Diagnosis and treatment of microsporidial keratoconjunctivitis: literature review and case series

PURPOSE: The purpose of this study is to describe the clinical characteristics, microscopic findings, and treatment response to albendazole of microsporidial keratoconjunctivitis among immunocompromised individuals with HIV/AIDS. METHODS: This is a retrospective case series. Diagnosis of microsporidial keratoconjunctivitis was confirmed by subspecialist examination and conjunctival swabs examined by light microscopy. HIV infection was documented, and absolute CD4+ T cell count was determined. Patients were treated with albendazole and followed for clinical response. RESULTS: Light microscopy from the conjunctival swabs demonstrated myriad small, round to oval microsporidial organisms that stained positively with modified acid-fast methods. Two of the patients initially not taking highly active antiretroviral therapy (HAART) and presenting with an absolute CD4+ T cell count less than 100 cells/μL had a more severe form of keratoconjunctivitis than the third patient (receiving HAART, with a CD4+ T cell count of 259 cells/μL). All patients were started or continued on HAART. Two of the patients responded to oral albendazole, with resolution of symptoms and signs. The third patient did not initially respond, perhaps because of an immune recovery inflammatory syndrome, but subsequently had temporary improvement with albendazole. CONCLUSIONS: Microsporidial keratoconjunctivitis is a rare ocular complication of HIV/AIDS. Light microscopic evaluation of conjunctival swabs may be a useful minimally invasive first step toward diagnosis of microsporidial keratoconjunctivis in settings where electron microscopy is not available. Based on the limited available information, albendazole often is effective for this condition, and is widely available in developing countries at low cost.