Influencing ocular blood flow in glaucoma patients: the cardiovascular system and healthy lifestyle choices

Retinal Vessel Density Changes on Optical Coherence Tomography Angiography and Predictive Factors in Normal-Tension Glaucoma Treated with Topical Beta-Blocker

(1) Background: Topical antiglaucoma medications may alter the microcirculation in the optic nerve head. We aimed to evaluate the changes in retinal vessel density (VD) on optical coherence tomography angiography (OCTA) in patients with newly diagnosed normal-tension glaucoma (NTG) treated with a topical beta-blocker. (2) Methods: This study included 80 patients diagnosed with NTG not using systemic medication, who received topical carteolol treatment between December 2019 and November 2020. We studied the changes in the OCTA VD/signal strength index (SSI) after the 6-month treatment period and determined the predictive factors affecting the changes in VD/SSI. (3) Results: After the 6-month treatment period, the peripapillary VD increased in 40 patients but decreased in the other 40 patients. The univariate and multivariate analyses revealed that old age and hypertension were significant factors associated with a VD/SSI decrease after carteolol treatment. Moreover, high baseline peripapillary, superficial, and deep macular VDs were significantly associated with the VD decrease after carteolol treatment. (4) Conclusions: Carteolol treatment could increase or decrease the VD in patients with NTG. The baseline VD, age, and hypertension could affect these VD changes. Patients with NTG and higher baseline peripapillary or macular VD, older age, and hypertension are more likely to have a decreased VD after carteolol treatment.

Association of Hypertriglyceridemia and Incident Glaucoma in a Rural Chinese Population: The Handan Eye Study

Purpose

The purpose of this paper was to investigate the association between baseline metabolic risk factors and incident glaucoma over a 5-year period in rural Chinese adults.

Methods

Population-based prospective cohort study. Participants aged 30 years and older without glaucoma at baseline who underwent comprehensive examinations at baseline and after a 5-year interval in the Handan Eye Study were enrolled. Incident glaucoma was defined as people without glaucoma in either eye at baseline that had developed glaucoma in at least one eye in the 5-year follow-up. Five metabolic syndrome components, mean blood pressure, fasting plasma glucose, total cholesterol, triglycerides (TGs), low density lipoprotein cholesterol, high-density lipoprotein cholesterol, and obesity, determined as body mass index ≥30 kg/m2 at baseline were considered as potential metabolic risk factors for incident glaucoma. Univariate and multivariate logistic regression analyses were carried out to determine baseline metabolic risk factors associated with incident glaucoma.

Results

A total of 5184 participants were included in our study. During the 5-year follow-up, incident glaucoma developed in 82 subjects. Age (odds ratio [OR] = 1.060, 95% confidence interval [CI] = 1.034, 1.086, P < 0.001) and TGs level (OR = 1.213, 95% CI = 1.030, 1.429, P = 0.021) were independently and positively associated with incident glaucoma.

Conclusions

Our study revealed that increased age and high TGs level, one of the baseline metabolic features, were independent risk factors for incident glaucoma. The data implied that the metabolic features be involved in the pathogenesis of glaucoma.

Translational Relevance

This study shed the light on that the TGs level was involved in the pathogenesis of glaucoma.

Optical Coherence Tomography Angiography Vessel Density Changes in Normal-tension Glaucoma Treated With Carteolol, Brimonidine, or Dorzolamide

PRECIS

In patients with normal-tension glaucoma (NTG), topical dorzolamide might enhance the vessel density (VD), topical carteolol decreased the VD in the inferior-temporal peripapillary retina, whereas topical brimonidine did not change the VD.

PURPOSE

Topical antiglaucoma medications may improve ocular perfusion pressure or microcirculation in the optic nerve head. The study evaluated responses of retinal VD to topical carteolol, brimonidine, and dorzolamide in NTG using optical coherence tomography angiography.

PATIENTS AND METHODS

This is a retrospective, nonrandomized, comparative study. The study included 131 individuals (77 men, 54 women) diagnosed with NTG, without systemic medication use, who visited the glaucoma clinic of Chang Gung Memorial Hospital, Taiwan, between January 2019 and May 2020. If both eyes were diagnosed with NTG, only the right eye was included. Of these, there were 80 carteolol-treated eyes, 27 brimonidine-treated eyes, and 24 dorzolamide-treated eyes. We studied the response of optical coherence tomography angiography parameters and retinal nerve fiber layer (RNFL) thickness to drugs, 6 months after treatment.

RESULTS

In dorzolamide-treated eyes, increases in the peripapillary superficial retinal VD, especially in the superior-nasal area, were significant; however, no RNFL thickness changes were observed. In contrast, the superficial retinal VD decreased at the inferior-temporal peripapillary area, and RNFL thickness decreased in the inferior-nasal peripapillary area of carteolol-treated eyes. Finally, in brimonidine-treated eyes, changes in either VD parameters or RNFL thickness were not significant.

