Dihydrolipoic acid (DHLA) is the reduced form of alpha-lipoic acid (ALA), a compound with recognized antioxidant properties. ALA and its reduced form have been investigated for their potential benefits in diabetic complications, including diabetic retinopathy (DR), primarily due to their ability to scavenge free radicals and reduce oxidative stress—a key factor in the pathogenesis of DR. Several animal studies and a few small human trials have shown that ALA supplementation may help reduce oxidative damage and vascular dysfunction in the retina, potentially slowing the progression of diabetic retinopathy. However, most clinical research focuses on ALA, not specifically DHLA. DHLA is the main active intracellular metabolite of ALA and is believed to mediate many of its effects, but direct clinical evidence for DHLA supplementation in diabetic retinopathy patients is lacking.

ALA has some clinical support, including studies that show improvements in oxidative stress markers and retinal blood flow in diabetic patients, but evidence remains preliminary and not robust enough for strong clinical recommendations. Guidelines do not routinely recommend DHLA or ALA for DR, and large-scale, well-controlled trials are still needed. Thus, while the use of DHLA is based on plausible biological mechanisms and some early scientific support, the direct evidence for DHLA in diabetic retinopathy is limited.