Abstract
Purpose:
Choroidal thickness may change after vitrectomy for proliferative diabetic retinopathy (PDR), because the surgery includes various procedures. One of the factors affecting choroidal thickness may be the application of endophotocoagulation. On the other hand, swelling the retina after photocoagulation was reported. The purpose of this study was to determine whether there was a thickening of the peripheral and posterior retina-choroid after PPV with photocoagulation.
Methods:
The medical charts of 24 eyes of 22 patients that had undergone 23 or 25-gauge PPV with endophotocoagulation for proliferative diabetic retinopathy were reviewed. For control, 26 eyes of 26 consecutive patients that had undergone PPV without photocoagulation for an epiretinal membrane were studied. All surgeries were performed at the Nagoya University Hospital from June to November 2012. The peripheral retina-choroid thickness (RCT) was measured at 5 mm from the limbus in the four quadrants with a swept source optical coherence tomography (SSOCT) before and 3 days, and 1, and 2 week(s) after surgery. The posterior RCT was measured by enhanced depth imaging OCT (EDI-OCT) at the same time points.
Results:
In the diabetic group with photocoagulation, the mean peripheral RCT before surgery, 3 days, 1, and 2 week(s) after surgery were 225 µm, 780 um, 351 µm, and 247 µm, respectively. The peripheral RCT at 3 days and 1 week after surgery was significant thicker than that before the surgery (P<0.001, P=0.003). In the control group, the mean peripheral RCT before surgery, 3 days, 1, and 2 weeks after surgery was 167 µm, 248 µm, 212 µm, and 191 µm, respectively. The increase in the peripheral RCT at 3 days after surgery in the diabetes group was significantly greater than in the control group (P<0.001). There was a significant correlation between the number of photocoagulation burns (mean, 1653 ±1057) and the peripheral RCT at 3 days after surgery (r=0.528; P=0.024). There was no significant difference in the posterior RCT between pre- and any postoperative period in both groups (P>0.05).
Conclusions:
The peripheral RCT after PPV with endophotocoagulation in the diabetic group became thicker in the earlier postoperative period and the increase in the thickness was significantly correlated with the number of photocoagulation burns.
Keywords: 499 diabetic retinopathy •
550 imaging/image analysis: clinical •
452 choroid