**4. Preoperative treatment**

Before therapeutic keratoplasty for infectious keratitis, the patient should be treated with topical and systemic therapy directed towards the offending microbe. This treatment applies to bacterial, fungal and *Acanthamoeba.* 

Regardless of the infectious etiologies, we always recommend topical antbiotic therapy to prevent bacterial super infection.

The preoperative antibiotic prophylaxis should be broad spectrum and nontoxic to help promote reepithelization and prefer an antibiotic that penetrates into the cornea, aqueous achieve levels above to MIC90 of most pathogenic bacteria.

We currently use a topical fourth –generation fluoroquinolone Gatifloxacin 0.3% (ZymarR; Allergan Inc, Irvine, CA) with a saturating dosage of one drop every 15 minutes for 1 hour before keratoplasty.
