Effects of the Topical Use of the Natural Antioxidant Alpha-Lipoic Acid on the Ocular Surface of Diabetic Patients with Dry Eye Symptoms

• Published in: Frontiers in bioscience (Landmark. Print) Vol. 27; no. 7; p. 202
• Main Authors: Roszkowska, Anna M., Spinella, Rosaria, Oliverio, Giovanni W., Postorino, Elisa I., Signorino, Giuseppe A., Rusciano, Dario, Aragona, Pasquale
• Format: Journal Article
• Language: English
• Published: IMR Press 27.06.2022
• Subjects: alpha-lipoic acid; dry eye; hypromellose; ocular surface; oxidative stress
• ISSN: 2768-6701; 2768-6698
• DOI: 10.31083/j.fbl2707202

PURPOSEThe purpose of this study is to investigate the effects of the treatment with eye-drops based on a combination of antioxidant and mucomimetic molecules, namely 0.1% alpha-lipoic acid (ALA) and 0.3% hydroxy-propyl-methylcellulose (HPMC) on the ocular surface of diabetic patients with dry eye symptoms. METHODSSeventy patients, 42 M and 28 F, aged from 50 to79 years (mean 62.1 ± 10.5), affected by type II diabetes mellitus, were enrolled and divided in two groups treated for 2 months as follows: Group 1 (35 patients), received topical ALA/HPMC three times a day, Group 2 (35 patients) received topical HPMC (0.3%) alone, three times a day. The main outcome measures were: Ocular Surface Disease Index (OSDI), tear film break-up time (TBUT), corneal fluorescein staining, Schirmer I test, corneal sensitivity. An examination of tear film morphology with confocal microscopy was carried out in a subset of patients of each group at baseline and after two months. Statistical analysis was performed with t-test for the parametric data and Mann-Whitney U-test or chi-squared test for the nonparametric data. RESULTSBoth treatments resulted in significant improvements of BUT, OSDI and tear film morphology, although the improvements observed in group 1 showed a higher trend than what observed for group 2. Moreover, only in group 1 a significant improvement was visible for corneal staining, and no significant improvements were observed in any group for Schirmer I and sensitivity. CONCLUSIONSThese results confirmed the efficacy of HPMC in the treatment of diabetic dry eye and indicated that the addition of a strong self-regenerating antioxidant like ALA may give a distinctive advantage for the healing of corneal defects (as evidenced by corneal staining), beside improving HPMC efficacy on three other parameters (BUT, OSDI score, tear morphology). Therefore, the addition of a strong antioxidant like ALA can be helpful in preventing or treating ocular surface defects in diabetic patients, in which the oxidative damage is predominant.