The Chronic Kidney Disease and Abnormal Retinal Blood Vessels

Abstract

Chronic kidney disease is a condition characterized by a gradual damage of kidney structure and function, irrespective of the underlying causes. The main manifestations are proteinuria, hematuria, edema, and hypertension, with or without renal dysfunction. The retinal vasculature is a unique site where the microcirculation can be noninvasively imaged in vivo, and it belongs to the small blood vessel category and is part of the systemic microcirculation. Most ophthalmologists and nephrologists consider that retinal vasculature monitoring for early diagnosis of chronic kidney disease is not a satisfactory method as yet, because the involvement of diabetes, hypertension, and other systemic diseases and the variability in retinal vascular abnormalities make the relationship between retinal vasculature and chronic kidney disease quite complicated. However, the diversified thinking mode of integrated medicine may provide further insights into the disease and clinical research: (1) Similarities account for the association between different diseases. Both glomerular and retinal blood vessels belong to microcirculation system. This similarity hints that the pathological changes of chronic glomerular disease, diabetic nephropathy, and hypertensive nephropathy may manifest themselves through the fundus tissues which serve as a special window. (2) Differentiation and integration is a unity of opposites, and integration is based on differentiation. There are many indicators of retinal vascular abnormalities, so it raises the following question: Which is the best predictor of kidney disease and renal dysfunction? Only through further breakdown of the indicators can the problems be better specified. Animal experiments have confirmed the association between retinal vascular abnormalities and nephropathy. Epidemiological studies have shown that this association can be repeated in populations of different geographical and ethnic backgrounds, suggesting that the association may be unaffected by environmental or genetic background. (3) Understanding of a disease should focus not only on the association between different factors, but also on the dynamic effects of different factors on the disease. For example, persistently elevated arterial pressure in hypertension can lead to retinal vasculopathy, renal arteriosclerosis, and other target organ damage. Meanwhile, abnormalities in the microcirculation system can also affect the systemic blood pressure, forming a vicious circle. Through following this train of thought, combined with prospective cohort studies, it is possible to achieve individualized predictions of chronic kidney disease by retinal blood vessels in the future.