Demodex blepharitis and contact lenses: an underestimated cause of intolerance?

Purpose. Demodex blepharitis is an inflammatory disease of the eyelids caused by an overgrowth of the hairfollicle mite demodex folliculorum and demodex brevis. Prevalence increases with age, but younger people also show increased rates of infestation, especially if there are risk factors such as rosacea or contact lens wear. Demodex mites are associated with contact lens intolerance in clinical practice. The purpose of this paper is to summarize the current understanding of the prevalence, diagnosis and treatment options for demodex blepharitis and, more important, to show possible correlations between the occurrence of demodex mites and contact lens wear.

Material and Methods. This literature review was conducted by means of a systematic search in the PubMed database, for the period from 2005 - 2024. The search strategy included the use of predefined keywords. The selection criteria included peer-reviewed articles, studies with specific methodology and certain population. Studies were screened for relevance based on title, abstract and full text.

Results. Typical symptoms of demodex blepharitis are itching, redness of the lid margin and complaints such as dry eyes. Cylindrical deposits (collarettes) on the base of the lashes, which can be diagnosed by slit lamp examination, are characteristic. Early diagnosis is crucial, as untreated demodex blepharitis can lead to complications such as meibomian gland dysfunction, chronic inflammation, dry eyes and the need to discontinue contact lense wear. Effective therapy include eyelid hygiene, tea tree oil-based products, Intense Pulsed Light (IPL) treatment and microblepharoexfoliation. The recently FDA-approved Lotilaner ophthalmic solution show promising therapeutic efficacy with minimal side effects. However, Lotilaner ophthalmic solution have not yet been approved in the European Union.

Conclusion. Demodex blepharitis is an often overlooked cause of eye problems, especially in patients with contact lens intolerance. The chronic nature of the disease requires long-term treatment and thorough diagnostics. New therapeutic approaches offer promising options with fewer side effects than conventional remedies such as tea tree oil.