Choroidal circulation in diabetic patients

Purpose To evaluate choroidal circulatory changes in diabetic patients with and without background diabetic retinopathy (BDR) by measuring the retrobu lbar circulation with colour Doppler imaging (CDI). Methods CDI was used to measure circulatory parameters of the PCA (posterio r ciliary artery), CRA (central retinal artery), OA (ophthalmic artery) and the respective veins in 73 diabetic patients and 22 controls in a sitting posture. Among the diabetic patients, 38 patients were without diabetic ret inopathy (NDR) and 35 had BDR. A non-parametric Kruskal-Wallis test with a Dunn correction was used for data analysis. Results End-diastolic velocity (EDV) in the PCA was decreased (2.55 +/- 0.8 0 cm/s) and resistivity index (RI) in the PCA was increased (0.70 +/- 0.08) in BDR patients compared with the control patients' EDV (3.23 +/- 1.08 cm/ s, P = 0.01) and RI (0.62 +/- 0.06, p = 0.0003). RI in the CRA was signific antly higher in the BDR group (0.74 +/- 0.09) than in the control group (0. 68 +/- 0.08, p = 0.006). RI in the OA was significantly higher in the BDR g roup (0.87 +/- 0.06) compared both with the NDR group (0.83 +/- 0.07) and w ith the control group (0.81 +/- 0.06; p = 0.007, p = 0.004). NDR patients h ad a significantly higher RI in the PCA (0.67 +/- 0.08) than control patien ts (0.62 +/- 0.06, p = 0.01, while the CRA RI (0.71 +/- 0.09) did not show significant differences from the control group (0.69 +/- 0.08, p = 0.32). D ecreased EDV in the CRA was detected in NDR patients (2.16 +/- 0.76 cm/s) c ompared with the controls (2.72 +/- 0.92 cm/s, P = 0.007). Conclusion The results from this study suggest that not only the retinal bu t also the choroidal circulation is affected in NDR and BDR patients.