Recalcitrant infectious crystalline keratopathy caused by Acanthamoeba and Fusarium coinfection

Purpose To report a case of successful resolution of infectious crystalline keratopathy caused by Acanthamoeba and Fusarium coinfection.Methods A 56-year-old man with a history of topical corticosteroid and antiviral treatment presented with severe ocular pain and progressive visual loss in the right eye. Clinical findings, microbiological investigations, treatment, and outcomes were reviewed.Results At the initial visit, the patient had decreased visual acuity, intense pain, and tearing in the right eye. Slit-lamp examination revealed a corneal infiltrate with an irregular margin of crystalline shape, epithelial defects, and hypopyon. Corneal smear with Gram stain showed Acanthamoeba cysts, and Fusarium growth was observed in cultures. Treatment with 0.5% moxifloxacin, 0.3% tobramycin, 1% voriconazole, and 0.04% chlorhexidine ophthalmic solution every hour was initiated. Corneal infiltration decreased and the hypopyon disappeared, but during a course of tapering eye drops, there was a recurrence of a crystalline corneal infiltrate, which eventually involved the central cornea. With extended aggressive treatment, the corneal infiltration decreased. The best-corrected visual acuity improved to 20/100 during the 6-month follow-up period.Conclusions Acanthamoeba and Fusarium coinfection can cause infectious crystalline keratopathy. Treatment was difficult due to the crystalline keratopathy itself and the concurrent coinfection. To prevent recurrent progression of infectious crystalline keratopathy caused by Acanthamoeba and Fusarium coinfection, vigilant follow-up with long-term aggressive medical treatment may be necessary, even when an early clinical improvement is observed.