Aminoglycoside Macular Toxicity After Subconjunctival Injection

To the Editor. —Aminoglycoside antibiotics are routinely injected subconjunctivally at the conclusion of routine cataract extraction by many cataract surgeons. Both tobramycin sulfate and gentamicin sulfate are highly effective againstStaphylococcusspecies and a broad range of gram-negative pathogens, especiallyPseudomonasspecies.1However, irreversible rapid retinal toxicity may occur if these drugs enter the eye. Report of a Case. —A 58-year-old woman underwent routine extracapsular cataract extraction with posterior chamber intraocular lens implantation in her left eye. A 4-mL retrobulbar injection of equal amounts of 1% xylocaine with epinephrine and 0.75% marcaine and 0.5 mL of hyaluronidase was given preoperatively. The procedure was uneventful and the posterior capsule was noted to be intact. At the conclusion of the procedure, 20 mg of tobramycin was injected subconjunctivally within the superior fornix-based conjunctival flap, thereby ballooning the flap over the corneoscleral wound. On the first postoperative day, a good red reflex