Heart-Rate Variability Correlates to Choroidal Thickness in Central Serous Chorioretinopathy

Abstract

Purpose Patients with central serous chorioretinopathy (CSC) have previously been shown to have a lower heart rate variability (HRV), implying a lower vagal tone. Vagal tone alters mineralocorticoids, which in turn affect the thickness of the choroid. Since increased choroidal thickness is characteristic of CSC, we wanted to investigate its correlation with HRV. Patients and Methods In this case–control study, 21 acute CSC patients and 31 healthy controls were included. Diagnosis was confirmed by optical coherence tomography (OCT) and retinal examination. HRV was evaluated following accepted standards. Outcome measures were chosen beforehand as follows: Standard deviation of N–N intervals (SDNN), root mean square of successive differences (RMSDD), low frequency/high frequency ratio (LF/HF ratio), and standard deviation ratio from commonly used Poincare plot (SD2/SD1 ratio). Choroidal thickness was measured using OCT directly under the foveola. Results Patients and healthy controls did not differ in health and medical characteristics in addition to CSC disease. Choroidal thickness was greatest in patients with CSC (mean±SD: 342±80 μm) compared to controls (235±60 μm, p<0.0001). A correlation was observed between LF/HF ratio and choroidal thickness in patients with CSC (Pearson correlation 0.63, p=0.02), where the CSC group had a lower LF/HF ratio (Median 2.39 ms 2 , IQR: 1.2–4.34 ms 2 ) compared to controls (Median 1.2 ms 2 , IQR: 0.9–2.4 ms 2 , p=0.06) and SD2/SD1 ratio (CSC 0.59±0.2 vs controls 0.74±0.3, p=0.06). Conclusion We found a correlation between the thickness of the choroid and the HRV-measured LF/HF ratio in patients with CSC and showed a borderline significant reduction in HRV measurements in patients with CSC. The data imply that vagal alterations exist in patients with CSC. Due to the low n, this should be considered as a pilot study. Further studies are warranted to elucidate mechanisms and validate findings.

Corneal neuropathy in central serous chorioretinopathy

“…Indeed, we have hypothesized that the vascular changes, observed in pachychoroid could originate, at least in part from a choroidal neuropathy 13 . The systemic dysfunction of the autonomous nervous system measured in patients with CSCR supports this hypothesis, such as low heart rate variability 29,30 , abnormal pupillometric response 31 and the correlation between choroidal thickness and heart rate variability in CSCR patients 32 . But whether choroidal nerves show neuropathic signs in CSCR is unknown.…”

“…In a recent paper, we have hypothesized that the choroidal hyperreflective organized structures, typically observed around the dilatated vessels in pachychoroid patients, could correspond to abnormal choroidal nerves 13 , similar to the abnormal structure of the choroidal nerves we could image in rats overexpressing the mineralocorticoid receptors and a pachychoroid-like phenotype 13,36 . The observation of abnormal nerves in the cornea of CSCR patients, together with the functional signs of dysautonomia in these patients 29,30 31 32 is highly suggestive that autonomic neuropathy contributes to the disease. Similar findings have been repeatedly reported in patients suffering from autonomic diabetic neuropathy 37 and in which the cornea has served as a sensor of the severity and the risk of cardiovascular events.…”