Diurnal Measurements of Macular Thickness and Vessel Density on OCT Angiography in Healthy Eyes and Those With Ocular Hypertension and Glaucoma

Abstract

Precis: Macular superficial capillary plexus (SCP) and thickness are reduced in eyes with glaucoma and ocular hypertension, but do not change significantly during the day. No relationships with age, intraocular pressure, systemic hypertension, or axial length were found. Purpose: The purpose of this study was to evaluate diurnal differences in retinal thickness and vessel density (VD) of the macular SCP and deep capillary plexus (DCP) using optical coherence tomography angiography among 3 groups: eyes with glaucoma, eyes with ocular hypertension, and healthy eyes. Methods: A consecutive series of individuals was recruited prospectively. Optical coherence tomography angiography was performed in the morning and in the evening. Results: Forty eyes from 23 individuals with glaucoma (58.35±6 y), 52 eyes from 32 individuals with ocular hypertension (58.84±7 y), and 73 eyes from 44 controls (57.84±6 y) were enrolled. Morning and evening measurements of all SCP-VD and retinal thickness parameters were statistically significantly different (P<0.04) among the 3 groups of eyes. None of the DCP-VD parameters were significantly different. Daily changes in SCP-VD, DCP-VD, and retinal thickness among the groups of eyes were not statistically significant. Systemic hypertension, age, axial length, and diurnal changes in intraocular pressure were not significantly associated with diurnal fluctuations of SCP-VD, DCP-VD, or retinal thickness (P>0.19). A positive linear correlation in diurnal changes was found between SCP-VD and DCP-VD in the fovea and in the parafovea (r=0.5567 and 0.5892, respectively) and between SCP-VD and retinal thickness in the fovea and in the parafovea (r=−0.2288 and 0.2418, respectively). Conclusions: Macular SCP-VD and thickness are reduced in eyes with glaucoma and ocular hypertension. Although diurnal changes in SCP-VD, DCP-VD and macular thickness were not significant among the groups, some linear correlations in increasing or decreasing values of the investigated parameters were found.

The Macular Choriocapillaris Flow in Glaucoma and Within-Day Fluctuations: An Optical Coherence Tomography Angiography Study

“…The diurnal stability of superficial and deep-macular VD, and of the retinal thickness, has already been described. 28 , 29 The retinal vasculature, although reduced in eyes with POAG and ocular hypertension, may be unaffected by diurnal circadian changes, at least to the extent that can be assessed using OCTA. In fact, abnormal autoregulation of ocular blood flow in glaucoma was evidenced using different technologies, such as color/laser Doppler flowmetry, 30 , 31 whereas OCTA can only assess quantitatively the vessel caliber volume, not the volume of blood flow.…”

Cerebral Modifications in Glaucoma and Macular Degeneration: Analysis of Current Evidence in Literature and Their Implications on Therapeutic Perspectives

“…9,16 In glaucoma, the existence of an unstable ocular perfusion has been previously demonstrated in the optic nerve, retina, and extraocular level, 17 either due to IOP fluctuation or to a to primary vascular dysregulation, which is responsible for both ischemic damage and subsequent reperfusion injury to the ganglion cells: 18 moreover, using OCT-A it was possible to observe an effective reduction of macular microvascular flow, particularly in the superficial retinal plexus. [19][20][21] This flow disturbance would lead to a reduction in the thickness of GCC and RNFL, anatomically more susceptible to this impairment, showing an association between visual field defect, flow reduction and thinning of the layer. 22 Interestingly, a reduction in macular flow has also been observed in AD, but this time involving both the superficial and deep retinal plexus.…”

OCT-angiography: Regional reduced macula microcirculation in ocular hypertensive and pre-perimetric glaucoma patients

“…As a semi-automated software, the EA-Tool offers a high reliability and reproducibility [7]. All recent studies in early glaucomatous eyes, available up to now in literature, investigate macular vessel density in two retinal layers [8][9][10][11][12][13][14]. In addition, early glaucoma is commonly defined as an eye with optic nerve alterations [11,13] or suspicious-looking optic nerve head [10].…”