you're going to hear many new cutting edge things going on in glaucoma. But I get to talk to you all about one of the workhorses of glaucoma, laser tubercular plasticity, and only but a goodie. I'm gonna go over triangular mesh word path of physiology, the development of laser tubercular plasticity and touch on the glaucoma, laser trial and ages trials. Hold and move on, um, to one of the most recent studies, the light trial, uh, and then discuss other predictors of success. When it comes laser tubercular plasticity will then touch on Perry laser drop regimens and review the salt trial. Uh, and then I'll touch on the way I use laser to regular plasticity and my glaucoma treatment algorithm. The triangular mesh work, uh, is responsible for the majority of acquis outflow through the conventional outflow pathway. It's a pressure dependent pathway, and the measure is composed of three layers. The usual layer the corneal scleral layer in the Jackson key molecular layer. These layers have collage this connective tissue as well as tubercular cells, which can contain pigment Granules. The inner wall of shrimps canal is composed of endothelial cells and vacuums that communicate with these intra trade regular spaces. There's three main theories regarding the effect of laser tubercular plasticity on the tubercular mesh work. There's a mechanical theory which postulates that the energy applied causes thermal contraction of the regular mesh work, which then opens up the adjacent triangular mesh work to allow more flow through the adjacent tissues. The cellular theory postulates that the energy increases, uh, tubercular metrics, cell division and repopulation. The biochemical theory, uh then postulates that the energy leads to increase in chemical mediator expressions such as interleukin six, tumor necrosis factor and matrix metallic. Pro tennis is which then lead to remodeling of the TM to improve flow. There's actually lots of different lasers that you can use to perform laser to regular placidity. For the purposes of my talk, we're really going to focus on lt uh SLT um, but regardless of which laser you use, the general treatment protocol is to apply 9200 and 20 non overlapping spots. The 360 degrees of the tribe, regular mesh work, or 45 to 60 non overlapping spots, 280 degrees of particular measure work. Using an indirect colonoscopy lens, the Argo and laser tubercular plasticky was first described in 1979 by Weiss and later as an alternative to Trebek elected me, uh, in the 1990 the glaucoma laser trial established lt is an alternative to medication as a first line treatment for primary opening of glaucoma. Ages published later on in the nineties looked at outcomes in patients with advanced glaucoma regards different treatment algorithms involving lt and Trebek elect to me, Uh, and, uh, further analyze those outcomes based on race, uh, in both racial groups. At 10 years, initial treatment with a L T. Failed in about 50% of patients. Uh, that's sort of a glass half empty way of looking at it. You could look at glass half full, uh, 50% of patients, uh, we're still in success at 10 years after undergoing ELT. It's pretty good for people with advanced glaucoma. SLT came around, uh, about 20 years after or 10 years after lt. Uh, and it was thought to be, um, more selectively targeting the pigmented cells with a triangular mesh work and limiting thermal damage to adjacent tissues. Many studies have compared to two compared to two lasers and they've really been shown to be equivalent in lowering. I'll help as an initial treatment. Some studies have suggested less inflammation and less PS formation with SLT, but this data is somewhat mixed. Um, there's also some benefit of SLT over a l T. When it comes to re treatment when I have previously undergone laser tubercular plasticity. But this data is also somewhat mixed. The light trial was published in 2019. Uh, and it was a study out of the UK, uh, done at multiple centers, um, comparing SLT two initial treatment with a prostaglandin analogue for treatments of patients with primary open angle glaucoma and ocular hypertension. It examined both clinical outcomes and looked at cost effectiveness and includes 718 patients. Um, and 651 of them completed the study follow up at 36 months. Um, when it came to i o P. Outcomes. So patients in both groups, uh, achieve similar I o P. Target at 36 months, 95% SLT group in 93% in the medication group. However, there was slightly more progression of disease during the trial, and the medication group compared to the SLT group, and those patients under had to undergo more treatment escalations. Um, what's really stunning is, uh, 11 patients in the treatment group had undergo Trebek elected to me, compared to zero in SLT Group. Also, when you look at 36 months follow up, 90% of patients were on one or no medications, and SLT Group, compared to only 67% in the medication group, were on one or no medications. Um, SLT was also found to be more cost effective, costing an average £451 of less compared to the medication group. And the quality life measures were similar in both groups. Um, one might say, Well, that was a study conducted, uh, in the UK, where they have the National Health Service. Uh, there was a group in California that looked at treating with SLT compared to medications, uh, in the USA, and they found that in most patients, even on generic lieutenant pros, um, after 13 months of treatment, it was, uh, more cost effective to perform SLT compared to treatment with just generic lieutenant pros, so predictors of success, we're