The relationship between choroidal blood flow and glaucoma progression in a Japanese study population

Evaluation of blood flow in arteritic anterior ischemic optic neuropathy using laser speckle flowgraphy: A case series

Background

Arteritic anterior ischemic optic neuropathy (AAION), primarily caused by giant cell arteritis, is a leading cause of blindness. This disease results in significant ocular blood flow (BF) impairment, though data on ocular hemodynamics are limited.

Methods

This observational case series enrolled four patients treated for AAION (age: 81.8 ± 7.8 years; male to female ratio: 3:1) who underwent laser speckle flowgraphy (LSFG) scanning at the initial visit and after steroid treatment in both eyes. Mean blur rate (MBR), an LSFG parameter that represents BF velocity, was obtained in the optic nerve head vessel area (ONH-MV), ONH tissue area (ONH-MT), and peripapillary choroid, in addition to common ophthalmologic parameters.

Results

At the initial visit, all affected eyes had no light perception in best-corrected visual acuity (BCVA) testing, and three cases had a severe increase in circumpapillary retinal nerve fiber layer thickness (cpRNFLT; 191.00 ± 42.03 μm). Pre-treatment, all affected eyes showed decreases in ONH-MV, ONH-MT, and choroidal MBR; this improved after steroid treatment by 80.3 ± 107.6 %, 39.1 ± 79.7 %, and 289.4 ± 303.4 %, respectively. Pre-treatment, all fellow eyes showed no impairment in BCVA or changes in the cpRNFLT. Post-treatment, two fellow eyes showed an increase in ONH-MV and ONH-MT parameters (72.8 ± 32.6 % and 82.2 ± 22.3 %, respectively), while all fellow eyes showed an increase in choroidal MBR (152.7 ± 126.1 %).

Conclusion

LSFG could be useful for monitoring ocular BF changes in eyes with AAION and asymptomatic fellow eyes before and after steroid treatment.

Laser Speckle Flowgraphy Reveals Widespread Reductions in Ocular Blood Flow in nonexudative Age-Related Macular Degeneration

PURPOSE

To evaluate whether and where laser speckle flowgraphy (LSFG)-derived indices of ocular blood flow are reduced in non-exudative age-related macular degeneration (AMD) compared with age-matched control subjects.

DESIGN

Retrospective case-control study.

METHODS

Subjects with nonexudative AMD in the early, intermediate, or advanced stage underwent blood flow imaging with LSFG and were compared to age-matched control subjects. 39 eyes of 24 subjects with AMD and 41 eyes of 21 healthy controls were included. Mixed-effects models accounted for correlations between eyes in the same patient. Logistic regression evaluated the effect of ocular perfusion pressure and other factors associated with blood flow. Blood flow data was analyzed in 2 ways: by binary threshold for the primary analysis and through a superpixel-based method to map the territory of very low flow. The main outcome measure was choroidal blood flow and inner retinal blood flow in AMD and control eyes.

RESULTS

Choroidal blood flow as measured by the LSFG in arbitrary units (AU) was reduced by 33% in AMD patients vs controls (5.3 ± 0.3 AU vs 7.9 ± 0.5 AU respectively, P = .00005). Inner retinal blood flow was also significantly reduced in AMD (12.5 ± 0.6 vs 15.6 ± 0.5 AU, P = .004). Ocular perfusion pressure showed no significant difference between AMD and control groups (50±5.5 vs 53±6.7 mm Hg respectively, P = .17), indicating that neither elevated intraocular pressure nor low blood pressure could account for the reduced blood flow. In most cases, the area of lowest blood flow was large and diffuse, exceeding the abnormal area affected by non-exudative AMD. Controlling for other subject and eye characteristics, an eye with 10%, 25%, or 50% below the average normal choroidal blood flow was more likely to have AMD, with an odds ratio of 2.27, 7.76, and 60.1, respectively (P = .026).

CONCLUSIONS

Laser speckle flowgraphy showed lower choroidal and inner retinal blood flow in non-exudative AMD patients compared to age-matched controls, not explained by low perfusion pressure. Areas of reduced blood flow greatly exceeded the territory of choroidal atrophy, emphasizing its role as a risk factor for the development and potential progression of dry AMD.