CONCLUSIONS

Topical dorzolamide possibly enhanced the VD of the peripapillary retina in NTG eyes. On the contrary, topical carteolol possibly decreased VD in the inferior-temporal peripapillary retina. Finally, in cases treated with topical brimonidine, peripapillary microcirculation remained unchanged. The study shows preliminary results and future large-scale studies are needed to confirm findings.

Correlation of Visual Field With Peripapillary Vessel Density Through Optical Coherence Tomography Angiography in Normal-Tension Glaucoma

Purpose

To investigate the retinal vessel density (VD) in healthy and normal-tension glaucoma (NTG) eyes through optical coherence tomography angiography (OCTA) and to determine the correlation between VD and the retinal nerve fiber layer (RNFL) thickness and functional visual field (VF) defects for different locations.

Methods

A total of 74 NTG eyes and 24 healthy eyes were included. OCTA VD at 4.5 × 4.5 mm peripapillary region and 3.0 × 3.0 mm macula area, RNFL thickness, and VF pattern deviation results were individually analyzed on the basis of the Garway-Heath sectorization. Correlations between VD and VF/RNFL and VF were compared.

Results

In the NTG group, peripapillary VD, superficial macula VD, RNFL thickness, and ganglion cell complex thickness were significantly lower. In the whole peripapillary area and inferotemporal sector, anatomic correlations between VD and VF pattern deviation values were significantly higher than those between the RNFL thickness and VF values. In the subgroup analysis, VD was anatomically correlated with VF in early-, moderate-, and severe-stage NTG eyes, whereas the RNFL thickness was correlated with VF in moderate- and severe-stage NTG eyes.

Conclusions

We observed VD reduction in the peripapillary retina and superficial macula area in NTG eyes. The microvascular dropout of VD in the peripapillary retina, especially in the inferotemporal sector, provided a more accurate anatomic correlation with functional VF defects than that of the RNFL thickness, especially in early-stage NTG eyes.

Translational Relevance

In patients who cannot comply VF exam, VD is a good tool for disease detection.

Risks of all-cause mortality and major kidney events in patients with new-onset primary open-angle glaucoma: a nationwide long-term cohort study in Taiwan

OBJECTIVE

Cardiovascular risk factors are associated with primary open-angle glaucoma (POAG) in the general population. However, long-term mortality and major kidney events in patients with new-onset POAG remain unclear.

METHODS

Using the Taiwan National Health Insurance Research Database between 1997 and 2011, 15 185 patients with a new diagnosis of POAG were enrolled and propensity score matched (1:1) with 15 185 patients without ocular disorders (WODs). All-cause mortality and major kidney events were analysed by a multivariate Cox proportional hazards regression model and a competing risk regression model.

RESULTS

The risk of all-cause mortality was significantly higher in patients with new-onset POAG than in those WODs (adjusted HR (aHR) 2.11, 95% CI 1.76 to 2.54; p<0.001). Patients with POAG had higher risks of acute renal failure (ARF) (competing risk aHR 2.58, 95% CI 1.88 to 3.55; p<0.001) and end-stage renal disease (ESRD) (competing risk aHR 4.84, 95% CI 3.02 to 7.77; p<0.001) than those WODs.

CONCLUSIONS

Our data demonstrate that POAG is a risk of all-cause mortality, ARF and ESRD, thus needing to notice mortality and major kidney events in patients with new-onset POAG.

Foveal Avascular Zone in Normal Tension Glaucoma Measured by Optical Coherence Tomography Angiography

Aim

To measure diameter of foveal avascular zone (FAZ), FAZ area, and vessel density using Optical Coherence Tomography Angiography (OCT-A) in patients with normal tension glaucoma (NTG) and to establish the possible role of OCT-A in diagnosis and follow-up of patients with NTG.

Methods

Twenty-one eyes of 21 patients with NTG and 30 eyes of 30 healthy subjects underwent complete ophthalmic examination as well as OCT-A on ZEISS AngioPlex. 3 × 3 macula scans were used to measure vertical, horizontal, and maximum diameter of FAZ by two graders. Mean values and interobserver variability were analyzed. Image J was used for analysis of FAZ area and vessel density.

Results

Mean vertical diameter (t = 5.58, p < 0.001), horizontal diameter (t = 3.59, p < 0.001), maximum diameter (t = 5.94, p < 0.001), and FAZ area (t = 5.76, p < 0.001) were statistically significantly enlarged in the NTG group compared to those in the control group. Vessel density (t = -5.80, p < 0.001) was statistically significantly decreased in the NTG group compared to that in the control group.

Conclusion

OCT-A could have an important role in the future in diagnosis of patients with NTG. In patients with NTG, there is larger FAZ area, while the vessel density is reduced in comparison to the control group.

