Visualization of the Macula in Gas-filled Eyes using Swept-Source Optical Coherence Tomography: Comparison with Spectral-Domain Optical Coherence Tomography

Abstract

Purpose : There have been several attempts to use optical coherence tomography to guide duration of facedown positioning following macular hole surgery. However, visualization of the macula in gas-filled eyes has been limited using current optical coherence tomography devices. We aimed to compare the visualization of the macula between spectral-domain optical coherence tomography (SD-OCT) and swept-source optical coherence tomography (SS-OCT).

Methods : Seventeen eyes of 17 patients with macular hole treated by pars plana vitrectomy and gas tamponade were included in this study. In the patients, SD-OCT (3D-OCT, Topcon, Japan) and SS-OCT (DRI-OCT, Topcon, Japan) were performed with single line scan, 6 × 6 mm macular volume scan, and 6 radial line scan at baseline and 1 day, 1 week, and 1 month after macular surgery. Visualization of the macula was graded depending on the visibility of the macula: good (visible macula in which hole closure can be determined), moderate (dimly visible macula), and poor (invisible macula).

Results : Both devices clearly visualized macula in all the patients at baseline and 1 month. One day after macular hole surgery, SD-OCT showed almost invisible macula, regardless of scan protocols. In SS-OCT, however, single line scan provided better visualization of the macula than other scan protocols. Whether macular hole is closed or not could be determined in none and 14 (82.4%) eyes imaged with SD-OCT and SS-OCT, respectively. Grades of visualization showed significant difference between the two devices. (P < 0.001)

Conclusions : Single line scan images of SS-OCT may be clinically useful to visualize the macula and determine hole closure at early postoperative period following macular surgery with gas tamponade. Based on the SS-OCT images, duration of facedown positioning may be guided.