OCT: New perspectives in neuro-ophthalmology

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Optical coherence tomography (OCT) is crucial for evaluating axonal/neuronal integrity and disease progression in the visual pathway.
• OCT serves as a biomarker for neurodegeneration and outcome measure in neuroprotective trials for multiple sclerosis (MS).
• Spectral-domain OCT (SD-OCT) enables quantification of individual retinal layers, with Ganglion Cell layer (GCL) analysis being particularly valuable.

Purpose of the Study:

• To highlight the utility of OCT, specifically GCL analysis, in neuro-ophthalmology.
• To compare the efficacy of GCL analysis versus peripapillary retinal nerve fiber layer (pRNFL) analysis in MS.
• To explore OCT's role in diagnosing and monitoring various optic neuropathies and neurodegenerative diseases.

Main Methods:

• Utilizing spectral-domain OCT (SD-OCT) for retinal layer quantification.
• Employing enhanced depth imaging OCT (EDI-OCT) for detailed optic nerve head drusen (ONHD) evaluation.
• Correlating OCT findings with clinical measures and perimetry.

Main Results:

• GCL analysis shows high correlation with perimetry, predicts progression, and is sensitive/specific for neuro-ophthalmic pathologies.
• GCL analysis may be superior to pRNFL analysis for examining MS neurodegeneration.
• OCT, particularly GCL analysis, offers accurate insights in conditions like optic disk edema and ONHD, potentially indicating irreversible neuronal loss.
• EDI-OCT allows in vivo quantification of ONHD dimensions.

Conclusions:

• OCT, especially GCL analysis, is a powerful tool for assessing neurodegeneration and guiding treatment in MS and other neuro-ophthalmic conditions.
• OCT provides critical structural information in optic neuropathies where RNFL analysis is limited.
• Emerging evidence supports OCT's role as a biomarker in Alzheimer's and Parkinson's diseases.