A narrative literature review about alpha-lipoic acid role in dry eye and ocular surface disease.

Ocular surface diseases (OSD) include various conditions that affect the eye's surface, causing discomfort and pain. One such condition, dry eye disease (DED), is a multifactorial disorder that significantly impacts patients' quality of life, with prevalence rates ranging from 5% to 50% and higher incidence in women. DED involves tear film instability, inflammation and neurosensory abnormalities, making its management challenging due to diverse underlying mechanisms. Conventional treatments typically focus on symptom relief, but new approaches targeting the disease's pathogenesis are emerging. Alpha-lipoic acid (ALA) is gaining attention for its potential in treating OSD and DED. ALA acts as a potent antioxidant, neutralizing reactive oxygen species. It protects cell membranes by interacting with vitamin C and glutathione, potentially recycling vitamin E. Its antioxidative properties are particularly relevant in meibomian gland dysfunction, a condition implicated in DED. By scavenging free radicals and modulating redox status in the meibomian glands, ALA can reduce oxidative damage, preserve glandular function and decrease inflammation. In diabetic patients with DED, ALA administration has been found to improve tear film parameters, reduce corneal defects, enhance antioxidant status and potentially prevent diabetic retinopathy and keratopathy. Its therapeutic effects on neurosensory abnormalities, especially in diabetic polyneuropathy and other neuropathies, are primarily due to its antioxidant, anti-inflammatory and metal-chelating properties. In summary, ALA holds promise as a therapeutic agent for DED and OSD and could be a promising treatment option for diabetic retinopathy and keratopathy, although further research is needed to confirm its efficacy.