CHOROIDAL THICKNESS IN DIABETIC PATIENTS WITHOUT DIABETIC RETINOPATHY

To compare choroidal thickness (CT) between diabetic patients without diabetic retinopathy and a nondiabetic group. To explore how CT relates to disease duration, mean arterial pressure, glycemia, glycosylated hemoglobin, intraocular pressure, and ocular pulse amplitude.

Choroidal thickness was assessed using a spectral-domain optical coherence tomography and enhanced depth mode at 13 locations (subfoveal and 3 measurements 500 μm apart in 4 directions-nasal, temporal, superior, and inferior). Linear regression models were used.

One hundred seventy-five patients were recruited (125 diabetic patients without diabetic retinopathy and 50 nondiabetic patients). In diabetic patients, although without statistical significance, CT showed a trend to be thicker in all locations (6.16-24.27 μm). Choroidal thickness was negatively associated with age (P < 0.001) in both groups, but only in the diabetic group, it was positively associated to ocular pulse amplitude (with a mean increase between 8.5 μm and 11.6 μm for each millimeter of mercury increase in ocular pulse amplitude). Diabetic patients' CT seems to stabilize after 150 months of diabetes, increase with higher glycemia levels (>160 mg/dL) while showing no fluctuation with glycosylated hemoglobin and mean arterial pressure.

There seems to be a thickening of the choroid in diabetic patients without diabetic retinopathy. Moreover, this tissue may be functionally different in diabetes, as the pattern of associations seems to differ between groups.