Topical ivermectin ointment treatment of Demodex blepharitis: a 6-year retrospective study.

Background: To evaluate the efficacy of topical ivermectin 1% ointment, for the treatment of Demodex blepharitis.

Methods: A retrospective study was designed to review electronic medical records of patients seen between January 2017 and December 2022, who had a diagnosis of Demodex blepharitis, treated with topical ivermectin 1% with at least 6 months of follow-up (Centro de Ojos Quilmes, Buenos Aires, Argentina). The presence of collarettes was graded from 0 to 4. An imaging system (Keratograph) was used, to evaluate tear meniscus height (TMH), non-invasive tear break-up time (NIKBUT), and degree of conjunctival redness. In addition, the ocular surface disease index (OSDI) test was performed. Results were compared before and after ivermectin treatment, which was performed once a day for 2 months.

Results: A total of 2157 patients (4314 eyes) were included. The mean age was 50.43 ± 15.3 years, and the follow-up time was 26.1 ± 8.5 months. No one discontinued treatment due to intolerance, although 14 cases (0.6 %) reported occasional discomfort. The grade of collarettes decreased with statistical significance, from 3.37 ± 0.7 to 0.1 ± 0.3 (p < 0.01), as well as conjunctival redness from 1.32 ± 0.3 to 0.94 ± 0.4 (p < 0.01) and OSDI score from 58.74 ± 17.9 to 17.1 ± 10.5 (p = 0.02). TMH and NIKBUT improved without statistical difference.

Conclusion: Treatment with ivermectin 1% topical ointment, once daily for 2 months, was effective in reducing the presence of collarettes and in improving symptoms in patients with Demodex blepharitis.