Conjunctival Changes in Wearers of Frequent Replacement Hydrogel and Frequent Replacement Silicone Hydrogel Contact Lenses: Comparison Using Impression Cytology Technique

Objectives: To compare the level of conjunctival changes using conjunctival impression cytology in wearers of frequent replacement hydrogel (FRHL) and frequent replacement silicone hydrogel contact lens FRSHL. Materials and Methods: Forty-two contact lens users who were seen at the Cornea and Contact Lens Unit, Department of Ophthalmology, Dokuz Eylül University were evaluated in this study. The first group consisted of wearers of FRHL used for minimum one year and maximum five years. The second group consisted of wearers who used FRSHL for minimum one year and maximum 5 years. Twenty healthy individuals with no contact lens history were included in the control group. Conjunctival impression cytology was applied to all contact lens users and the control group in order to evaluate the conjunctival changes, and the results of impression cytology were graded by the Nelson’s method. Results: In the comparison of the groups according to impression cytology scoring, there was no difference between the users of FRHL and FRSHL. Similar amounts of squamous metaplasia and goblet cell loss were encountered in both groups. Nonetheless, impression cytology grading was significantly lower in the control group than in the other two groups. Conclusion: In conclusion, the use of FRHL and FRSHL for over a year causes some histological changes in the conjunctiva such as squamous metaplasia and goblet cell loss eventually leading to dry eye symptoms. However, no differences were determined between FRHL and FRSHL users with regard to severity of conjunctival changes. (Turk J Ophthalmol 2014; 44: 47-52)