The role of systemic antibiotics in the treatment of bacterial endophthalmitis remains controversial. While penicillin is a highly effective antibiotic against bacteria that frequently cause endophthalmitis, the ability of systemically administered Penicillin G to penetrate into the vitreous at adequate therapeutic concentrations has not been studied. Its role in the treatment of endophthalmitis, particularly for bacteria for which it is the antibiotic of choice, therefore remains unknown. We sought to determine whether intravenous administration of Penicillin G leads to adequate therapeutic concentrations in the vitreous for the treatment of bacterial endophthalmitis. This study was conducted in an ambulatory setting, at the Ottawa Hospital Eye Institute, a university-affiliated tertiary care center, where a 77-year old gentleman with chronic post-cataract surgery Actinomyces neuii endophathalmitis was treated with intravenous Penicillin G (4 × 106 units every 4 h) and intravitreal ampicillin (5000μg/0.1 m1). Intravitreal concentration of Penicillin G and ampicillin were obtained at the time of intraocular lens removal, measured by high-performance liquid chromatography. The intravitreal concentration of penicillin and ampicillin was 3.5μg/ml and 0.3μg/ml, respectively. Both the concentration of penicillin and ampicillin were within the level of detection of their respective assays (penicillin 0.06-5μg/ml, ampicillin 0.12–2.5μg/ml). This study shows that intravenous Penicillin G administered every four-hours allows for adequate intravitreal concentrations of penicillin. Future studies are required to determine if the results of this study translate into improved clinical outcomes.

中文翻译：

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青霉素的静脉内给药导致慢性术后眼内炎的治疗性玻璃体内水平

全身性抗生素在治疗细菌性眼内炎中的作用仍存在争议。虽然青霉素是一种非常有效的抗生素，可对抗经常引起眼内炎的细菌，但尚未研究全身给药青霉素 G 在足够治疗浓度下渗入玻璃体的能力。因此，它在治疗眼内炎中的作用，特别是对于选择抗生素的细菌，仍然未知。我们试图确定静脉注射青霉素 G 是否会在玻璃体内产生足够的治疗浓度以治疗细菌性眼内炎。这项研究是在一个门诊环境中进行的，在渥太华医院眼科研究所，一个大学附属的三级护理中心，其中一位患有慢性白内障手术后的 77 岁绅士接受了静脉注射青霉素 G（每 4 小时 4 × 106 单位）和玻璃体内氨苄青霉素（5000μg/0.1 m1）治疗。在人工晶状体摘除时，通过高效液相色谱法测定玻璃体内青霉素 G 和氨苄青霉素的浓度。青霉素和氨苄青霉素的玻璃体内浓度分别为3.5μg/ml和0.3μg/ml。青霉素和氨苄青霉素的浓度均在各自测定的检测水平内（青霉素0.06-5μg/ml，氨苄青霉素0.12-2.5μg/ml）。该研究表明，每四小时静脉注射青霉素 G 可使玻璃体内的青霉素浓度达到足够高。