Anterior Optic Nerve Capillary Blood Flow Response to Diurnal Variation of Mean Ocular Perfusion Pressure in Early Untreated Primary Open-Angle Glaucoma

Abstract

The mean rim flow did not change during the day, implying that the anterior optic nerve capillary blood flow was autoregulated in both normal subjects and in patients with uPOAG, despite significant changes in IOP and MOPP. However, the regions of greatest diurnal change in rim topography (MTF) had significant diurnal change in capillary blood flow in patients with uPOAG but not in normal subjects.

Twenty-four Hour (Nyctohemeral) Rhythm of Intraocular Pressure and Ocular Perfusion Pressure in Normal-Tension Glaucoma

“…This last point probably explains why most studies which reported IOP and BP data had measurements performed the same day. 6,11,26,41,62 Another difficulty in comparing studies may be related to the different definitions of the nocturnal dip, as a decrease of BP between 5% and 10% 26 or between 10% and 20% (our study). 12,20 This may also explain the lowest number of overdipper patients in our study compared with the number in a recent study.…”

Effect of Aging on Nocturnal Blood Flow in the Optic Nerve Head and Macula in Healthy Human Eyes

“…Under the same experimental conditions and with the same technical limitations of scanning laser Doppler flowmetry, 12,20,25,27,28 the diurnalto-nocturnal changes in ocular blood flow were not statistically different in a group of healthy younger volunteers. Ocular biometric parameters between the older group and the younger group were not different ( Table 1).…”

“…[9][10][11][12][13] Previous studies showed that variations in ocular blood flow throughout the diurnal/ wake period were not significant in both younger and older adults. 20,31 One study suggested that ocular blood flow in the optic nerve head decreased at the end of the diurnal/wake period in younger adults. 32 In the present study, we extended the measurement times into the nocturnal/sleep period.…”

Autoregulation of optic nerve head blood flow and its role in open-angle glaucoma

“…Median flow, however, showed no such relationship. Also, a postprandial drop in MAP and OPP correlated with an increase in flow only in the POAG group, suggesting that the POAG group had insufficient autoregulation [163].…”