Toxic Anterior Segment Syndrome (TASS) is a non-infectious inflammation of the anterior segment that typically occurs within 12-48 hours of anterior segment surgery. It is caused by a toxic insult from contaminants like endotoxins on surgical instruments or from irrigating solutions, medications, or ointments used during or after surgery. TASS presents as limbus-to-limbus corneal edema, breakdown of the blood-aqueous barrier, and intense inflammation that responds well to intensive topical steroid treatment. Proper cleaning and sterilization of instruments and careful consideration of all solutions, medications, and devices used during anterior segment surgery can help prevent TASS.

1. Toxic Anterior
Segment Syndrome
DR NSD Raju
Past President All India Ophthalmological Society
Chairman International Relations Wing AIOS

2. Introduction
• It is a specific severe anterior segment
inflammation previously termed as sterile
Endophthalmitis
• Now termed Toxic Anterior Segment Syndrome
• TASS

3. Introduction
• Anterior segment surgery
• Toxic insult to tissues
• Typically within 12-48 hrs
• Limbus to Limbus edema
• Breakdown of blood aqueous barrier
• Damage to iris and trabecular meshwork
• Response to intensive topical steroids

4. Pathogenesis
• Toxic insult to endothelium by either an endotoxin
or other toxic phenomenon
• Breakdown of blood aqueous barrier intense flare
cellular reaction and hypopyon
• Toxic damage to iris , damage to trabecular
meshwork and consequent secondary glau coma

5. TASS Causes
Multifactorial
• Instrument cleaning and sterilisation
• Inadequate flushing occluded port
• Enzymatic cleaners
• Ultrasonic bath
• Preservatives and stabilisers in medication
• Inappropriate chemical composition solutions

6. Causes of TASS
• contaminants on surgical instruments
• irrigating solutions or ophthalmic medications
• Topical ointments and talc during or after surgery
• Enzymatic cleaner in ultrasonic bath

7. TASS Task Force
• Larege outbreak of Tass throughout North
America in 2006
• Establishment of American Society of Cataract
and Refractive Society TASS Task Force

8. Recent Developments
• Increasing incidence in the last Decade
• Is a specific non infectious condition
• Responds well to local intensive steroid therapy
• That it occurs within days of surgery
• Major causes are endotoxin contamination and
inadequate instrument sterilisation/preparation
Current Opinion in Ophthalmology:February 2007 - Volume 18 - Issue 1 - p 4–8

9. Clinical Presentation
• Within 12 - 48 hrs post op
• Limbus to limbus c. edema
• Blood aqueous barrier break
down
• Intense A C reaction
• Hypopyon

10. Severe TASS
• Damage to iris and trabecular
meshwork
• Secondary Glaucoma
• Moderate to severe TASS
respond well to intensive
topical steroids

11. Very Severe Cases
• Persistent corneal edema
• Iris thinning
• Permanently dilated or
irregular pupil
• Peripheral anterior synechiae
• Refractory glaucoma

12. Updated Causes
• Endotoxins, denatured OVD
• Preservative and stabilising agents
• Residue after cleaning and sterilisation
• Incorrect pH osmolarity ionic composition
• Retained cortical material
• Inadequate flushing

13. use of eye ointments post
operative or at the end of
surgery

14. TASS
• Acute non infectious
inflammation
• Cataract Surgery
• Anterior segment procedures
• Multifactorial
• Solutions medications
Ophthalmic devices
Cleaning and sterilisation of
instruments

15. Differential Diagnosis

16. TASS
• Entry of a non infectious
material in the anterior
segment
• 12 to 48 hours after surgery
• Limited to anterior segment
• Gram stain and culture
negative

18. Differential Diagnosis
Onset
Vision
Pain
Corneal edema
Culture negative

19. Differential
Diagnosis
Posterior segment
involvement

20. Incidence
• Increased incidence in the last decade
• Large outbreaks in early 2006 in North America
• Establishment of ASCRS TASS Task Force
• Many potential causes detected and detailed
analysis of data done

21. Prevention of TASS
• Appropriate protocols for cleaning and sterilising
surgical equipment
• Paying careful attention to all solutions, medications,
and ophthalmic devices used during anterior segment
surgery
• Recommended Practices for Cleaning and Sterilising
Intra ocular Surgical Instruments
• www.eyeworld.org/ewsupplementarticle.php?id=200

23. • Onset
• Signs and symptoms
• Inflammation in A C
• Culture Negative
• Response to intensive Corticalsteroid

24. Malignant Glaucoma

25. BCVA – 6/6p

26. Malignant Glaucoma

27. 25 G PPV
Intracameral air

28. Pearls in the diagnosis and
Management
• Relatively early occurrence
• Typical Limbus to limbus corneal edema
• Culture negative
• Dramatic response to cortico steroids
• Possibility of Endophthalmitis

29. Management of very severe
TASS
• Severe Endothelial Damage and decomposition
• Corneal transplantation
• Refratory glaucoma
• Filtering shunt surgery

30. Out break of TASS
• An environmental and toxic control issue
• Analysis of all medications and fluids
• Complete review of operating room
• Review of cleaning of instruments and
sterilisation process

31. Prophylaxis
• May occur in cluster
• Need thorough evaluation and preventive
measures the operation theatre processes and
cleaning protocols and instrument cleaning
procedures

32. Conclusion
• Commonest cause Inadequate cleaning and
sterilisation process
• Inadequate flushing of cannulas and hand pieces
• Denatured residues of OVDs
• Medications and solutions with
• Contact with IOL intra ocular surface of instruments
with gloved hands