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Diurnal Variation of Corneal Dendritic Cell Density
Sultan Alotaibi1,2, Jerome Ozkan1, Eric Papas1
1School of Optometry and Vision Science, University of New South Wales, Sydney, Australia.
Current Eye Research
|June 21, 2022
Summary
Corneal dendritic cell density remains stable throughout the sleep/wake cycle in healthy individuals. However, the proportion of mature dendritic cells in the central cornea increases significantly after overnight sleep.
Area of Science:
- Ophthalmology
- Immunology
- Cell Biology
Background:
- Corneal dendritic cells (DCs) are crucial immune cells residing in the cornea.
- Understanding their dynamics during the sleep/wake cycle is important for ocular health.
- Previous research has not extensively explored diurnal variations in corneal DC populations.
Purpose of the Study:
- To quantify changes in corneal dendritic cell density over a 24-hour period.
- To assess the variation in the percentage of mature versus immature dendritic cells.
- To investigate these changes specifically in healthy individuals during their sleep/wake cycle.
Main Methods:
- Employed *in vivo* confocal microscopy to image the subbasal nerve plexus.
- Recruited 19 healthy participants who were not contact lens wearers.
- Captured images of the central cornea and inferior whorl at three time points: midday, before sleep, and upon awakening; categorized DCs by maturity (immature/mature).
Main Results:
- Total corneal dendritic cell density showed no significant variation between midday, before sleep, and upon awakening (p > 0.05).
- The percentage of mature dendritic cells in the central cornea was significantly higher upon awakening compared to midday (p = 0.02).
- No significant diurnal changes were observed in dendritic cell density or maturity at the inferior whorl.
Conclusions:
- Corneal dendritic cell density is relatively stable throughout the sleep/wake cycle in healthy eyes.
- There is a notable increase in the relative proportion of mature corneal dendritic cells following overnight sleep.
- These findings suggest a diurnal modulation of corneal immune cell maturation, potentially linked to overnight rest.
