Conjunctival histologic findings of dry eye and non-dry eye contact lens wearing subjects.

PURPOSE

To determine if contact lens wearers with dry eye (DE CL) have greater histological and inflammatory conjunctival epithelial changes compared to non-dry eye contact lens wearers (CL).

METHODS

Fifty-eight myopic subjects were recruited for the study: DE CL group (N=27), CL group (N=11), and control group (N=20). Contact lens groups were matched for proportions of rigid gas permeable (RGP) lenses, disposables, and conventional soft contact lenses. Dry eye was defined by McMonnies dry eye symptom survey score of > or =14, fluorescein break up time (FBUT) of <10 seconds, and the presence of rose bengal staining. Ocular surface samples were taken using conjunctival impression cytology to determine nucleo-cytoplasm ratio, goblet cell density (GCD), and expression of conjunctival antigens to HLA DR and CD23.

RESULTS

HLA DR and CD23 expression were significantly greater for the DE CL group compared to the CL group (P=0.0122 and P=0.0072, respectively). The CL group had a significant reduction in GCD (P=0.0001), and greater expression of ocular surface antigens to HLA DR (P=0.04) and CD23 (P=0.04) compared to the control group.

CONCLUSIONS

The results of this study support the view that mechanical influences are responsible for the conjunctival squamous metaplasia changes in contact lens wear. Dry eye in contact lens wear is associated with allergic and immune mediated inflammatory processes.