Demodex infestation of the lash follicles and the eyelid glands is fairly common and may contribute to the pathogenesis of some cases of chronic lid margin and ocular surface inflammation and Meibomian gland dysfunction. TTO has been shown to be effective in reducing Demodex populations. However, because it is known that 50% TTO can be toxic to the ocular surface, the College Clinical Management Guideline on Blepharitis recommends that only experienced practitioners should carry out this particular treatment. Great care is needed in the use of strong preparations of TTO, so that only lid tissue is treated, and afterwards the lid margins should be carefully wiped with dry cotton buds in order to remove residual TTO.

John G Lawrenson and Roger Buckley