**Background:** Toxic anterior segment syndrome (TASS) is an acute, sterile postoperative inflammatory reaction caused by noninfectious agents entering the anterior segment during surgery, leading to toxic damage to intraocular tissues. First described in 1980, TASS has been reported after cataract surgery, penetrating keratoplasty, intravitreal injections, and vitreoretinal surgery. The incidence is estimated at more than 1 in 1000 after cataract surgery, with a retrospective study in India reporting 60 cases out of 26,408 surgeries (0.22%). The exact causative agent often remains unidentified, but potential causes include toxins, contaminants, medications, preservatives, residues on instruments, and disinfectants. Recent reports highlight outbreaks from contaminated balanced salt solutions (BSS), intracameral antibiotics, and IOL-related contaminants like aluminum and silicon.
**Methods:** This is a narrative review summarizing the literature on TASS, covering incidence, etiopathogenesis, clinical manifestations, diagnosis, treatment, and prevention. The review synthesizes findings from multiple studies, including case series, outbreak investigations, and retrospective analyses. Key studies cited include Sengupta et al. (0.22% incidence in 26,408 cataract surgeries), Kutty et al. (112 cases from contaminated BSS), Wijnants et al. (28 cases from contaminated IOLs), and Oshika et al. (147 cases from IOL heavy metal contamination). The review also references guidelines from ASCRS, AAO, and AORN.
**Key Results:** TASS typically presents 12-48 hours postoperatively with blurred vision, mild pain, and limbus-to-limbus corneal edema, which is a specific finding. Hypopyon and fibrin in the anterior chamber are common. Delayed onset cases have been reported, with mean presentation at 38 days (Suzuki et al.) or 42-137 days (Miyake et al.). Complications include irreversible corneal endothelial damage, fixed dilated pupil, iris atrophy, secondary glaucoma, and cystoid macular edema. Treatment involves intensive topical steroids (e.g., prednisolone acetate 1% every 1-2 hours), cycloplegics, and IOP monitoring. In severe cases, oral prednisolone up to 40 mg/day, subconjunctival or intravitreal steroids, or recombinant tissue plasminogen activator (r-tPA) may be used. Surgical interventions include anterior chamber washout, glaucoma surgery, or endothelial keratoplasty (DMEK/DSAEK) for corneal decompensation. Oshika et al. reported that 29.3% of 147 eyes required surgical intervention. Prognosis is generally good with early treatment; mild cases resolve within days, but severe cases may lead to permanent damage. Moyle et al. reported 11 patients achieving 20/20 vision after treatment. Kaur et al. found that DSAEK performed >3 months after TASS onset had 100% success.
**Clinical Implications:** TASS is a preventable condition that requires strict adherence to sterilization protocols, proper cleaning of instruments, and use of preservative-free intracameral solutions. Outbreak management involves thorough investigation of all medications, solutions, and instruments used, with reporting to registries like the ASCRS TASS Task Force. Patient factors such as uncontrolled diabetes, hypertension, and hyperlipidemia may increase risk. Early recognition and aggressive steroid therapy are critical to minimize permanent damage. The review emphasizes the need for ongoing education of surgical teams and reporting of even single cases to prevent larger outbreaks.