Short- and long-term impact of silicone hydrogel contact lens wear on the ocular surface and anterior segment: a confocal microscopy study.

PURPOSE: To investigate short- and long-term effects of silicone hydrogel contact lens (SHCL) wear on the ocular surface and anterior segment, with a particular focus on corneal subbasal nerve morphology and corneal sensitivity using in vivo confocal microscopy (IVCM). METHODS: Thirty eyes of 30 male participants without previous CL use were prospectively evaluated. Ocular Surface Disease Index (OSDI), tear film breakup time (TBUT), Schirmer's test, corneal sensitivity, and tear meniscus area (TMA) were measured at baseline, 1 month, and 1 year. Corneal subbasal nerve parameters and dendritic cell density were assessed by IVCM. RESULTS: OSDI scores increased significantly after 1 month of SHCL wear (9.8 ± 2.34 vs. 16.6 ± 3.34; p < 0.001), accompanied by a significant rise in dendritic cell density (14.65 vs. 29.75 cells/mm2; p < 0.001). Both parameters returned to baseline after 1 year (p > 0.05). Corneal sensitivity remained stable at 1 month but declined significantly after 1 year (3.32 ± 1.06 vs. 2.03 ± 1.26 cm; p < 0.001). Subbasal nerve density, morphology, tortuosity, and reflectivity showed no significant alterations at either time point (p > 0.05). CONCLUSION: Short-term SHCL wear was associated with transient ocular surface inflammation and discomfort, whereas long-term wear was associated with reduced corneal sensitivity. No structural alterations were detected under the conditions of the present study.