Recurring infection after penetrating keratoplasty (PK) for severe microbial keratitis can lead to devastating outcomes, including graft failure and even evisceration. Researchers in India recently reviewed the medical charts of 229 patients who had PK for microbial keratitis and identified risk factors for post-op infection.

They found only 21.8% of treated eyes were clear, while 60.7% experienced graft failure and another 8.3% ultimately required evisceration. Within 16.2 ± 13.8 days, 27.5% of patients had recurrence of microbial keratitis.

The researchers also noted several independent, significant risk factors for recurring infection, including a fungal etiology, retro-iris exudates, coexisting endophthalmitis and grafts 10mm2 or larger. Other risk factors included an ulcer greater than 60mm2, limbal involvement, corneal perforation, and endothelial exudates.

The researchers found only 17% of eyes had 20/200 or better visual acuity and 11.4% had no light perception three months post-op.

Despite these risks for recurrence, the researchers still advocate for PK as an effective treatment for severe cases of unresponsive microbial keratitis.

Chatterjee S, Agrawal D. Recurrence of infection in corneal grafts after therapeutic penetrating keratoplasty for microbial keratitis.  Cornea. June 26, 2019. [Epub ahead of print].