Cataract Extraction with Phacoemulsification and Posterior Chamber Intraocular Lens
I am Daniel Hu. I am an assistant professor of ophthalmology at Tufts University School of Medicine and New England Eye Center, Tufts Medical Center. And today we will be talking about cataract extraction using phacoemulsification with implantation of the posterior intraocular lens.
After prepping and draping the patient, you know, we - I like to use a Lieberman speculum to, you know, keep the lids open. And then we'll create a paracentesis to access the anterior chamber. And we'll fill the anterior chamber with viscoelastic, and then we'll use a keratome blade to create the main incision. Then with a cystotome and Utrata forceps, we'll create the capsulotomy. We'll hydrodissect and hydrodelineate the - the lens nucleus. We'll then fragment the lens nucleus with phacoemulsification handpiece and then remove the cortical remnants with automated irrigation aspiration. We will then inject the intraocular lens in the capsular bag and remove any remaining viscoelastic materials. And then check the wounds, seal everything up, and case is done.
I'll be showing the divide and conquer technique. I believe it's one of the easier techniques to learn for beginning surgeons. One of the benefits of it is that it can be very gentle to the capsular bag if done properly. In doing so, it creates very little zonular stress and, I think, lowers the potential risk for complications, so it's a very safe and gentle procedure.
Okay so, here in my right hand I have a 0.12 clear B [3:16] forceps to stabilize the globe. I have a 1.1 mm Sideport blade to create the paracentesis.
And this patient had a peribulbar block, so the next step here is to inject dispersive viscoelastic to fill the anterior chamber to the appropriate tension. Here it’s important to note that the appropriate tension is important as a too soft eye will predispose you to a long incision and an over inflated eye may create a short incision. And here I am stabilizing the eye with a 0.12 clear Bs [3:59] to the paracentesis and with a 2.5 mm keratome blade I am creating the temporal main incision just anterior to the limbus. Here, I am creating a triplanar corneal incision, which is important in creating a watertight incision.
And here, we are initiating the capsulotomy with a cystotome. I like to place the cystotome on a cohesive viscolastic. This allows me - if I encounter any trouble with the capsule running out or not turning in the direction I like with the cystotome, I can immediately inject the - the cohesive viscoelastic to try to aid in redirecting the capsulotomy. Here Utrata forceps are then used to propagate the initial capsulotomy with a continuous curvilinear capsulorhexis. And here, as we create the continuous curvilinear capsulorhexis, I like to shoot typically for proximally 5 mm capsulotomy, and this gives excellent overlap of the lens optic, which is appropriately 6 mm.
So, following a completion of the capsulotomy, we mobilize the lens nucleus with hydrodissection. I like to use a flat cannula for hydrodissection. It propagates a nice fluid wave. Here, we've also hydrodelinated the lens as you can see with the golden ring sign here. And following hydrodissection, we ensure good mobilization of the lens by turning the lens nucleus in both clockwise and counterclockwise direction.
Once we've demonstrated good mobility and rotation of the lens anterior with the phacoemulsification handpiece - here, we're initiating the initial groove, in order to split the nucleus into two halves. And I'm using a Grayson as my second instrument, and we're placing both the Grayson and the phacoemulsification handpiece deep into the base of the groove. Following the initial crack, move on to groove the first heminucleus. And again, crack it into quadrants. And this process is repeated for the second heminucleus.
After creating four quadrants, we switch to the quadrant removal setting on the phacoemulsification machine, and we bring the initial quadrant forward into the iris plane. There I was unable to purchase the first piece. We were able to debulk it somewhat, and moving on to the second piece, we were able to elevate it up into the iris plane. Elected to move forward to the second piece as most of the central nucleus - I haven’t aspirated, and I don't like to reach too far out into the periphery with a phacoemulsh - emulsification handpiece. Any surge or instability can create capsular rupture. So again, you can notice that throughout quadrant removal, the second instrument, the Grayson, has been useful to help mobilize and essentially feed the phacoemulsification handpiece.
And here we have the last quadrant, and it's important to be careful at this stage with the last quadrant as the posterior capsule can be very floppy. And, with any post occlusion surge, the posterior capsule can move anteriorly and be popped by the phacoemulsification - phacoemulsification handpiece. As we were able to achieve good hydrodelineation in this case, epinuclear shell was then removed on the epinuclear setting on the phacoemulsification machine. Now the nucleus and the epinucleus has been cleared from the capsular bag.
Irrigation-aspiration handpiece is introduced to remove the cortical remnants. I like to go after the subincisional cortex first as the residual cortex - fill in the capsular bag, tends to help hold the posterior capsule back. So, as you can see, I’m - I've turned the port down. You'll notice that I have quite long capsular tags. This is intentional as I didn't do any central cortical cleanup prior to initial phacoemulsification. That helps me to facilitate cortical cleanup, especially with the subincisional cortex. So, we slowly make our way around, clearing up the cortex 360 degrees.
