[Therapeutic penetrating keratoplasty for microbial keratitis].

BACKGROUND Microbial keratitis is a potentially sight threatening disease. Most cases respond well to antimicrobial therapy. However, in cases that progress despite intensive medical therapy, an urgent therapeutic penetrating keratoplasty (TPKP) is required. AIM To evaluate the indications and results of TPKP in Israel. METHODS A retrospective study reviewed the TPKP performed at the Goldschleger Eye Institute, Sheba Medical Center, between 1990-2003. The study included 18 cases of at least one-year follow-up. RESULTS The indications for TPKP included severe infectious keratitis unresponsive to medical treatment in 33% of the patients and severe corneal destruction in 66% of them. The infectious keratitis was diagnosed as bacterial keratitis in 44% of the patients, unidentified pathogen in 39%, mycotic in 11% and acanthamoeba in 6% of the patients. Risk factors in the patients with microbial keratitis requiring TPKP included: previous ocular disease in 39%, previous ocular surgery in 66%, systemic disorders in 28% and ocular risk factors in 28% patients. TPKP was successful in bacterial and acanthamoeba keratitis as far as the transparency of the graft and elimination of the infection and improvement of visual acuity. However, TPKP failed in mycotic and unidentified keratitis. The risk factors for failure included: previous ocular disease or surgeries, systemic disorders or large corneal grafts. CONCLUSIONS Therapeutic penetrating keratoplasty is an important and effective therapeutic tool for intractable bacterial and acanthamoeba keratitis. Prognostic factors for graft success include lack of ocular disease or previous surgeries, lack of systemic disorders or small corneal graft size.