Abstract: Inflammation and dry eye (aqueous vs MGD)

This is a really interesting study looking at cytokines of patients with healthy tears, aqueous deficient dry eye and MGD dry eye. From this perspective, the MGD eye looks more like a healthy eye than an aqueous deficient eye.

Pro-inflammatory cytokine profiling of tears from dry-eye patients by means of antibody-microarrays.

Purpose:
In the pathogenesis of keratoconjunctivitis sicca immune processes are thought to play an important role. However, the exact details of the pathomechanisms are still unknown. In this study we analyzed the expression patterns of pro-inflammatory cytokines in the tears of patients suffering from different subtypes of dry-eye.

Methods:
143 subjects subdivided into healthy controls (CTRL, n=38), patients having an aqueous deficient dry-eye (DRYaq, n=35), patients showing changes of the lipid-layer (DRYlip, n=36) or a combination of both (DRYaplip, n=34) were examined. Expression patterns of proteins, e.g. IL-1β, IL-6, ITNFα and IFNγ, were examined using an advanced antibody microarray approach.

Results:
We detected several highly significant differences in the cytokine levels of dry-eye patients compared to healthy controls. In comparison to healthy subjects, patients suffering from aqueous deficient dry-eye or those with a combined pathogenesis showed elevated levels for most of the tested proteins. E.g. IL-1-β was found to be elevated 2.4 fold in DRYaq patients, respectively 2.75 fold in DRYaqlip patients (both P<8.00E-6). The detected protein amounts of patients suffering from dry-eye induced by lipid layer changes and healthy controls showed only minimal differences (fold increase/decrease for all proteins >1.2, P>0.5).

Conclusions:
The similarity between profiles of healthy controls and patients with a lipid layer induced dry-eye justifies the assumption that the pathomechanism of this dry-eye subtype is rather based on other mechanisms than inflammation, whereas it seems to be the case for patients suffering from aqueous deficient dry-eye.

Invest Ophthalmol Vis Sci. 2011 Jul 20. [Epub ahead of print]
Boehm N, Riechardt AI, Wiegand M, Pfeiffer N, Grus FH.
. Experimental Ophthalmology, Department of Ophthalmology, University Medical Center of the Johannes Gutenberg University Mainz, Germany.