Purpose: The authors' clinical experience has suggested that there is a form of dry eye with only decreased tear break-up time, which is associated with allergic conjunctivitis. The current study was performed to verify this hypothesis.
Method: The authors recruited patients with two types of dry eye syndrome, those with only decreased tear break-up (BUT type) and those with positive vital staining (staining type). Individuals without any symptoms or signs served as controls. All subjects were compared regarding symptoms, Schirmer and tear clearance test results, conjunctival papillary formation, antigen-specific serum-IgE level (s-IgE), and goblet cell density of the palpebral conjunctiva. Antigen-induced allergic conjunctivitis was produced in guinea pigs, and histopathologic changes of the conjunctiva were examined.
Results: Patients with the BUT-type dry eye syndrome were younger and their symptoms were as severe as the staining type. The Schirmer and tear clearance test results were better, and the papillary formation and s-IgE were observed more than in the BUT type. The average goblet cell density in the BUT-type syndrome was 625.4 +/- 193.2/mm2, which was significantly less than 1005.6 +/- 294.5/mm2 in the controls (P < 0.01). The average goblet cell density was significantly decreased in the allergic animals (10.40 +/- 1.11/0.2 mm) compared with that of the controls (16.21 +/- 0.26/0.2 mm) or the anti-allergic drug-treated group (13.69 +/- 0.30/0.2 mm) (P < 0.01).
Conclusion: These results support the authors' hypothesis that decreased break-up time is in part associated with the decreased goblet cell density caused by allergic conjunctivitis.