Abstract
Purpose: :
Lissamine green is a vital stain currently used to diagnose ocular surface damage. The aim of our study was to test the hypothesis that the extension of lissamine green staining of the conjunctiva correlates with the expression of inflammatory markers and immune cell infiltration in dry eye patients.
Methods: :
Thirty patients with dry eye have been selected by means of Ocular Surface Disease Index questionnaire, Schirmer I test, tear break-up time, and fluorescein corneal staining. Lissamine green conjunctival staining was recorded according to NEI scoring system. Impression cytology specimens were collected by applying one filter paper in the non-exposed bulbar conjunctiva, placed in cell culture medium containing 10% foetal calf serum, cells stained for the expression of CK19, CD3, CD4, CD8, CD56, CD19, CD20, CD14 and HLA-DR, and analyzed by flow cytometry. Statistical analysis for possible correlations was performed.
Results: :
In dry eyes there was a significant difference in the CD4/CD8 ratio respect to what observed in normal subjects, and an increased number of CD45+CD14+ cells. HLA-DR expression was increased in CK19+ conjunctival epithelial cells of dry eye patients. Significant correlation was found between lissamine green staining of the conjunctiva and CD45+CD14+ cells infiltration of the conjunctiva only.
Conclusions: :
This pilot study indicates that lissamine green staining of the conjunctiva could be related to infiltration of immune cells in the epithelial layer, opening newscenarios in the diagnosis of dry eye and on the evaluation of treatments in clinical studies.
Keywords: cornea: tears/tear film/dry eye • conjunctiva • anterior segment