OCT Variability Prevents Their Use as Robust Biomarkers in Multiple Sclerosis

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Multiple Sclerosis (MS) is a demyelinating disease affecting the central nervous system.
• Optical Coherence Tomography (OCT) is crucial for assessing neurodegeneration in MS.
• Peripapillary retinal nerve fiber layer (pRNFL) and foveal thickness (FT) are key biomarkers in MS.

Purpose of the Study:

• To evaluate the agreement of pRNFL and FT measurements across three different Spectral Domain-Optical Coherence Tomography (SD-OCT) devices.
• To compare measurement consistency in healthy individuals and multiple sclerosis (MS) patients, including those with a history of optic neuritis (ON).

Main Methods:

• An observational cross-sectional study involving healthy subjects and MS patients (with and without prior ON).
• Measurements of pRNFL and FT were performed using three SD-OCT instruments: OCT PRIMUS 200, OCT CIRRUS 500, and OCT 3D 2000.
• Statistical analysis to assess agreement between devices and differences between patient groups.

Main Results:

• No significant differences in pRNFL and FT were found between healthy subjects and MS patients without ON across all instruments.
• MS patients with a history of ON exhibited significantly thinner pRNFL and FT (P<0.01) compared to controls.
• OCT PRIMUS and CIRRUS demonstrated better agreement for pRNFL and FT measurements in both healthy and MS eyes, while OCT 3D showed lower agreement with CIRRUS.

Conclusions:

• While SD-OCT is valuable for MS patient assessment, significant inter-device variability exists.
• Differences in measurement accuracy among SD-OCT devices necessitate careful consideration in clinical practice.
• Standardization of measurement conditions and establishment of normative databases are essential for reliable international MS research and patient monitoring.