A South Korean retrospective longitudinal clinical study of retinal vein occlusion (RVO) in patients with end stage renal disease (ESRD) has shown that a significant association between ESRD and the subsequent incidence of RVO, following adjustment for possible confounding factors. The study accessed a national database of 1,025,340 randomly selected individuals and focused on an ESRD group of just under 1,000 patients with a formal diagnosis of ESRD over an approximate 11-year period. A random selection of almost 5,000 individuals, representing a ratio of almost 5:1 of normal: ESRD was used to compare the risk of RVO development between the two groups.
RVO is second only to diabetic reinopathy among the most common causes of retinal vascular disease. Risk factors for RVO include hypertension, hypercholesterolemia, myocardial infarction, diabetes and cerebral vascular accidents. According to the South Korean researchers, “the retinal and renal circulations share homologous anatomic, physiologic, and pathologic characteristics” and, consequently, kidney disease may also be considered a risk factor for RVO. However, the researchers contend that a shortage of evidence-based studies has yet to establish clear evidence of an association between RVO and ESRD, leading the investigators to conduct the Korean study.
The research, undertaken by investigators at the Institute of Vision Research, Yonsei University College of Medicine, Seoul, and published in IOVS (January 2018 Vol. 59 No. 1, 39-44) showed that over a mean follow-up period of 7.37 years, the incidence of RVO was 3.95% in the ESRD group and 2.17% in the normal (control) group (P = 0.001). The data collected suggested that ESRD was associated with a greater risk of RVO development after adjustment for several possible confounders (adjusted hazard ratio [HR], 2.122; 95% confidence interval [CI], 1.396–3.226; P = 0.0004). The research also showed that analyses of 50 to 60 year olds (adjusted HR, 2.635; 95% CI, 1.100–6.313; P = 0.0297) and of 60 to 70 year olds (adjusted HR, 2.544; 95% CI, 1.059–6.110; P = 0.0368) demonstrated a higher risk of RVO than that in an <40-year age group. In addition to ESRD, hyperlipidemia (adjusted HR, 1.670; 95% CI, 1.176–2.371; P = 0.0042) and hypertension (adjusted HR, 1.896; 95% CI, 1.165–3.086; P = 0.01) were also shown to be associated with RVO. In conluding their analysis the researchers stated, “we found an association between ESRD and subsequent RVO development during an 11-year follow-up period after adjustment for possible confounding factors, and the ESRD patients exhibited an approximately 2-fold higher HR relative to the comparison group. Nephrologists can educate ESRD patients about the possibility of RVO, and ophthalmologists should perform more careful fundus examinations when examining ESRD patients.”