Quantitative analysis of retinal layer optical intensities on three-dimensional optical coherence tomography

Area of Science:

• Ophthalmology
• Medical Imaging
• Biomedical Engineering

Background:

• Accurate measurement of retinal layer optical intensities is crucial for understanding ocular health.
• Three-dimensional spectral-domain optical coherence tomography (3D SD-OCT) offers detailed cross-sectional imaging of the retina.
• Automated analysis methods can enhance the efficiency and reproducibility of OCT data interpretation.

Purpose of the Study:

• To investigate the optical intensities of all retinal layers using automated analysis on 3D SD-OCT in normal subjects.
• To assess the correlation between retinal layer intensities, image quality, and subject age.
• To establish a baseline for automated intensity measurements in retinal imaging.

Main Methods:

• Forty healthy participants underwent macula-centered 3D SD-OCT scans.
• Automated segmentation identified 10 distinct retinal layers using a 3D graph search approach.
• Correlation analyses were performed between layer intensities, image quality index, and participant age.

Main Results:

• Strong correlations (r > 0.934) were found between optical intensities from the ganglion cell layer (GCL) to the outer nuclear layer (ONL).
• Moderate correlations were observed in the retinal nerve fiber layer (RNFL), photoreceptor, retinal pigment epithelium (RPE), and choroid (0.410 < r < 0.800).
• Optical intensities correlated significantly with image quality across most layers, and RNFL intensity showed a negative correlation with age (r = -0.365).

Conclusions:

• Automated assessment of retinal layer optical intensities using 3D SD-OCT is feasible in normal subjects.
• Image quality is a significant factor influencing retinal layer optical intensities.
• Normalization strategies using outer nuclear layer intensity or image quality index are recommended, and RNFL intensity declines with age.