Abstract
Purpose: :
To determine the ocular toxicity of intravitreal injections of tigecycline, linezolid and daptomycin in a rabbit model
Methods: :
In this study, New Zealand White Rabbits were used to evaluate toxicities of intravitreal antibiotics. Two rabbit eyes for each medication were injected with linezolid (2 mg/mL and 0.2 mg/mL), daptomycin (50 mg/mL and 5 mg/mL), and tigecycline (1 mg/mL and 0.1 mg/mL). Two rabbit eyes injected with 0.1 mL of normal saline. Eye examinations were performed before injection and on days 1, 3, 7, and 14. lectroretinography was performed at day 0, before injection, and at day 14. The rabbits were euthanized on day 14, and the eyes were enucleated for light microscopy.
Results: :
All eyes treated with 50 mg/mL and 5 mg/mL daptomycin showed signs of ocular toxicity including conjunctival injection and cataract formation. The electroretinograms of these eyes were also extinguished. Histologic examination demonstrated extensive signs of retinal toxicity. One eye in the 2 mg/mL linezolid group developed a sectoral cataract. Electroretinograms and histologic examinations were otherwise normal as compared with the saline group with all linezolid treated eyes. Tigecycline treated eyes did not show signs of toxicity. Electroretinograms and histologic examinations were also otherwise normal in this group.
Conclusions: :
Based on the data, linezolid appears to be nontoxic at the commercially available dose of 2 mg/mL, while daptomycin appears to have considerable ocular toxicity at the commercially available dose of 50 mg/mL and at a lower dose. Further testing is necessary at lower doses to assess for both retinal and ocular toxicity for Daptomycin. Tigecycline also appeared to be nontoxic at the commercially available dose of 1 mg/mL.
Keywords: antibiotics/antifungals/antiparasitics • endophthalmitis • bacterial disease