Fluid produced in the eye is a natural barrier to a corneal infection. Blepharitis is inflammation of the eyelid margin, and a common cause of dry eye. Blepharitis can lead to insufficient fluid or poor-quality fluid to be generated by the eyelid margin, which is needed to mix with eye fluids from the lacrimal glands and goblet cells, to and maintain the health of the corneal surface. Chronic dry eye can lead to vision problems, vision fluctuation, less resistance to infection on the ocular surface, and make contact lens wear difficult. Chronic blepharitis can shed pathogens across the cornea from the base of the eyelashes, which can invade the cornea if the epithelium is damaged.
Blepharitis can be caused by pathogens, such as H-pylori, chlamydia pneumonia or chlamydia trachoma; or by p-acnes, a bacteria that lives on the skin and can become pathogenic when it invades an anaerobic environment, at the base of the eyelashes. Blepharitis predisposes a patient to ocular surface disease and corneal thinning, by making the ocular surface more hospitable to pathogens and less protected by healthy fluid. Women are particularly prone to blepharitis, “dry eye syndrome”, and corneal thinning diseases, due to use of eye make-up that can transfer pathogens to the eyelid margin.
Eye make-up, particularly mascara and eye make-up containing sparkles or powder, may contain indigestible materials that can cause blepharitis, and trigger the immune system to attack foreign particles. Eye make-up has not been tested for safety, due to a grandfather clause in the Food Drug and Cosmetic Act, of 1938, which allowed all cosmetics on the market to remain on the market, without safety testing. Any new eye make-up is approved under the grandfather clause, based on substantial equivalency to cosmetics which were sold, prior to 1938.
