[Study on preferred retinal locus].

Preferred retinal locus (PRL) is always found in the age-related macular degeneration and other macular damages in patients with low vision, and it is a very important anatomic position in patients with central vision impairment to achieve the rehabilitation. In recent years, the training of preferred retinal locus (PRL) has become a research hotspot of low vision rehabilitation, it can clearly improve functional vision and quality of life. The authors reviewed relevant literatures, and summarized the definition, position, characteristics, training and clinical implications of the PRL.

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.