Subclinical Inflammation of the Ocular Surface in Soft Contact Lens Wear

To investigate the inflammatory response of the ocular surface with different soft contact lens (CL) replacement frequencies and materials.

Twenty soft CL wearers were required to wear 3 lens types: reusable Acuvue 2 (A2), reusable Acuvue Oasys (AO), and daily disposable Acuvue Oasys (AODD), for 1 week in random sequence in 1 eye with the nonlens-wearing eye acting as a control. Three methods were used to assess the subclinical response: tear cytokine evaluation, in vivo confocal microscopy (IVCM), and impression cytology.

Of 13 cytokines investigated, differences were observed only for IL-12p70, which was present in greater concentrations for A2 (interocular difference 8.8 pg/mL, 95% confidence interval 5.5-12.1) and AO (8.9 [5.7-12.1]) compared with AODD (3.7 [0.6-6.8]). For IVCM, corneal presumed dendritic cell density was lower for AODD (interocular difference 1.9 [-0.1 to 3.9] cells/mm) than for both A2 (9.3 [7.2-11.4]) and AO (10.6 [8.6-12.6]). This trend was the same for the other 5 IVCM measures evaluated. The proportion of CD45 cells in the bulbar conjunctiva was lower for AODD (0.6 [-0.3 to 1.5]%) compared with A2 (4.6 [3.7-5.6]) and AO (4.8 [3.9-5.8]). Similar findings were observed for cells in the upper lid margin.

This work has demonstrated for the first time that daily disposable CL wear produces a minimal subclinical inflammatory response compared with no lens wear over 1 week. By contrast, this inflammatory response is upregulated with reusable lenses but appears to be similar between hydrogel and silicone hydrogel materials over this short time frame.