Choroidal thickness maps from spectral domain and swept source optical coherence tomography: algorithmic versus...

Area of Science:

• Ophthalmology
• Medical Imaging
• Retinal Imaging Analysis

Background:

• Choroidal thickness is a key indicator of ocular health.
• Standardized measurement protocols are essential for accurate clinical assessment.
• Comparing different optical coherence tomography (OCT) devices and segmentation methods is crucial.

Purpose of the Study:

• To establish a standardized protocol for choroidal thickness measurements.
• To evaluate the interchangeability of choroidal thickness measurements between spectral domain optical coherence tomography (SD-OCT) and swept source (SS-) OCT.
• To compare manual and automated segmentation algorithms for choroidal thickness assessment.

Main Methods:

• Volumetric OCT scans were acquired from 18 healthy volunteers.
• Choroidal thickness was measured using both SD-OCT and SS-OCT devices.
• Manual segmentation by expert graders and automated segmentation algorithms were compared.

Main Results:

• A systematic difference in choroidal thickness was observed between SD-OCT and SS-OCT, with automated segmentation showing a larger discrepancy.
• Automated and manual segmentations yielded comparable results, with minimal differences in thickness.
• High correlation coefficients (0.975 for manual, 0.955 for automatic) were found between SD-OCT and SS-OCT measurements within eyes.

Conclusions:

• SD-OCT and SS-OCT are interchangeable for choroidal thickness measurements in healthy retinas, with minor differences not clinically significant.
• The automated algorithm for choroidal thickness segmentation is validated and reliable for use in healthy individuals.