Abstract
Purpose: :
To evaluate the relationship between central corneal thickness (CCT) and retrobulbar blood flow in patients with newly diagnosed ocular hypertension (OHT) using Colour Doppler Imaging (CDI).
Methods: :
Forty-five consecutive patients with recently diagnosed OHT underwent a complete ophthalmic examination including corneal pachimetry and CDI. CDI reproducibility was assessed performing three consecutive measurements, separated by five minutes. The peak systolic (PSV) and end-diastolic blood flow velocities (EDV) and resistance indices (RI) of the ophthalmic artery (OA) and central retinal artery (CRA) were measured and correlated with CCT values.
Results: :
RI measurements had the best flow measurement reproducibility for both arteries (Intraclass Correlation Coefficient > 0.90). The mean CCT was significantly correlated with CRA's EDV (σ = 0.528, P = 0.000) and with CRA's RI (σ = -0.379, P = 0.010 respectively). Patients with a CCT thinner than 576 µ had a statistically significant higher CRA's RI than patients who had CCT thicker than 576 µ (P = 0.026). Regression analysis showed that for every 50 µm of CCT decrease, there was a 5% increase in CRA's RI.
Conclusions: :
Ocular blood flow of patients newly diagnosed of OHT was assessed by CDI and quantitatively correlated with CCT. A statistical significant association between CCT and CRA's EDV and RI was found in this OHT sample of patients. As thinner was the central cornea, as lower was CRA's EDV and higher CRA's RI.
Keywords: optic flow • pathobiology • optic nerve