Differentiating optic neuropathies using laser speckle flowgraphy: Evaluating blood flow patterns in the optic nerve head and peripapillary choroid

PURPOSE

To compare blood flow (BF) impairment patterns in different optic neuropathies using laser speckle flowgraphy (LSFG).

METHODS

This retrospective study enrolled 24 eyes of 24 patients with non-arteritic anterior ischemic optic neuropathy (NAAION), 59 eyes of 59 patients with optic neuritis (ON), 677 eyes of 677 patients with open-angle glaucoma (OAG), and 110 eyes of 110 controls. The patient backgrounds of all groups were compared. Ophthalmologic findings were evaluated, adjusting for age, sex, blood pressure, pulse rate, and underlying systemic diseases with 1:1 optimal propensity score matching. We used LSFG to obtain optic nerve head (ONH) vessel-area mean blur rate (MBR; ONH-MV), ONH tissue-area MBR (ONH-MT), and choroidal MBR. The NAAION and ON groups were compared with the control and OAG groups.

RESULTS

Best-corrected visual acuity was worse in the NAAION, ON, and OAG groups than in controls (p < 0.001). Circumpapillary retinal nerve fibre layer thickness was higher in the NAAION and ON groups and lower in the OAG group than in controls (p < 0.001). Compared to controls, the NAAION and OAG groups had significantly lower ONH-MV, ONH-MT, and choroidal MBR (p < 0.05). Additionally, the NAAION group had lower ONH-MV and choroidal MBR than the OAG group (p = 0.003 and p < 0.001, respectively) but no difference in ONH-MT (p = 0.857). The ON group had significantly lower ONH-MV and choroidal MBR compared to the controls (p < 0.001 and p = 0.022, respectively) but no difference in ONH-MT (p = 0.773).

CONCLUSION

Optic neuropathies showed different patterns of ocular BF impairment. Therefore, LSFG can be a useful tool for differentiating optic neuropathies.

Impairment of flicker-induced increase in retinal blood flow in diabetic pigs

PURPOSE

To evaluate retinal blood flow (RBF) regulation in response to RBF stress in maturity-onset diabetes of the young type 3 (MODY3) pigs.

STUDY DESIGN

Case-control study.

METHODS

MODY3 pigs (diabetes mellitus [DM] group, n = 8) transfected with the human mutant hepatocyte nuclear factor-1⍺ and normal pigs of the same age (normal group, n = 8) were used as subjects. After confirming DM onset, the experiment was performed under inhalation anesthesia with isoflurane at 2 months of age before the cataract progressed. Ocular blood flow was assessed by calculating the optic papillary mean blur rate using laser speckle flowgraphy, modified for pig eye measurements. After baseline ocular blood flow measurements, flicker stimulation (12 Hz, 3 min) was applied, and ocular blood flow was measured over time.

RESULTS

Blood glucose was 81.8 ± 5.1 mg/dL in the normal group and 311.4 ± 23.1 mg/dL in the DM group (mean ± standard error). The percent change in ocular blood flow at 3 min after flicker stimulation was +31.0 ± 10.9% in the normal group and -6.6 ± 6.5% in the DM group compared to the preload value, and the difference was statistically significant (Mann-Whitney test, P = 0.015).

CONCLUSION

RBF response to flicker stimulation is reduced at 2 months of age in MODY3 pigs, suggesting that retinal neurovascular coupling is impaired from the early onset of DM.

The Effect of β-Blocker Eye Drops on Pulse Rate, Ocular Blood Flow, and Glaucoma Progression: A Retrospective Longitudinal Study

INTRODUCTION

Our study was conducted to determine factors associated with the effectiveness of a β-blocker eye drop add-on in altering pulse rate (PR) in glaucoma patients.

METHODS

This retrospective study examined 236 eyes of 138 patients who received a β-blocker eye drop add-on during follow-up. Patients were included if at least one PR measurement was available both before and after the add-on was started. We collected data on ophthalmic parameters: longitudinal PR; longitudinal choroidal blood flow, represented by laser speckle flowgraphy-measured mean blur rate (MBR); and diacron-reactive oxygen metabolites (d-ROMs). We used a multivariable linear mixed-effects model to investigate the effectiveness of the β-blocker eye drop add-on in altering PR and examined factors contributing to a larger PR alteration after the add-on was started by analyzing the effect on PR of the interaction term between the add-on and clinical factors. We used the k-means method to classify the patients.

