Hemodynamics of the pectinis oculi artery in American pekin ducks ( Anas platyrhynchos domestica )

Objective To measure blood velocity parameters of the main detectable branch of the pectinis oculi artery and compare with values found in other arteries in other species to form a hypothesis of the function of the pecten oculi in birds. Methods Eleven American pekin ducks ( Anas platyrhynchos domestica ) without ocular diseases were examined with ocular Doppler ultrasonography. The pectinate artery resistive index ( RI ) and pulsatility index ( PI ) were calculated. Results The mean of RI and PI values resulted, respectively, in: left eye (0.43 ± 0.07; 0.58 ± 0.13), right eye (0.37 ± 0.09; 0.47 ± 0.14), and both eyes (0.40 ± 0.08; 0.53 ± 0.14). Discussion The low RI and PI values found in the main branch of the pectinis oculi artery compared with other arteries in other tissues suggest a high metabolic activity in the pecten oculi, and it could indicate a nutritional function and/or intraocular pressure regulation.