Patients needing glaucoma surgery may also be candidates for a combined procedure with cataract removal and IOL implantation. For a variety of reasons, cataract surgery may present challenges in eyes with glaucoma. Alan S. Crandall, MD, provided cases to demonstrate the complexities encountered when performing cataract surgery in glaucoma patients and strategies for achieving successful outcomes.
Patients needing glaucoma surgery may also be candidates for a combined procedure with cataract removal and IOL implantation. For a variety of reasons, however, cataract surgery may be challenging in eyes with glaucoma.
Alan S. Crandall, MD, provided a sampling of cases to demonstrate the complexities encountered when performing cataract surgery in glaucoma patients and strategies for achieving successful outcomes.
“Considering the number of combination cases we perform, I have always felt that glaucoma surgeons should also be the best cataract surgeons,” said Dr. Crandall, professor and senior vice chairman of ophthalmology and visual sciences, and director of glaucoma and cataract at the John A. Moran Eye Center, University of Utah, Salt Lake City.
Videos from cases with pseudoexfoliation and traumatic glaucoma highlighted the potential for encountering eyes with weak, loose, and missing zonules. In eyes with traumatic glaucoma, Dr. Crandall cautioned that the extent of the zonular dialysis is probably much greater than what is initially perceived.
“In eyes with trauma, the area of zonular dialysis is probably doubled or tripled,” Dr. Crandall said. “If you see 100 degrees of dialysis, you can expect at least 2 clock hours of additional involvement on the other side.”
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The likelihood of zonulopathy in eyes with glaucoma and pseudoexfoliation or a history of trauma emphasizes the important role of capsular-support devices for enhancing surgical safety and maintaining capsular and IOL stability postoperatively in these cases. Dr. Crandall presented the use of various temporary and permanent devices.
He noted that capsular tension rings (CTR) should not be used in the presence of an anterior capsular tear or posterior capsular rent. However, by performing a posterior capsulorhexis, a central posterior capsular rent can usually be converted into a circular tear to allow placement of the CTR without placing stress on the area of weakened zonules.
Alan S. Crandall, MD, discusses the complexities encountered when performing cataract surgery in patients with glaucoma.
Discussing the timing of inserting a CTR, Dr. Crandall quoted Ken Rosenthal, MD, who said it could be done “as late as you can and as early as you need it.” Insertion prior to phacoemulsification has the advantage of improving nuclear stability, but may be difficult in the presence of a very dense nucleus.
Early CTR placement will also make lens rotation and cortical removal more challenging. With those limitations, Dr. Crandall said his preference is to place the CTR as late as possibly, while employing one of the temporary devices earlier that will provide capsular bag support and not interfere with phacoemulsification.
In terms of the temporary devices, Dr. Crandall favors the capsular hooks from MicroSurgical Technologies and in the Mackool Cataract Support System (Impex Surgical). He often finds a need for using a Cionni modified CTR (Morcher) when performing cataract surgery in eyes with glaucoma. The most common scenarios are eyes with pseudoexfoliation or that had previous retinal or glaucoma surgery. In addition to providing stabilization, the Cionni modified CTR has integrated eyelets that allow for suture fixation to the sclera. Therefore, its presence proves valuable in cases where secondary IOL repositioning surgery becomes needed.
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Dr. Crandall noted that a newer version of the CTR (type 1G) is significantly easier to place into a loose capsular bag because it is preloaded, and it also makes scleral IOL fixation easier.
In discussing considerations for performing specific steps of the procedure in eyes with zonulopathy, Dr. Crandall said that when performing manual capsulorhexis, the direction of the tear should always be toward the area of weakness. However, he observed that femtosecond lasers have emerged as a helpful tool for achieving safe and effective capsulorhexis in these cases.
Laser treatment is also the most capsular bag friendly technique for facilitating safe cataract removal in eyes with hard nuclei. The next best method is pre-chopping, using an ultrasonic chopper that attaches to a standard phaco tip (Ultrachopper, Alcon), which is followed in descending order by vertical chop, horizontal chop, and then, divide and conquer.
Dr. Crandall noted that particular care must be taken when rotating the lens in eyes with a loose capsular bag. He recommended using a bimanual technique to minimize stress. He also advocated a tangential approach (“hurricane method”) for cortical cleaning, as it is faster and gentler to the zonular apparatus compared with radial stripping.
He also pointed out that because of multiple reasons, including the development of posterior synechiae, chronic use of miotic medications, chronic angle closure, presence of pseudoexfoliation, and a history of trauma, poor pupil dilation is common in eyes with glaucoma undergoing cataract surgery. Therefore, surgeons should be skilled in pupil expansion techniques, including the use of the range of mechanical modalities that are now available.
Dr. Crandall noted his preferred device is the Malyugin Ring (MicroSurgical Technology). He also showed a video underscoring that when releasing posterior synechiae, the adhesions must be broken all the way out to the periphery and not just at the pupillary margin.