Abstract
Purpose: :
The present investigation is aimed to evaluate the effect of a new artificial tear (SIFI emulsion) on tear secretion and ocular surface signs in a mouse model of dry eye.
Methods: :
A new oil-in-water emulsion, containing natural apolar triglycerides and phospholipids, a 0.2% sodium hyaluronate solution or their combined administration were given to mice maintained in a Controlled Environment Chamber (CEC) treated with scopolamine (0.75mg transdermal patch). The mice were divided into 4 treatment groups: group A received 10 µl emulsion, group B received 10 µl 0.2% sodium hyaluronate, group C received 5µl 0.2% sodium hyaluronate followed by 5µl emulsion and group D was not treated (ctrl+). Treatments were performed four times a day. A negative control group (ctrl-) of mice was kept under standard temperature and humidity to confirm the occurrence of dry eye in CEC. Tear production and corneal damage were assessed after 3 and 7 days of CEC by cotton thread test and fluorescein staining, respectively.
Results: :
Tear production and corneal staining were significantly worsened in the group of mice maintained under CEC (ctrl+) with respect to the control group (ctrl-).As regards tear volume, sodium hyaluronate did not show a statistically significant effect at both the endpoints, the emulsion was effective (p< 0.001) after 7 days, while the combined administration of sodium hyaluronate and emulsion counteracted both at 3 days (p< 0.05) and 7 days (p< 0.001) the lachrymal decrease induced by the model, suggesting a synergism between the two products. Corneal damage was reduced in all treated groups with respect to ctrl+. This effect was statistically significant after 3 days when the emulsion, either alone (p< 0.01) or in combination with sodium hyaluronate (p< 0.05), was used; while hyaluronate improved this clinical sign after 7 days (p< 0.05).
Conclusions: :
The CEC can be used to test the effects of artificial tears on tear volume and corneal damage. In particular, our data demonstrate that artificial tears containing lipids can be effective, alone or in combination with hyaluronate, in treating dry eye.
Keywords: cornea: tears/tear film/dry eye