Noninvasive optical coherence tomography imaging correlates with anatomic and physiologic end-organ changes in healthy normotensives with systemic blood pressure variability

Choroidal vascularity index in pseudoexfoliative glaucoma

PURPOSE

To evaluate choroidal vascular involvement in pseudoexfoliative glaucoma (PEXG) by applying the choroidal vascularity index (CVI) to optic coherence tomography (OCT) images.

METHODS

Seventy-eight eyes from 40 subjects were included the study. Group 1 included healthy eyes (n = 20), group 2 eyes with PEX (n = 16), and group 3 eyes with PEXG (n = 42). OCT imaging of macular and peripapillary regions and retinal nerve fiber layer (RNFL) analyses were performed. CVI was calculated using ImageJ software.

RESULTS

The mean age was 64.89 ± 5.8, 71.2 ± 7.8, and 68.24 ± 7.4 years in groups 1, 2, and 3, respectively (p = 0.046). There were no significant differences between the groups in terms of sex (p = 0.777). In macula, mean CVI rates were 66.97 ± 1.9%, 64.23 ± 1.2%, and 64.63 ± 1.6%, and in the peripapillary areas, mean CVI rates were 67.04 ± 1.5%, 65.20 ± 1.5%, and 64.14 ± 2.1% in groups 1, 2, and 3, respectively (group 1 vs. group 2 and 3, p = 0.000; group 2 vs. group 3, p > 0.05). The decrease in average RNFL thickness was statistically significant in group 3 compared to groups 1 and 2.

CONCLUSION

CVI could be used to assess choroidal vascular changes in ocular diseases. CVI was found to be reduced in PEX and PEXG, indicating an ocular vascular involvement in pseudoexfoliative process.

Recent Advances in Atherosclerotic Disease Screening Using Pervasive Healthcare

Atherosclerosis screening helps the medical model transform from therapeutic medicine to preventive medicine by assessing degree of atherosclerosis prior to the occurrence of fatal vascular events. Pervasive screening emphasizes atherosclerotic monitoring with easy access, quick process, and advanced computing. In this work, we introduced five cutting-edge pervasive technologies including imaging photoplethysmography (iPPG), laser Doppler, radio frequency (RF), thermal imaging (TI), optical fiber sensing and piezoelectric sensor. IPPG measures physiological parameters by using video images that record the subtle skin color changes consistent with cardiac-synchronous blood volume changes in subcutaneous arteries and capillaries. Laser Doppler obtained the information on blood flow by analyzing the spectral components of backscattered light from the illuminated tissues surface. RF is based on Doppler shift caused by the periodic movement of the chest wall induced by respiration and heartbeat. TI measures vital signs by detecting electromagnetic radiation emitted by blood flow. The working principle of optical fiber sensor is to detect the change of light properties caused by the interaction between the measured physiological parameter and the entering light. Piezoelectric sensors are based on the piezoelectric effect of dielectrics. All these pervasive technologies are noninvasive, mobile, and can detect physiological parameters related to atherosclerosis screening.

Relation between nocturnal decline in blood pressure and choroidal thickness: a comparative analysis in dipper vs. non-dipper hypertensive patients

PURPOSE

To compare choroidal thickness (ChT) and echocardiographical changes in patients with dipper and non-dipper systemic arterial hypertension (HT).

METHODS

Patients with HT were evaluated in two groups according to the 24-hour ambulatory BP monitoring. Compared to day-time values, those whose night-time SBP decreased ≥10% were defined as dippers, and those whose SBP decreased <10% were defined as non-dippers. Transthoracic echocardiography was conducted in all patients. ChT and central macular thickness were measured with spectral-domain optical coherence tomography. ChT was obtained at the subfoveal, 1500 µm nasal and temporal to the fovea.

