Yau C W, Busin M, Kaufman H E
Am J Ophthalmol. 1986 Jan 15;101(1):44-8. doi: 10.1016/0002-9394(86)90463-0.
To determine if the storage of corneal tissue in a preserving medium containing gentamicin results in therapeutically effective concentrations of antibiotics in the ocular tissues after penetrating keratoplasty, we stored rabbit donor corneas in McCarey-Kaufman medium containing 100 micrograms of gentamicin per milliliter for three days before surgery. Gentamicin concentrations were determined by agar-diffusion bioassay in ocular tissues one, two, three, four, and six hours after surgery. On the average, the concentration of antibiotic one hour after surgery was 8.8 micrograms of gentamicin per gram of donor cornea, 6.25 micrograms of gentamicin per milliliter of iris, and 2.8 micrograms of gentamicin per milliliter of aqueous humor. The minimal inhibitory concentration for sensitive strains of Pseudomonas aeruginosa is 1.6 micrograms of gentamicin per milliliter of medium. Thus, gentamicin levels sufficient to inhibit the growth of sensitive bacteria were still present in the donor cornea three hours and in the iris two hours after penetrating keratoplasty. By six hours, only trace amounts of gentamicin were found in the donor cornea and aqueous humor. The presence of gentamicin in ocular tissues after penetrating keratoplasty appears to prolong the antibacterial effect of the preserving medium, and to provide tissue concentrations of antibiotic effective against intraoperative contamination.
为了确定将角膜组织储存在含有庆大霉素的保存介质中，在穿透性角膜移植术后眼组织中是否会产生治疗有效的抗生素浓度，我们在手术前将兔供体角膜在每毫升含100微克庆大霉素的麦卡雷 - 考夫曼介质中储存三天。通过琼脂扩散生物测定法在术后1、2、3、4和6小时测定眼组织中的庆大霉素浓度。平均而言，术后1小时抗生素浓度为每克供体角膜含8.8微克庆大霉素，每毫升虹膜含6.25微克庆大霉素，每毫升房水含2.8微克庆大霉素。铜绿假单胞菌敏感菌株的最低抑菌浓度为每毫升培养基含1.6微克庆大霉素。因此，在穿透性角膜移植术后3小时供体角膜中以及术后2小时虹膜中仍存在足以抑制敏感细菌生长的庆大霉素水平。到6小时时，在供体角膜和房水中仅发现痕量的庆大霉素。穿透性角膜移植术后眼组织中庆大霉素的存在似乎延长了保存介质的抗菌作用，并提供了对术中污染有效的抗生素组织浓度。
