Evaluation of ocular surface in different contact lens usage protocols

Purpose: To evaluate the effects of different contact lens (CL) protocols and different CL materials on the ocular surface and tear functions. Methods: This prospective study included 71 consenting individuals who wished to use CL. The subjects were divided into three groups according to the features of CL used. Disposable hydrogel CL (1-Day Moist, Johnson & Johnson) was given to 22 individuals at the first group, disposable silicone hydrogel CL (Dailies Total, CIBA Vision) was given to 25 individuals at the second group and monthly silicone hydrogel CL (Purevision-2 HD, Bausch&Lomb) was given to 24 individuals at the third group in daily using protocol. Evaluation was made in respect of tear function tests, ocular surface disease index (OSDI) scores and inflammatory marker [interleukine (IL)-6, IL-8, IL-17A, matrix metalloproteinase (MMP)-9] levels before and at 1 and 3 months after CL usage. Impression cytology was evaluated before and at 3 months after CL usage. The groups were compared with each other in terms of ocular surface changes and intragroup evaluations were made in terms of time-related changes. Results: Prior to CL usage, no differences were determined between the groups in terms of age, gender, tear function tests (tear osmolarity, tear break-up time (BUT), Schirmer's test, Oxford staining score and the OSDI score) (p>0.05). Prior to CL usage, there were no significant differences in terms of inflammatory cytokines in the tears (IL-6, IL-8, IL-17A, MMP-9) and in terms of the phases of Nelson which is evaluated by impression cytology (p>0.05). No significant difference was determined between the groups in respect of tear function tests at 1 and 3 months of CL usage (p>0.05). In the first month, a statistically significant difference was determined between the groups in the levels of IL-6, IL-8, IL-17A in the tears, with the highest level in group 3 and the lowest in group 1 (all; p<0.05). No significant difference was determined between the groups at first month in respect of the level of MMP-9 (p=0.49). At third month, a statistically significant difference was determined between the groups in the levels of IL-6, IL-8, IL-17A, and MMP-9 in the tears, with the lowest level in group 1 and the highest level in group 3 (all; p<0.05). A significant decrease over time was determined in only the Schirmer's test in group 1 (p=0.01), only in GYKZ in group 2, and no significant differences in other tear function tests. In group 3, a statistically significant increase was determined over time in the OSDI score and a decrease in the BUT and Schirmer's test (p=0.05, p=0.02, p=0.03 respectively).A statistically significant increase was determined over time in the levels of IL-6, IL-8, IL-17A and MMP-9 in all three groups. In the third month evaluation of impression cytology, a significant progression was observed in the phase of Nelson (p<0.05), and a significant decrease in goblet cell density (p<0.05) in all 3 groups. Conclusion: In the early period, there was increased inflammation on the ocular surface and a series of cell changes in the conjunctiva related to CL use. Therefore, there was a tendency for the development of dry eye in those using CL. The use of daily disposable CL can be considered to cause less damage to the ocular surface and less development of dry eye. Key Words: Contact lens, tear function tests, inflammation, impression cytology.