Orbital Doppler evaluation of blood flow velocities in patients with diabetic retinopathy.

BACKGROUND

There have been conflicting results in relation to impaired ocular hemodynamics in the orbital vessels of patients with diabetic retinopathy (DR). Clarification of the early signs of retinopathy in diabetic patients is urgently needed.

AIMS

We aimed to evaluate orbital blood flow velocities using Doppler and gray-scale sonography in patients with DR, and to compare the results with those of their non-diabetic and diabetic peers without retinopathy.

METHODS

Orbital Doppler and gray-scale sonography were performed in 123 patients aged 29-77 who had been divided into 3 groups: non-diabetic controls (n = 25), diabetes and impaired glucose tolerance with minimal clinical retinopathy (n = 74), and diabetes with untreated non-proliferative retinopathy (n = 24). Retinopathy was diagnosed by an ophthalmologist on the basis of fundoscopic examination. The peak systolic (PSV) and end-diastolic (EDV) blood flow velocities, and the resistivity and pulsatile indices, of the ophthalmic artery, central retinal artery, posterior ciliary artery, and central retinal vein were measured.

RESULTS

Compared with healthy controls, the age-adjusted resistivity and pulsatile indices of the ophthalmic artery were significantly higher in patients with DR (p < 0.05). PSV and EDV of the posterior ciliary arteries were significantly lower in diabetic patients with DR. After further adjustment for age, gender, HbA1c, fasting plasma glucose, blood pressure, BMI, cholesterol, HDL, LDL, and triglycerides, only the resistivity index of the ophthalmic artery and the central retinal vein remained significantly higher in patients with DR compared with healthy controls (p < 0.005 after Bonferroni adjustment).

CONCLUSIONS

Resistivity index alteration of the ophthalmic artery and central retinal vein may be prevalent among patients with early changes in DR.