Contact lens-induced corneal parainflammation involving Ly6G+ cell infiltration requires IL-17A and γδ T cells

Compatibility of a New Ocular Surface Dye with Disposable and Bi-Weekly Soft Contact Lenses: An Experimental Study

Ocular surface staining for assessing corneal and conjunctival epithelium integrity is typically conducted using fluorescein, lissamine green, or rose Bengal dyes. Recently, a novel vital dye, REmark®, based on riboflavin, has been proposed for ocular surface examination. In the management of corneal and ocular surface diseases (OSD), the use of contact lenses is integral to therapeutic strategies. This study explores the compatibility of REmark® with four different types of disposable or bi-weekly soft contact lenses. Morphological variations observed under stereomicroscopy and ultraviolet (UV) ray transmittance in the visible spectrum (VIS) were evaluated at 2 and 4 h post-immersion of the contact lenses in both the original fluid and the new dye. The findings indicate no significant differences between the group treated with the original liquid and those immersed in REmark®, except for a yellow hue observed in the latter group, which dissipates after 8 h in physiological solution. This study highlights the potential of utilizing the new vital dye for ophthalmologic examinations even in the presence of applied soft contact lenses, offering a promising avenue for improved diagnostic practices and patient comfort.

Persistence of Contact Lens-Induced Corneal Parainflammation Following Lens Removal

Purpose

Contact lens wear induces corneal parainflammation involving increased immune cell numbers after 24 hours' (CD11c+, Lyz2+, γδ-T cells) and six days' (Ly6G+ cells) wear. We investigated the time course of onset and resolution of these responses.

Methods

LysMcre or C57BL/6J mice were fitted with a contact lens (four to 48 hours). Contralateral eyes did not wear lenses. After lens removal, Lyz2+, MHC-II+ or Ly6G+ cells were examined by quantitative imaging. RT-qPCR determined cytokine gene expression.

Results

Lens wear for 24 hours increased corneal Lyz2+ cells versus contralateral eyes approximately two-fold. Corneas remained free of visible pathology. The Lyz2+ response was not observed after four or 12 hours' wear, nor after 12 hours' wear plus 12 hours' no wear. Lens removal after 24 hours' wear further increased Lyz2+ cells (∼48% after one day), which persisted for four days, returning to baseline by seven days. Lyz2+ cells in contralateral eyes remained at baseline. MHC-II+ cells showed a similar response but without increasing after lens removal. Lens wear for 48 hours showed reduced Lyz2+ cells versus 24 hours' wear with one day discontinuation, correlating with reduced IL-1β and IL-18 gene expression. Lens wear for 24 hours did not induce Ly6G+ responses six days after removal.

Conclusions

Lens-induced corneal parainflammation involving Lyz2+ cells requires 24 hours' wear but persists after lens discontinuation, requiring seven days for reversal. Lens wear for 48 hours may suppress initial Lyz2+ cell and cytokine responses. The significance of parainflammation during and after lens wear remains to be determined.

Epithelial Immune Cell Response to Initial Soft Contact Lens Wear in the Human Corneal and Conjunctival Epithelium

Purpose

The purpose of this study was to assess the immediate ocular immune response to soft contact lens (CL) wear by examining presumed epithelial immune cell (EIC) density and morphology at the central, peripheral, limbal cornea, and conjunctiva.

Methods

Fifty-four participants naïve to CL wear (mean age = 24.8 ± 9.8 years, 44% female participants), were examined using in vivo confocal microscopy at baseline and after 2 hours of CL wear (1-Day ACUVUE MOIST). Images were captured at the central, temporal far peripheral and limbal cornea, and bulbar conjunctiva. EIC density was counted manually and morphology was graded. Differences in EIC parameters pre- and post-CL wear were examined using a generalized estimating equation model with appropriate post hoc analyses.

Results

After 2 hours of soft CL wear, there was a significant increase in EIC density in all regions other than the central cornea (all P < 0.001). Cell body size was significantly larger, and a higher proportion of participants exhibited EIC with long dendrites after lens wear at the central and peripheral cornea (both P < 0.001). There was a significant increase in the number of participants displaying EIC with thick dendrites at the peripheral (P = 0.04) and limbal cornea (P < 0.001) after lens wear.

Conclusions

EICs were primarily recruited to the peripheral regions, whereas the central cornea shows no significant recruitment after short-term CL wear. Both central and peripheral corneas exhibited an enhanced antigen capture capacity, whereas migratory capacity was increased in the peripheral corneal regions suggesting EIC activation following a short period of CL wear.

TRPA1 and TPRV1 Ion Channels Are Required for Contact Lens-Induced Corneal Parainflammation and Can Modulate Levels of Resident Corneal Immune Cells

Purpose

Contact lens wear can induce corneal parainflammation involving CD11c+ cell responses (24 hours), γδ T cell responses (24 hours and 6 days), and IL-17-dependent Ly6G+ cell responses (6 days). Topical antibiotics blocked these CD11c+ responses. Because corneal CD11c+ responses to bacteria require transient receptor potential (TRP) ion-channels (TRPA1/TRPV1), we determined if these channels mediate lens-induced corneal parainflammation.

Methods

Wild-type mice were fitted with contact lenses for 24 hours or 6 days and compared to lens wearing TRPA1 (-/-) or TRPV1 (-/-) mice or resiniferatoxin (RTX)-treated mice. Contralateral eyes were not fitted with lenses. Corneas were examined for major histocompatibility complex (MHC) class II+, CD45+, γδ T, or TNF-α+ cell responses (24 hours) or Ly6G+ responses (6 days) by quantitative imaging. The quantitative PCR (qPCR) determined cytokine gene expression.

Results

Lens-induced increases in MHC class II+ cells after 24 hours were abrogated in TRPV1 (-/-) but not TRPA1 (-/-) mice. Increases in CD45+ cells were unaffected. Increases in γδ T cells after 24 hours of wear were abrogated in TRPA1 (-/-) and TRPV1 (-/-) mice, as were 6 day Ly6G+ cell responses. Contralateral corneas of TRPA1 (-/-) and TRPV1 (-/-) mice showed reduced MHC class II+ and γδ T cells at 24 hours. RTX inhibited lens-induced parainflammatory phenotypes (24 hours and 6 days), blocked lens-induced TNF-α and IL-18 gene expression, TNF-α+ cell infiltration (24 hours), and reduced baseline MHC class II+ cells.

Conclusions

TRPA1 and TRPV1 mediate contact lens-induced corneal parainflammation after 24 hours and 6 days of wear and can modulate baseline levels of resident corneal immune cells.