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

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.

Clinical treatment of ocular demodecosis by lid scrub with tea tree oil.

PURPOSE: To report clinical outcome of treating ocular demodecosis by lid scrub with tea tree oil (TTO). METHODS: Retrospective review of clinical results in 11 patients with ocular Demodex who received weekly lid scrub with 50% TTO combined with daily lid hygiene with tea tree shampoo. RESULTS: These 11 patients also had meibomian gland dysfunction (n = 7) manifesting abnormal lipid film with slow lipid film spread, intermittent trichiasis (n = 5), and subjective lash loss (n = 4), suggesting damage to the meibomian glands and lash follicles. In addition, conjunctival inflammation (n = 8) was associated with conjunctivitis (n = 5), conjunctivochalasis (n = 3), findings suspicious for pemphigoid (n = 2), and recurrent pterygium (n = 2). After TTO lid scrub, the Demodex count dropped to 0 for 2 consecutive visits in less than 4 weeks in 8 of 11 patients. Ten of the 11 patients showed different degrees of symptomatic relief and notable reduction of inflammatory signs. Significant visual improvement in 6 of 22 eyes was associated with a stable lipid tear film caused by significant reduction of lipid spread time. Lid scrub with 50% TTO caused notable irritation in 3 patients. CONCLUSION: Demodex potentially causes ocular surface inflammation, meibomian gland dysfunction, and lash abnormalities. Lid scrub with TTO can effectively eradicate ocular Demodex and result in subjective and objective improvements. This preliminary positive result warrants future prospective investigation of Demodex pathogenicity.

In vitro and in vivo killing of ocular Demodex by tea tree oil.

AIMS: To compare the in vitro killing effect of different agents on Demodex and to report the in vivo killing effect of tea tree oil (TTO) on ocular Demodex. METHODS: Survival time of Demodex was measured under the microscope. Sampling and counting of Demodex was performed by a modified method. RESULTS: Demodex folliculorum survived for more than 150 minutes in 10% povidone-iodine, 75% alcohol, 50% baby shampoo, and 4% pilocarpine. However, the survival time was significantly shortened to within 15 minutes in 100% alcohol, 100% TTO, 100% caraway oil, or 100% dill weed oil. TTO's in vitro killing effect was dose dependent. Lid scrub with 50% TTO, but not with 50% baby shampoo, can further stimulate Demodex to move out to the skin. The Demodex count did not reach zero in any of the seven patients receiving daily lid scrub with baby shampoo for 40-350 days. In contrast, the Demodex count dropped to zero in seven of nine patients receiving TTO scrub in 4 weeks without recurrence. CONCLUSIONS: Demodex is resistant to a wide range of antiseptic solutions. Weekly lid scrub with 50% TTO and daily lid scrub with tea tree shampoo is effective in eradicating ocular Demodex.

Ocular Halicephalobus (syn. Micronema) deletrix in a horse.

Ocular contents from a horse with a 4-week history of severe unilateral uveitis were submitted for histopathologic examination. A severe unilateral granulomatous chorioretinitis with intralesional Halicephalobus deletrix was diagnosed. The horse developed progressive neurologic signs several days following the surgery to remove ocular contents and implant a prosthesis and was subsequently euthanatized. A severe multifocal granulomatous encephalitis with intralesional H. deletrix, localized primarily to the optic chiasm, thalamus, and brain stem, was diagnosed from tissues acquired at necropsy. The other eye was not affected. This is the first report of ocular parasitism by H. deletrix and suggests possible systemic dissemination from a primary site in the eye.