By Michael G. Haas, MD
This retrospective study published in December in the British Journal of Ophthalmology describes the ophthalmic side effects of topical imiquimod when used for periocular skin lesions. Based on their review of the 47 cases, the authors report that conjunctivitis and ocular stinging were the most common ophthalmic side effects encountered. However, these effects were temporary and resolved upon termination of imiquimod therapy, and most patients were able to complete the treatment.
I’m intrigued by this study because even though imiquimod topical therapy in the periorbital region caused minor ocular surface disease issues, there were no long-term ophthalmic complications with its use. All side effects cleared with cessation of treatment or additional therapy.
The study included all 47 patients with periocular actinic keratoses (n = 37), squamous cell carcinoma in situ/Bowen disease (n=7) or basal cell carcinoma (n = 3) seen at one of two oculoplastic centers in Australia during a five-year period and treated with topical imiquimod (Aldara, 3M Pharmaceuticals, St Paul, Minn.). The lower lid was the site most frequently involved (68 percent).
At a mean follow-up of 16 weeks, 34 patients had clinical resolution of periocular lesions and no patient had any residual ophthalmic side effects from imiquimod. There were no long-term ophthalmic sequelae.
Application site erythema occurred in all patients. Conjunctivitis occurred in 15 patients. Six patients complained of ocular stinging on application of imiquimod. One patient was diagnosed with a staphylococcal keratitis, which responded quickly with topical antibiotic and steroid therapy and without residual corneal scarring. Two patients required oral antibiotics for preseptal cellulitis. Three patients had delayed conjunctivitis at a mean of 2.3 weeks. Nine patients discontinued imiquimod due to ocular irritation and conjunctivitis, although four of them later restarted treatment and finished it after a rest period.
The authors say that the ophthalmic side effects of imiquimod may be partially related to other components of imiquimod cream, in particular benzyl alcohol, cetyl alcohol and stearyl alcohol. However, they did not look at the constituent elements of the vehicle used in the formula and their effect on ocular and periocular surfaces. They say that cases of conjunctivitis noted in the study may also be related to the effect of imiquimod on sun-damaged tissue, such as pterygium.
The authors conclude that imiquimod’s ophthalmic side effects can be managed with topical treatment and most patients can complete the treatment. However, five patients had subsequent recurrence requiring surgical excision. The authors advocate further long-term prospective randomized controlled studies to assess the efficacy of imiquimod for treating periocular skin lesions and the associated recurrence rates.