Estudo hemodinâmico das artérias oculares e retrobulbares em cães e gatos

Abstract

Doppler ultrasound is lacking information in the ophthalmology area applied to dogs and cats. Changes in ocular blood flow may serve as a sentinel to changes in the cardiovascular system and other systems. In this context, the objectives of this study was to: 1) identify the retrobulbar and eye vessels by Doppler ultrasound and determine the resistance index (RI) and pulsatility index (PI) of the external ophthalmic artery (OA) of healthy cats; 2) define the Doppler indices (RI and PI) of the AO and short posterior ciliary (ACPC) in healthy dogs and cataracts, 3) check if there is hemodynamic difference between the stages of cataract and the control group, and 4) correlate them electroretinogram parameters with the total photopic field, intraocular pressure, mean arterial pressure and ocular perfusion pressure. 20 cats, 10 healthy dogs and 31 dogs with cataracts were used. Chemical restraint was performed with animals ketamine S (+) and xylazine. the following values were obtained in cats: PVS (33.78 ± 5.54 cm / s), EDV (23.1 ± 4.32), IR (0.31 ± 0.05) and IP (0.38 ± 0.09). In dogs with cataracts the following results: IR AO (0.54 ± 0.14), AO IP (0.90 ± 0.42), IR ACPC (0.50 ± 0.10), IP ACPC (0.77 ± 0.26). With the studies it can be concluded that: 1) contributed to the sonographic characterization of the main retrobulbar and eye vessels, as well as standardization of the AO Doppler indices in healthy cats; 2) dogs with cataract showed higher Doppler indices that healthy animals, creating the hypothesis that this disease and its potential consequences, such as changes in the retina, may affect the self-regulation mechanisms of ocular blood flow or be a relevant factor to the pathogenesis of cataract and visual changes in the retina.