JAN 2014

EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.

Issue link: https://digital.eyeworld.org/i/233841

Contents of this Issue


Page 38 of 66

36 EW FEATURE February 2011 Phaco and vitrectomy January 2014 Limbal, pars plana approaches useful in complicated cataract cases by Erin L. Boyle EyeWorld Senior Staff Writer AT A GLANCE • Both pars plana and limbal approaches can be effective for different cases. • The limbal approach might provide a better comfort level to anterior segment surgeons. • The pars plana approach has many advantages but is potentially more difficult for anterior segment surgeons. • Refer to retina specialists for the following: posterior dislocation of large cataract fragments or the IOL, suspected retinal tear or detachment, or choroidal hemorrhage. Cataract surgeons should know how to proceed for best results with either a limbal or pars plana approach W hen cataract surgeons encounter posterior chamber (PC) rupture and vitreous loss, deciding whether to use a limbal approach vs. a pars plana approach in a vitrectomy procedure depends on the specifics of the case, experts say. "It's not which do you do, it's when do you do either one or the other. It depends on the situation," said Garry P. Condon, MD, associate professor, College of Medicine, Drexel University, Pittsburgh. "I think it behooves us as anterior segment surgeons in this day and age with the beautiful instrumentation that we have now to do [both] so that we can be comfortable." Cataract surgeons should be prepared for these complications to happen at any time, with instrumentation and additional viscoelastic agent readily at hand to proceed, he said. The many advantages of using small gauge vitrectomy probes have enhanced the process, Dr. Condon said, including for cataract surgeons. Vitreous loss after posterior capsule rupture, pictured here, can be cause for an anterior vitrectomy using one of two approaches, either limbal or pars plana. Source: David Allen, FRCOphth The limbal approach provides access through the conjunctiva at the limbus or the corneo-scleral junction. The pars plana approach allows access to the vitreous through the pars plana, which is 3–5 mm behind the corneal limbus. Both approaches have advantages, physicians say. "Vitreous loss for the anterior segment surgeon can obviously be a stressful experience, but an event all cataract surgeons face at some point in their career. Being prepared can improve the patient's outcome and reduce the surgeon's anxiety," said Howard F. Fine, MD, clinical associate professor, Rutgers University, Robert Wood Johnson Medical School, New Brunswick, N.J. Dr. Fine is a retina specialist. For cataract surgeons, there can be real dangers in addressing these cases, said cataract specialist Steven H. Dewey, MD, Colorado Springs Health Partners. "Anyone who is not fully trained in retinal procedures has the concern of incarcerating vitreous in the pars plana incision," Dr. Dewey said. "Or iatrogenic retinal tears. These are things that don't happen with a tremendous amount of frequency but certainly can." What to do A cataract surgeon's first step when encountering PC rupture and vitreous loss during cataract surgery should be to determine precisely what is happening, Dr. Dewey said. "Determining which approach is going to be better, I assess how far along in the process of damage things have gone," Dr. Dewey said. "If the tear is very small but the vitreous prolapse is significant and it's going to impede my ability to place the lens implant in the capsulorhexis, many times it's just a matter of getting it in the sulcus with vitreous strands coming through the pupil; then the first decision is, you go to the pars plana." Dr. Condon also suggested assessing the situation to determine how to best move forward and which approach to choose. He said to not immediately pull out the phacoemulsification instrument if you see capsular rupture vitreous presentation. Instead, stop. Stabilize the situation with viscoelastic agent. Then remove the phaco instrument. "I assess what's really happened, and how can I salvage what I'm left with and make the best possible outcome for this patient. That's the difference between being comfortable at that point and proceeding, versus thinking, 'I just want to get out of here,'" Dr. Condon said. Then, move on to determine the full situation, he said. "Look at what you have to deal with and say, 'I want to go through the pars plana here because I have a bunch of vitreous up here extending into the anterior chamber wound,'" Dr. Condon said. "That's versus, 'I think I have a little small opening in the posterior capsule; I'm going to tamponade that with some viscoelastic, maybe put the lens in the eye because I have good enough capsule support or zonular support to do that.'" "Then at the end, it's a microclean up, which might be a perfectly appropriate time to remove viscoelastic with a vitrector from the anterior chamber, and remove any little strands of vitreous," he said. This is where a 23-gauge limbal vitrectomy incision has advantages, he said, because "you don't want to go in with high aspiration flow rates to remove residual viscoelastic for fear of inviting more vitreous prolapse." Vitrectomy instrumentation is highly effective at removing viscoelastic agent in cases that are pre- carious and where further vitreous prolapse has to be avoided, he said. Dr. Fine said that if the cataract surgeon thinks that vitreous loss has occurred, he should take a moment to create a plan of action. Stabilize the eye with adjunctive tools, which could include viscoelastic to hold the vitreous back, triamcinolone acetonide to show vitreous, and a capsular tension ring for capsular bag stabilization. But if the cataract surgeon is not comfortable with the outcome of the situation, the next step is to seek assistance, Dr. Fine said. "Prompt referral to your retina colleagues is advisable if there is posterior dislocation of large cataract fragments or the IOL, suspected retinal tear or detachment, or choroidal hemorrhage," he said. Referring can be a good idea with some cases using the pars plana approach, Dr. Dewey said. "I think what's most important is if a pars plana approach is performed, then either the operating surgeon needs to be comfortable with a good peripheral retinal examination or refer the patient to someone who is." Two approaches For the limbal approach, cataract surgeons are often more comfortable because of introducing surgical instruments through corneal incisions, Dr. Fine said. "There is direct visualization of the vitrectomy probe at all times. Utilize a biaxial approach, with the infusion and vitrectomy probe separate," he said. For the pars plana approach, cataract surgeons can be a little less comfortable, but it has many advantages, including: "The vitreous is drawn posteriorly, minimizing vitreous incarceration in the corneal wounds. Vitreous and retained lens fragments can be more easily removed posterior to the capsule without risking further capsular damage. Posterior levitation of subluxing lens fragments and removal with the cutter can be performed, albeit with caution," Dr. Fine said. There are dangers to this approach, he said, especially for those continued on page 38

Articles in this issue

Archives of this issue

view archives of Eyeworld - JAN 2014