always looking for how we can find the people that are going to respond well to treatment. So typically, um, one can expect about 20 to 30% reduction with laser tubercular plasticity, but this can diminish over time. Um, and it depends on the patient population that you're treating, but there's somewhere between 40 to 75% chance of success with GOP control at one year. Um, there are some, uh, some, uh, factors that we can reliably count on. So the higher the pre lazer I o p uh, the greater reduction uh, absolute I o p. Reduction one can expect to get from the procedure laser tubercular plastic success in one eye tends to correlate with success in the fellow I, um, and the effect of i o p reduction with additional laser regular plasticky treatments can diminish over time. The data on chemo of energy and improved I o P. Is mixed. Um, that's why some people continue to 3 60. Some people do 1 80. The data is not clear on that, uh, whether or not angle pigmentation plays a role in the success of later trick policy. The data is also mixed on that, um and then similarly, some studies have showed prior use of a prostaglandin dialogue can improve outcomes, and others have shown that it reduces outcomes. So the data is still out on that, Um, there's always a question of post laser anti inflammatory drops and whether or not that helps with long term outcomes. So again, in 2019, the salt trial was completed. Um, and this was a double mask randomized, placebo controlled trial. It looked at patients with ocular hypertension and primary open angle glaucoma to receive SLT. Um, and um, The patients in each of these groups were found to have pressures between 22 23 at Week 12. Their pressures reduce between 17 and 19. This study did find a statistically significant increased reduction in patients that were treated with insets and steroids. Compared to the placebo, there was no difference and objective or subjective signs and symptoms of inflammation or ocular surface issues between these two groups. However, some have scrutinized this trial because the inset group and the steroid group had slightly higher pre op laser i O P. Although this was not statistically significant and by happenstance they happen to have more patients that received 360 degrees of treatment, compared to 180 degrees of treatment. Uh, in the placebo group. This also was not statistically significant, but people have pointed to that as a potential confound. Er I think the reason why people are taking the salt trial with a grain of salt is there have been other studies, uh, that have looked at using anti inflammatory drops, and none of them have shown an effect on I O. P at one year or other ranges of follow up. However, these studies have had smaller sample sizes. They did have lower pre op I O P compared to the assault trial. Um, and then they did have standardized degrees of treatment with everybody treated. Um, so I personally don't use anti inflammatory drops when we go back to the biochemical theory. Um, one, uh, can postulate that, uh, you know, you want to induce a little bit of inflammation some, uh, inflammatory cytokines, because that is potentially helping, uh, the effect of the laser on the triangular mesh work and remodeling. Um, so I would say, uh, some of these childs, the data is still mixed and out. It's hard to give clear recommendations. So post up, laser follow up. Um uh, you always want to give an alpha two agonist before and after. Um, this can reduce the risk of an i O P. Spike, but by as much as tenfold. I usually have patients come back somewhere between 4 to 8 weeks to monitor for the effective laser. And then I see them every three months for the first year after that to ensure the duration of effect. Now, if you achieve an i o. P lowering response with the laser, but it's not enough that can be repeated within the year. However, if no, i o p effect occurs, repeating the laser is not really going to be helpful. So, um, where do I use it? Uh, I use it when the angles are open. Uh, used it as initial therapy patients with non compliant and other ocular surface issues. Um, patients who want to reduce their drop burden and prior to escalating drop or surgical therapy. When do I consider other options? Obviously, if the angle is closed, uh, there's already p A s or its neo vascular rise. Uh, I tend to, uh, try medication or other alternatives when the pressure is over. 35. Um, just because if this patients already on maximum medical therapy and you get a spike with the laser, you can kind of run into an emergency situation. And also, if you're expecting to get a 20 to 30% reduction, that may not be enough. When the pressure is already over 35 history, you ve itis, uh, this can go both ways. However, there is some evidence that you can reactivate HSV and V C V with the laser and then traumatic Glaucoma has always been thought to be, uh, an area where the laser is not effective. Some have reported case series where it has shown, uh, an i o p. Response. So again, everything you can always, uh uh, tailored to the specific patient. Uh, and then, if they've already failed, lt your SLT within the last 6 to 12 months, and I would move on to something else. Time. I typically treat 3 60 but times when I only consider doing 1 80 is if the patient has pigment dispersion or to exfoliation, or if the patient has severe glaucoma and it's affecting fixation um, so we're not going to take any questions now. Um, but, uh, we can I'm happy to take some more in the question. Answer section later.
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