PURPOSE.To investigate the effect of trabeculectomy on the waveform changes of laser speckle flowgraphy (LSFG) in the optic nerve head (ONH) in patients with glaucoma.METHODS. Forty-eight eyes of 48 patients with open angle glaucoma were included in this prospective study. LSFG was performed before and 1, 3, and 6 months after trabeculectomy. Longitudinal changes in average mean blur rate (MBR), blow out score (BOS), resistivity index (RI), falling rate, skew, acceleration time index, and blow out time in the tissue area of the ONH were analyzed by using mixed-effects models.RESULTS. Intraocular pressure (IOP) decreased and ocular perfusion pressure increased significantly at each postoperative time point (P < 0.001, each). BOS increased (P < 0.001, each) and RI decreased (P < 0.001, each) significantly at each postoperative time point, although average MBR and other waveform parameters did not change significantly. Multivariate analyses revealed that younger age (coefficients ¼ À0.13 and 0.0014, P ¼ 0.006 and 0.03 for BOS change and RI change, respectively), worse baseline mean deviation of visual fields (coefficients ¼ À0.18 and 0.0026, P ¼ 0.009 and 0.005), larger IOP reduction (coefficients ¼ À0.29 and 0.0037, P < 0.001, each), and larger pulse rate increase (coefficients ¼ 0.17 and À0.0024, P < 0.001, each) are significantly associated with postoperative BOS increase and RI decrease. CONCLUSIONS.Given that postoperative BOS increased and RI decreased with the average MBR remaining unchanged, IOP reduction by trabeculectomy may contribute to stable blood flow throughout the duration of the heartbeat in the tissue area of the ONH.

No abstract

Purpose: To investigate the association between asymmetry of visual field (VF) defects and optic nerve head (ONH) blood flow in patients with glaucoma using laser speckle flowgraphy. Methods: In total, 170 eyes of 85 patients with primary open-angle glaucoma were included. Intraocular pressure, VF (Humphrey 24-2, SITA program), mean blur rate in the tissue area (MBR-T) of the ONH measured by laser speckle flowgraphy, axial length, circumpapillary retinal nerve fiber layer thickness (cpRNFLT), disc area, cup/disc area ratio, and parapapillary atrophy (PPA) area was measured in each eye. The paired eyes were divided into better and worse eyes according to the mean deviation (MD) of VF, and intereye differences of various parameters (better MD eye minus worse MD eye) were examined. Factors associated with MD difference, MBR-T difference, or cpRNFLT difference were investigated. Results: MD of the VF in better and worse eyes were −10.2±7.3 dB and −16.8±7.4 dB, respectively. In stepwise multiple regression analysis, MBR-T differences, cpRNFLT differences and sex (male) were significantly correlated with MD differences (β, 0.26, 0.21, 0.20; P=0.01, 0.04, 0.047, respectively). MD differences were significantly associated with MBR-T differences (β, 0.28; P=0.01). For cpRNFLT differences, differences in β-PPA area and MD differences were identified as significant factors (β, −0.26, 0.22; P=0.02, 0.04, respectively). Conclusions: Asymmetry of ONH blood flow is significantly associated with asymmetry of visual field defects in patients with glaucoma independently of cpRNFLT.

A prospective study was conducted on 33 eyes of 33 patients with open-angle glaucoma who underwent trabeculectomy to investigate hemodynamic changes in the temporal optic nerve head (ONH) and peripapillary atrophy (PPA) after trabeculectomy. Laser speckle flowgraphy of ONH and PPA was performed at baseline and at 1, 3, and 6 months postoperatively. The waveforms of the mean blur rate in the tissue area (MT) in the temporal ONH, βPPA (with Bruch’s membrane), and γPPA (without Bruch’s membrane) were evaluated. Mean intra-ocular pressure (IOP) decreased from 19.1 ± 0.8 to 8.5–9.6 ± 0.7 mmHg at postoperative visits. The average MT in the βPPA region increased significantly at all postoperative time points, whereas those in the ONH and γPPA regions remained unchanged. The blowout score (BOS) increased significantly, and the resistivity index decreased significantly at all time points in all regions, which was associated with decreased IOP. The current study showed two novel findings: MT increased after trabeculectomy only in βPPA, where the choroid was present. IOP decrease-associated BOS increase occurred postoperatively in all regions, which indicates that IOP reduction may decrease vascular transmural pressure and contribute to stable blood flow uniformly, despite structural differences between the regions.