Abstract
Purpose: :
To determine whether the thickness of pars plana changes in the presence of diabetic macular edema (DME).
Methods: :
In patients with DME (n=17), the pars plana and foveal thickness were measured with ultrasound biomicroscopy (UBM) and optical coherence tomography (OCT) before vitrectomy and at 1, 2, and 4 months after vitrectomy for surgical relief of DME. UBM was also done in diabetic patients who had severe nonproliferative diabetic retinopathy without DME (n=11) as diabetic control group, and in healthy volunteers (n=7) as healthy control group.
Results: :
The thickness of pars plana based on UBM was significantly increased in DME group (0.44 ± 0.77 mm) compared with diabetic (0.38 ± 0.04 mm) and healthy controls (0.31 ± 0.03 mm) (P = 0.002). In DME group, the thickness of pars plana decreased significantly at 1 month after vitrectomy (0.38 ± 0.07 mm, P = 0.009), which maintained up to 4 months after vitrectomy. The foveal thickness based on OCT were 381 ± 164 µm before surgery, and 315 ± 129 µm, 307 ± 138 µm, 310 ± 147 µm after 1, 2, 4 months after surgery respectively, which were correlated with the changes in the thickness of pars plana after vitrectomy.
Conclusions: :
This study indicates that the thickness of pars plana may be increased in patients with DME compared to diabetic patients without DME or healthy controls, and vitrectomy may be effective in decreasing pars plana edema as well as macular edema in the patients with DME.
Keywords: diabetic retinopathy • ciliary body