Diagnosis and treatment of filamentary keratitis in a patient with Demodex infestation--an overlooked risk factor: a case report.

BACKGROUND: Filamentary keratitis is an ocular condition that is tricky to handle for the difficulty to find the underlying cause. Here we report a case of filamentary keratitis associated with Demodex infestation which highlights the importance of Demodex mites as an easily-overlooked risk factor. CASE PRESENTATION: A 63-year-old woman had recurrent symptoms of foreign body sensation and sometimes painful feelings in her left eye soon after her surgical correction of ptosis in this eye. She was then diagnosed as conjunctivitis and given antibiotic eye drops. After one week, the patient complained of aggravation of symptoms with small corneal filaments in the left eye under slit-lamp examination. Despite the removal of filaments and addition of topical corticosteroids and bandage contact lenses, the patient's condition persisted with enlarged filaments and severe ocular discomfort. 3 days later, eyelashes with cylindrical dandruff were noticed and Demodex infestation was confirmed by microscopic examination of these eyelashes at our clinic this time. She was asked to use tea tree oil lid scrub twice daily. After 3 weeks, her filamentary keratitis was resolved with a dramatic improvement in symptoms and signs. And no recurrence of filamentary keratitis was noticed during the one-year follow-up. CONCLUSIONS: In this case, filamentary keratitis was resolved only with treatment of Demodex infestation while conventional treatment failed. Considering the fact that Demodex infestation is a common but easily overlooked condition, it may be suggestive to take Demodex infestation into account as a risk factor of filamentary keratitis, especially in refractory cases.

Treatment of ocular itching associated with ocular demodicosis by 5% tea tree oil ointment.

PURPOSE: To determine whether ocular itching associated with ocular demodicosis can be treated by lid massage with 5% tea tree oil ointment (TTOO). METHODS: Twenty-four patients with ocular itching and ocular Demodex were treated with chlortetracycline hydrochloride eye ointment lid massage for 4 weeks and then treatment was switched to TTOO for another 4 weeks. They were examined every 2 weeks and their itching was graded as 0 (none), 1 (mild), 2 (moderate), or 3 (severe). Changes of itching scores and Demodex counts were compared. RESULTS: Before the treatment, all 24 patients reported itching graded as 1 (n = 3), 2 (n = 15), and 3 (n = 6) for a period of 2 weeks to 2 years despite previous topical antibiotics, antiinflammatory medications, or antiallergy medications. Demodex counts per 8 epilated lashes were 5.5 ± 1.6 for all patients but 4.6 ± 1.5, 4.8 ± 1.9, and 7.1 ± 2.1 for patients with grade 1, grade 2, and grade 3 itchiness, respectively (P < 0.05 between grade 2 and grade 3). After 4 weeks of chlortetracycline hydrochloride eye ointment treatment, little changes were observed regarding itching and Demodex counts in all patients (P > 0.05). In contrast, after 5% TTOO treatment, 16 patients were totally free of itching and the remaining 8 patients had different degrees of relief (P < 0.01). The Demodex count decreased to 0.7 ± 0.8 for total (P < 0.01). CONCLUSIONS: There is a strong correlation between ocular itching and Demodex infestation and between symptomatic resolution and reduction of Demodex counts by daily lid massage with 5% TTOO.