Association between Systemic Antioxidant Capacity and Retinal Vessel Diameters in Patients with Primary-Open Angle Glaucoma

The retinal vessel narrowing may be implicated in the pathogenesis of glaucoma; however, the association between systemic oxidative stress and retinal vessel diameter remains largely unknown. We examined the relationship between serum oxidative stress markers and retinal vessel diameters in eyes with primary open-angle glaucoma (POAG) and cataract, using central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE). We included 66 eyes of 66 patients with POAG (37 men, 29 women; 65.4 ± 11.7 years) and 20 eyes of 20 patients with cataract (7 men, 13 women; 69.4 ± 9.0 years) as the controls. The CRAE (p < 0.0001), CRVE (p < 0.0001), and serum biological antioxidant potential (BAP) (p = 0.0419) were significantly lower in the POAG group compared to the controls. The BAP showed significant correlation both with CRAE (ρ = 0.2148, p = 0.0471) and systolic blood pressure (ρ = −0.2431, p = 0.0241), while neither Diacron reactive oxygen metabolites nor sulfhydryl test correlated with them. The multivariate analyses indicated that age, best corrected visual acuity, and BAP were independent factors for CRAE or CRVE. The present study suggested that lower systemic antioxidant capacity was significantly associated with the intraocular pressure-independent vascular narrowing in POAG patients. This study provided a novel insight into the pathophysiology of glaucoma and highlighted the clinical impact on systemic antioxidant treatment for patients with glaucoma.

Retinal Vessel Diameters and Blood Pressure Progression in Children

The prevalence of high childhood blood pressure (BP) is rising globally and has been associated with subclinical vascular impairments in children. Longitudinal data on the association of microvascular alterations with the development of high BP in children are lacking. We aimed to analyze the association of central retinal arteriolar (CRAE) and venular (CRVE) diameters with development of higher BP over 4 years in young school children. In 2014, 391 children aged 6 to 8 years were screened for BP and retinal vessel diameters using standardized protocols. Retinal vessel analysis was performed using a retinal vessel analyzer to determine CRAE and central retinal venular equivalent. In the follow-up of 2018, all parameters were assessed in 262 children using the same standardized protocols. During follow-up, systolic and diastolic BP increased significantly (Δ 3.965±8.25 and 1.733±7.63 mm Hg, respectively), while CRAE decreased by Δ −6.325±8.55 µm without significant changes in central retinal venular equivalent (Δ −0.163±7.94 µm). Children with narrower CRAE at baseline developed higher systolic BP after four years (β [95% CI] 0.78 [0.170–1.398] mm Hg per 10 µm decrease, P =0.012). Children with increased systolic or diastolic BP at baseline developed narrower CRAE (β [95% CI] −0.154 [−0.294 to −0.014] µm per 1mmHg, P =0.031 and β [95% CI] −0.02 [−0.344 to −0.057] µm per 1 mmHg, P =0.006, respectively) at follow-up. Narrowing of retinal arterioles predicted evolution of systolic BP. In turn, higher initial systolic and diastolic BP was associated with subsequent development of microvascular impairments. Our results give good evidence for a bivariate temporal relationship between BP and microvascular health in children.

Structural analysis of retinal blood vessels in patients with COPD during a pulmonary rehabilitation program

Cardiovascular diseases are frequently present in chronic obstructive pulmonary disease (COPD). Population-based studies found associations between retinal vessel diameters and cardiovascular health, but it is unknown whether this also applies to COPD patients. Therefore, we measured retinal vessel diameters in COPD patients and aimed to determine the association with cardiovascular risk factors, lung function, and functional outcomes. In addition, we investigated whether an exercise-based pulmonary rehabilitation (PR) program would change retinal vessel diameters, as a proxy for improved microvascular health. Demographics and clinical characteristics, including pulmonary function, exercise capacity, blood pressure, blood measurements and level of systemic inflammation were obtained from 246 patients during routine assessment before and after PR. Retinal vessel diameters were measured from digital retinal images. Older age and higher systolic blood pressure were associated with narrower retinal arterioles (β: −0.224; p = 0.042 and β: −0.136; p < 0.001, respectively). Older age, higher systolic blood pressure and lower level of systemic inflammation were associated with narrower retinal venules (β: −0.654; −0.229; and −13.767, respectively; p < 0.05). No associations were found between retinal vessel diameters and lung function parameters or functional outcomes. After PR, no significant changes in retinal venular or arteriolar diameter were found. To conclude, retinal vessel diameters of COPD patients were significantly associated with systolic blood pressure and systemic inflammation, whilst there was no evidence for an association with lung function parameters, functional outcomes or other cardiovascular risk factors. Furthermore, an exercise-based PR program did not affect retinal vessel diameter.

4095Exercise and vascular ageing: a cross-sectional and randomized controlled trial

Background Vascular ageing can be quantified at subclinical stages by use of sensitive vascular biomarkers of the macro- and microcirculation. Detection of vascular impairments enables initiation of timely treatment strategies to counteract development of CV disease and improve CV outcome. Purpose To (a) compare large artery stiffness and retinal microvascular diameters in healthy life-long active and healthy sedentary older adults with CV risk patients, and (b) to assess the effects of short-term high-intensity exercise training on vascular health in these patients. Methods Seven hundred and eighty-three participants were screened for their CV risk and physical activity profile. We included 38 healthy active (HA, mean age 60±7 years) and 36 healthy sedentary (HS, mean age 60±7 years) as well as 84 sedentary patients with ≥2 CV risk factors (SR, mean age 59±6 years) in the cross-sectional approach. SR were randomized to a 12-week high-intensity interval training (HIIT) or physical activity recommendations after the baseline assessment. Carotid-femoral PWV (cfPWV) was measured as a marker of large artery stiffness and the central retinal arteriolar (CRAE) and venular (CRVE) diameters as well as the retinal arteriolar-to-venular diameter ratio (AVR) were measured as a marker of the microcirculation. Standard procedures of anthropometric measurements were implemented. Results Anthropometric parameters differed between the groups according to the inclusion criteria. cfPWV was highest in SR (8.2±1.4m/s) compared to HS (7.5±1.6m/s) and HA (7.0±1.1 m/s). HA had a lower cfPWV compared to HS (p<0.05) and SR (p<0.001). HA had wider CRAE (179±14μm) and narrower CRVE (204±17μm) compared to HS (CRAE: 172±11 μm; CRVE: 209±11 μm) resulting in a higher AVR in HA (0.88±0.05) compared to HS (0.83±0.04, p<0.001). By contrast, SR showed narrower CRAE (171±14 μm) and wider CRVE (218±16μm, p<0.05) compared to HS resulting in a lower AVR (0.79±0.05, p<0.001) compared to HS and HA. HIIT in SR improved most classic CV risk factors. Additionally, CRAE increased (pre: 175±14μm vs post: 181±13μm, p=0.001) and CRVE decreased (pre: 222±14μm vs post: 220±14μm, p=0.007) in the HIIT group without changes in the cfPWV. PWV was significantly but moderately associated with AVR (r=−0.2, p=0.01). Conclusions Life-long physical activity and fitness were associated with lower arterial stiffness and favourable retinal vessel diameters in healthy individuals. CV patients had higher arterial stiffness and lower AVR. Short-term HIIT improved retinal microvascular phenotype without changes in large artery stiffness. Retinal vessel diameters are sensitive diagnostic tool for CV risk stratification and subclinical vascular disease monitoring in CV patients. Short-term HIIT may postpone development of small vessel disease in older patients. Acknowledgement/Funding Swiss National Science Foundation, Nora van Meeuwen-Häfliger Stiftung