Abstract
Purpose:
To compare the effectiveness the 12-line radial scan pattern to the standard 25-line raster in detecting intraretinal/subretinal fluid in neovascular age-related macular degeneration (AMD).
Methods:
Retrospective observational series of patients with neovascular AMD imaged between December 2013 and May 2014. A total of 200 eyes that underwent Heidelberg SD-OCT image acquisition using both 12-line radial and 25-line raster patterns were evaluated by two independent graders. All scans included in the study had subretinal/intraretinal fluid present in at least one of the acquisition patterns. Manual measurements were also performed to evaluate eccentricity from the foveal center of missed fluid on either scan protocol.
Results:
A total of 394 SD-OCT scans were interpreted (mean: 1.97 scans/eye). The 12-line radial detected fluid in all but 7 scans (1.7%; 95% CI 0.7-3.6%), resulting in a sensitivity of 98.3%. The 25-line raster identified fluid in all but 10 scans (2.5%; 95% CI 1.2-4.6%), resulting in a sensitivity of 97.5% (Figure 2). The difference in fluid detection between the patterns was not statistically significant (P=0.6276). The majority of 25-line raster scans which failed to detect fluid were intraretinal (70%), while the majority of 12-line radial scans that missed fluid were subretinal (57.2%) in location. Subgroup analysis was performed to determine whether foveal eccentricity impacted the 25-line raster or 12-line radial scan pattern's ability to detect fluid. Of the ten 25-line raster scans which missed fluid, the average distance from the foveal center to the pathology by the 12-line radial scan was 779.5 ± 682.1 µm. In contrast, of the seven 12-line radial scans which missed fluid, the average distance from the foveal center on the 25-line raster scan was 1402 ± 1297 µm. The difference in average distance from the foveal center on 12-line radial compared to 25-line raster demonstrated a trend towards statistical significance (P=0.056).
Conclusions:
The SD-OCT 12-line radial scan is statistically comparable to the 25-line raster scan in detecting the presence of intraretinal/subretinal fluid in neovascular AMD. The 12-line radial pattern alone may be adequate to guide day-to-day clinical decisions in a more time-efficient manner.