TASS

DR ALI SALEHI

TOXIC ANTERIOR SEGMENT SYNDROM(TASS)

TASSSterile postoperative inflammatory reaction caused by a noninfectious substance that enters the anterior segment resulting in toxic damage to intraocular tissues. (mason et al in1992)

TASSThepathologic changes are limited to the anterior chamber.

TASSis an acute inflammation of anterior segment of the eye following cataract surgery.A variety of substances have been implicated as causes of TASS.

Extraocular substancesa) Topical anti-septic agentsb) Talc from surgical glovesc) Topical ophthalmic ointment2) Products that are introduced into the anterior chamber as a part of the surgical procedurea) Anesthetic agentsb) Preservativesc) IOLd) drugs

TASS The symptoms and signs of TASS may mimic those of infectious endophthalmitis and include:pain, photophobia, severe reduction in visual acuity, marked anterior chamber reaction occasionally with hypopyon.

TASS presents within 12-24 hours whereas acuteinfectious endophthalmitis typically develops 2-7 days after surgery.

TASSOther potentiallydistinguishing features of TASS include diffuse, limbus-to-limbus corneal edema; anterior chamberopacification 3) a dilated, irregular or nonreactive pupil4) and elevated lOP.

TASSSkin cleansers containingchlorhexidine gluconate (eg, Hibiclens) have been reported to cause irreversible corneal edemaand opacification if they come into contact with the endothelial surface.

TASSPreservatives present in prediluted epinephrine (I: I0,000) added to irrigating solutionshave been implicated in corneal decompensation. Unpreserved I: 1000 epinephrine is preferred.. Substitution of sterile water for balanced salt solution,

Treatmentconsists of intensive topical corticosteroids until the inflammation subsides. A brief course of systemic corticosteroids may be beneficial. Frequentfollow-up is necessary to monitor lOP and to reassess for signs of bacterial infection.

Infectious endophthalmitis caused by bacteria and fungi is often difficult to distinguishfrom other types of intraocular inflammation.

TASSExcessive inflammation without endophthalmitisis often encountered postoperatively in the setting of complicated surgery, preexisting uveitiskeratitis, diabetes, glaucoma therapy, and previous surgery

TASSThe most helpful distinguishing characteristic of true infectious endophthalmitis isthat the vitritis is progressive and out of proportion to other anterior segment findings.When in doubt, the clinician should manage the condition as an infectious process

THE END

Figure 1. Acute bacterial endophthalmitis with conjunctival injection, irritation and a large hypopyon.

TASS

Figure 2. Acute sterile postoperative inflammation with diffuse corneal edema and anterior chamber reaction

Figure 3. Acute, sterile postoperative anterior segment inflammation with associated hypopyon and mild corneal edema.

Figure 6. Chronic postoperative inflammation secondary to phacoanaphylactic endophthalmitis with large keratic precipitates and recurrent anterior segment inflammation.

Figure 1. Acute bacterial endophthalmitis with conjunctival injection, irritation and a large hypopyon.

TASS

Figure 2. Acute sterile postoperative inflammation with diffuse corneal edema and anterior chamber reaction

Figure 3. Acute, sterile postoperative anterior segment inflammation with associated hypopyon and mild corneal edema.

Figure 6. Chronic postoperative inflammation secondary to phacoanaphylactic endophthalmitis with large keratic precipitates and recurrent anterior segment inflammation.