The Use of Fiji Image J as an Image Analysis Tool for Measuring Retinal Vessel Diameter in Rodent Model of Diabetic Retinopathy

The purpose of this study was to evaluate the use of Fiji Image J application for digital fundus image analysis of retinal vessel diameter in diabetic retinopathy rat model. Male Sprague-Dawley rats, weighing 200-250 grams, were divided into two groups: normal and diabetic. The diabetes was induced by intraperitoneal (IP) injection of streptozotocin (STZ, 55 mg/kg body weight). Normal rats received IP citrate buffer. Fundus images were captured at week 0, 6 and 12 post-induction to observe changes in retinal veins and arteries. Images obtained were then analyzed using Fiji Image J software. Retinal venous diameter was increased in both groups at week 6 and 12 compared to baseline (p<0.05). However, no significant differences were seen in the retinal venous diameter at week 12 compared to week 6 in both groups. When comparing between the groups, retinal venous diameter in diabetic group was significantly greater compared to normal group at week 6 and 12 by 1.37- and 1.35-folds (p<0.001), respectively. For the retinal arterial diameter in diabetic group, an increase was observed at week 6 and 12 compared to baseline by 1.17- and 1.2-folds (p<0.05) respectively, however, similar changes were not observed in normal group. There was also no significant difference between the retinal arterial diameter of normal and diabetic group at week 6 and 12. In conclusion, retinal vessels diameter analysis of fundus images using Fiji Image J can be utilized to determine quantitative changes between normal and rats with STZ-induced diabetic retinopathy.

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Nitric oxide regulates retinal vascular tone in humans

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00111.2003 ◽

2003 ◽

Vol 285 (2) ◽

pp. H631-H636 ◽

Cited By ~ 137

Author(s):

Guido T. Dorner ◽

Gerhard Garhofer ◽

Barbara Kiss ◽

Elzbieta Polska ◽

Kaija Polak ◽

...

Keyword(s):

Nitric Oxide ◽

Vascular Tone ◽

Retinal Vessel ◽

Vessel Diameter ◽

Arterial Diameter ◽

Retinal Vessel Diameter ◽

Venous Diameter ◽

Flicker Stimulation ◽

Young Subjects

The purpose of the present study was to investigate the contribution of basal nitric oxide (NO) on retinal vascular tone in humans. In addition, we set out to elucidate the role of NO in flicker-induced retinal vasodilation in humans. Twelve healthy young subjects were studied in a three-way crossover design. Subjects received an intravenous infusion of either placebo or NG-monomethyl-l-arginine (l-NMMA; 3 or 6 mg/kg over 5 min), an inhibitor of NO synthase. Thereafter, diffuse luminance flicker was consecutively performed for 16, 32, and 64 s at a frequency of 8 Hz. The effect of l-NMMA on retinal arterial and venous diameter was assessed under resting conditions and during the hyperemic flicker response. Retinal vessel diameter was measured with a Zeiss retinal vessel analyzer. l-NMMA significantly reduced arterial diameter (3 mg/kg: –2%; 6 mg/kg: –4%, P < 0.001) and venous diameter (3 mg/kg: –5%; 6 mg/kg: –8%, P < 0.001). After placebo infusion, flicker induced a significant increase in retinal vessel diameter ( P < 0.001). At a flicker duration of 64 s, arterial diameter increased by 4% and venous diameter increased by 3%. l-NMMA did not abolish these hyperemic responses but blunted venous vasodilation ( P = 0.017) and arterial vasodilation ( P = 0.02) in response to flicker stimulation. Our data indicate that NO contributes to basal retinal vascular tone in humans. In addition, NO appears to play a role in flicker-induced vasodilation of the human retinal vasculature.

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