Purpose: To investigate the effect of acute diabetic control on choroidal thickness in patients with Type 2 diabetes.
Methods: Seventeen eyes of 17 patients with Type 2 diabetes were included in this prospective observational study. The patients with Type 2 diabetes who were scheduled to undergo a program of intensive diabetic control underwent prototype high-penetration optical coherence tomography before and 2 weeks after the start of treatment. The choroidal thickness changes 2 weeks after the protocol of intensive diabetic control were assessed, and associated ophthalmologic and general parameters were explored. Seventeen eyes of 17 healthy volunteers were included to compare diabetic patients. The choroidal thickness also was measured in this group at baseline and after 2 weeks. And the intraobserver and interobserver reproducibility were verified using this control group.
Results: The intraobserver (intraclass coefficient, 0.992) and interobserver reproducibility (0.982) in our subfoveal choroidal thickness measurement were high. The mean subfoveal choroidal thickness after 2 weeks (226 ± 56 μm) was significantly greater than at baseline (215 ± 52 μm, P < 0.05); there was no difference between the baseline and 2-week values in the control group (baseline, 312 ± 113 vs. 2-week value, 307 ± 103 μm; P = 0.17). The changes in refractive error (P < 0.001), axial length (P < 0.01), and diastolic blood pressure (P < 0.01) were associated significantly with changes in choroidal thickness 2 weeks after the intensive control. The pretreatment body mass index (P < 0.05) and hemoglobin A1c (P < 0.005) also were associated significantly with increased choroidal thickness.
Conclusion: Diabetic patients showed a significant increase of choroidal thickness after the intensive control. Various ophthalmologic and systemic parameters seem to affect the choroidal thickness changes. This may be related to the progression of retinopathy after acute glycemic control.