Toxic anterior segment syndrome (TASS) following cataract surgery is differentiated from infectious endophthalmitis primarily by which clinical feature?

• A TASS presents with vitritis, severe pain, and positive vitreous cultures
• B TASS occurs within 12–24 hours and shows diffuse limbus-to-limbus corneal edema with hypopyon but minimal pain ✓
• C TASS occurs 5–7 days postoperatively with lid edema and severe photophobia
• D TASS is distinguished by fibrin membrane on IOL surface and high IOP

Explanation

TASS is a sterile inflammatory reaction from a non-infectious substance entering the anterior segment (denatured OVD, preservatives, irrigation solution contaminants). It presents within 12–24 hours with diffuse corneal edema extending to the limbus, hypopyon, dilated/fixed pupil, and minimal or no pain. This contrasts with infectious endophthalmitis which typically presents 2–7 days postoperatively with severe pain, dense vitritis, and reduced red reflex. Management is with intense topical corticosteroids; no antibiotics needed.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

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Written and medically reviewed by the StethoPrep medical team.