Ocular surface discomfort and Demodex: effect of tea tree oil eyelid scrub in Demodex blepharitis

Abstract

The purpose of this study was to evaluate the relation between ocular discomfort and ocular Demodex infestation, and therapeutic effects of tea tree oil (TTO) in Demodex blepharitis patients. Three hundred and thirty-five patients with ocular discomfort were evaluated for ocular Demodex infestation and subjective symptoms with ocular surface discomfort index (OSDI) score. Among them, Demodex-infested patients were randomized to receive either eyelid scrubbing with TTO (TTO group,106 patients) or without TTO (Control group, 54 patients) for 1 month. Demodex were found in 84% of patients with ocular discomfort. The number of Demodex was significantly correlated with age (P = 0.04) and OSDI score (P = 0.024). After eyelid scrub treatment, Demodex count was reduced from 4.0 ± 2.5 to 3.2 ± 2.3 in the TTO group (P = 0.004) and from 4.3 ± 2.7 to 4.2 ± 2.5 in the control group (P = 0.27). Also, OSDI score was reduced from 34.5 ± 10.7 to 24.1 ± 11.9 in the TTO group (P = 0.001) and from 35.3 ± 11.6 to 27.5 ± 12.8 in the control group (P = 0.04). In conclusion, Demodex number showed a significant positive correlation with age and subjective ocular discomfort. The tea tree oil eyelid scrub treatment is effective for eliminating ocular Demodex and improving subjective ocular symptoms.

Keywords: Blepharitis; Demodex; Ocular Surface; Tea Tree Oil.

Fig. 1

Flow chart shows the total numbers of eyes enrolled, treated, and observed during the follow-up of the study.

Fig. 2

Correlation of Demodex with age and ocular surface discomfort index. The number of Demodex showed significant positive correlations with increasing age (A; P = 0.04, correlation coefficient R = 0.563) and ocular surface discomfort index (OSDI) score (B; P = 0.024, correlation coefficient R = 0.512) in ocular discomfort patients.

Fig. 3

Changes in Demodex count (A) and OSDI score (B) after eyelid scrub in TTO group and control group. Group comparisons were performed using ANOVA and Scheffe's post hoc tests. Only significant P values are shown.