Laboratory Studies
Patients who present with toxic anterior segment syndrome (TASS) should be assessed carefully, and infectious endophthalmitis should be ruled out. [1, 2]
If at all unclear as to the exact etiology, the protocol for infectious endophthalmitis should be performed. This protocol includes performing an anterior chamber aspirate, a vitreous tap, and/or a vitreous biopsy for Gram stains and microbiologic cultures.
The US Food and Drug Administration's (FDA's) Center for Devices and Radiological Health staff has embarked on a number of projects to mitigate medical device–related TASS outbreaks. These include conducting animal studies to explore various etiologies of TASS, capturing the clinical information necessary to assist investigations of potential future outbreaks, and partnering with the US Centers for Disease Control and Prevention to facilitate a potential TASS investigation, including expediting the analysis of potentially contaminated medical devices. [5]
Imaging Studies
The vitreous should be examined carefully to rule out vitritis. A B-scan ultrasound may be needed if the view is obscured by corneal edema and/or anterior chamber inflammation.
-
Diffuse limbus-to-limbus corneal edema and anterior segment inflammation noted in a patient with toxic anterior segment syndrome (TASS).
-
Long-term sequelae of toxic anterior segment syndrome (TASS) with persistent corneal edema.
Tables
Signs and Symptoms |
TASS |
Infectious Endophthalmitis |
Onset |
12-24 hours usually |
2-7 days usually |
Pain |
Usually none but can be mild to moderate |
Usually severe |
Corneal edema |
Limbus to limbus |
Specific to area of trauma |
Intraocular pressure |
May increase suddenly |
Usually not elevated |
Anterior chamber inflammation |
Moderate-to-severe anterior chamber reaction with increased white blood cells and fibrin. Hypopyon may be noted. |
Moderate-to-severe anterior chamber reaction. Fibrin is variable. Hypopyon often present (75% of the time). |
Vitritis |
Very rare |
Always present |
Pupil |
Fixed and dilated |
Reactive |
Lid swelling |
Usually not evident |
Often present |
Visual acuity |
Decreased |
Decreased |
Response to steroids |
Dramatic improvement |
Equivocal |