RESULTS

The β-blocker eye drop add-on reduced PR (- 7.61 bpm, P < 0.001). Female gender, higher PR when the add-on was started, lower central corneal thickness, and a higher d-ROM level were associated with greater reduction in PR (P < 0.05). In a cluster of patients with these clinical features, choroidal MBR increased by + 3.42% when we adjusted for change over time; MD slope, which represents the speed of glaucoma progression, improved by + 0.64 dB/year (P < 0.05).

CONCLUSIONS

We identified a glaucoma subgroup in which PR decreased, choroidal blood flow increased, and glaucoma progression slowed after a β-blocker eye drop add-on was started.

The Relationship Between Kiritsu-Meijin-Derived Autonomic Function Parameters and Visual-Field Defects in Eyes with Open-Angle Glaucoma

PURPOSE

This retrospective cross-sectional study aimed to investigate the association between autonomic parameters measured using the Kiritsu-Meijin device and visual-field defects in patients with open-angle glaucoma.

METHODS

A total of 79 eyes of 42 patients with open-angle glaucoma were enrolled in this study. Kiritsu-Meijin testing comprised three phases: sitting, standing, and sitting again (2 min, 2 min, and 1 min, respectively). Continuous electrocardiograms were recorded for five minutes. Autonomic parameters were extracted from the resulting data and analyzed, including activity, balance, reaction, switchover, and recovery; these are five representative parameters derived from Kiritsu-Meijin testing. Correlations between these parameters and mean deviation from Humphrey visual field testing were determined. Additionally, we used a linear mixed-effects model to observe sectoral differences in the relationship between total deviation and the Kiritsu-Meijin parameters. In this study, we focused on superior, central, and inferior total deviations.

RESULTS

Significant positive correlations were observed between activity, balance, and recovery and mean deviation values (β = 0.29-0.38, p < .05). The β value between activity and inferior total deviation was higher than that between activity and superior total deviation (β = 0.22, p < .05). Balance did not show any sectoral differences (p > .05). Recovery was more strongly associated with central to inferior total deviation than superior total deviation (β = 0.17-0.25, p < .05).

CONCLUSION

Our findings suggest that in patients with open-angle glaucoma, lower activity and recovery are associated with more severe central and/or inferior visual field defects in the superior quadrant. These results imply that measurements of autonomic function made with the Kiritsu-Meijin device may have clinical utility in the management of glaucoma.

[Effectiveness and safety of a hypotensive preservative-free drug in long-term therapy of glaucoma]

PURPOSE

To investigate the condition of the ocular surface and the effectiveness of Taflotan for long-term therapy in patients with newly diagnosed primary open-angle glaucoma in real clinical practice.

MATERIAL AND METHODS

This publication presents data form a retrospective observational study that analyzed newly diagnosed glaucoma patients that have been using 1 drop/day of Taflotan in the evening for 12 months. All patients were examined at baseline, and after 1 month and 12 months of treatment, recording intraocular pressure (IOP), retinal photosensitivity indicators (MD, PSD), thickness of the retinal nerve fiber layer (RNFL), and assessing the condition of the ocular surface by Schirmer test, tear breakup time (TBUT), ocular surface disease index (OSDI) questionnaire, as well as measurement of the lacrimal meniscus height and corneal staining with lissamine green.

RESULTS

IOP effectively decreased in all patients using Taflotan, reaching the target pressure by 1 month after therapy initiation. IOP decreased from 25±4 mm Hg at baseline to 17±3mm Hg after 1 month with further decrease down to 16±3 mm Hg after 12 months of therapy. Retinal photosensitivity (MD and PSD) and RNFL thickness did not differ from baseline, and correlated to glaucoma stage. The indicators of the condition of the ocular surface had no significant differences between the baseline, 1-month and 12-month time points.

CONCLUSION

Taflotan effectively decreases IOP in newly diagnosed glaucoma patients, maintains stable automated perimetry indices and RNFL thickness, and does not affect the ocular surface throughout 12 months of therapy.