Waveform parameters of retrobulbar vessels in glaucoma patients with different demographics and disease severity

Introduction: To identify novel velocity waveform parameters of the ophthalmic artery and central retinal artery by computer-aided image processing of Doppler ultrasonography measurements, and to evaluate correlations between the waveform parameters and different demographics and disease severity of open-angle glaucoma patients. Methods: Thirty-six images of 36 open-angle glaucoma patients were considered. A semiautomated image processing code was used to detect the digitalized ophthalmic artery and central retinal artery velocity waveforms and to extract the waveform parameters. Concordance correlation coefficient, two-sample t-test, and Pearson’s correlation coefficient were used to test for similarities, differences, and associations among variables. Results: Female glaucoma patients showed a statistically higher ophthalmic artery normalized distance between ascending and descending limb (p=0.004), hypertensive glaucoma patients a statistically higher ophthalmic artery peak systolic velocity time (p=0.025), glaucoma patients with hyperlipidemia a statistically higher ophthalmic artery resistivity index (p=0.023) and a statistically higher ophthalmic artery peak systolic velocity acceleration (p=0.025), glaucoma patients with cardiovascular diseases a statistically lower central retinal artery normalized distance between ascending and descending limb of the wave (p=0.033) and a statistically higher central retinal artery period (p=0.028), and patients with different body mass index a statistically different central retinal artery normalized distance between ascending and descending limb of the wave (p=0.016). Groups with different disease severity, classified following the Brusini glaucoma staging system 2, showed statistically different central retinal artery normalized distance between ascending and descending limb of the wave (p<0.001) and central retinal artery period (p=0.016). No statistical differences were found in regard to race, diabetes status, glaucoma family history, and smoking. Discussion: Ophthalmic artery and central retinal artery computer-aided analysis of velocity waveforms could identify novel waveform parameters capable of differentiating among different demographics and disease severity of open-angle glaucoma patients.