Combined corneal cryotherapy and conjunctival flap as a bridge to optical keratoplasty in progressive Acanthamoeba keratitis: a case series

Abstract Purpose To describe outcomes of combined corneal cryotherapy and conjunctival flap placement used as an adjunctive procedure and bridge to delayed optical penetrating keratoplasty (PKP) in selected patients with progressive Acanthamoeba -associated keratitis. Methods A retrospective case series was performed of three patients with polymerase chain reaction (PCR) or pathology-supported Acanthamoeba keratitis, including one case with possible polymicrobial involvement. Each patient underwent corneal cryotherapy and conjunctival flap placement because of progressive stromal disease, severe pain, stromal thinning, medication intolerance, or concern for poor outcome with immediate keratoplasty in an actively inflamed eye. Clinical features, microbiologic results, medical treatment including polyhexamethylene biguanide (PHMB) when used, surgical details, and postoperative outcomes were reviewed. Results Combined corneal cryotherapy and conjunctival flap placement was followed by substantial improvement in pain or inflammation in all three eyes. Subsequent optical PKP was performed 8 to 9 weeks after the cryotherapy/flap procedure, after clinical quiescence. No eye required enucleation or exenteration. Final best-corrected visual acuity after optical PKP ranged from 20/25 to 20/40. Conclusions In selected cases of progressive or medically difficult Acanthamoeba -associated keratitis, combined corneal cryotherapy and conjunctival flap placement may serve as an adjunctive globe-sparing bridge to delayed optical PKP. This small retrospective series does not establish efficacy in truly refractory Acanthamoeba keratitis, and further study is needed.