CONICET | Buscador de Institutos y Recursos Humanos

Doppler ultrasound (US) evaluation is a complementary technique to B-mode scanning and allows a non-invasive study of local vascularization, identifying alterations of blood vessels diameter and their path, and determining quantitative parameters of blood flow and vascular resistance. Evaluation of the effects of pharmacological and surgical interventions in the ocular circulation is important in many retinal diseases such as diabetic retinopathy, age-related macular degeneration, glaucomatous optic neuropathy and retinal vascular occlusion. The aim of this work is to report the development of the Doppler US technique for evaluation of hemodynamic parameters in rabbit eyes. Twenty New Zealand adult male rabbits from CMC (ICIVET Litoral) were used. After systemic and ocular local anesthesia, the animals were subjected to US by a 6-14 MHz linear probe (L14-6P, Mindray) added to a color Doppler equipment (Z6 Vet, Mindray, China), carefully supporting the transducer on the eyeball. Color and spectral Doppler settings were optimized for evaluation of blood velocity (peak systolic velocity, end-diastolic velocity, and mean velocity), the resistance index (RI), and the pulsatility index (PI) of the central retinal artery and the central retinal vein. Blood velocity, RI and PI were obtained for each eye of every rabbit on the study. Doppler evaluation allowing us to determine and characterize hemodynamic parameters of the vessels of the posterior segment of rabbit eyes. There have been few previous reports of using Doppler ultrasound to measure blood velocity in the retinal vessels in laboratory animals due to the small diameters and low flow rates of these vessels. This technique provides a different and non-invasive tool for the evaluation of hemodynamic parameters in ophthalmological preclinical studies.