Effects of gentamicin on healing of transdifferentiating conjunctival epithelium in rabbit eyes

We examined the effects of commercially prepared gentamicin, a wide-spectrum topical antibiotic, on the healing of epithelial defects of the rabbit cornea. Abrasions were created by: (1) removing the corneal epithelium and 3 mm of the conjunctival epithelium (Group 1); and (2) producing the same initial trauma and subsequently removing the central 8 mm of epithelium 28 days after initial healing (Group 2). The complete healing of the large corneal and conjunctival epithelial defects was not delayed when gentamicin solution was used four times a day (Group 1). When the healed epithelium was reinjured while transdifferentiating from conjunctival to corneal epithelium (day 28, Group 2), treatment with the gentamicin solution and its vehicle, both containing benzalkonium chloride, delayed epithelial healing significantly compared with treatment with saline (P less than .01).