Obstructive Sleep Apnea and Retinal Nerve Fiber Layer Thickness: A Meta-analysis

Area of Science:

• Ophthalmology
• Sleep Medicine
• Neurology

Background:

• Obstructive sleep apnea syndrome (OSAS) is a prevalent condition with potential systemic effects.
• Retinal nerve fiber layer (RNFL) thickness is a key indicator of optic nerve health.
• Previous studies on the association between OSAS and RNFL thickness have yielded inconsistent results.

Purpose of the Study:

• To conduct a meta-analysis evaluating the association between obstructive sleep apnea syndrome (OSAS) and retinal nerve fiber layer (RNFL) thickness.
• To synthesize findings from existing studies to provide a more robust conclusion on this relationship.

Main Methods:

• A systematic literature search was performed on PubMed.
• Included studies were reviewed, and their reference lists were examined.
• A fixed-effects model was utilized to calculate the summary mean difference (MD) for RNFL thickness.

Main Results:

• Six studies comprising 1034 eyes were included in the meta-analysis.
• A significant association was found between OSAS and reduced RNFL thickness (MD = -2.03 µm, P=0.01).
• RNFL thickness reduction was more pronounced with increasing OSAS severity (moderate: -2.49 µm, severe: -6.36 µm) and in the inferior quadrant (MD = -3.31 µm).

Conclusions:

• This meta-analysis confirms that obstructive sleep apnea syndrome is associated with decreased RNFL thickness.
• The severity of OSAS directly correlates with the degree of RNFL loss.
• The inferior quadrant of the RNFL is most affected, suggesting OSAS may impact optic nerve health and warrants clinical attention.