RESULTS

Thirty non-dipper (18 females and 12 males) and 23 dipper (16 females and seven males) hypertensive patients were recruited. Sex distribution and the mean age were similar between the groups (P = 0.472; P = 0.12). Disease duration was longer in the non-dipper group (8 ± 3.39 vs. 4.96 ± 1.19 years, P = 0.001). The non-dipper group had lower ChT in subfoveal and temporal locations (P = 0.02 and 0.03, respectively) and higher left atrial volume index (LAVI) and pulmonary valve maximum flow (PV-max; P < 0.001). The night-time SBP was negatively correlated with ChT (P = 0.048) and positive correlated with LAVI and PV-max (P < 0.05). However those correlations were not significant when were controlled by the possible confounding factors as disease duration, age and gender.

CONCLUSION

Non-dipper HT patients may have thinner choroid than dippers due to longer duration of HT and higher ambulatory BP levels.

The relationship between glycemic variability and blood pressure variability in normoglycemic normotensive individuals

BACKGROUND AND AIM

Glycemic fluctuations around a mean glucose level, referred as glycemic variability and blood pressure variability (BPV) are considered as independent risk factors for cardiovascular diseases, all-cause mortality, and cardiovascular disease-mortality. With this background in mind, we aimed to investigate the association between glycemic variability and BPV and their association in normoglycemic and normotensive individuals.

MATERIALS AND METHOD

Twenty-seven normotensive normoglycemic individuals were recruited. Twenty-four hour Holter devices were utilized to measure ambulatory blood pressure (BP) while continuous glucose monitoring (CGM) devices were applied to measure glycemic variability simultaneously to the subjects. These devices were kept on for 48 h. For BP recordings, daytime, nighttime, and 24-h BP determinations, their mean and SD were calculated. From CGM measurements, mean blood glucose (MBG), SD of blood glucose, the mean amplitude of glycemic excursions (MAGE), the mean of daily differences (MODD), coefficient of variation (correction of variability for the MBG), and daytime and nighttime blood glucose were determined.

RESULTS

The mean age of the subjects was 23.8 ± 2.7 years and 66% were women (18/27). In the correlation analysis between glycemic variability parameters and BPV parameters, SD of 24-h SBP was correlated with the SD of MBG (r = 0.52, P = 0.006), MAGE (r = 0.49, P = 0.009), and MODD (r = 0.46, P = 0.015). SD of daytime SBP was correlated with, MAGE (r = 0.42, P = 0.03) and MODD (r = 0.43, P = 0.02).

CONCLUSION

We report correlation between glycemic variability and BPV variables in normoglycemic and normotensive healthy individuals.

Relationship of choroidal thickness with pulsatile hemodynamics in essential hypertensive patients

Controversy exists about the association of choroidal thickness (CTh) with blood pressure (BP) values. There is some evidence suggesting that central hemodynamics changes are associated with microvascular disease. Our study was aimed to assess the relationships between CTh and clinic and 24‐h BP and between CTh and estimated 24‐h aortic pulse pressure (aPP), 24‐h aortic systolic BP (aSBP), and 24‐h aortic augmentation index (aAIx) in a group of hypertensive patients. We enrolled 158 hypertensive subjects (mean age 48 ± 13 years) all of which underwent evaluation of the choroidal district by Swept‐Source optical coherence tomography (SS‐OCT) and 24‐h BP monitoring, in order to measure peripheral BP and to estimate central hemodynamic parameters. Inverse significant correlations of clinic PP, 24‐h aPP, 24‐h aSBP, and 24‐h aAIx with thicknesses of central ring, inner ring, and outer ring of the choroid and its overall average were found. The strongest of these correlations was that relating 24‐h aPP with overall average choroidal thickness (r = −.531; P < .001). When we divided the study population in subjects with 24‐h aPP above and below the median value (35 mm Hg), CTh were thinner in subjects with higher values of 24‐aPP as compared to those with lower ones, even after adjustment for age, and other potential confounders. The relationships of CTh with 24‐h aPP remained significant also taking into account the effects of various covariates in linear multiple regression analyses. Our findings support the concept of a cross‐talk between macro‐ and microcirculation.