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Purpose: To analyze the progression of structural and functional retinal impairment in type 1 diabetes mellitus (T1DM) patients with no clinical signs of diabetic retinopathy (DR) during a 3-year follow-up. Methods: This was an observational longitudinal study. Post-pediatric T1DM patients without clinical signs of DR, and sex- and age-matched healthy subjects were recruited at San Raffaele Hospital (Milan, Italy). Each patient underwent a comprehensive ophthalmological evaluation, including optical coherence tomography (OCT), OCT-angiography (OCT-A), retinal static and dynamic vessel analysis (DVA), and microperimetry. Results: 21 eyes of 21 T1DM patients (10 females; 24 ± 2 years old), and 21 age and sex-matched healthy subjects were enrolled. At baseline, T1DM eyes revealed a significantly decreased vessel length density using OCT-A (p < 0.001 and p = 0.046 in 3 × 3 and 6 × 6 mm images) and a significantly increased vessel density index (p = 0.013 and p = 0.087 in 3 × 3 and 6 × 6 mm images) of deep capillary plexus. DVA detected a significantly decreased vessel response to flicker light (p = 0.002). A significantly increased thickness of ganglion cellular layer 6-mm-diameter subfields in inferior and superior quadrants was found in diabetic patients (p < 0.001 in both subfields). At 3-years-follow-up no significant longitudinal changes were disclosed in all analyses. Conclusions: Concomitant subclinical microvascular and neurodegenerative damages could be early signs of DR onset that precede functional alterations and clinical signs of DR development. These alterations demonstrated a stable trend over time. [ABSTRACT FROM AUTHOR]

Retinal vessels show various biological temporal variations that can impact diagnosis using a static vessel analysis. In this study, Mayer waves in the retinal vessel diameter and arterial blood pressure (BP) signals were characterized, and the temporal correlation between these two modalities was investigated. The arterial and venous vessel diameters and arterial BP were recorded simultaneously on human subjects. The obtained vessel diameters showed vasomotion amplitudes over time. The vessel diameter and BP signals contained multiple signals in the frequency domain and varied over time. The signal characteristics were similar within the measurements. The BP and arterial and venous vessel diameters were correlated. The highest correlation values between the signals were observed for shifts of 1 or 0 periods. The spectrum and amplitudes of the Mayer waves showed a high variability. The Mayer waves in the retinal vessel diameters showed the same characteristics as those in the arterial BP. A temporal dependency between the oscillations in the arterial BP and retinal vessel diameters was shown.

Retinal vessels show various biological temporal variations that can impact diagnosis using a static vessel analysis. In this study, Mayer waves in the retinal vessel diameter and arterial blood pressure (BP) signals were characterized, and the temporal correlation between these two modalities was investigated. The arterial and venous vessel diameters and arterial BP were recorded simultaneously on human subjects. The obtained vessel diameters showed vasomotion amplitudes over time. The vessel diameter and BP signals contained multiple signals in the frequency domain and varied over time. The signal characteristics were similar within the measurements. The BP and arterial and venous vessel diameters were correlated. The highest correlation values between the signals were observed for shifts of 1 or 0 periods. The spectrum and amplitudes of the Mayer waves showed a high variability. The Mayer waves in the retinal vessel diameters showed the same characteristics as those in the arterial BP. A temporal dependency between the oscillations in the arterial BP and retinal vessel diameters was shown. [ABSTRACT FROM AUTHOR]

