 Good morning. My name is Abid Farooqi and I'm also an ophthalmic pathology and research fellow with the Mamelis and Warner Lab. Thank you to my colleagues for giving us such a fascinating talk on intraocular lenses. I hate to break the trend, but I'm going to be talking about another subject that I've become very intimately involved with as a member of the ACS, ASCRS form task force, toxic anterior segment syndrome. So I'll start off with a case presentation and talk about what TAS is. The causes, diagnosis, treatment, and how we can kind of assess the outcomes of... So we have a case, a case report from the VA hospital in Indiana in which five men ages 64 through 81 years underwent a clear corneal incision, fecal emulsification surgery with the insertion of an Alcon SN60WF lens. There was significant past medical history in four out of the five men for hypertension and diabetes. However, none of them had any significant ocular history. All surgeries were similar in respect to the cataract densities, the amount of energy dissipated during the procedures, and the length of the surgery itself. All medications and solutions used were the same for each surgery, and there were no recent changes to any medications or surgical procedures or surgical equipment at the VA facility. On postoperative day one, all patients had a diffuse 1 plus to 2 plus corneal edema, a 2 plus to 4 plus anterior chamber white blood cells. Two of the patients had hypopionic fibrin formation in the anterior chamber, and none of the patients complained of ocular pain. Visual acuity ranged from 2070 to 2400, and all patients had normal intracular pressures. These patients were felt to have a diagnosis of toxic anterior segment syndrome, and were treated accordingly. So I'll refer to toxic anterior segment syndrome as TAS now, and TAS is a sterile inflammation of the anterior segment following any anterior segment surgery. Most commonly, this complication arises after cataract surgery. However, any anterior segment surgery can result in TAS, such as glaucoma surgery or a corneal transplant. Presentation of the symptoms of TAS generally occur within 12 to 48 hours postoperatively, with the majority of the patients presenting within the first 24 hours. The pathophysiology of this process is thought to be an activation of the inflammatory cascade mediated by a toxic insult that enters the anterior segment of the eye, either during or immediately after the surgery. This inflammatory cascade causes the toxic substance is damaging to the corneal endothelium and other sensitive tissues in the anterior segment of the eye, causing corneal edema from the damaged corneal endothelium. Also, the trabecular mesh work and the iris are also sensitive structures in the eye for increasing the risk of glaucoma or other iris effects. The prognosis of the inflammation and this cascade varies depending on the amount and the type of substance that enters the anterior segment, how long that substance is within the anterior segment, and how long before treatment is initiated. Some of the symptoms that patients will come into the clinic presenting with are blurred vision, conjunctival injection, and photophobia. However, pain is usually absent and this will be helpful in distinguishing tasks from another very critical diagnosis, which I will discuss in a few minutes. Some of the signs on slit lamp examination is this characteristic limbis-to-limbis corneal edema. You'll see increased cell and flare in the anterior chamber. You'll also possibly see hypopion formation and fibrin formation and a dilated or irregular pupil and increased intraocular pressure. These last two are more commonly seen with more severe cases of tasks. However, it is also likely that patients will present with some of these findings. Just a quick note on the increased intraocular pressure. Usually most patients will have normal pressures upon presentation, but as the healing process resumes, their pressures will increase. However, some patients will present with a more severe case with damage to the trabecular mesh work already and will have intraocular pressures up to 50 to 60. Here are some of the pictures of the findings that I was just discussing. You'll have a diffuse limbis-to-limbis corneal edema on the left. You see this increased conjunctival injection with the hypopion in the anterior chamber. This last picture is a picture of a severe case of tasks in which there is iris atrophy with a fixed dilated irregularly shaped pupil and iris droma defect allowing for transillumination of the iris. It's difficult to see here, but the haptics are able to be visualized through the iris. One of the distinguishing diagnoses that is very important to rule out when thinking of tasks is infectious endothelmitis. This chart right here is to help distinguish some of the main differences between the two entities. One of the first I want to draw your attention to is the onset of symptoms. In tasks, this generally occurs very acutely within 12 to 48 hours. However, in infectious endothelmitis it takes a little bit longer, usually two to seven days post-operatively. Even the most virulent strains of bacteria won't result in symptoms until a few days after. The corneal edema is limbis-to-limbis, and I hate to sound repetitive, but it's very characteristic in tasks. In infectious endothelmitis, you might have focal edema or none at all. In the anterior segment inflammation, it's generally a little bit more severe in infectious endothelmitis with greater hypopion and fiber information. Also, as I mentioned earlier, the pain usually with infectious endothelmitis will have the majority of patients complaining of pain, whereas the opposite is true of tasks. If there's ever any uncertainty about the diagnosis