Abstract
Purpose: :
To evaluate the prognostic factors for the best corrected visual acuity (BCVA) and foveal average retinal thickness after vitrectomy with internal limiting membrane (ILM) peeling for diabetic macular edema.
Methods: :
This retrospective study was conducted on 31 eyes of 27 patients who underwent pars plana vitrectomy with ILM peeling from January 2005 to March 2008. We evaluated statistically the relationship between systemic factors or ocular factors and BCVA or foveal average retinal thickness before and after operation. Systemic factors were body mass index, blood pressure, control of blood glucose, hypertension, hyperlipidemia, dialysis, ischemic disease, and blood test. Ocular factors were epiretinal membrane, type of macular edema, proliferative diabetic retinopathy (PDR), panretinal photocoagulation, and foveal hard exudates. BCVA, fundus examination, and optical coherence tomography (OCT) were undergone preoperatively and postoperatively until after 6 months. Multiple regression analysis was used as statistical calculations. Statistical significance was considered at P<0.05.
Results: :
Mean logMAR (minimal angle of resolution) was improved from 0.84±0.64 (mean±standard deviation) before operation to 0.64±0.38 6 month after operation. Foveal average retinal thickness was 473±146µm before operation, but was improved to 318±108µm at 6 months. Preoperative foveal average retinal thickness was significantly thicker with ischemic disease (P=0.0019) and with cystoid macular edema (P=0.0028). Preoperative BCVA was significantly better without epiretinal membrane (P=0.042). Foveal average retinal thickness at 6 months was significantly thicker with higher body mass index (P=0.0088), without dialysis (P=0.012), and PDR (P=0.013). BCVA at 6 months was significantly worse in group with no history of treatment for diabetes until diabetic retinopathy found (P=0.023), and higher HbA1c before operation (P=0.033).
Conclusions: :
BCVA and foveal average retinal thickness were primarily associated with ocular factors before operation, but they were strongly associated with systemic factors after operation. It might be because ocular factors were improved by operation.
Keywords: diabetic retinopathy