Purpose: The purpose of this study was to report a rare case of late-onset subconjunctival abscess associated with an unexposed Ahmed glaucoma valve implant secondary to Serratia marcescens, a rare conjunctival pathogen.
Methods: Case description including clinical imaging and literature review of glaucoma drainage device (GDD)-related infections.
Case presentation: A 73-year-old man presented with blurring of vision, redness, and pain on his right eye 2 months after Ahmed glaucoma valve implantation for advanced postpenetrating-keratoplasty glaucoma. The patient was nonsmoker, had fairly controlled type 2 diabetes mellitus on insulin, and had undergone multiple eye surgeries on the right eye. On ocular examination, the conjunctiva was injected with fairly delineated yellowish-white subconjunctival material in the superotemporal quadrant with no associated tube exposure or leak, and the anterior chamber was quiet. The patient was assessed with Ahmed glaucoma valve infection with subconjunctival abscess and was treated by Ahmed glaucoma valve explant with directed systemic and topical antimicrobial therapy. The culture and sensitivity results revealed S. marcescens sensitive to ciprofloxacin, ceftazidime, gentamicin, and amikacin. Despite the virulence of the pathogen, the eye was saved.
Conclusions: Ahmed glaucoma valve infection with subconjunctival abscess secondary to S. marcescens is rare. GDD-related infections should be suspected in patients presenting with blurring of vision, pain, and redness even in the absence of tube exposure. Early diagnosis and treatment with culture-guided antimicrobial therapy combined with GDD explant is fundamental in optimizing the visual outcome.