Demodex Blepharitis Treatment Study

This is a randomized clinical trial to determine the safety and efficacy of terpinen-4-ol (T4O), the most active ingredient of tea tree oil (TTO), in eradicating ocular demodicosis (reducing ocular demodex counts and achieving the clinical improvement with minimal or no irritation).

Inclusion Criteria: * Patients with symptomatic Demodex blepharitis for duration of at least 3 months. * Age range: 15-80 years old. * Both genders and all ethnic groups comparable with the local community. * Able to understand and willing to sign a written informed consent * Able and willing to cooperate with the investigational plan. * Able and willing to complete all mandatory follow-up visits. Exclusion Criteria: * Patients who are currently engaged in another clinical trial, unwilling or unable to give consent, to accept randomization, or to return for scheduled visits. * Children under 15. * Pregnant women or expecting to be pregnant during the study. * Systemic immune deficient conditions such as AIDS or under systemic immunosuppressant. * Concomitant use of ophthalmic topical medications (excluding non-preserved tear substitutes). * Concomitant use of systemic antibiotics or steroids. * Contact lens wear (unless discontinued for ≥ 30 days before randomization) * Active ocular infection or allergy * Unable to close eyes or uncontrolled blinking * Presence of aqueous tear deficient dry eye defined by the Fluorescein Clearance Test as less than 3 mm wetting in 1-minute Schirmer test with anesthesia. * Previous allergic reaction to TTO-containing products or cosmetic fragrance.