Should ocular Demodex be checked and treated in refractory keratitis patients without blepharitis?

Abstract

AIM: To evaluate the correlation between Demodex infestation and keratitis, and to assess demodicosis using a simple approach. METHODS: A modified slit lamp illumination (at 40× magnification) was used to observe Demodex tails in 40 patients with refractory keratitis and 80 healthy controls. Bacterial smear and culture of the conjunctival sac and corneal lesion were performed to identify the pathogen. Tea tree oil ointment (TTOO) was added as a Demodex killing agent for lid scrubs to the treatment when Demodex infestation was confirmed. RESULTS: Demodex tails were found in all patients compared to 42/80 of the controls (P<0.01). Seventeen patients presented blepharitis, while 23 were free of scales and inflammation at the lid margin. The demodicosis was mild, moderate, and severe in 8, 19, and 13 patients, respectively, compared to mild in 42 controls (P<0.01). The keratitis was mild, moderate, and severe in 13, 19, and 8 patients, respectively. The severity of Demodex infestation was not correlated to the severity of keratitis (P=0.126). The growth of Staphylococcus was revealed in nine patients who did not react to antibiotic eye drops prior to the TTOO treatment. Patients’ signs and symptoms got resolved after the lid scrub with TTOO. CONCLUSION: Ocular Demodex needs to be checked and treated in refractory keratitis patients with or without blepharitis. A slit-lamp illumination under high magnification favors the judgment of the severity of Demodex infestation.

Double-Blind Comparison of Eyelash Epilation Techniques for the Purpose of Demodex folliculorum Mite Retrieval

“…Nevertheless, the overgrowth of these microorganisms, and/or their exotoxins, can spill onto the ocular surface and may have clinical consequences such as corneal staining, reduced tear film stability, itching of the lid margin, contact lens intolerance, and/or overall ocular discomfort. [9][10][11][12][13] One of the types of anterior blepharitis is due to the Demodex mites, the most common parasites inhabiting the outer part of the human body (i.e., ectoparasite). 9 Demodex can be found in humans of all ages and has been well established that its prevalence increases with age.…”

“…Nevertheless, the overgrowth of these microorganisms, and/or their exotoxins, can spill onto the ocular surface and may have clinical consequences such as corneal staining, reduced tear film stability, itching of the lid margin, contact lens intolerance, and/or overall ocular discomfort. 9–13…”