EC Ophthalmology

Introduction: The phylum of microsporidia consists of several different genera of resilient, obligate, eukaryotic, spore-forming, intracellular eukaryotes. Microsporidia often affects the cornea and conjunctiva and results in microsporidial keratoconjunctivitis. Risk factors for microsporidial keratoconjunctivitis include ocular trauma, contact lens wear, immunodeficiency, and exposure to contaminated soil or water. We present a case of severe, unilateral microsporidial keratoconjunctivitis in an immunocompetent eight-year-old male with no known risk factors that was successfully treated with topical voriconazole and moxifloxacin after failed response to topical ofloxacin.

Case Presentation: An eight-year-old male presented to an outside eyecare provider with a one-week history of worsening redness, tearing, mucus discharge, and blurred vision of the left eye without an identifiable inciting event. The patient progressed over the following week and developed subepithelial infiltrates, superficial punctate keratitis, and worsening mucus discharge despite being treated with neomycin-polymyxin-dexamethasone (neo-poly-dex) drops. Neo-poly-dex was stopped and he was transitioned to topical ofloxacin ophthalmic drops before being referred to our eye center. No clinical response was observed with ofloxacin drops, so the patient was transitioned to a regimen of topical voriconazole drops, topical moxifloxacin drops, and erythromycin ointment in the left eye. This combination of treatment resolved the patient’s signs and symptoms and returned his best-corrected visual acuity (BCVA) back to baseline.

Conclusion: First-line therapy for microsporidial keratoconjunctivitis is topical fumagillin, which is currently unavailable in the United States of America. We present a case of successfully treated microsporidial keratoconjunctivitis in an immunocompetent pediatric patient without known risk factors who failed monotherapy with topical ofloxacin. This case report highlights the effectiveness of combination therapy with topical voriconazole and moxifloxacin for microsporidial keratoconjunctivitis that has failed monotherapy with topical ofloxacin. Furthermore, clinicians should be aware that stromal inflammation following microsporidial keratoconjunctivitis may not represent persistent infection, but instead, may represent an immune stromal keratitis (ISK) that rapidly responds to steroids. Accurate differentiation between persistent infection and ISK is essential to guide appropriate management and optimize recovery. 

Keywords: Microsporidia; Immunocompetent; Pediatrics; Infectious Keratitis; Microsporidial Keratitis; Microsporidial Keratoconjunctivitis

Abbreviations: BCVA: Best-Corrected Visual Acuity; ISK: Immune Stromal Keratitis; IOP: Intraocular Pressure; PCR: Polymerase Chain Reaction; neo-poly-dex: Neomycin-Polymyxin-Dexamethasone

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