Are preservative-free artificial tears are really better for dry eyes?
Hypoallergenic preservatives, which are also nontoxic, may be used without harm. Those with hydrophilic properties as an adsorbed layer can even be beneficial. In any case, solely the lack of preservatives per se does not make the formulation to be efficacious. – Unfortunately, the preservative-free label is often just a marketing tool. Slide 21: Preservation of Aqueous Tears To preserve existing tears either the drainage of the tears should be diminished or the evaporation lessened. Slide 22: Punctal Plugs to improve the tear meniscus A normal tear meniscus surrounding the tear film along the lid edges contains tears several-fold more than needed for the tear film. Scanty, uneven tear meniscus can be observed in dry eye patients. By decreasing tear drainage using punctual plugs, the tear meniscus can be restored. If the tear secretion rate is significant, however, this procedure results in epiphora. Punctal plugs placed into either the upper or lower puncta, or often into both, have g
