Changes in corneal Langerhans cell density during the first few hours of contact lens wear

• We examined the corneas of 10 participants who wore hydrogel contact lenses.
• We evaluated changes in central corneal Langerhans cell density over 8 h.
• Langerhans cells increased 2X after 2 h, indicating sub-clinical inflammation.

PurposeTo determine the impact of contact lens wear on Langerhans cell density (LCD) in the central cornea over an 8 h period.MethodsTen participants wore a hydrogel lens in one eye (the experimental eye) for 8 h. The contralateral non-lens-wearing eye served as a control. The central cornea of each eye was examined at the level of the subbasal nerve plexus using a laser scanning corneal confocal microscope, at baseline (prior to lens wear), then every 2 h for 8 h.ResultsAt baseline, LCD was 18 ± 19 and 20 ± 19 cells/mm2 in the experimental and control eyes, respectively. In the experimental eye, LCD increased to 36 ± 32 cells/mm2 after 2 h and then decreased gradually to 30 ± 31 cells/mm2 after 6 h. LCD was greater in the experimental eye than the control eye at the 2, 4, 6 and 8 h time points (p < 0.05). LCD remained constant in the control eye throughout the 8 h experiment.ConclusionsLCD increases two-fold within the first 2 h of lens wear, indicating a rapid, sub-clinical inflammatory response to uncomplicated lens wear.