Tear Function and Ocular Surface Mucin Alterations in Atopic Dermatitis Patients

Abstract

Abstract: : Purpose:To study the tear functions and ocular surface mucin alterations in patients with atopic dermatitis ( AD) Methods: Twenty eyes of 10 patients (9 males, 1female; mean age: 24 years) with AD as well as 14 eyes of 7 age and sex matched healthy control subjects were recruited. All patients had atopic keratoconjunctivitis (AKC).None of the patients or controls had any other ocular or systemic disease. All patients had the same treatment including topical antiallergic and steroids. Subjects underwent corneal sensitivity measurements, Schirmer test –I, BUT measurements, Rose–Bengal and fluorescein vital stainings, upper tarsal conjunctival impression and brush cytology(BC). Informed consents and ethic board review for the procedures were also obtained. Impression cytology (IC) specimens were evaluated by PAS and immunohistochemical staining employing MUC 1 and 4 antibodies. BC specimens obtained from upper tarsal conjunctiva were studied for expression of inflammatory cells and with Real Time RT PCR to assess the MUC 1 and 4 mRNA expression. Results: The mean corneal sensitivity and BUT values were significantly lower in atopic eyes which also had higher staining scores, compared to control eyes ( p<0.001). BC revealed significantly higher numbers of inflammatory cells in atopic eyes . IC showed significant goblet cell loss and squamous metaplasia in eyes with AKC compared to control eyes. Real Time RT PCR showed decreased MUC 1 and 4 mRNA expression in eyes with AKC. Immunohistochemistry staining for MUC 1 and 4 in eyes with AKC showed a scanty staining for mucin compared to control eyes. Conclusions: The inflammatory process, tear instability and decreased MUC 1 and 4 mRNA expression were thought to be important factors in the pathogenesis of ocular surface disease in atopic dermatitis.

Keywords: cornea: tears/tear film/dry eye • cornea: clinical science • cornea: surface mucins