Subfoveal choroidal thickness in ipsi- and contralateral eyes of patients with carotid stenosis before and after carotid endarterectomy: a prospective study

Purpose To compare subfoveal choroidal thickness (SFCT) and associated clinical variables in patients with carotid stenosis (CS) before and 6 months after carotid endarterectomy (CEA). Methods The prospective non-randomized Helsinki Carotid Endarterectomy Study - Brain and Eye Sub-sTudy included seventy patients (81% male, mean age 69 years) and 40 control subjects (77% male, 68 years), from March 2015 to December 2018. Ophthalmological examination included SFCT measured with enhanced-depth imaging-optical coherence tomography. Carotid stenosis (CS) was more severe (>= 70% stenosis in 92%) ipsilateral to the CEA than contralaterally (<50% stenosis in 74%; p < 0.001). Results At baseline, patients had thinner mean SFCT than control subjects in both eyes (ipsilateral, 222 versus 257 mu m and contralateral, 217 versus 258 mu m, p <= 0.005). At follow-up, SFCT did not change in ipsi- and contralateral eyes compared to baseline in patients (p = 0.68 and p = 0.77), or in control subjects (p = 0.59 and p = 0.79). Patients with coronary artery disease had thinner mean SFCT versus those without it in ipsilateral eyes before CEA (200 versus 233 mu m, p = 0.027). In ipsilateral eyes of patients before CEA, thinner SFCT and ocular signs of CS, plaque and hypoperfusion related findings combined, were associated (p = 0.036), and the best-corrected visual acuity, measured in logMAR, increased with increasing SFCT (r = -0.25; p = 0.046). Conclusions Subfoveal choroidal thickness (SFCT) is thinner in patients with CS without association between SFCT and the grade of CS. Unchanged SFCT after CEA suggests, that choroidal vessels in severe CS are unable to react to increased blood flow. Bilaterally thin SFCT could be considered as yet another sign of CS.