of tasks, obtaining a gram stain and culture, obtaining aqueous and vitreous fluid for a gram stain and culture, is very important in ruling out infectious endothelmitis. Here are some of the findings characteristic of infectious endothelmitis. The conjunctival injection is much greater. There isn't a diffuse limbo-to-limbo corneal edema. However, there is greater hypopion. Also, the visualization of the posterior pole will be obscured by a classification of the vitreous. Moving on to the causes of tasks. Given that the causes of tasks are numerous and varied, there is an evaluation of all surgical procedures and protocols when a case of task arises. To simplify, I'll categorize the causes of tasks into two of the more common causes. Intracular medications and solutions can commonly cause tasks. Balanced salt solutions, any solutions used in the eye, can cause tasks if there is irregular pH measurements. Ionic composition is off, or if there's some contamination within the solution. More commonly, topical ophthalmic drops that contain preservatives and stabilizing agents are damaging to the corneal endothelium, which is very sensitive to these agents. That's one of the more common causes of tasks. Epinephrine that's added to VSS during the surgery to help with tuple dilation commonly contains stabilizing agents like bisulfites and metasulfites. These are preservatives like benzalconium chloride, and these are very toxic to the corneal endothelium. Also, I just want to bring your attention to OVDs, ophthalmic viscoseurgical devices, which are toxic in and of themselves if they're left in the eyes, but there's also a chance that if the surgical equipment used is not cleaned properly, that they may retain some into lumen, and upon subsequent surgical procedures, these can be released into the anterior chamber of the eye, causing an inflammatory reaction. One of the other major causes of tasks that was noted to be one of the most common causes during a 2006 task outbreak in North America was a cleaning and sterilization of instruments. This includes reusable cannulas and handpieces, and also talks about the enzymes and detergents and ultrasound vats. Like I mentioned earlier, these lumens of these handpieces may have retained cortical material or dried OVD that is not removed sufficiently. Through the sterilization process, these persist and allow for further contamination in subsequent surgeries. The enzymes and detergents are also noted to not be necessary, given that the bio burden accumulated on these equipment during the procedure itself is not so great compared to other general surgical techniques and instruments. Therefore, the toxicity of the enzymes and detergents, if not rinsed away properly, will create more problems than they help. And ultrasound vats similarly are not necessary given the low bio burden during cataract surgeries, and these have a tendency to get contaminated with gram-negative bacteria, producing endoscores that are not denatured during sterilization. And finally, poorly constructed wounds can also allow for substances to enter the anterior segment during surgery and after surgery. So treatment, as I mentioned, prevention is the best form of treatment, so making sure that surgical procedures and protocols are adhered to strictly is the best way to avoid complication of tasks. However, if there is a complication of tasks, you'd want to immediately treat them to reduce the inflammatory response. Removing any residual material that may be causing the toxic insult is necessary, but then the medical treatment is generally a topical prednisolone acetate, 1% every one hour, with close observation and follow-ups to visualize the improvement of the inflammation in the anterior chamber and also to make sure that intraocular pressures are maintained. Then it's also important to analyze the outbreak. ASCRS has created an ad hoc task force that will help analyze any of these outbreaks of tasks. It's readily available on a website that I'll mention soon. And just going to the prognosis and outcomes of tasks, usually most cases of tasks are mild, and there'll be resolution of the anterior segment inflammation and corneal edema within days to weeks, with no residual sequelae. To moderate tasks, there's a little bit longer time for resolution of the corneal edema and the anterior segment inflammation. Some will have mild residual corneal edema, most will resolve completely, and this group is more susceptible to elevated intraocular pressure increases. And in severe tasks, there is permanent damage to the anterior segment of the eye. There's persistent corneal edema, possible assistoid macular edema, iris atrophy like that fixed dilated pupil that we saw in the picture with a thinned iris stroma, and severe glaucoma that is difficult to treat medically and will usually require some surgical intervention. And rarely these severe task cases will require systemic medical treatment. So in summary, if you see a patient with diffuse limbo-to-limbo corneal edema that is normalizing 12 to 48 hours post-anterior segment surgery, think of tasks. However, it's imperative to rule out infectious and ophthalmitis, and also initiate treatment immediately and monitor closely for any progression of the disease. And also it's important to analyze the outbreak. If you have a task outbreak, there's a standardized protocol and survey that is available on the ASCRS website that will allow you to receive advice on an evaluation on what may be causing the task by a task-created task force. That's an awful. Anyways, I will be one of those individuals this year that would help to analyze the outbreak as is our Dr. Mamelis. Here are my references, and thank you for listening. Dr. Mamelis would have a better understanding.