Fig 1.
Measurement of the retinal vessel outer and lumen diameters in an optical coherence tomography (OCT) image using the microdensitometry method.
(Top left) A line scan was performed across the vessel in zone B, and the line was aligned manually as perpendicular as possible to the running direction of the vessel. (Top right) The cross-sectional structure of the retinal arteriole (red arrow) and venule (blue arrow) could be identified in the OCT image. (Bottom left) The line selection vertically crossed the middle of the upper and lower vessel walls to produce an intensity profile. (Bottom right) The boundary points (arrow heads) were estimated at half maximum intensity for each side of the two parabolas in the profile. The distance between the boundary points was calculated for the vessel outer and lumen diameters.
Table 1.
Inter-rater reproducibility of retinal vessel measurements using manual and FWHM methods.
Fig 2.
Agreement between manual and full width at half maximum (FHWM) methods for measurement of the retinal arteriolar diameter.
RAOD = retinal arteriolar outer diameter; RALD = retinal arteriolar lumen diameter.
Fig 3.
Agreement between manual and full width at half maximum (FHWM) methods for measurement of the retinal venular diameter.
RVOD = retinal venular outer diameter; RVLD = retinal venular lumen diameter.
Fig 4.
Bland-Altman plots presenting the inter-rater variability of the two methods to measure the retinal arteriolar diameter.
Manual (left side); full width at half maximum (FWHM; right side). RAOD = retinal arteriolar outer diameter; RALD = retinal arteriolar lumen diameter.
Fig 5.
Bland-Altman plots presenting the inter-rater variability of the two methods to measure the retinal venular diameter.
Manual (left side); full width at half maximum (FWHM; right side). RVOD = retinal venular outer diameter; RVLD = retinal venular lumen diameter.
Table 2.
Clinical characteristics of the subjects with and without hypertension.
Table 3.
Comparison of the morphometric data of the retinal arteriole in the study groups.
Table 4.
Comparison of the morphometric data of the first branch retinal arteriole in the study groups.
Fig 6.
Boxplots showing the distribution of the retinal arteriolar (top) wall thickness, (middle) wall cross-sectional area and (bottom) wall to lumen ratio obtained from normal subjects (N), non-diabetic hypertensive patients (H) and hypertensive patients associated with diabetic mellitus (H+DM).
The boxes represent the 25% to 75% interquartile ranges. The horizontal line represents the median values, the bars represent the 5% and 95% confidence intervals, and the dots represent outliers.
Fig 7.
Representative optical coherence tomography images showing the retinal arteriolar structure obtained from (top row) a 63-year-old normotensive female subject and a 66-year-old non-diabetic hypertensive female patient.