An Oral Polyphenol Formulation to Modulate the Ocular Surface Inflammatory Process and to Improve the Symptomatology Associated with Dry Eye Disease

Abstract

Due to their antioxidant, anti-inflammatory, neuroprotective, and anti-angiogenic effects, polyphenols are first-rate candidates to prevent or treat chronic diseases in which oxidative stress-induced inflammation plays a role in disease pathogenesis. Dry eye disease (DED) is a common pathology, on which novel phenolic compound formulations have been tested as an adjuvant therapeutic approach. However, polyphenols are characterized by limited stability and solubility, insolubility in water, very rapid metabolism, and a very short half-life. Thus, they show poor bioavailability. To overcome these limitations and improve their stability and bioavailability, we evaluated the safety and efficacy of an oral formulation containing among other compounds, polyphenols and omega-3 fatty acids, with the addition of a surfactant in patients with DED. Subjects were randomly assigned to one of four study groups including the study formulation (A), placebo (P), the study formulation + eye lubricant (A + L), and placebo + eye lubricant (P + L). Patients from the A and P groups were instructed to take two capsules every 24 h, while patients in the L groups also added one drop of lubricant twice a day for 12 weeks as well. Regarding safety, non-ocular abnormalities were observed during study formulation therapy. Liver function tests did not show any statistically significant difference (baseline vs. week 4). Concerning efficacy, there was a statistically significant difference between baseline, month 1, and month 3 in the OSDI (Ocular Surface Disease Index) test results in both treatment groups (group A and group A + L). Furthermore, both groups showed statistically significant differences between baseline and month 3 regarding the non-invasive film tear breakup time (NIF-BUT) score and a positive trend related to Shirmer’s test at month 3. The non-invasive average breakup time (NIAvg-BUT) score showed a statistically significant difference at month 3 when compared with baseline in the A + L group. The P + L group showed a statistically significant difference in terms of the OSDI questionary between baseline and month 3. Regarding the lissamine green staining, the A + L group showed a statistical difference between baseline and month 3 (p = 0.0367). The placebo + lubricant group did not show statistically significant differences. Finally, the placebo group did not show any data with statistically significant differences. Consequently, this polyphenol formulation as a primary treatment outperformed the placebo alone, and the polyphenol oral formulation used as an adjuvant to artificial tears was superior to the combination of the placebo and the artificial tears. Thus, our data strongly suggest that this polyphenol oral formulation improves visual strain symptoms and tear film status in patients with mild to moderate DED.