Retina Flowmeter(HRF Heidelberg Engineering GbmH, heidelberg, Germany) is known to be useful in the evaluation of retinal and optic nerve head microcirculation. The objective of this study is to present the changes of retinal and optic nerve head blood flow with regard to the age in normal subjects, thus providing the reference values of retinal and optic nerve head microcirculation. Twenty subjects of each decade from third to eighth, total 120 were included in this study. Microcirculations were measured by HRF at nasal and temporal juxtapapillary retina, nasal and temporal neuroretinal rim, and optic cup area. The mean flow was measured to be 385.14 at temporal neuroretinal rim, 432.62 at nasal neuroretinal rim, and 157.12 at optic cup area. Student`s t-test revealed that there was o significant difference in flow between nasal and temporal neuroretinal rim(0.45), and between nasal and temporal juxtapapillary retina(p=0.36). Pearson`s correlation analysis revealed significant linear inverse relationship between the age and flow at neuroretinal rim(NRR) and juxtapapillary retina(JPR)(correlation coefficient r=-0.83, p=0.034 for NRR and r=-0.87, p=0.012 for JPR), but not at optic cup(r=-0.62, p=0.13).