In this presentation, Dr. Harper discusses about various retinal conditions where laser can be used.
Lecturer: Dr. Clio Armitage Harper III, Austin Retina Associates, Austin, USA
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DR HARPER: So we have many conditions that we can treat with laser, including proliferative diabetic retinopathy, macular edema, secondary to diabetic retinopathy, neovascular venous occlusive disease, macular edema secondary to venous occlusive disease, extrafoveal or parafoveal neovascular disease from AMD, central serous retinopathy, either PDT laser, photodynamic therapy, or MicroPulse. Transpupillary thermotherapy for malignant melanoma, transpupillary thermotherapy for retinoblastoma, for retinal tears and subclinical retinal detachment, for Coats disease and other exudative vascular disorders, and of course for retinopathy of prematurity. When we talk about proliferative diabetic retinopathy, laser is still the mainstay of treatment. When we laser the retina, we’re decreasing the hypoxic load on the retina, and we subsequently decrease the VEGF level in the retina. And this was demonstrated in multiple studies, including the ETDRS and the diabetic retinopathy study. And it is still the most common indication for laser, is proliferative diabetic retinopathy. Recently, the DRCR Protocol S found that anti-VEGF monotherapy is as effective as conventional laser therapy. However, clinical and economic advantages are still within the realm of PRP, as opposed to the injections. So this is an example of a patient who has had some laser before, but you can see along the superior arcade there’s a big branch of neovascular blood vessels. So when we look at the fluorescein angiogram of the same patient, you can see that the vessels are still fairly prominent along that superior arcade. The FA also demonstrates severe capillary dropout around the peripheral retina, and also macular ischemia, indicating severe production of vascular endothelial growth factor. So this is a very good indication for PRP laser, fairly extensively. The nice thing about performing PRP laser in a case like this is that once that amount of laser is performed, as we did this morning, that patient probably won’t have to have laser again. Here’s an example of what we want the laser to look like. And you can see that the laser is all the way up to the arcades. Another indication for laser, as we performed today, is macular edema and lipid secondary to diabetes. If the lipid is directly in the fovea, then we can only inject anti-VEGF, as we can’t get to that area with the laser without causing severe damage. When the lipid is outside the center, in the parafoveal location where the edema is, we can use a combination of focal and grid laser therapy for this condition. You can also use MicroPulse laser for chronic edema secondary to diabetes as well. And you can see on the left vision is 20/50, and on the right, after the MicroPulse, it’s 20/30. MicroPulse is not good for lipid or exudate. But it is really good for chronic edema that’s very stubborn and is not dissipating, even with anti-VEGF therapy. And here’s an example of a similar patient that we see this morning, where you have an extensive amount of lipid. And it really is a good indication for that grid-type laser that we perform today. And here’s an example of a patient that was treated. The left eye you can see the lipid, and after the focal laser and the grid laser, the lipid on the right — you can see it dissipated centrally. Neovascular venous occlusive disease also lends itself for laser. Here you have a branch retinal vein occlusion that shows severe ischemia. And so by placing PRP laser, we will protect this patient from neovascularization. And here’s an example of another branch retinal vein occlusion. You can see the shunt vessels on the optic nerve and the exudate just superior to the fovea. When we do have this macular edema, secondary to a BRVO, laser can be used either as primary therapy or in conjunction with anti-VEGF or steroids. Here’s an example of a case that will benefit from both anti-VEGF therapy, intravitreal injection of Avastin, possibly steroid, and laser. Again, here’s a good grid pattern of laser, following an inferior BRVO, in the side. When you have macular degeneration, most generally, anti-VEGF is still the treatment of choice. However, there are still cases where thermal laser can be very beneficial. This is a well demarcated, classic macular degeneration lesion in the parafoveal location that was treated with successful focal laser. Also, we know that central serous choroidopathy can be treated with either PDT laser or MicroPulse laser. This is a patient of ours in the practice with chronic central serous retinopathy for over one year, with a vision of 20/50, that was treated with MicroPulse laser. Ended up with vision of 20/30, following the MicroPulse laser. Here’s the color of the OCT. The upper one being pre-op, and the middle one being the postop picture. Here’s the classic central serous, and this could be either — will respond to either PDT or the MicroPulse laser on the right eye. And you could even use focal laser in the left eye. We also use laser — we use the red diode laser for treatment of malignant melanoma, combined with I-125 radioactive plaques. And here’s an example of a tumor along the inferior arcade that was treated with both an I-125 plaque and the red diode laser, causing complete regression of the tumor. We also use it to treat retinoblastoma in our practice. This is a patient of mine. We enucleated the right eye. This is an 18-month-old child who presented with a very large lesion next to the optic nerve in the left eye. So he underwent six rounds of chemotherapy and is continuing to have laser, and you can see these two isolated lesions, and then that large lesion, which we’ve surrounded with laser, and is stable at this point. And of course, retinal tears or subclinical retinal detachment is a very common indication for laser. And again, I usually use the indirect laser, because it’s easier for me to see the peripheral retinal tears. And here’s a good picture of the way retinal tears should be treated. And you can see that’s a horseshoe tear with almost a bridging vessel. But laser’s surrounding the entire area. We can also treat Coats disease, and we have two of those coming to the plane this week. Coats disease is a vascular disease of unknown origin, where the blood vessels begin to leak fluid, and can lead to blindness. This is a 15-year-old girl who presented to my clinic with a vision of 20/400. And the peripheral Coats disease, as you can see. You can see the classic lightbulb-like appearance on the fluorescein angiogram. This is the advantage of a wild field FA, because you can see the whole peripheral retina. And Coats disease usually starts far in the periphery. So this is the later part of the angiogram, where you see all the leakage. And she actually had a lot of lipid in her fovea too. And you can see that stellate pattern of lipid. And this is the reason her vision was so diminished, because of that stellate pattern. So we applied laser in the far periphery. And I had to take her back to surgery probably three times for laser. With Coats, it has to be done on a gradual basis, so multiple treatments are often needed. In addition, I did use anti-VEGF in her too, to decrease the central foveal swelling. But laser was of critical importance in decreasing the overall amount of edema in her retina. And of course, we use red diode laser, either as primary treatment or secondary treatment for retinopathy of prematurity. This is a patient of mine who presented to me when he was 18 months old. He was blind in his right eye, and he was injected four times with Avastin in the left, with no laser. And you can see the macula is severely distorted, which oftentimes occurs with Avastin. Oftentimes occurs with Avastin and ROP. In addition, at 18 months of age, after Avastin injections, he’s still very active with leakage of the blood vessels and neovascularization. So we applied extensive laser twice to him, to decrease that amount of neovascularization. And you can see the laser scarring starting to take effect, and cause the regression, and decrease of the overall VEGF and neovascularization in his retina. Questions? Oh, you want to go back to that one? Okay. This one? So when we look at this picture, it’s almost impossible to pick out every microaneurysm. So the classic description of focal grid laser is to perform a C-shaped pattern. In a C. All around here. And it’s usually a light grey spot, light grey, and 50 to 100 microns in size. And somewhere about 180 to 200 milliwatts, usually, depending on the laser. With a 100-millisecond duration. That answer your question? It’s a pattern. So it’s a C-shaped pattern, all in here like this, in the shape of a C. If you laser it very heavy, you’ll cause a paracentral scotoma. But if you don’t treat this, it’s gonna end up in the fovea, and then they’ll have no vision. Not for this. Not for lipid this thick. It won’t knock out that lipid. So edema, yes. But not lipid. Lipid is very difficult for us to resolve. You should continue to use the anti-VEGF, but if you add laser, you will really benefit the patient.