Automatic computerized measurement of retinal blood vessels with adaptive tracking algorithm and association with blood pressure

• Main Authors: Andrej Ikica, Uroš Prelesnik, Branko Ikica
• Format: Article
• Language: English
• Published: Slovenian Medical Association 2007-05-01
• Series: Zdravniški Vestnik
• Subjects: blood pressure; fundus images; automatic measurement of retinal vessels diameter
• Online Access: http://vestnik.szd.si/index.php/ZdravVest/article/view/1733

<p><strong>Background:</strong> To validate an automatic computer-based method for measuring the caliber of retinal blood vessels and use it to determine the effects of arterial hypertension on the calibers of these vessels and on their ratio.</p><p><strong>Methods:</strong> 295 patients with increased blood pressure were analyzed. All arterioles and venules located in the area between one half and one disc diameter from the optic disc margin were measured with the computer based program. These measurements were combined to provide the average diameters of retinal arterioles and venules and the association with blood pressure was analyzed. The arteriole-to-venule ratio (AVR) was also calculated.</p><p><strong>Results:</strong> The average arteriolar diameter of patients who had hypertension from 5 to 15 years was 89.311 μm. Patients with hypertension for more than 15 years they had value of 79.276 μm. Average venular diameters were very similar in both groups (103.319 μm vs. 101.392 μm). We noticed differences in average arteriolar diameter between control group and hypertonic patients who had hypertension for more than 15 years (92.083 μm vs. 79.276 μm). Venular differences were minimal. The average of retinal venules in control group was 106.029 μm, in patients with hypertension for more than 15 years it was 101.392 μm.</p><p><strong>Conclusions:</strong> Using a computer-assisted method to measure retinal vessel diameter we found out that the diameter of retinal arterioles narrowed with blood pressure level. Our findings demonstrate a relation between presence and severity of hypertension and retinal diameter. Diameter of retinal venules hardly changed. Such relationship was similar with men and women. Fully automated system for analyzing retinal vessels is simple to use, quick and reliable.</p>