The effect of Blephadex™ Eyelid Wipes on Demodex mites, ocular microbiota, bacterial lipase and comfort: a pilot study

Abstract

Purpose: To investigate the effect of Blephadex™ Eyelid Wipes on Demodex mites, ocular microbiota, bacterial lipase, tear film characteristics and ocular comfort after one month of daily use.

Methods: Twenty subjects were randomly assigned to use the Blephadex™ Eyelid Wipes on either eye once daily for 30 days whilst the contralateral eye was left untreated in this observer-masked, within-subject study. Demodex count, eyelid bacterial colony count, Tearscope Plus non-invasive tear break up time (NITBUT), Lipiview® tear film lipid layer thickness and phenol red thread test tear volume were measured at baseline and 30 days. Bacterial lipase was quantified from single bacterial colonies using a glycerol monolaurate assay. Ocular comfort was assessed at both visits using the Ocular Surface Disease Index (OSDI) questionnaire and visual analogue scales (VAS) to capture monocular symptoms of itching, dryness and overall discomfort.

Results: Six males and 14 females, median age 63.5 (range 48-76) completed the study. A statistically significant reduction in Demodex count was observed in treated eyes only (median ± IQR: treated eyes 2 ± 3 vs. 0 ± 2, ANOVA p = 0.04). Bacterial colony count, lipase production, NITBUT, lipid layer thickness and tear volume remained unchanged (p > 0.05). Overall comfort improved over time in treated eyes only (15 ± 32 vs. 10 ± 16, p = 0.05). Dryness symptoms significantly reduced in both treated and untreated eyes (23 ± 42 vs. 12 ± 21 and 23 ± 41 vs. 10 ± 15, p = 0.02). The OSDI and ocular itch scores remained unchanged (p > 0.05).

Conclusion: In this pilot study, no changes were observed in ocular microbiota, tear film characteristics or bacterial lipase in eyes treated with Blephadex™ Eyelid Wipes after one month of daily use in this normal healthy population. Although a statistically significant reduction in Demodex count was observed in treated eyes, overall numbers of Demodex were low. A parallel group, placebo-controlled, randomised clinical trial in a population with active blepharitis is warranted to further elucidate these preliminary findings.

Keywords: Comfort; Demodex; Eyelid; Lid hygiene; Microbiota.