This Week's Eye-Openers

AJO

Pretty in Pink: When a Biofilm Points to Serratia marcescens

Never forget to check the water tank…

Serratia marcescens is an opportunistic Gram-negative pathogen that can cause contact lens-associated keratitis and corneal ulcers. A 38-year-old female with soft contact lenses presented to the ophthalmology emergency department after two days of a painful, red eye with purulent discharge and blurred vision after showering with rainwater stored in a farm water tank. Initial slit-lamp exam showed severe conjunctival and limbal injection, fibrinous reaction with +2 cells in the anterior chamber, and a central corneal stromal infiltrate (2 x 2 mm) with an overlying epithelial defect and positive fluorescein staining. Anterior segment optical coherence tomography confirmed stromal involvement with an associated endothelial plaque. Confocal microscopy revealed intense stromal inflammation with hyperreflective inflammatory cells without hyphae or cysts suggestive of Acanthamoeba. After corneal scraping, the patient received hourly topical moxifloxacin and tobramycin. After six weeks of tapering treatment, slit-lamp exam and AS-OCT showed complete resolution, with a final best-corrected visual acuity of 20/25.  

This is one of the few reported cases in which a visible environmental prodigiosin-associated biofilm provided an indirect diagnostic clue linking the environmental source to the Serratia marcescens pathogen before microbiological confirmation.This case highlights the importance of a thorough environmental history, particularly when non-sterile water may be used for personal hygiene.

A 31 year old female presents to the eye clinic after noticing some blurring in her right eye along with an increased amount of floaters for the past several weeks. She denies any pain or photophobia. She denies any fever or chills. She has negligible past medical history including ocular history. Visual acuity is 20/30 OD and 20/20 OS. IOP is 27 mmHg OD and 14 mmHg OS. Slit-lamp exam OD demonstrates fine, diffuse, stellate keratic precipitates coating the entire corneal endothelium, trace anterior chamber cell, and loss of the iris pupillary ruff. Dynamic gonioscopy reveals fine blood vessels bridging the trabecular meshwork in the right eye. Dilated fundus examination shows 1+ vitreous cells without active retinochoroidal lesions in the right eye; the left fundus is unremarkable. Which of the following is the most appropriate management strategy for this patient's intraocular inflammation?

A) High-dose topical prednisolone acetate 1% drops every hour 

B) Periocular triamcinolone acetonide injection

C) Topical cyclopentolate 1% to prevent posterior synechiae formation

D) Observe the intraocular inflammation and treat the elevated intraocular pressure with topical hypotensive agents

E) Perform urgent laser peripheral iridotomy

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