Physiological variation of segmented OCT retinal layer thicknesses is short-lasting

Area of Science:

• Ophthalmology
• Neuroscience
• Exercise Physiology

Background:

• Spectral domain optical coherence tomography (SD-OCT) is a potential tool for assessing neurodegeneration.
• Understanding physiological variations in retinal layer thickness is crucial for interpreting SD-OCT data.
• Exercise-induced physiological changes may affect retinal layer measurements.

Purpose of the Study:

• To investigate the impact of a 10-km run on retinal layer thicknesses.
• To compare changes in retinal layer thickness between runners and a control group.
• To assess the reversibility of exercise-induced retinal thickness changes.

Main Methods:

• Prospective study comparing runners (n=27) and controls (n=15).
• SD-OCT imaging with eye-tracking and automated scan registration at baseline, post-run, and post-rehydration.
• Retinal layer segmentation with artifact suppression.

Main Results:

• Runners showed increased retinal nerve fibre layer, inner plexiform/ganglion cell layer, and outer nuclear layer thickness post-run compared to controls.
• The outer nuclear layer increase was linked to rehydration during exercise.
• Most thickness differences normalized after rest and rehydration, except for the retinal nerve fibre layer.

Conclusions:

• Exercise causes transient, quantifiable changes in retinal layer axial thickness.
• These changes are likely due to cellular volume shifts, potentially from H2O shifts.
• Physiological variations like those from exercise must be considered when using SD-OCT for neurodegeneration assessment.