Comparison of subfoveal choroidal thickness and retinal nerve fiber layer thickness in patients with coronary slow flow phenomenon and microvascular angina: Optical coherence tomography based study.

Background: The aim of this study was to evaluate and compare the subfoveal choroidal thickness (SFCT) and peripapillary retinal nerve fiber layer thickness (pRNFLT) in patients with microvascular angina (MA), coronary slow flow phenomenon (CSFP) and healthy controls.

Methods: Thirty-two consecutive patients with MA, 35 consecutive patients with CSFP and 40 age and sex-matched controls were enrolled. SFCT, average pRNFLT and four quadrants of pRNFLT were measured by spectral domain- optical coherence tomography (SD-OCT).

Results: The mean SCFT in patients with CSFP (267.57 ± 30.61 μm) was significantly thinner than those of patients with MA (288.84 ± 28.25 μm) and control (291.21 ± 31.75 μm) (p = 0.002) while SFCT of patients with MA were similar with those of controls. Patients with CSFP had thinner superior and inferior pRNFLT compared to patients with MA and controls (p < 0.001 and p = 0.005, respectively) while there were no significant differences in average pRNFLT, nasal and temporal quadrant of pRNFLTs among three groups. In the multivariate linear regression analyses, the presence of CSFP was found negatively correlated with SFCT and superior pRNFLT.

Conclusion: Patients with CSFP had thinner SFCT, superior and inferior quadrants of pRNFLT proposing the presence of a generalized endothelial dysfunction and increased microvascular resistance in these patients.