Abstract
Purpose: :
Our vascular research center serves as a reading center for analysis of color Doppler imaging (CDI) from various research sites. This study investigated the differences in blood flow velocities of the ophthalmic artery (OA) and central retinal artery (CRA) of glaucoma patients from four different countries: the United States, Lithuania, Belgium and Poland.
Methods: :
We have summarized the baseline blood flow velocities of 26-28 randomly selected glaucoma patients from each of the four countries’ studies. We compared the peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) in the OA and CRA from each cohort of glaucoma patients. A one-way analysis of variance model was used to model the mean CDI parameters across the 4 country centers. Tukey’s multiple comparison procedure was used to perform pair-wise comparisons among the centers. All tests were performed at the alpha = 0.05 significance level.
Results: :
The baseline OA PSV in the Belgium and Poland studies were found to be similar (mean 38.01±13.56, 36.36±9.25, respectively) but were higher than the PSV of the OA in the United States and Lithuania (29.43±9.38, 28.98±9.11, respectively). The baseline EDV values in the OA were found similar in Belgium, the United States and Lithuania centers (7.65±4.52, 7.21±2.79, 8.29±2.76, respectively) and higher in Poland (11.09 ±4.02). The OA RI was highest in Belgium glaucoma patients followed by the United States and was similar in Lithuania and Poland patients (0.8±0.08, 0.75±0.06, 0.7±0.08, 0.7 ±0.07, respectively). PSV in the CRA was similar in Belgium, the United States and Poland (9.76±4.43, 8.52±1.83, 10.8±2.76, respectively) and was higher in patients from Lithuania (14.72±4.12). CRA EDV was lowest in glaucoma patients from the United States (20.8±0.74) and highest in Lithuania (5.3±1.89). The RI of the CRA was similar in patients from Belgium, Lithuania and Poland (0.68±0.07, 0.63±0.08, 0.66±0.47, respectively) and was higher in glaucoma patients from the United States (0.76±0.06).
Conclusions: :
While it is possible that the reported differences reflect an innate variation of differing glaucoma cohorts from the various countries, standardization of CDI to image the retrobulbar blood vessels is needed. The resistive indices of the OA and CRA appear to be the most consistent outcome parameter across all glaucoma cohorts.
Keywords: blood supply • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical