Eyelid examination for Demodex infestation

Abstract

Background Blepharitis caused by Demodex infestation is very common in clinical practice.There are various methods mentioned in the study of Demodex infestation in China, but a unified introduction and evaluation of the operating procedures is lacked.A quick and accurate clinical diagnostic method for Demodex infestation needs to be further studied. Objective This study aimed to establish operation procedures for the clinical examination of eyelid Demodex infestation, which were applied to evaluate the conditions of eyelid Demodex infestation in ocular patients with discomfort. Methods One thousand and fifty-two patients with eye dryness, eye itchiness or other symptoms were selected for slit lamp examination and photographing of the eyelid margin area.Three eyelashes with associated scurf from each superior eyelid were plucked out for examination of Demodex under the microscope.Positive findings included observation of Demodex mites or eggs.Their amounts were recorded individually for all eyelash samples. Results A procedure for observing, recording and reporting eyelid Demodex infestations in patients was successfully established.By using this procedure, 1 052 patients were investigated for the examination of Demodex infestations.Demodex mites or eggs were found in 582 cases (55.3%). The positive rate of Demodex infestation increased with age, and the population over 60 years group had the highest positive rate, showing a significant difference among the different age groups (χ2=10.547, P=0.001). There was no significant difference in positive rate between male patients and female patients (P=0.352). The test turnaround time (TAT) for one examination was (11.4±5.2) seconds. Conclusions The operational procedure for examining the palpebral margin Demodex infestation by the slit-lamp, optical microscope, photographing and laboratory reports is established.It is simple and quick in the appliation for the clinical diagnosis of eyelid Demodex infestation. Key words: Eyelid; Demodex; Infestation; Diagnosis/methology