Triglycerides and Open Angle Glaucoma - A Meta-analysis with meta-regression

Although intraocular pressure is the main the risk factor for the development of glaucoma, other risk factors such as vascular dysfunction might play an additional pathogenic role. Hypertriglyceridemia, which may lead to vascular dysfunction, has been implicated in the development of glaucoma. The objective of this meta-analysis was to investigate the association of triglyceride levels with the risk of glaucoma in case-control studies. Seventeen case-control studies were included investigating the difference in triglyceride levels in patients with glaucoma (N = 1 391) compared to subjects without glaucoma (N = 25 575). In random effects meta-analysis, the pooled mean triglyceride level across all studies and patients with and without glaucoma was 132.9 mg/dL (95%CI: 124.0-141.7). Patients with glaucoma had significantly higher mean triglyceride levels than patients without glaucoma (absolute difference = 14.2 mg/dL, 95%CI: 5.8-22.5, p < 0.0001). A considerable amount of heterogeneity of included studies was observed (I2 = 66.2%, heterogeneity χ2 = 47.4 on 16 degrees of freedom, p < 0.0001). In conclusion, this meta-analysis of case-control studies found that patients with glaucoma had higher mean triglyceride levels than patients without glaucoma. This finding is consistent with the concept that hypertriglyceridemia represents an additional risk factor for glaucoma. Whether this association is causal and/or might be modified by glaucoma medications remains to be investigated.

Canadian Journal of Ophthalmology Lecture: translational research advances in glaucoma neuroprotection

Given that glaucoma is a disease of the central nervous system, there must be greater emphasis and focus on developing intraocular pressure-independent therapies. In addition, scientific research investigating the role of sustained drug delivery is critical for advancing the field. Exciting innovation will require close collaboration and full integration of clinical and basic research efforts. Thus, translational research advances in neuroprotection may lead to future development of truly revolutionary therapies for glaucoma (e.g., neuroregeneration).

Pulsatile ocular blood flow in subjects with sleep apnoea syndrome

INTRODUCTION

The aim of the study was to determine the correlation between pulsatile ocular blood flow (POBF) and sleep apnoea syndrome (SAS).

MATERIAL AND METHODS

Patients were recruited from those who underwent polysomnography in the "Sleep Unit" of the physiology department (Medical University, Lodz, Poland). A total of 52 Caucasian patients, 34 with SAS and 18 age- and gender-matched controls, were included in the study. Comprehensive ophthalmic examination included the pulsatile ocular blood flow (POBF) measurements, disc analysis with Heidelberg Retina Tomograph II and Oculus Centerfield computerized perimetry as well as the best visual acuity, a slit lamp and indirect ophthalmoscopic evaluation of anterior and posterior segments and applanation tonometry.

RESULTS

The observed prevalence of glaucoma in SAS patients was 5.9% (2 of 34). The mean values of POBF were 1069.21 ±235.94 µl/min in the SAS group and 1061.78 ±174.63 µl/min in the control group. The study revealed that the differences of mean POBF between the SAS patients and the control group were not statistically significant: Mann-Whitney U-test p > 0.05. No correlations were found between sleep apnoea syndrome and mean intraocular pressure (IOP), mean retinal nerve fibre layer (RNFL) thickness and visual field mean defect (MD).

CONCLUSIONS

No correlation was found between pulsatile ocular blood flow and sleep apnoea syndrome. Although some previous studies found an association between IOP, MD, RNFL thickness and sleep apnoea syndrome, our study did not confirm that. However, a high prevalence of glaucoma was found among SAS patients in Poland.

Lifestyle strategies for the prevention of vision loss

As the baby boom generation ages, it is anticipated that half a million cases per year will be added to the 19 to 21 million Americans not living in institutions or serving in the military who have low vision or blindness. The 4 major causes of vision loss and blindness in the United States are cataract, diabetic retinopathy, glaucoma, and age-related macular degeneration. All 4 diseases involve change in the microcirculation in eye structures. Holistic approaches to health incorporate attention to individuals' lifestyle choices. Relevant research literature was reviewed to identify strategies for lifestyle modification that nurses can use to prevent or slow progression of these diseases. Prevention strategies in general are those that promote avoidance of cardiovascular disease and diabetes. Because vision loss has been shown to be associated with diminished quality of life and increased mortality, lifestyle changes that prevent or moderate the impact of these diseases are an important focus of nursing care.

Relationship between optic nerve head and finger blood flow

PURPOSE

To examine the relationship between optic nerve head (ONH) and finger blood flow in subjects with and without a primary vascular dysregulation (PVD).

METHODS

ONH blood flow and finger blood flow was measured in 15 subjects with PVD and in 24 subjects without PVD. PVD was defined as being present if it was detected in patient history as well as by nailfold capillaromicroscopy. PVD was defined as being absent if the patient history for PVD was negative and the results of nailfold capillaromicroscopy were negative. Scanning laser Doppler flowmetry (LDF) was used to measure ONH and finger blood flow. Finger temperature was measured in all subjects using a contact sensor.

RESULTS

ONH blood flow is significantly related to finger blood flow in subjects with PVD (p<0.01), but not in subjects without a PVD. Subjects with PVD had a significantly lower finger skin temperature in comparison to those without PVD (p<0.01)

CONCLUSIONS

The present study indicates a relationship between ONH and finger blood flow in subjects with PVD. This might be an indirect sign of a disturbed autoregulation of ocular blood flow in PVD subjects.