Toxic Anterior Segment Syndrome (TASS) Follow-up

Updated: Apr 04, 2023
  • Author: Jean Deschênes, MD, FRCSC; Chief Editor: John D Sheppard, Jr, MD, MMSc  more...
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Further Outpatient Care

Initially, patients with toxic anterior segment syndrome (TASS) should be examined on a daily basis to assess their response to treatment.

Once the inflammation is resolved, patients need to be assessed carefully for corneal and/or trabecular meshwork damage. [1, 2]



All preoperative, intraoperative, and postoperative steps at the surgical center should be thoroughly assessed, including the following [1, 2] :

  • Surgical equipment and instruments

  • Sterilization process

  • Preoperative, intraoperative, and postoperative medications

  • Ultrasound water

  • Irrigating solutions



Depending on the type of toxin, duration of exposure, and response to treatment, the following complications may result [1, 2] :

  • Corneal endothelial cell loss with resultant edema

  • Trabecular meshwork damage causing glaucoma

  • Iris sphincter muscle damage with resultant permanent dilated pupil

  • Cystoid macular edema



Prognosis generally is divided into 3 groups depending on the severity of TASS.

A mild presentation of TASS will result in rapid clearing of the corneal edema with no long-term corneal or trabecular damage and normal or near normal visual acuity.

A moderate presentation of TASS will result in a persistent corneal edema that will take several weeks to clear, intraocular pressure that is difficult to control, and a moderate effect on visual acuity.

A severe presentation of TASS will result in a marked corneal edema that does not clear, iris and trabecular meshwork damage with resultant glaucoma, and possible cystoid macular edema. Visual outcome is usually poor despite medical or surgical intervention. A potential sequel manifestation of TASS is Urrets-Zavalia syndrome (UZS). [7]

Despite the above descriptions, predicting the outcome for patients remains difficult because of the multiple etiologies and associations linked to TASS.


Patient Education

Patients should be instructed to immediately report any pain and/or a decline in visual acuity postoperatively. The sooner that TASS can be detected and treated, the better the outcome will be for the patients.