Intraocular vancomycin levels after intravitreal injection in post cataract extraction endophthalmitis.
OBJECTIVE
Intravitreal antibiotics are the mainstay of treatment of endophthalmitis following cataract surgery. The purpose of this study is to determine the range of intraocular vancomycin found after intravitreal therapy and assess the optimum time for repeat injections.


METHODS
Aqueous and vitreous vancomycin was assayed at the time of reinjection in 14 patients with endophthalmitis showing a poor clinical response after their primary injection. Nine patients received vancomycin 2 mg and another five received vancomycin 1 mg. In six patients the injection was repeated at 48 hours and in seven at 72 hours. Two patients received three injections.


RESULTS
Aqueous vancomycin varied from 8.4 to 170 mg/L and the vitreous vancomycin level ranged from 21.2 to 220 mg/L.


CONCLUSIONS
In the current study vitreous vancomycin levels were variable, but well within the therapeutic range for sensitive Gram-positive organisms. At times they exceeded the putative retinotoxic levels (100 mg/L). Higher aqueous levels were found after an injection of 2 mg than after 1 mg. Vancomycin levels were still very high 3 days after injection of 2 mg where results were available. Assay at the time of repeat injection may provide insight into the adequacy of vitreous levels and guide future therapy.
Haider
S A
SA
Institute of Ophthalmology, Mayo Hospital, Lahore, Pakistan.
Hassett
P
P
Bron
A J
AJ
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use; D001082:Aqueous Humor / Q000378:metabolism*; D001682:Biological Availability; D002387:Cataract Extraction / Q000009:adverse effects*; D009877:Endophthalmitis / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism*; D015818:Eye Infections, Bacterial / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism*; D006801:Humans; D007267:Injections; D008875:Middle Aged; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism*; D013290:Streptococcal Infections / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism*; D013997:Time Factors; D014018:Tissue Distribution; D014640:Vancomycin / Q000493:pharmacokinetics* / Q000627:therapeutic use; D014822:Vitreous Body / Q000187:drug effects / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D014640:Vancomycin