Fig 1.
Measurement of parapapillary choroidal vessel density (pCVD).
The boundaries of the optic disc and β-parapapillary atrophy margins, excluding large retinal vessels, were manually demarcated (yellow outline) using ImageJ software on en-face images obtained by using optical coherence tomography angiography scanning laser ophthalmoscopy (A and D). The demarcation lines are also shown above on en-face images of OCTA choroidal layer (B and E). The selected area of interest was converted to range of interest and 8-bit binary slab was created according to the mean threshold algorithm of ImageJ software of choroidal en-face image to measure pCVD (C and F). The orange demarcation outline shows choroidal microvascular dropout (CMvD) in figure E.
Table 1.
Demographic and clinical characteristics of the subject eyes (patients) with normal-tension glaucoma in the non-dipper, dipper, and over-dipper groups.
Table 2.
Comparison of in-hospital 24-hour IOP and BP data in the subject eyes (patients) with normal-tension glaucoma in the non-dipper, dipper, and over-dipper groups.
Table 3.
OCT/OCTA measurements of the subject eyes (patients) with normal-tension glaucoma in the non-dipper, dipper, and over-dipper groups.
Table 4.
Logistic regression analysis to determine the clinical factors related to “over-dipper”.
Table 5.
Linear regression analysis for determining the clinical factors associated with the amount of pCVD.
Fig 2.
24-hour mean arterial pressure (MAP) patterns of upper and lower parapapillary choroidal vessel density (pCVD) quartile groups.
The 2 dashed horizontal lines indicate diurnal MAP mean (upper panel) and diurnal MAP mean minus 10 mmHg (lower panel). Dark area represents nocturnal dip below diurnal MAP mean minus 10 mmHg.
Fig 3.
A representative case showing the relationship between parapapillary choroidal vessel density and nocturnal blood pressure dip.
A 55-year-old over-dipper normal-tension glaucoma patient with axial length 23.49 mm and nocturnal blood pressure dip of 23.90% showed superotemporal and inferotemporal neural rim loss on optic disc photography and retinal nerve fiber layer (RNFL) loss on red-free RNFL photography. According to spectral-domain optical coherence tomography, RNFL and macular ganglion cell-inner plexiform thickness loss corresponding to the same locations of neural rim loss on optic disc photography were also evident. Visual field exam revealed corresponding central scotoma with a mean deviation of -5.13 dB. Parapapillary choroidal vessel density measurement using choroidal layer en-face images showed vessel density of 48.80%.
Fig 4.
A representative case showing the relationship between parapapillary choroidal vessel density and nocturnal blood pressure dip.
A 61-year-old non-dipper normal-tension glaucoma patient with axial length 23.54 mm and nocturnal blood pressure dip of 7.21% showed superotemporal neural rim loss on optic disc photography and retinal nerve fiber layer (RNFL) loss on red-free RNFL photography. Upon spectral-domain optical coherence tomography imaging, RNFL and macular ganglion cell-inner plexiform thickness loss corresponding with superotemporal location were also noted. Visual field exam showed corresponding inferonasal scotoma with a mean deviation of -5.22 dB. Parapapillary choroidal vessel density measurement by choroidal layer en-face images showed vessel density of 58.76%.