Purpose: The 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. Methods: Seventy 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. Results: Both 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.
Conclusions: These 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.
