A unique case of Cryptococcus laurentii keratitis spread by a rigid gas permeable contact lens in a patient with onychomycosis

Purpose. We report the first case of fungal keratitis caused by Cryptococcus laurentii, a nonneoformans species. Methods. A case of C. laurentii keratitis in a diabetic, gas permeable contact lens wearer was diagnosed after microbiologic evaluation of the corneal button after emergent keratoplasty. The excised cornea was also culture positive for Staphylococcus aureus and Fusarium solani. The medical history was significant for onychomycosis of the right great toe 2 months previously. Cultures of the toenail and of the contact lens case were also positive for C. laurentii and F. solani. Results. An initial penetrating keratoplasty with histopathologically clear margins was unsuccessful in preventing intraocular spread of the fungal infection. Despite a repeat limbus-to-limbus therapeutic keratoplasty, pars plana vitrectomy, multiple anterior chamber washouts, intravitreal antifungal injections, and systemic antifungal treatment, the eye was ultimately lost due to ongoing inflammation, ocular hypotony, and a total retinal detachment. Histopathologic examination of the enucleated eye demonstrated filamentous fungi but no yeast forms. Conclusions. C. laurentii, a nonneoformans species, should be included in the differential diagnosis of fungal keratitis. This unique case also demonstrates the importance of a thorough clinical history and proper contact lens hygiene, particularly in a diabetic patient.