Experiments with rabbits demonstrated no toxic effects on the retina after vitrectomy when the infusion fluid contained either 20 .mu.g/ml chloramphenicol saline, 10 .mu.g/ml amikacin saline, 10 .mu.g/ml tobramycin saline, or 10 .mu.g/ml clindamycin saline. Abnormal electroretinograms and abnormal histologic findings were found in eyes receiving vitreous replacement with these same drugs in higher concentrations.