Now we inspect the posterior capsule and do see some lens epithelial cells persisting on the posterior capsule. So, I'm doing a little bit of mechanical polishing with the irrigation-aspiration handpiece. And here I've - despite the mechanical rubbing, some of the lens epithelial cells persist, so I turn the port down. I do attempt to polish, but posterior capsule came up to the port a bit - so I elected to switch to a Nightingale capsular polisher. This is done without any viscoelastic, and this does a very nice job of removing any central lens epithelial cells.
Following completion of capsular polish, inject a cohesive viscoelastic to fill the capsular bag. And this creates the appropriate amount of space for the lens - for the injection of the lens implant.
Here, I'm injecting a one-piece acrylic intraocular lens with a wound-assisted technique. And I like to inject the lens directly into the capsular bag. Here, I'm using a Kuglen Hook to ensure that the lens and the haptics are completely in the capsular bag, and I use the Kuglen hook to center the lens properly. I like to keep my lens haptics with these 1-piece acrylic lenses with the square edge at the 3- and 9-o'clock positions to try to limit any chance of negative dysphotopsia postoperatively.
Following centration of the IOL, automated irrigation aspiration is used to remove the remaining viscoelastic material. Here, I'm cleaning - clearing the anterior chamber of both the cohesive and any leftover dispersive viscoelastic. I'm tilting and tapping the IOL to remove or capture any of the viscoelastic that might be trapped behind the intraocular lens. I also like to sweep the angles for any dispersive viscoelastic.
Now, the case is completed. We're - I am reforming the anterior chamber and hydrating the temporal corneal incision. A little hydration of the paracentesis as well. Checking the ocular tensions. It's a little soft so, inject a little bit more balanced salt solution. Then, checking the incisions with the Weck-Cel.
I like to press on the posterior wound edge. Here we see a little bit of an egress of BSS - so a little bit more stromal hydration. Again, checking the tension. And, again the Weck-Cel’s to check for any leakage at the temporal wound. And a little bit of pressure when it appears dry. One last check of the tension. The - I was a little bit firm, so burp in the paracentesis to release a little bit of balanced salt solution. One last check of the wound. Both the temporal incision and paracentesis appear to be watertight. We remove the lid speculum. The drapes are removed, and then the eye’s dressed with antibiotic/steroid ointment, and a soft patch, and hard shield.
We'll be doing a surgery today with an Alcon infinity machine, and we'll be using 2.5 mm incision. And for my second instrument, I'll be using a Grayson spatula. I like to use that instrument because it's got sort of a wide-flat end to it without any sharp edges. So, for this particular technique, it's particularly useful because I won't be needing to do - be doing any chompings; primarily, I'll be using it for lens manipulation, rotation, and splitting. And so, it's an excellent instrument for that purpose.
Hydrodissection in any phacoemulsification technique is very important. Good rotation of the lens nucleus is critical for lens manipulation and reducing zonular stress. It allows for better stability of the capsular lens complex and positioning of the implant, so it really decreases the risk of - of complications by having good hydrodissection. After that, you know, for this particular technique, a good deep central groove, I find, is more important than having long grooves, so the thickest part of the lens is centrally. So here, a good deep central groove is really critical to get through any dense posterior plates that might be in the nucleus, and it will allow good propagation of your nuclear cracking. The other tip that I would suggest is before the initial groove, instead of doing a little bit of cortical cleanup, to leave the cortical tags there after all the nucleus is removed. Those long cortical tags really help to facilitate cortical remove, especially the sub-incisional cortex.
I'll be using a one-piece acrylic lens. It's the AMO Technis one. I like to use it because of the ease of injection, and the way that it sits in the capsular bag is very nice. It has good optical quality and a good stability, and the design with the square edge is thought to really minimize the risk of posterior capsule opacity.
Phacoemulsification machines are quite efficient. The fluidics are quite good. There - I'm sure the - there will continue to be small incremental changes in the efficiency and the fluidics of the machines, but phacoemulsification seems to sort of stabilize in its advancements in terms of the ultrasound technology itself. The improvements I feel will be more related to the - the fluidics and s - the stability of the fluids within the eye during the surgery. As far as, you know, what we have available where the future lies in supplements to the surgery to improve our outcomes, I mean, there are several things that are available - several technologies that are already available that can help to improve our outcomes and safety of our surgeries. Intraoperative aberrometry is really become an important tool in our ability to predict or improve upon the predictability of our outcomes. This allows us to obtain real time data after the cataract has been removed to confirm the power of our lens implants. And there also - these aberrometers can also help us to align any astigmatic correction that we're planning to use as well. Additionally, femtosecond have been incorporated into cataract surgery as well. Again, to try to improve upon the safety profile of already an extremely safe procedure by improving the reproducibility of the capsulotomy as well as decreasing the use of ultrasound by presoftening the lens nucleus.
Patients are typically on topical medications for approximately one month. These include an antibiotic drop, topical nonsteroidal, and a topical steroid. Most patients will have some limited physical activity - no heavy lifting or straining. Generally, I tell my patients not to lift anything of more than 5 or 10 pounds for at least the first week - first month would be preferable. Try not to have them get any water in the eye or - really critical is that they don't rub their eyes during the procedures. And we have them wear a shield at nighttime for the first week or two, also - just when they're sleeping at night to try to limit any sort - unintended trauma while they’re sleeping at night.