Early postoperative changes of the foveal surface in epiretinal membranes: Comparison of 23-gauge macular surgery with air vs. balanced salt solution

摘要

Objective: To analyze the foveal surface using binary image analysis after spectral-domain optical coherence tomography (SD-OCT) following 23-gauge macular surgery in epiretinal membranes (ERM) using either air tamponade (AIR) or balanced salt solution (BSS). Methods: One hundred twenty-four eyes (124 patients) with ERM that had undergone membrane peeling with installation of air or BSS were analyzed retrospectively. Ophthalmic examination was performed at baseline and 3 months. Outcome measures: The foveal area and surface symmetry, area matched thickness, area matched contour, and best-corrected visual acuity (BCVA). The OCT images were analyzed after binary conversion with ImageJ software. Results: Eighty eyes (80 patients) of 124 screened patients were included (AIR group: 39 patients, BSS group: 41 patients). Median follow-up time was 14 weeks (range, 9-19 weeks). Three months after surgery, the median horizontal area decreased significantly in both groups (p<0.0001). At follow-up, the foveal surface symmetry values for the BSS group (median, 22.73 μm, range, 0-153) were significantly lower than for the AIR group (median, 23.95 μm, range, 0-160.43) (p<0.0001). The area-matched thickness increased significantly in both groups (p<0.001). The AIR group showed a significant increase of the area matched contour for the nasal located measurement-areas N1 (p<0.0003), N2 (p<0.0079), N3 (p<0.007). The BSS group showed a significant increase of the area-matched contour for the measurement areas N1 (p<0.019), N2 (p<0.0014), and N4 (p<0.022). After surgery, median BCVA for both groups increased significantly to 0.3 logMAR. Conclusions: The analysis of early contour changes after ERM surgery was technically possible. Long-term data have to be looked at before the clinical impact of this methodology can be estimated. Although there were no big differences between both groups (AIR vs. BSS), this could change within a longer and more representative follow-up.