Abstract
Purpose: :
Several methods have been used to assess the dimensions of retinal vessels. These methods are unreliable in the evaluation of non–linear segments. IMAGEnetTM 2000 (Topcon, Inc.) has two methods that can be used for the assessment of non–linear segments. We compared both methods, which are useful for investigative purposes in study of the retinal vasculature.
Methods: :
IMAGEnetTM 2000 (Topcon, Inc.) was utilized in a cohort of 15 patients who had undergone fluorescein angiography. The superotemporal arterial length along its pathway was measured from the neuroretinal rim to the second degree–branching arteriole using two methods. The first method made use of the "curvo–linear" function, where several small and continuous lines were drawn over the vessel. The second method involved "area" function, where a continuous line was drawn over the vessel of interest. All quantitative distance measurements were provided by the program.
Results: :
The mean using the "curvo–linear" function was 6.13 mm (SD 2.52 mm), versus 5.57 mm (SD 2.29) for the "area" method. There was a trend toward lesser variance in "area" method using the mixed linear mode (p=0.067), but this was not statistically significant. The correlation between the methods is 0.98 using 2–way mixed model.
Conclusions: :
The two methods produce similar distance measurements. The fact that variance is less in the "area" method suggests that this method may produce more precise estimates than the "curvo–linear".
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical • retina