Reliability of Macular Ganglion Cell-Inner Plexiform Layer Thickness Measurements Across Scan Protocols in...

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Reliable measurement of the ganglion cell inner plexiform layer (GCIPL) thickness is crucial for monitoring neurodegenerative diseases like multiple sclerosis (MS).
• Optical coherence tomography (OCT) is a key imaging modality, but acquisition parameters may influence measurement reliability.

Purpose of the Study:

• To evaluate if modified OCT acquisition parameters enhance the reliability of GCIPL thickness measurements.
• To compare the test-retest reproducibility and inter-protocol agreement of different OCT scan protocols for GCIPL assessment.

Main Methods:

• Participants with multiple sclerosis (PwMS) and healthy controls (HC) underwent Spectralis OCT scans using five different macular protocols (standard, high-ART, high-lines, high-resolution, maximum) at multiple time points.
• Reliability was assessed using intraclass correlation coefficients (ICC) for inter-protocol agreement and mean absolute difference (MAD) for test-retest reproducibility.
• Acquisition time for each protocol was recorded and compared.

Main Results:

• All tested OCT protocols demonstrated excellent inter-protocol agreement (ICC 0.99) and test-retest reliability for GCIPL measurements in both PwMS and HC.
• The high-ART and high-lines protocols showed marginally lower absolute measurement variability (MAD).
• The high-lines protocol offered the most favorable balance between measurement reliability and acquisition time.

Conclusions:

• All evaluated OCT acquisition protocols provide reliable GCIPL thickness measurements.
• The high-lines protocol is recommended for longitudinal GCIPL monitoring due to its optimal combination of accuracy and efficiency.
• These findings support the use of optimized OCT protocols for precise GCIPL assessment in clinical studies and practice.