Toxic anterior segment syndrome (TASS) is a sterile postoperative inflammatory reaction caused by a noninfectious substance that enters the anterior segment, resulting in toxic damage to intraocular tissues. The process typically starts 12 to 48 hours after cataract/anterior segment surgery, is limited to the anterior segment of the eye, is always Gram stain and culture negative, and usually improves with steroid treatment. The primary differential diagnosis is infectious endophthalmitis. Review of the literature indicates that possible causes of TASS include intraocular solutions with inappropriate chemical composition, concentration, pH, or osmolality; preservatives; denatured ophthalmic viscosurgical devices; enzymatic detergents; bacterial endotoxin; oxidized metal deposits and residues; and factors related to intraocular lenses such as residues from polishing or sterilizing compounds. An outbreak of TASS is an environmental and toxic control issue that requires complete analysis of all medications and fluids used during surgery, as well as complete review of operating room and sterilization protocols.

Toxic anterior segment syndrome

PURPOSE To review the current state of evaluation and management of various forms of endophthalmitis. METHODS A review of the literature is included, encompassing endophthalmitis occurring after ocular surgeries, intravitreal injection, trauma, and systemic infection. Based on this review, current principles and techniques for evaluating and treating these forms of endophthalmitis are discussed. RESULTS Postoperative endophthalmitis after cataract surgery is the most common presentation. Conclusions from the Endophthalmitis Vitrectomy Study (EVS) remain a foundation for management of postcataract surgery endophthalmitis, notably prompt intravitreal antibiotic administration after vitreous sampling, with consideration for pars plana vitrectomy in severe cases. The potential impact of advances since the EVS, such as oral fourth generation fluoroquinolones and new vitrectomy techniques, are also discussed. The management of postcataract endophthalmitis is compared and contrasted to endophthalmitis occurring after other ocular surgeries, intravitreal injection, trauma, and systemic infection. Although some principles remain common, treatment rationales differ with other forms of endophthalmitis based on differing clinical circumstances, such as the virulence of organisms that are frequently encountered. CONCLUSIONS Endophthalmitis is a serious, potentially vision threatening condition which can present in various settings. Prompt recognition and treatment are key in maximizing outcomes.

Endophthalmitis: a review of current evaluation and management.

Various pathologic processes may lead to clinically significant opacification or discoloration of the optic component of intraocular lenses (IOLs) manufactured from different biomaterials and in different designs. Factors such as the patient's associated conditions, the manufacturing process, the method of IOL storage, the surgical technique and adjuvants, or a combination of these may be involved. The complication may be observed intraoperatively or postoperatively from a few hours after implantation to many years after surgery, depending on the processes involved. Based on a review of the literature as well as our own laboratory analyses, the following types of processes were identified: formation of deposits/precipitates on the IOL surface or within the IOL substance; opacification by excess influx of water in hydrophobic materials; direct discoloration by capsular dyes or medications; coating by substances such as ophthalmic ointment and silicone oil; and a slow, progressive degradation of the IOL biomaterial.

Causes of intraocular lens opacification or discoloration.

To describe the incidence, features, management, and risk factors of post-intravitreal anti-VEGF endophthalmitis (PIAE) in patients undergoing treatment for exudative age-related macular degeneration in the United Kingdom. Prospective observational case control study. Forty-seven cases of PIAE were identified through the British Ophthalmological Surveillance Unit from January 2009 to March 2010. Data collected at diagnosis and at 6 months follow-up included patient demographics, intravitreal injection details, pre- and post-injection management, visual acuity, clinical features and management of PIAE, causative organisms, and clinical outcomes. Details were compared with 200 control cases from 10 control centres to identify potential risk factors. Estimated PIAE was 0.025%. Culture-positive PIAE incidence was 0.015%. Mean age of presentation was 78 years. Mean number of intravitreal injections before PIAE was 5. Mean days to presentation was 5 (range 1–39). Positive microbiology culture was found in 59.6%. The majority of causative organisms were Gram positive (92.8%). Significant risk factors were failure to administer topical antibiotics immediately after the injection (P=0.001), blepharitis (P=0.006), subconjunctival anaesthesia (P=0.021), patient squeezing during the injection (P=0.021), and failure to administer topical antibiotics before anti-VEGF injection (P=0.05). The incidence of PIAE in the United Kingdom is comparable to other studies at a rate of 0.025%. The most common causative organisms were Gram positive. Measures to minimise the risk of PIAE include treatment of blepharitis before injection, avoidance of subconjunctival anaesthesia, topical antibiotic administration immediately after injection with consideration to administering topical antibiotics before injection.

