Cap-puncturing mechanism for ophthalmic postoperative antibiotic eye drops: friend or foe?

A retrospective case series highlights two cases of postoperative endophthalmitis, in which similar improper technique of puncturing the antibiotic bottle with a nonsterile needle was noted. Patient A, a 65-year-old man with three weeks’ history of uneventful combined cataract and pars plana vitrectomy (PPV) presented with acute painful right eye and vision blurring from 6/12 to 1/60 for two days. Examination showed severe anterior chamber activity and hazy fundal view. B-scan showed dense vitritis. Vitreous sampling revealed gram positive cocci, but no culture growth. Patient B, a 69-year-old man presented with three days’ history of right painful red eye and vision dropped to light perception following an uneventful cataract surgery. Examination showed severe anterior chamber activity with hypopyon, raised intraocular pressure, and no fundal view. B-scan detected dense vitritis with loculation. Vitreous sampling cultured Pseudomonas aeruginosa in Patient B. In both cases, the patients reported piercing the generic topical ciprofloxacin 0.3% bottle tip with a nonsterile needle instead of the prescribed method of using the sterile, inner aspect of the bottle cap. However, the cultures of the bottle contents were negative in both cases. Both patients received intravitreal, topical, and systemic antibiotics and subsequently underwent PPV. Patient A recovered vision to baseline, while Patient B recovered to counting finger vision. The cap-puncturing mechanism for eye drop bottles is designed to maintain the sterility of the contents. However, this may backfire when patients do not understand the prescribed technique. We postulate that this improper technique predisposed the two cases to endophthalmitis.