June 2019

CATARACT

YES Connect
Gaining experience to manage zonulopathy


by Liz Hillman EyeWorld Senior Staff Writer


Samuel Lee, MD

According to the results of the 2018 ASCRS Clinical Survey, the majority of ophthalmologists in residency training report that they are not comfortable managing a case with zonulopathy. Many report not having used tools such as capsular tension rings or hooks during their training. This seems to change in fellowship and the first 5 years in practice, but the question remains: Should we be preparing our resident surgeons to deal with zonular deficiency during their residency training? If so, how much training is appropriate? In this month’s YES Connect column, we interview two attending surgeons who routinely train resident cataract surgeons and have significant experience dealing with zonular issues.

—Samuel Lee, MD,
YES Connect co-editor

 


A Sinskey hook can be used to guide the leading eyelet of a capsular tension ring so it does not stress the weakened zonules during insertion.
Source: Naveen Rao, MD

Residents should be able to place iris hooks and pupil expansion rings by the end of their training, said Naveen Rao, MD.
“I’d consider these to be part of the basic skill set for a competent cataract surgeon,” he added. “Capsular hooks, capsular tension segments, and capsular tension rings are a different story, though, since their use is much less common.”
In general, the 2018 ASCRS Clinical Survey reflects this sentiment. It found that 59% of residents had not used hooks, rings, or segments. In fact, only 14% of residents reported being confident in managing zonulopathy. Fellows were more confident (32% were confident in managing zonulopathy), and nearly half (49%) of those within their first 5 years of practice were confident in management of loose zonules. The use of rings, hooks, and pupil expansion devices among fellows and those in their early years of practice was more common than that reported by residents.
Uday Devgan, MD, said that residents should be exposed to a wide range of cataract cases in training, including those where capsular support hooks or tension rings are used. A sewn-in capsular segment is something that could be handled by a senior resident under the guidance of a more senior-level ophthalmologist, he said.
“Residencies and fellowships will span the spectrum with some providing much more surgical experience than others,” Dr. Devgan said. “Ultimately, the surgeon in training reaps what he sows, and those who work hard and hunt for good cases from which to learn will do best.”
Even if experience with these devices in training is limited, knowledge in how to use them is important. Skills transfer sessions at conferences are a great way to gain experience, Dr. Rao said, as is working under direct supervision of an experienced surgeon who can provide pearls.
“Watching YouTube videos is also helpful, but especially with capsular tension segments, there is a steep learning curve,” Dr. Rao said. “It helps to understand how to position the segment in the Z-axis, and this is only possible when looking through an operating microscope. Three-dimensional video recording is now possible with Alcon’s NGENUITY device, so this could be a promising new way for experienced surgeons to teach these techniques to surgeons who can’t join them in the operating room or in the wet lab.”
Dr. Devgan advised finding a mentor in your area, asking them for advice often, and even considering working with a more experienced surgeon on more complicated surgeries.
How to manage only a small amount of zonular dialysis versus global zonular weakness varies. When there is only 1 clock hour of zonular dialysis, Dr. Rao prefers placing a three-piece IOL with the haptics oriented in the direction of the missing zonules. Dr. Devgan said he will do the same thing, provided the zonular laxity is not expected to progress.
When there are 3–4 clock hours of zonular dehiscence, which occurs frequently, Dr. Rao said he places a capsular tension ring followed by a single-piece or three-piece IOL in the capsular bag.
In cases of diffuse zonular weakness (more than 4 clock hours), if he thinks the bag can withstand manipulation, Dr. Rao said he places one or two capsular tension segments sutured to the sclera, then uses a capsular tension ring to expand the bag, and places a single- or three-piece IOL in the bag. If there is a focal posterior capsular tear with intact zonules, he usually places a three-piece IOL in the sulcus with optic capture. However, if there is an anterior capsular tear that extends around posteriorly, especially if that tear occurs inferiorly, he prefers to not place the IOL in the sulcus because it is more likely to dislocate inferiorly through the zonular defect. In these situations, he arranges for a vitreoretinal colleague to perform a pars plana vitrectomy, followed by his placement of a scleral-fixated IOL using the Yamane intrascleral haptic fixation technique.
“Pseudoexfoliation is a global and progressive process where we can expect future weakness,” Dr. Devgan said. “In many cases, nothing special may be needed, such as the situation of a nonagenarian patient with reasonable capsular support. This patient is likely to pass away prior to suffering late dislocation of the capsular bag-lens complex. In other patients, placement of a capsular tension ring can be helpful, but it will not prevent future weakening of the zonular support. You must tailor the approach to the patient.”
Overall, Dr. Rao said he thinks that residents should have direct experience inserting iris hooks and pupil expansion rings in training, but becoming proficient with capsular hooks, tension segments, and tension rings requires significantly more surgical experience.
“If you don’t feel comfortable rescuing the bag, there is nothing wrong with leaving the patient aphakic and referring them to an anterior segment surgeon experienced with these techniques,” Dr. Rao said. “Just do a good anterior vitrectomy, if needed, and suture your main incision. I would not recommend putting in an anterior chamber IOL anymore. … It’s better for the patient to be left aphakic for a few days or weeks and have a secondary IOL implantation with a scleral-fixation technique once the eye settles down a bit.”
Dr. Devgan, who still teaches his residents how to use anterior chamber lenses, said, “A well-placed anterior chamber IOL can have the same visual performance of an iris-sutured or scleral-fixated posterior chamber IOL. Ultimately the surgeon should have a wide range of options and do what is most compatible with the eye.”

About the doctors

Uday Devgan, MD
Clinical professor of ophthalmology
Jules Stein Eye Institute
University of California,
Los Angeles

Naveen Rao, MD
Lahey Hospital and Medical Center
Burlington, Massachusetts

Financial interests

Devgan
: CataractCoach.com
Rao: None

Contact information

Devgan: devgan@gmail.com
Rao: naveen.k.rao@lahey.org

Gaining experience to manage zonulopathy Gaining experience to manage zonulopathy
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