To determine the size of the foveal avascular zone (FAZ) by optical coherence tomography angiography before and after idiopathic epiretinal membrane surgery.Methods:
Thirteen consecutive patients (13 eyes) with unilateral epiretinal membrane were studied retrospectively. Optical coherence tomography angiography was used to measure the FAZ area within 3 mm2 × 3 mm2 scans of the superficial (superficial FAZ) and deep plexus layers (deep FAZ) before and 6 months after vitrectomy. The unaffected fellow eyes were used as controls.Results:
The mean superficial and deep FAZ areas at 6 months after vitrectomy (0.080 ± 0.038 and 0.113 ± 0.045 mm2, respectively) were significantly (P < 0.0001, P = 0.0035) larger than the corresponding mean preoperative FAZ areas (0.056 ± 0.030 and 0.082 ± 0.035 mm2). However, the areas of FAZ expansion were small (0.024 ± 0.013 and 0.031 ± 0.031 mm2). The mean postoperative superficial and deep FAZ areas were significantly (P < 0.0001, P < 0.0001) smaller than those of fellow eyes (0.295 ± 0.108 and 0.410 ± 0.142 mm2). Multiple regression analysis showed that preoperative FAZ area had the highest correlation with postoperative FAZ area (P < 0.05).Conclusion:
This study showed horizontal contraction of the FAZ area in eyes with epiretinal membrane. Because preoperative FAZ area correlates with postoperative FAZ area, FAZ area may be a useful parameter for determining timing of surgery for epiretinal membrane.