Macular Cube Definition
A macular cube is a three-dimensional OCT scan protocol that captures a dense grid of cross-sectional images centered on the macula, typically covering 6×6 mm or 7×7 mm areas, enabling detailed volumetric analysis of retinal layer thickness and structure 1, 2.
Technical Specifications
The macular cube scan acquires multiple parallel B-scans across the macular region in a raster pattern. Common protocols include:
- Cirrus HD-OCT: 512×128 scan pattern (512 A-scans per B-scan, 128 B-scans total) covering 6×6 mm 3
- Triton SS-OCT: 7×7 mm coverage 1
- Maestro SD-OCT: 6×6 mm coverage 1
The cube generates a high-density dataset containing thousands of measurement points—up to 60×60 grid points (0.01-mm² resolution)—allowing precise topographic mapping of individual retinal layers 4.
Clinical Applications
Macular cube scans enable:
- Layer-specific thickness measurements: Automated segmentation quantifies retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer nuclear layer (ONL), and other layers 4, 5
- Topographic mapping: Color-coded thickness maps identify focal abnormalities across the macula 6
- Volumetric analysis: Three-dimensional reconstruction reveals structural changes in glaucoma, macular degeneration, and neuro-ophthalmic conditions 3, 5
The cube format provides superior diagnostic information compared to single-line B-scans by capturing the entire macular architecture in one acquisition 5.