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Abstract:

Purpose 1) To evaluate intra- and inter-observer reproducibility of retrobulbar Color Doppler Imaging (CDI). 2) To compare retrobulbar fl ow velocities as well as Ocular Pulse Amplitude (OPA) between healthy subjects and patients with normal tension or high tension glaucoma. 3) To study the correlation between OPA and CDI parameters. Methods CDI and OPA measurements were performed twice with one month interval in patients with normal tension (n=30) or high tension glaucoma (n=18), and healthy individuals (n=22). Th e CDI measurements were performed on the central retinal artery, short posterior ciliary arteries and ophthalmic artery, and analysed by the observer and a masked reading center. Diff erences were calculated by a student T-test and correlations with Spearman analysis. Results 1) Th e CDI measurements were comparable between the two study visits. Moreover, analysis of the CDI pictures by the masked reading center resulted in values that were comparable to those obtained by the observer. 2) OPA as well as CDI parameters were signifi cantly reduced in patients with primary open angle or normal tension glaucoma, as compared to non-glaucomatous individuals (p=0.000001-0.05). 3) A correlation was observed between the OPA and the systole/diastole ratio as well as the resistive index in the healthy individuals in all measured blood vessels (P=0.009- 0.05). Th is correlation was not obvious in the glaucomatous patients. Conclusion Retrobulbar CDI is reproducible over time and between reading centers. OPA and fl ow velocity parameters are signifi cantly reduced in normal tension as well as high tension glaucoma patients. OPA and CDI parameters strongly correlate in healthy individuals, but not in glaucoma patients.