Aims: To investigate the short-term effects of intravitreal ranibizumab on retinal vessel functionality in patients with diabetic macular edema (DME) by Dynamic Vessel Analyzer (DVA). Methods: Patients presenting with DME were enrolled in the study. All patients underwent a complete ophthalmic evaluation, including optical coherence tomography and dynamic and static vessel analysis, using the DVA before (baseline), 1 week and 1 month after administration of intravitreal ranibizumab. DME subject were compared with diabetic retinopathy (DR) without DME subjects, and with normal non diabetic subjects (controls) matched for age and sex. Results: A total of 45 eyes of 45 subjects (15 eyes for each group) were included in the analysis. In DME patients, dynamic analysis showed a significant decrease in mean arterial dilation from baseline to 1 week. Mean central retinal artery equivalent (CRAE) of DR patients without DME was significantly different from baseline and week 1 of DME eyes. In healthy control subjects, CRAE was significantly different from CRAE at baseline and 1 week on DME patients, but not significantly different from DR patients without DME. Conclusions: Using DVA in patients with DME, dynamic analysis showed a significant decrease in mean arterial dilation from baseline to 1 week in DME eyes. A significant reduction in arterial vessels could be demonstrated in DME patients compared to DR patients without DME and controls. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the dynamic and static retinal vascular functionality in young females using combined hormonal contraceptive (CHC). Methods: Thirty-eight consecutive young female subjects were enrolled in this study between January 2015 and December 2015. Subjects were divided in two groups: CHC group, defined as CHC use for ≥6 months, and control group, defined as no current and prior CHC use. Participants underwent a dynamic and static retinal vessel analysis using the Dynamic Vessel Analyzer (DVA, Imedos, Jena, Germany). Results: Seventeen subjects continuously took CHC for 54.6 ± 29.3 months, while 21 subjects belonged to control group. No difference was found between the CHC and control groups for age ( p = 0.1), smoking status ( p = 0.6), and systolic ( p = 0.3) and diastolic ( p = 0.1) blood pressure. With regard to dynamic analysis, women taking CHC exhibited a marked significant vasoconstriction following flicker stimulation in comparison with control group (−2.43 ± 2.5 vs 0.63 ± 2.1, respectively; p = 0.0002). No significant difference was observed between groups for mean arterial ( p = 0.2) and venous dilatations ( p = 0.3), arteriovenous ratio ( p = 0.09), central retinal artery equivalent ( p = 0.4), and central retinal venous equivalent ( p = 0.5). Conclusions: CHC may affect vessel reactivity to flicker light by increasing arteries constriction. This may reflect systemic changes in vascular functionality in subjects using CHC. Moreover, CHC should be considered as a confounding bias in studies involving DVA. [ABSTRACT FROM AUTHOR]

Purpose: To analyze device-dependent variability of two non-mydriatic fundus cameras to obtain arterio-venous ratio (AVR), central retinal arteriolar equivalent (CRAE), and central retinal venular equivalent (CRVE) in static vessel analysis (SVA). Methods: We examined 53 participants (29 men, 24 women; median age 46 years) of the Study of Health in Pomerania (SHIP). We took 45° optic-disc-centered fundus images of the right eye with two different non-mydriatic fundus cameras. The first photograph was obtained from the TRC-NW 200, the second from the OCT 2000 (both Topcon Corporation, Tokyo, Japan). One experienced grader graded image quality from 1 'ideal quality' to 5 'not analyzable' and determined AVR, CRAE, and CRVE with the software Vesselmap3 (Imedos, Jena, Germany). Results: Average image quality was 1.8 for the TRC-NW 200 and 1.6 for the OCT 2000. AVR could not be determined in 5 images of the TRC-NW 200 due to low image quality, while six images of the OCT 2000 were not analyzable. The difference between AVR taken from two different non-mydriatic cameras was 0.01 ± 0.03 in Bland-Altman plots. The difference between CRAE was 0.17 ± 10.15 and between CRVE was −2.32 ± 11.76. Conclusions: The two different non-mydriatic cameras showed good agreement with respect to image quality. When using the same reading software, AVR, CRAE, and CRVE agreed well. Thus, funduscopy and SVA seem to be robust against inter-device variability. As a result, device dependency can remain unconsidered in follow-up examinations with different technical equipment. However, variability might impact more with devices from different manufacturers. [ABSTRACT FROM AUTHOR]