Retinopathy and Progression of CKD: The CRIC Study

Background and objectives

Retinal abnormalities may be associated with changes in the renal vasculature. This study assessed the association between retinopathy and progression of kidney disease in participants of the Chronic Renal Insufficiency Cohort (CRIC) study.

Design, setting, participants, & measurements

This was a prospective study in which patients with CKD enrolled in CRIC had nonmydriatic fundus photographs of both eyes. All CRIC participants in six clinical sites in which fundus cameras were deployed were offered participation. Photographs were reviewed at a reading center. The presence and severity of retinopathy and vessel calibers were assessed using standard protocols by graders masked to clinical information. The associations of retinal features with changes in eGFR and the need for RRT (ESRD) were assessed.

Results

Retinal images and renal progression outcomes were obtained from 1852 of the 2605 participants (71.1%) approached. During follow-up (median 2.3 years), 152 participants (8.2%) developed ESRD. Presence and severity of retinopathy at baseline were strongly associated with the risk of subsequent progression to ESRD and reductions in eGFR in unadjusted analyses. For example, participants with retinopathy were 4.4 times (95% confidence interval [95% CI], 3.12 to 6.31) more likely to develop ESRD than those without retinopathy (P<0.001). However, this association was not statistically significant after adjustment for initial eGFR and 24-hour proteinuria. Venular and arteriolar diameter calibers were not associated with ESRD or eGFR decline. The results showed a nonlinear relationship between mean ratio of arteriole/vein calibers and the risk of progression to ESRD; participants within the fourth arteriole/vein ratio quartile were 3.11 times (95% CI, 1.51 to 6.40) more likely to develop ESRD than those in the first quartile (P<0.001).

Conclusions

The presence and severity of retinopathy were not associated with ESRD and decline in eGFR after taking into account established risk factors.