Ocular blood flow velocities in patients with proliferative diabetic retinopathy after panretinal photocoagulation

Color Doppler imaging allows for simultaneous two-dimensional anatomical imaging and Doppler measurement of blood-flow velocity. Because hemodynamic changes have been seen in diabetic patients after photocoagulation by other techniques, the author compared 25 eyes of 25 patients with proliferative diabetic retinopathy before and 6 months and 1 year after panretinal photocoagulation with a matched control group of 30 eyes of 30 healthy volunteers. The ophthalmic artery, short posterior ciliary artery, central retinal vessels, and vortex veins of all patients were examined, and the systolic, diastolic, and mean arterial velocities were measured. Panretinal photocoagulation was performed with these parameters: 800-1000 spots, 0.1 second, 500 microm argon laser. The blood velocity was significantly lower in diabetic patients than in normals in the ophthalmic artery and the central retinal artery. After treatment, blood-flow velocities were significantly lower than before photocoagulation in the ophthalmic artery, the central retinal artery and the central retinal vein. No statistically significant differences were found between 6 months and 1 year after panretinal photocoagulation. No significant correlations were found between age and blood velocities in diabetics and healthy volunteers. Eyes with proliferative diabetic retinopathy showed lower ocular perfusion velocities than normals in the ophthalmic artery and the central retinal artery. Photocoagulation resulted in a reduction in ocular blood-flow velocities in the ophthalmic artery, the central retinal artery and the central retinal vein; these values did not change significantly during 1 year of follow-up.