PURPOSE: To assess accuracy and reproducibility of retinal vessels caliber measurement in Heidelberg retina tomographer (HRT II) images by new developed method.
METHODS: 76 images of optic nerve head were obtained from 76 eyes. Eight vessels' diameters were measured in each case in the area of 0.5 to 1.0 disc diameter from the optic disc margin. The window for "interactive measurements" was used to determine three-dimensional coordinates (x,y,z) of each vessel diameter. Diameter of each vessel was calculated according to the Pythagorean Theorem (value of "z" coordinate remained unchanged).
RESULTS: Diameter of retinal arterioles varied from 55,0 to 106,5 μm. Diameter of retinal venulas ranged from 68,9 to 140,1 μm. The standard deviation value changed from 0,6 to 16 micron. Artetiole/venule ratio mean value was 0,702±0,039.
CONCLUSIONS: Measurement of retinal vessels diameter in images obtained during retinal tomography is exact and informative. The described method is the unique way of retinal vessels caliber measurement in absolute values.
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