The report of the World Dry Eye Working Group in 2007 pointed out that "the only and most important progress in the treatment of dry eye is the elimination of preservatives", because preservatives are very toxic to the eye surface, especially when dry eye patients use eye drops containing preservatives to aggravate the condition of dry eye. Sodium Hyaluronate eye drops produced in Germany are the only eye drops in the world that can be bottled without preservatives and can be used for a long time. So it is very popular in Europe and most recommended in China. The toxicity of preservatives is as follows: 1, cytotoxicity, destruction of ocular surface cells, resulting in ocular surface damage.
2, causing allergies. But it doesn't mean that there will be an allergic reaction immediately, which may be a chronic process. At first, the eyes can bear it, but after a while, chronic allergic reactions may occur.
3. Accelerate the clearance rate of high-energy metabolites (glucose, lactic acid and acetone).
4. Delaying epithelial cell regeneration
5, emulsified tear film, causing dry eyes.