Impaired microvascular properties in uncomplicated type 1 diabetes identified by Doppler ultrasound of the ocular circulation

Abstract

Objective: Quantification of Doppler flow velocity waveforms has been shown to predict adverse cardiovascular outcomes and identify altered downstream haemodynamics and vascular damage in a number of organ beds. We employed novel techniques to quantify Doppler flow velocity waveforms from the retro bulbar circulation. Methods and results:In total, 39 patients with uncomplicated Type 1 diabetes mellitus, and no other significant cardiovascular risk factors were compared with 30 control subjects. Flow velocity waveforms were captured from the ophthalmic artery (OA), central retinal artery (CRA) and the common carotid artery. The flow velocity profiles were analysed in the time domain to calculate the resistive index (RI), and time-frequency domain using novel discrete wavelet transform methods for comparison. Analysis of flow waveforms from the OA and CRA identified specific frequency band differences between groups, occurring independently of potential haemodynamic or metabolic confounding influences. No changes were identified in the calculated RI from any arterial site. Conclusion: Novel analysis of the arterial flow velocity waveforms recorded from the retro bulbar circulation identified quantifiable differences in Doppler flow velocity waveform morphology in patients with diabetes prior to the development of overt retinopathy. The technique may be useful as an additional marker of cardiovascular risk.

The Effects of 23-Gauge Pars Plana Vitrectomy on Orbital Circulation Using Doppler Ultrasonography in Diabetic Macular Edema with Epiretinal Membrane and Taut Posterior Hyaloid

“…41 In our study, the postoperative decrease in CRA RI values in both groups could not be shown statistically, which suggest that vascular resistances remained unchanged. Furthermore, both the pre-and postoperative CRA's RI values were greater in Group 2 than in Group 1, and postoperative CRA RI changes differed between the groups.…”

Early Changes of Blood Flow Parameters of Ophthalmic Artery in Patients with Type 1 Diabetes Mellitus

“…Arai et al (10) found that the RI of central retinal artery was significantly higher in DM patients without DR. Gil et al (14) observed that there was an increase in OA resistance as the duration of DM increased. However, Ovali et al (8) and Lockhart et al (11) reported no change in the RI of the OA in patients with type 1 DM without DR. Many factors, such as age, race, duration of DM, glycemic control, site of measurement, and measurement technique, may affect ocular hemodynamics and lead to conflicting results (14)(15)(16).…”

“…The period before DR develops in patients varies; however, it has been found that retinal and vascular changes can occur even if no clinically significant DR is present (4,5). Vascular changes have an impact on ocular hemodynamics, and previous studies have documented how DM influences ocular hemodynamics (6)(7)(8). In the current body of literature, several studies have reported similar results for ocular hemodynamic changes, such as lower blood velocity and higher peripheric vascular resistance, in patients with DR (9, 10), however, conflicting results have been described with regard to ocular hemodynamic changes before the development of clinically significant DR (8,11).…”

Estudo do perfil hemodinâmico da artéria oftálmica em gestantes com diabetes mellitus gestacional

“…A vasculopatia é a intercorrência frequente entre as pacientes diabéticas, e tem levado muitos pesquisadores a estudar a impedância vascular orbital por meio do emprego da doplervelocimetria das artérias retinianas 12,13 . O primeiro estudo da artéria oftálmica em gestantes foi publicado em 1992 14 .…”