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Background/Aims: Individuals who reach end-stage kidney disease (CKD5) have a high risk of vascular events that persists even after renal transplantation. This study compared the prevalence and severity of microvascular disease in transplant recipients and patients with CKD5. Methods: Individuals with a renal transplant or CKD5 were recruited consecutively from renal clinics, and underwent bilateral retinal photography (Canon CR5-45, Canon). Their retinal images were deidentified and reviewed for hypertensive/microvascular signs by an ophthalmologist and a trained grader (Wong and Mitchell classification), and for vessel caliber at a grading centre using a computer-assisted method and Knudtson's modification of the Parr-Hubbard formula. Results: Ninety-two transplant recipients (median duration 6.4 years, range 0.8 to 28.8) and 70 subjects with CKD5 were studied. Transplant recipients were younger (p<0.001), with a higher eGFR (p< 0.001), but were just as likely to have a moderate-severe hypertensive/microvascular retinopathy (46/92, 50%) as subjects with CKD5 (38/70, 54%; OR 0.84, CI 0.45 to 1.57, p=0.64), and had similar mean arteriole and venular calibres (135.1 ± 7.5 µm and 137.9 ± 14.9 µm, p=0.12; and 199.1 ± 17.8 µm and 202.4 ± 27.8 µm, p=0.36, respectively). Arteriole and venular caliber were not different in nine patients examined before and after transplantation (p=0.62 and p=0.11, respectively). Conclusions: Hypertensive/microvascular disease occurred just as often and was generally as severe in transplant recipients and subjects with CKD5. Microvascular disease potentially contributes to increased cardiac events post-transplantation. [ABSTRACT FROM AUTHOR]

Background/Aims: The effects of haemodialysis on the microcirculation are poorly understood. This study examined the changes in small vessel calibre. Methods: 24 patients (including 12 males, median age 62.5 years, range 30–87) underwent digital retinal photography immediately before and after routine haemodialysis. Arteriolar and venular calibres were measured from the images by a trained grader using a highly reproducible, computer-assisted method. Results: Patients had an average 2.0 ± 0.3 litres of fluid removed with dialysis, and their mean arterial blood pressure fell by 6.8 mm Hg (CI 13.8–0.2, p = 0.06). Retinal arteriole calibre did not change (mean difference 2.3 µm, CI –1.1 to 5.7, p = 0.17) but the venules dilated (mean difference 12.7 µm, CI 7.3–18.3, p < 0.001). Calibre returned to baseline by 2 h. Venules dilated less in diabetics than non-diabetics (mean difference –6.2 µm, CI –9.6 to –2.9, p < 0.01). Retinal venular dilatation correlated positively with the volume of fluid removed per kilogramme body weight (5.9, CI 0.2–11.5, p = 0.04), and negatively with the fall in mean arterial pressure (–0.36, CI –0.72 to –0.01, p < 0.05) after adjusting for age, gender, diabetes and dyslipidaemia. Conclusion: Haemodialysis is associated with systemic venular dilatation. [ABSTRACT FROM AUTHOR]