Comparison of CIRRUS 6000 Macular Cube 512x128 and Macular Cube 200x200 scan measurements

Abstract

Purpose : Many retinal pathologies are characterized by a change in retinal thickness, which can be quantitatively measured by optical coherence tomography (OCT). The CIRRUS^® OCT 6000 (ZEISS, Dublin, CA) Macular Cube 512x128 and Macular Cube 200x200 scan types provide ganglion cell and macular thickness measurements. The Macular Cube 200x200 scan provides isometric area and volume measurements, whereas the 512x128 scan provides higher quality B-scan images. In this study, the quantitative measurements between the two scans were compared.

Methods : An IRB approved prospective study was performed where healthy subjects without ocular pathology were enrolled. Each subject underwent acquisition of the CIRRUS 6000 Macular Cube 512x128 and 200x200 scan types on the same eye. Each ganglion cell and macular thickness value was compared by mean difference, 95% confidence intervals of the mean difference between the 2 scan types, percent difference of the mean, and by using paired equivalence t-tests (α = 0.05). Limits of equivalence were chosen as +/-1% of the Macular Cube 512x128 mean. Additionally, results were compared against CIRRUS 6000 Macular Cube 512x128 reproducibility limits.¹

Results : One eye of 30 subjects were used for analysis. The comparison of macular and ganglion cell thickness parameters between the Macular Cube 512x128 and Macular Cube 200x200 scans can be found in Table 1. The differences between the means of all parameters were within 1.05µm, which is less than 1% difference between the means. All Macular Cube 512x128 and Macular Cube 200x200 scan measurements were statistically equivalent (largest p-value was 0.032). The % differences of each parameter were below the CIRRUS 6000 reproducibility coefficients of variation.

Conclusions : The differences between the Macular Cube 512x128 and Macular Cube 200x200 were very small and may be attributed to device variability. The CIRRUS 6000 Macular Cube 512x128 and Macular Cube 200x200 macular thickness and ganglion cell thickness value outputs are comparable and clinically equivalent.

References
[1] Manivannan et al. ARVO 2024 Annual Proceedings. Submitted Abstract.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Table 1. Comparison of Macular Cube 200x200 and Macular Cube 512x128 results.