Abstract
Purpose: :
To compare the anti-inflammatory properties of artificial tears with 0.05% cyclosporine emulsion in a murine model of dry eye.
Methods: :
Experimental dry eye (EDE) was induced for 10 days in C57BL/6 mice without or with bilateral topical therapy with 2 ul of one of the following agents: 0.05% cyclosporine ophthalmic emulsion (CsA, Allergan, Inc., Irvine, CA), preservative free (PF) Blink Tears [Blink, Abbott Medical Optics, Santa Ana, CA], PF Vismed Artificial Tears [Vismed, TRB Chemedica, Munchen, Germany] or PF Systane [Systane, Alcon Fort Worth, TX]). Untreated (UT) mice served as controls. Conjunctivae were surgically excised and lysed for RNA extraction. Expression of IL-1α, IL-1β, TNF- α, IP-10, IFN-γ, IL-17A, and IL-13 were evaluated by real time PCR.
Results: :
EDE significantly increased IL-1β (p <0.01), TNF- α (p < 0.01), IFN-γ (p<0.05) and IL-17A (p<0.05) mRNA levels in the conjunctiva compared to the untreated control. Groups treated with artificial tears showed either similar or increased levels of these biomarkers compared to the EDE group (Systane vs. EDE: TNF- α, p=0.0027, IL-17A, p<0.0001; Vismed vs. EDE IL-1β, p=0.0079). In contrast, CsA showed a significant decrease in expression of IL-17A (p<0.01) and IFN-γ (p=0.05). No difference in levels of IP-10, IL-1α or IL-13 mRNA transcripts was observed between the groups.
Conclusions: :
Artificial tears had no anti-inflammatory activity and in some cases showed increased inflammation in the conjunctivae of dry eye mice. Topical therapy with CsA significantly decreased expression of the Th1 and Th17 associated cytokines IFN-γ and IL-17A, respectively, in the conjunctiva in response to dry eye.
Keywords: cyclosporine • conjunctiva • inflammation