Impression cytology in atopic dermatitis

Purpose: This study aimed to describe the ocular surface disorder in patients with atopic dermatitis (AD). Design: A prospective case-controlled study. Participants: A total of 44 patients with active AD seen at Kobe University School of Medicine, Department of Ophthalmology, during 1994 through 1996 and 22 normal control subjects were studied. Intervention: The subjects underwent routine ophthalmic examinations, tear film break-up time (BUT), Schirmer test, and conjunctival impression cytology. Main Outcome Measures: Patients and control subjects were compared for tear function parameters, goblet cell density, and conjunctival squamous metaplasia grade. The relation of duration and recurrences of AD to the ocular surface disorder also was looked for. Results: The duration of atopic disease ranged from 18 to 32 years (mean, 22.8 years). The average for exacerbations was 4.5 times. Chronic allergic conjunctivitis with superficial punctate keratitis was the most frequent clinical presentation. The BUT and Schirmer test values were significantly lower in patients with AD compared with those of the control subjects. Impression cytology showed goblet cell loss and conjunctival squamous metaplasia, both of which related to the number of recurrences of AD rather than the duration of disease. Facial atopy and allergic keratoconjunctivitis (AKC) related to the metaplasia of the ocular surface (P < 0.001). Patients with reduced goblet cell density also showed low BUT levels (P < 0.001). Conclusion: Ocular surface disorder of AD characterized by goblet cell loss and conjunctival squamous metaplasia seemed to evolve independently of the duration of disease but worsen with increased number of flare-ups. Direct epithelial damage by the allergic reaction, disorder of tear quality, and quantity may be important in the genesis of the atopic ocular surface disease.