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Post-intravitreal anti-VEGF endophthalmitis in the United Kingdom: incidence, features, risk factors, and outcomes

Purpose To identify the most common risk factors associated with toxic anterior segment syndrome (TASS). Setting Ophthalmic surgical centers in the United States, Argentina, Brazil, Italy, Mexico, Spain, and Romania. Methods A TASS questionnaire on instrument cleaning and reprocessing and extraocular and intraocular products used during cataract surgery was placed on the American Society of Cataract and Refractive Surgery web site. A retrospective analysis of questionnaires submitted by surgical centers reporting cases of TASS was performed between June 1, 2007, and May 31, 2009, to identify commonly held practices that could cause TASS. Members of the TASS Task Force made site visits between October 1, 2005, and May 31, 2009, and the findings were evaluated. Results Data from 77 questionnaires and 54 site visits were analyzed. The reporting centers performed 50 114 cataract surgeries and reported 909 cases of TASS. From January 1, 2006, to date, the 54 centers reported 367 cases in 143 919 procedures; 61% occurred in early 2006. Common practices associated with TASS included inadequate flushing of phaco and irrigation/aspiration handpieces, use of enzymatic cleansers, detergents at the wrong concentration, ultrasonic bath, antibiotic agents in balanced salt solution, preserved epinephrine, inappropriate agents for skin prep, and powdered gloves. Reuse of single-use products and poor instrument maintenance and processing were other risk factors. Conclusions The survey identified commonly held practices associated with TASS. Understanding these findings and the safe alternatives will allow surgical center personnel to change their practices as needed to prevent TASS. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Toxic anterior segment syndrome: Common causes

Purpose To report clinical and laboratory findings of 8 cases of toxic anterior segment syndrome (TASS) related to an oily substance in the anterior chamber of patients following cataract surgery with intraocular lens (IOL) implantation. Setting John Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Methods Eight patients had uneventful phacoemulsification by the same surgeon via clear corneal incisions with implantation of the same 3-piece silicone IOL design. Postoperative medications included antibiotic/steroid ointment and pilocarpine gel; each eye was firmly patched at the end of the procedure. On the first postoperative day, some patients presented with diffuse corneal edema, increased intraocular pressure, and an oily film-like material within the anterior chamber coating the corneal endothelium. The others presented with an oily bubble floating inside the anterior chamber, which was later seen coating the IOL. Additional surgical procedures required included penetrating keratoplasty, IOL explantation, and trabeculectomy. Two corneal buttons were analyzed histopathologically. Two explanted IOLs had gross and light microscopic analyses (as well as surface analyses of 1 of them), and 4 other explanted IOLs had gas chromatography-mass spectrometry. Results Pathological examination of the corneas showed variable thinning of the epithelium with edema. The stroma was diffusely thickened and the endothelial cell layer was absent. Evaluation of the explanted IOLs confirmed the presence of an oily substance coating large areas of their anterior and posterior optic surfaces. Gas chromatography-mass spectrometry of the lens extracts identified a mixed chain hydrocarbon compound that was also found in the gas chromatography-mass spectrometry analyses of the ointment used postoperatively. Conclusions The results indicate that the ointment gained access to the eye, causing the postoperative complications described. These cases highlight the importance of appropriate wound construction and integrity, as well as the risks of tight eye patching following placement of ointment.

Toxic anterior segment syndrome and possible association with ointment in the anterior chamber following cataract surgery

Method for minimizing the sorption of tear lipids on frequent replacement, or extended-wear, contact lenses, the method comprising (a) contacting the contact lens selected from the group consisting of senofilcon A, lotrafilcon A, lotrafilcon B, and comfilcon A B with a lens care solution for a period of at least three hours to minimize the accumulation of tear lipids on the contact lens. The lens care solution comprises 0.5 ppm to 10 ppm α-[4-tris(2-hydroxyethyl)-ammonium chloride-2-butenyl]poly[1-dimethyl ammonium chloride-2-butenyl]-ω-tris(2-hydroxyethyl) ammonium chloride; citrate, citric acid or a mixture thereof; and 0.005 wt. % to 0.05 wt. % hyaluronic acid. The method also includes (b) inserting the soaked contact lens into one's eye, and (c) repeating steps (a) and (b).

X. Michael Liu

Papers

Toxic anterior segment syndrome and possible association with ointment in the anterior chamber following cataract surgery

Minimizing biological lipid deposits on contact lenses