Abstract
Purpose :
Contact lens wear can induce para-inflammatory responses in the cornea in humans and mice. In mice, lens-induced corneal parainflammation involves a significant increase in CD11c+ (dendritic) cells and γδ T cell numbers after 24 h of wear, and in Ly6G+ cells (neutrophils) after 6 days of wear. Here, we studied the resolution of corneal parainflammation after 24 h of lens wear.
Methods :
LysMcre mice were used to visualize corneal Lyz2+ (myeloid-derived immune) cells and C57BL/6 mice used to label MHC Class II+ cells. One eye of each mouse was fitted with a mouse contact lens. Contralateral eyes and naïve mice served as no lens wear controls. Mice wore lenses for 24 h, then were euthanized at various times after lens removal (0 h, 24 h, 4, 7,10 days). Freshly enucleated eyes were fixed in 2 % paraformaldehyde. Confocal imaging was used to quantify Lyz2+ cells. Immunohistochemistry was used to quantify MHC Class II+ cells. One-Way ANOVA was used for statistical analysis with P < 0.05 considered significant.
Results :
Lens wearing corneas showed increased Lyz2+ cells vs. contralateral controls (mean ± SD: 71 ± 7 vs. 32 ± 7; P = 0.001) but remained free of visible pathology and retained optical clarity similar to no-lens wear controls. Lens removal was associated with a 48 % increase in Lyz2+ cells 24 h after discontinuation (105 ± 21 vs. 71 ± 7; P = 0.003) which remained evident 4 days after discontinuation (97 ± 16 vs. 71 ± 7; P = 0.019). Lyz2+ cell numbers in contralateral eyes were unchanged at 24 h and 4 days after lens removal (31 ± 5, 31 ± 4, respectively). Lyz2+ numbers returned to baseline 7 days after lens wear cessation. Corneas of LysMcre and C57BL/6 mice showed a similar pattern of lens-induced MHC Class II+ cell responses and persistence after lens removal, although greater persistence was noted in LysMcre mice. Contact lens wear for 24 h did not result in Ly6G+ cell responses, even up to 7 days after lens discontinuation.
Conclusions :
Contact lens-induced para-inflammatory responses in the murine cornea after 24 h of wear can persist for at least 4 days after lens discontinuation. However, the persistence of Lyz2+ and MHC Class II+ cell responses is not sufficient to generate Ly6G+ cell para-inflammatory responses observed after 6 days of lens wear. Further research is needed to determine mechanisms and significance of immune cell persistence after lens removal.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.