A 64-year-old white woman presents with complaints of pain, decreased vision, and a red eye for the past 2 days. Her medical history reveals that she had a trabeculectomy for primary open-angle glaucoma in this same eye 6 months before. What would a Gram stain of the vitreous fluid of this patient most likely show?
- Gram-negative coccobacilli
- Gram-positive rods
- Branching pseudohyphal forms
- Gram-positive cocci in clusters
This patient has filtering bleb–associated endophthalmitis. The most common organisms responsible for this condition include Streptococcus species (gram-positive cocci in pairs or chains) and Haemophilus influenzae (gram-negative coccobacilli). Other organisms, such as S. epidermidis (gram-positive cocci in clusters) and gram-negative species, have been implicated less frequently. Fungal causes are rarely associated with filtering bleb–associated endophthalmitis. The organisms are thought to enter the eye through either intact or leaking conjunctival filtering blebs. Often, Seidel testing is negative. Common presenting symptoms include conjunctival discharge and injection, pain, and decreased vision. The prognosis for eyes with bleb-associated endophthalmitis is generally poor, and the end result is often phthisis.