PURPOSE: This study aimed to determine whether circular RNAs (circRNAs) in whole 
blood could be served as novel non-invasive biomarkers for proliferative 
diabetic retinopathy (PDR).
METHODS: This retrospective cross-sectional study comprised 34 healthy 
participants, 34 PDR patients and 34 non-proliferative DR (NPDR) patients. 
High-throughput whole transcriptome sequencing was performed to explore the 
expression profile of circRNAs in the whole blood, and the candidate circRNAs 
were validated by quantitative real-time polymerase chain reaction (qRT-PCR). 
Receiver operating characteristic (ROC) analysis evaluated the ability of these 
candidate circRNAs in discriminating PDR patients from NPDR patients and healthy 
subjects. Finally, the networks of circRNA-miRNA-mRNA based on the candidate 
circRNAs were constructed.
RESULTS: Using sequencing and qRT-PCR, hsa_circ_0001953 was found to be elevated 
in PDR patients in contrast with the other two groups. Statistical analysis 
showed that the expression levels of hsa_circ_0001953 in PDR patients were 
positively related to the duration of diabetes and HbAc1. Receiver operating 
characteristic (ROC) curve analysis revealed that hsa_circ_0001953 was 
associated with a high diagnostic accuracy in discriminating PDR patients from 
NPDR patients and healthy controls, resulting in an area under the curve (AUC) 
of 0.87 and 0.92, respectively. The circRNA-miRNA-target gene networks for 
hsa_circ_0001953 showed that hsa_circ_0001953 could interact with dozens of 
miRNAs and some targeted mRNAs have been potentially involved in the 
pathogenesis of diabetes.
CONCLUSION: The present findings indicate that hsa_circ_0001953 in the whole 
blood may serve as a novel diagnostic biomarker and potential therapeutic target 
for PDR.