Omega-3 index in patients with severe diabetic ocular complications

The aim of the study was to assess the omega‑3 index and the proportions of other relevant fatty acids (FAs) in patients undergoing vitrectomy due to severe diabetic ocular complications. According to evidence, an optimal omega‑3 index range is 8–11% and a high level of saturated FAs correlate with advanced diabetic retinopathy (DR).

Patients with diabetes mellitus (DM) undergoing vitrectomy due to diabetic macular edema or vitreous hemorrhage secondary to proliferative DRP were recruited for this study. Prior to surgery, the omega‑3 index, defined as the proportion of omega‑3 FAs in the membranes of erythrocytes, and the proportions of omega‑6, omega‑9, saturated and trans FAs were assessed using “high-sensitivity” gas chromatography with flame ionization detection.

In total, 12 patients with DM type 1 (n = 2) and type 2 (n = 10) were enrolled. Their age was 69 ± 12 years and their HbA_1c averaged 7.6 ± 1.2%. The omega‑3 index was 4.5 ± 1.2%. There was a moderate negative correlation between HbA_1c and the omega‑3 index (r = −0.51, p = 0.09). The proportions of other FAs were within the normal ranges. However, the proportions of omega‑6 and saturated FAs were in the upper range (33.3 ± 2.2% and 41.1 ± 1.3%, respectively).

Patients with severe diabetic ocular complications who require vitreoretinal surgery are generally under-supplied with omega‑3 FAs and over-supplied with omega‑6 and saturated FAs. Patients with diabetes might consequently benefit from early omega‑3 FA supplementation and a reduction of saturated FAs in order to prevent or at least slow down the development of DRP and ultimately preserve vision.