Purpose
Retinal vessel response to flicker was shown to be altered in glaucoma, hypertension, diabetes mellitus and other ocular and systemic diseases. Chronic hemodialysis patients are usually multimorbid and show structural and functional vascular alterations. Whether the dynamic reaction to flicker stimulation in retinal vessels is changed in these patients is investigated.
Methods
Retinal arterial and venous reaction to flicker stimulation was examined by Dynamic Vessel Analyzer (DVA, IMEDOS Systems) in 123 hemodialysis patients (age 63,9 ± 14,8 years old) and in 25 medically validated healthy volunteers of similar age (58,7 ± 6,4 years old) and gender distribution. After baseline assessment of 50 s monochromatic rectangular flicker stimulation (530-600 nm, 12,5 Hz, 20 s) was applied 3 consecutive times. Parameters of dynamic vascular response were assessed and analyzed independent from the commercial DVA software.
Results
In most subjects fast vessel dilation compared to baseline was observed. There were a number of abnormal individual reactions in hemodialysis patients. Values of basic parameters of dynamic retinal vessel reaction in the examined groups are presented in the table. [mean±std. deviation (range)].
Conclusions
Functional retinal arterial and venous reaction to flicker stimulation differs significantly in hemodialysis patients compared to healthy subjects of the same age and gender. In average the magnitude of the vascular reaction is similar but the reaction is significantly delayed both in arteries and in veins. Since dynamic retinal vessel analysis provides a direct non-invasive assessment of microcirculatory damage, it would allow for practical and task-oriented risk stratification in dialysis patients.
Keywords: 688 retina •
464 clinical (human) or epidemiologic studies: risk factor assessment •
550 imaging/image analysis: clinical