Diabetic Retinopathy in Patients With Diabetic Foot Ulcer: A Systematic Review

This review discusses the evidence on diabetic retinopathy (DR) in patients with diabetic foot ulceration (DFU). A systematic literature review was performed on PubMed, Medline, Springer Nature, and Scopus, following the PRISMA guidelines, using the following terms, individually or in combination: "diabetic foot ulcer" OR "diabetic foot syndrome" OR "DFU" and "diabetic retinopathy." The initial search yielded 648 articles published between 1975 and 2020. After applying exclusion and inclusion criteria, a total of 9 articles were analyzed, assessing the correlations between DR and DFU. In all cases, DR and especially proliferative diabetic retinopathy were significantly higher in the presence of DFU, though the frequency of DR showed large variability (22.5% to 95.6%). There was a significant correlation between advanced stages of DFU and increased frequency of DR and proliferative diabetic retinopathy. On the other hand, there is a risk of accelerated progression of DR in nonhealing DFUs, possibly related to chronic inflammation and associated infection. Hence, patients with DFUs should be monitored by an ophthalmologist, and those with DR should be promptly referred to a specialized diabetic foot clinic.