Ocular surface changes induced by contact lens wear

Purpose. To evaluate subclinical inflammation and mucus production of the c onjunctiva in asymptomatic contact lens (CL) wearers, and to obtain an esti mation of the chronologic variations in each group. Methods. Eighteen eyes fitted with rigid CL (RCL) and 28 eyes with soft CL (SCL) worn daily were c ompared with 10 eyes from five healthy non-CL wearers. Impression cytology (IC) specimens were collected after clinical examination and were analyzed by flow cytometry using antibodies directed to HLA DR and intercellular adh esion molecule type 1 (ICAM-1) (CD 54), as inflammatory markers, and to the peptidic core of the conjunctival mucin (M1/MUC5AC) for mucus and goblet c ell detection. The percentage of positive cells was calculated, and levels of fluorescence expression were quantified and compared between each group. Results. A significant increase of HLA DR and ICAM-1 was observed in the S CL group in comparison with the control Group. The two inflammatory markers were highly positively correlated with each other. Mucin detection with M1 /MUC5AC did not find a significant difference between each group in terms o f percentage of positive cells, but analyses of mean levels of fluorescence showed a significant decrease in the two CL groups. Evolution in time was different for each group, with a regular low level of inflammation in the R CL group in the first 10 years in comparison with the SCL group. In the SCL group, inflammation seemed to be higher before 2 years and after 10 years of wear. Mucin expression was variable in time, but without significant dif ference at any time. Conclusion. This study confirms difference in expressi on of subclinical conjunctival inflammation in asymptomatic CL wearers, wit h lower levels for RCL than SCL wearers with daily or extended wear. The mu cin system is also modified by this low but chronic aggression of the ocula r surface, with a tendency to decrease with time in the RCL and SCL groups.