Imaging the posterior segment of the eye using swept-source optical coherence tomography in myopic glaucoma eyes: comparison with enhanced-depth imaging

Purpose: To compare the detection rates of identifying the posterior border of the sclera and lamina cribrosa and measurement reproducibility of scleral and laminar thicknesses using the enhanced depth imaging (EDI) of Heidelberg Spectralis optical coherence tomography (OCT) and swept-source OCT.

Design: Cross-sectional design.

Methods: Both EDI-OCT and swept-source OCT images were obtained in 32 myopic glaucoma patients. Subfoveal choroidal, subfoveal scleral, and central laminar thicknesses were measured from obtained B-scan images. Each measurement was performed at 3 locations by 2 masked observers. The detection rates and measurement reproducibility were evaluated from selected B-scans.

Results: The posterior border of the sclera was visible in 10 eyes (31%) using EDI-OCT. This was improved to be visible in 17 eyes (53%) using swept-source OCT. According to the McNemar χ(2) test, the detection rate of the posterior border of the sclera was significantly different between EDI-OCT and swept-source OCT (P = 0.008). The detection rate of the posterior border of the lamina cribrosa was similar for the 2 devices. In highly myopic eyes, the detection rate of the posterior border of the sclera and lamina cribrosa was not statistically different between EDI-OCT and swept-source OCT. Intersystem ICCs was 0.769 (95% CI, 0.714-0.893) for subfoveal scleral thickness and 0.900 (95% CI, 0.887-0.917) for laminar thickness. The mean subfoveal scleral thickness was 464.32 ± 213.24 μm using EDI-OCT and 650.26 ± 222.30 μm using swept-source OCT. There was statistical difference in the measured subfoveal scleral thickness by the 2 devices (P = 0.018).

Conclusions: Compared with EDI-OCT, swept-source OCT had an advantage in imaging the posterior sclera. Imaging the lamina cribrosa was similar when using both devices.