Do levels of stress markers influence the retinal nerve fiber layer thickness in young adults?

Precis: Although mental or emotional stress may result raise in intraocular pressure (IOP) we found weak associations between endogenous stress markers concentrations and retinal nerve fiber layer (RNFL) thickness, thus limited evidence that stress affects retinal ganglion cells integrity.

Purpose: Increased exposure to glucocorticoids is linked to elevated IOP, which is a risk factor for glaucoma. We explored the RNFL thickness for changes that may mimic preclinical glaucomatous changes, in relation to the hormonal stress response.

Materials and methods: Young healthy adults (n=863) underwent a Trier Social Stress Test. Endogenous plasma adrenocorticotropic hormone (ACTH) and cortisol were measured for those who provided biological samples, and adrenal sensitivity was calculated. On the basis of cortisol levels before and after the Trier Social Stress Test, participants were categorized into one of 3 stress response types: anticipatory-responders, reactive-responders, and nonresponders. Participants underwent an eye examination that included spectral-domain optical coherence tomography to measure peripapillary RNFL thickness.

Results: Higher levels of ACTH were associated with thinner RNFL globally (P=0.009), and at the inferotemporal (P=0.015), superotemporal (P=0.044), and temporal sectors (P=0.046). Lower adrenal sensitivity was associated with thinner RNFL inferotemporally (P<0.001) and temporally (P=0.037). However, these effect sizes were small; for example, a 10 pg/mL increase in baseline ACTH was associated with only a 3 µm thinner RNFL. RNFL thickness was not associated with plasma cortisol levels and or significantly different between groups of acute stress response patterns.

Conclusions: Although there was a link between ACTH or adrenal sensitivity and RNFL thickness, this association was weak and its clinical significance is unclear. Despite the close associations between levels of endogenous stress markers and IOP, we found limited evidence of a link to RNFL integrity.