The mechanism, although not entirely clear, appears to be caused by the reduction of telangietic blood vessels that supply inflammatory factors to the eye. When these pathways are closed, the inflammatory cycle is reduced. In the aesthetic/cosmetic world, IPL has been long known to improve OSD symptoms in facial rosacea patients.
Deeper in the ocular microbiome
is associated with both facial and ocular rosacea. The parasite is a component of MGD, which in turn, is part of DED—it is a vicious cycle. In large numbers, Demodex itself becomes an inflammatory nidus for the eye, consuming bacteria called Bacillus oleronius. It is hypothesized that the interaction of the parasite and the lid’s bacterial load underlies eye lid margin inflammation.14-17
IPL has been shown to dramatically reduce Demodex when studied via punch biopsy
before and after treatment. IPL lowers the inflammatory cytokine matrix metalloproteinase 9, a protease that literally “eats” the cornea. Questions remain around the exact mechanism at work and if IPL is definitively killing Demodex—I am in the process of gathering this evidence.
In my practice, I take a comprehensive “holistic” approach to OSD. I consider everything from the gut microbiome—recommending an anti-inflammatory diet (e.g., omega-3 supplementation)—to devices like IPL and manual expression of the glands to prescription drops to scleral contact lenses for crippling disease.