Oftalʹmologiâ (Dec 2019)
Study of the Effectiveness of Precision Doses of Antibiotics in the Treatment of Induced Acute Bacterial Postoperative Endophthalmitis in an Experiment
Abstract
Objective: to conduct a clinical and histomorphological study of the efficacy and safety of individually calculated doses of antibiotic in an experimental model of acute endophthalmitis in laboratory animals. Materials and methods. The study group included 15 adult laboratory white rabbits of the Chinchilla breed, male, aged from 2 to 3 months (2.6 ± 0.44 months). Determination of the anatomical parameters of the eyeball was performed on an ultrasound biometer — Compact Touch Quantel Medical (France). The obtained data were exported to the original program of an electronic computing machine of its own design, for automatic calculation of the dose of antibacterial drug for intravitreal injection. In the course of the experiment, the native lens was removed from animals with intraoperative administration of a culture of epidermal staphylococcus in a volume of 0.1 ml (10,000 colony forming units). After surgery, the animals were divided into 4 treatment groups: group 1 — without treatment, group 2 — standard dose of vancomycin for intravitreal administration (1 mg / 0.1 ml), group 3 — double dose (2 mg / 0.1 ml), group 4 — individual a dose of 0.25 mg / 0.1 ml (according to the calculation of the computer program). After a period of clinical observation, the enucleation of the eyeball was performed with a histomorphological study. Results. Group 1 — increase of the inflammation signs, deep irreversible structural damage to all intraocular structures according to histomorphology. Group 2 — regression of clinical manifestations by the first week of observation, the processes of alteration and initial regeneration of intraocular structures according to histomorphology. Group 3 — diffuse opacification of the cornea with the impossibility of further analysis, signs of toxic damage to intraocular structures according to histomorphology. Group 4 — complete regression of clinical symptoms, residual signs of aseptic inflammation according to histomorphology.Conclusions. Clinical and histomorphological studies of enucleated eyeballs in experimental animals demonstrate clinical efficacy and safety of vancomycin concentration in the vitreal cavity equal to or close to 128 μg/ml. Individual (personalized) calculation of the antibacterial drug dose eliminates the risk of toxic damage to the retina when the antibiotic concentration is excessive in the vitreal cavity. The toxic effects of excessive doses of antibiotics increase with increasing concentration of the active substance.
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