Effect of three tear supplements on signs, symptoms and pro-inflammatory markers in subjects with dry eye disease

Purpose: A preliminary study to investigate the effect of three commercial tear supplements (Optive Plus - Allergan, Refresh Contacts - Allergan and Systane Balance - Alcon) when used in dry eye patients for one week. The signs and symptoms of dry eye disease, along with inflammatory status pre- and post-treatment, were compared for each tear supplement.

Methods: Eighteen dry eye subjects were recruited (Schirmer =10mm in 5 minutes), comprising 14 females and 4 males, with a mean age of 52.8 years (±15.8). In a crossover design subjects received each treatment for 1 week (4 times a day), followed by 1 week washout, where subjects received no treatment. At each visit, ocular surface disease index questionnaire (OSDI), tear evaporation rate, tear stability, tear film interferometry, tear osmolarity and tear samples were taken. All of these measures, except tear film interferometry, were carried out in an environmental chamber at 22°C and 20% relative humidity.

Results: A reduction was observed in the concentrations of all 7 cytokines measured (IL-1ß, IL-2, IL-6, IL-8, IL-17, IFN-¿ and TNF-a) post treatment, with each of the products tested. The greatest percentage reduction was seen in IL-17 for both Refresh Contacts and Systane Balance, with a median of -43.1% and -83.8%, respectively. TNF-a showed the greatest percentage reduction (-42.2%), for Optive Plus, however, none of these reductions were statistically significant. Interestingly, the changes to all 7 cytokines showed significant correlations with each other, i.e. as one cytokine’s concentration reduced, there was a corresponding change in all of the others. No statistically significant change was observed pre- and post- treatment for any of the clinical measurements used, except for a significant improvement in OSDI with Refresh Contacts (p=0.012).

Conclusions: A consistent trend was observed for a reduction in the levels of all 7 cytokines measured following 1 week of treatment. Although the cytokines were reduced, this was not reflected in a reduction in clinical signs and symptoms. This could indicate a time-lag between inflammatory status and clinical improvement, or a lack of sensitivity on the part of the clinical tests used. Further work with a larger patient population, longer duration of treatment, and more specificity as to dry eye etiology may be useful to extend and confirm the present results.