Choroidal changes and duration of diabetes.

PURPOSE: We investigate changes in macular choroidal thickness in eyes without diabetic retinopathy of patients with various durations of diabetes, using enhanced depth imaging optical coherence tomography (EDI OCT). METHODS: The 134 Type-2 diabetic patients who presented without diabetic retinopathy were prospectively imaged using EDI OCT on Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany) sd-OCT. The patients with diabetes were classified into three groups, according to the duration of diabetes: Group I (5-9 years, n = 63); Group II (10-14 years, n = 37); Group III (15-40 years, n = 34). The retinal and choroidal thickness was evaluated between these groups at central fovea and at the regions at 500-mm intervals up to 1500 mm temporal and nasal to the fovea. RESULTS: The central foveal retinal thickness was significantly different between groups (group I: 273.05 ± 19.51 µ, group II: 267.12 ± 20.78 µ, group III: 261.34 ± 22.27 µ; p = 0.04). The choroidal thickness measurements at central fovea, at 500, 1000, and 1500 micron intervals temporal and nasal to the center of the fovea were not significantly different between groups. The duration of diabetes was weakly correlated with choroidal thickness in all measured distances and they were not statistically significant. The central foveal choroidal thickness was weakly correlated with serum creatinine (r = -0.18, p = 0.03). CONCLUSION: Foveal retinal thickness was significantly decreased in patients with longer duration of diabetes. Duration of diabetes does not seem to be related to foveal chorodial thickness. On the other hand, the weak relation between creatinine and choroidal thickness may be evaluated further. The choroidal thickness changes that may be an early sign of nephropathy can be submitted to an easy, noninvasive scanning test at the same time.