BASICS

DESCRIPTION

Toxic anterior segment syndrome (TASS) is a sterile postoperative inflammatory reaction which typically occurs 12–48 h following cataract or anterior segment surgery. It is caused by a noninfectious substance and is limited to the anterior segment of the eye. Gram stain and culture samples are negative and the condition is managed with intensive topical steroid treatment.

EPIDEMIOLOGY

Incidence of TASS is rare but typically occurs in “outbreaks” at a specific surgical center.

RISK FACTORS

• Any medication injected in or around the eye or placed topically at the time of surgery can be implicated in TASS.

• Preservatives and pH incompatibilities can lead to TASS as can contaminants from sterilization.

• Intraocular solutions with inappropriate chemical composition, concentration, pH, or osmolality

– Preservatives

– Denatured ophthalmic viscosurgical devices

– Enzymatic detergents

– Bacterial endotoxin

– Oxidized metal deposits and residues

– Intraocular lens residues

GENERAL PREVENTION

• Following appropriate protocols for instrument sterilization and cleaning

• Following appropriate protocols for administration and ordering of intra- and periocular medications

PATHOPHYSIOLOGY

The acute inflammatory response induces cellular necrosis and/or apoptosis as well as extracellular damage.

ETIOLOGY

See risk factors

COMMONLY ASSOCIATED CONDITIONS

Occurs at time of anterior segment surgery

DIAGNOSIS

HISTORY

• Inflammatory process which starts within 12–24 h of cataract surgery

• Gram stain and cultures are negative.

• Improves with topical and/or oral steroids

PHYSICAL EXAM

• Severe anterior segment inflammation

• Hypopyon is often present.

• Limbus to limbus corneal edema is present.

• Vitreous cavity is rarely involved.

• Gonioscopy can be helpful to look for posterior synechiae.

DIAGNOSTIC TESTS & INTERPRETATION

Lab

Initial lab tests

Gram stain and culture

Follow-up & special considerations

Will be negative in TASS but can also be negative in infectious endophthalmitis

Pathological Findings

• Hypopyon

• Limbus to limbus corneal edema

DIFFERENTIAL DIAGNOSIS

Infectious endophthalmitis

TREATMENT

MEDICATION

First Line

Topical steroids

Second Line

Oral steroids

ADDITIONAL TREATMENT

Issues for Referral

• Permanent corneal edema may require DSEK or PK.

• Scarring of trabecular meshwork may lead to glaucoma.

SURGERY/OTHER PROCEDURES

Permanent corneal edema may require surgery as described above

ONGOING CARE

PROGNOSIS

• Depends on severity of inflammation

• Patients can have permanent corneal edema

• Patients can have fixed and dilated pupil

• Patients can develop glaucoma

COMPLICATIONS

• Glaucoma

• Tonic pupil

• Persistent corneal edema

ADDITIONAL READING

• Mamalis N, Edelhauser HF, et al. Toxic anterior segment syndrome. J Cataract Refract Surg 2006;32:322–323.

• Kutty PK, Forster TS, Wood-Koob C, et al. Multistate outbreak of toxic anterior segment syndrome, 2005. J Cataract Refract Surg 2008;34:585–590.

CODES

ICD9

• 360.19 Other endophthalmitis

• 364.05 Hypopyon

• 379.8 Other specified disorders of eye and adnexa

CLINICAL PEARLS

• As opposed to endophthalmitis, which typically occurs at 4–7 days postoperatively, TASS is usually seen in the 1st 24 h.

• Adnexal inflammation, which is commonly seen with infectious endophthalmitis, is not typical with TASS

• An inflammatory response in the vitreous cavity is uncommon in TASS and common in infectious endophthalmitis

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