2024 Top Story in Eye Care: The Mighty Mite

For many decades, Demodex blepharitis has been in and out of the literature. This year, we reviewed two articles dealing with Demodex blepharitis. Ayres et al¹ presented the collected opinions of 12 ocular surface disease experts regarding Demodex blepharitis. They sought to reach a consensus about chronic Demodex blepharitis concerning signs, symptoms, and diagnosis using three sequential surveys. Although consensus was reached on aspects of Demodex blepharitis, including signs, symptoms, diagnosis, and associated ocular and systemic conditions, consensus was not reached on the best therapeutic option and the best way to grade Demodex blepharitis. Sadri et al² evaluated the long-term outcomes of lotilaner ophthalmic solution 0.25% (Xdemvy) in the treatment of Demodex blepharitis, with 115 patients in the study group and 105 in the control group. They concluded that there were no safety concerns during 1 year of observation following treatment. They found that the efficacy of lotilaner ophthalmic solution 0.25% against Demodex blepharitis may last well after the completion of therapy.

The parasitic mite, Demodex folliculorum, lives in human hair follicles, especially around the nose and eyelashes. In general, the mite is well-tolerated and rarely causes symptoms. In rare instances, however, usually related to a suppressed immune system or caused by stress or illness, the mite population can increase dramatically, resulting in a condition known as demodicosis, or a Demodex mite bite, which is characterized by itching. Demodex mites feed on oils and sebum produced by the skin's sebaceous glands. An overproduction of sebum can create a conducive environment for the growth and proliferation of these mites. There is some thought that large numbers of mites cause acne rosacea, especially in immunosuppressed patients. Mites are often seen in sections of lid biopsies; the mites are usually observed in hair follicles without an inflammatory reaction. When mites do cause chronic blepharitis, it is difficult to control. Now, lotilaner ophthalmic solution 0.25%, the first and only FDA-approved treatment to directly target Demodex mites (the root cause of Demodex blepharitis), is effective in treating this infestation.