Ocular Allergy as a Risk Factor for Dry Eye in Adults and Children

Edoardo Villani; Giovanni Rabbiolo; Paolo Nucci


Curr Opin Allergy Clin Immunol. 2018;18(5):398-403. 

In This Article

Ocular Allergy and Ocular Surface Damage

Epithelial cells death, loss of goblet cells, and squamous cell metaplasia are well known key components of the DED vicious cycle, especially in advanced forms. This type of ocular surface damage is due to several concomitant elements, including frictional damage, hyperosmolar environment, and chronic inflammation with IFN-γ overexpression.[18]

Several studies, using conjunctival impression and brush cytology to investigate the grade of metaplasia, the density of goblet cells and the level of secretory mucins (mainly MUC5AC) expression, clearly demonstrated squamous metaplasia in AKC and VKC. The ocular surface damage was correlated to severity and duration of the allergic inflammation, and it was negatively correlated to the tear film stability, probably because of a 'mucin-deficient dry eye state'. The over-expression of some membrane-associated mucins might be interpreted as a manifestation of an ocular surface defense response.[15,22–24,37]

Mild forms of allergic conjunctivitis don't seem to induce this type of ocular surface damage.[38]