Bag-in-the-lens inventor reviews long-term outcomes, new developments
BIL also offers opportunities for special cases, such as abnormally large eyes and pediatric cataract.
With more than 20,000 procedures performed worldwide and a follow-up of almost 12 years, bag-in-the-lens cataract surgery has proven to be a successful technique, with no cases of posterior capsule opacification, even in unusual cases.
OSN Europe Edition Associate Editor Marie-José Tassignon, MD, PhD, who developed this method of cataract surgery with IOL implantation, has a personal experience of approximately 10,000 cases, performs bag-in-the-lens (BIL, Morcher) routinely and has patients come from all over Europe to be implanted with her technique.
“There are centers performing BIL surgery in most European countries, Canada, Brazil, Australia, India and South Africa. None of the patients who was successfully implanted, with both capsules properly secured in the IOL groove, have developed PCO. We have stopped using the YAG laser since the adoption of this lens,” Tassignon said.
As opposed to a conventional lens-in-the-bag approach to cataract surgery, after anterior and posterior capsulorrhexis, both capsular leaves are inserted within a groove that circumferentially surrounds the lens haptic. With the capsule sealed within the lens, migration of lens epithelial cells is prevented.
What is new with BIL
Recently, the use of intraoperative microscope-integrated OCT allowed direct visualization of the capsulo-hyaloidal interspace known as Berger’s space.
“What was considered to be a virtual space behind the lens is in fact a real space. We could also observe that the ligament of Wieger, which attaches the anterior hyaloid to the lens, has become loose in some cases,” Tassignon said.
These findings, she said, are important and give new insights into the anatomy and physiology of the anterior segment of the eye.
“We should reconsider the anterior segment, or even the anterior chamber as a whole, as one big compartment between the posterior cornea and the anterior hyaloid, filled with the same liquid with the same concentration. During accommodation, the posterior part of the lens is getting more bulged than the anterior part, and this is possible because of the space of Berger. These new findings should convince BIL skeptics that the posterior lens flanges rest in the Berger space, optimally used to guarantee PCO-free postoperative results,” Tassignon said.
Patients who do not have adequate capsular or zonular support can benefit from the use of specially developed bean-shaped rings (Morcher) that provide capsular tension over the defective area and support to the BIL IOL.
“The inner side is positioned in the groove of the lens, and the outer side can be positioned in the sulcus. In some rare indications, it can be glided in between the two leaves of the capsular bag after they have been emptied of lens material and opened with anterior and posterior CCC, to re-stretch the capsular bag,” Tassignon said.
Bean-shaped rings have been successfully implanted by Tassignon in more than 100 patients, including outlier cases such as those with megalophthalmos.
“One patient had a white-to-white of 15 mm. These eyes are very rare. We had to adapt the size of the rings, and it worked very well. It’s nice to have something for patients in which a traditional IOL cannot fit. BIL was the only lens that could be implanted, and we had remarkable results,” she said.
Long-term follow-up of BIL in pediatric patients is the topic of two papers that will soon be published. Children are a relatively small cohort, about 400 cases altogether, approximately 50 per year now in Tassignon’s department. Long-term stability and no PCO have been found, as well as a lesser myopic shift compared with other IOLs.
“Our children don’t have the extreme myopization that you find with traditional lens implantation, and this is because our technique preserves the lens epithelial cells in their original state. LECs keep the capsular bag transparent and flexible while it continues to grow,” Tassignon said.
Another study already accepted in the Journal of Cataract and Refractive Surgery deals with the rate of retinal detachment after BIL in a 5-year follow-up. The cumulative rate turned out to be similar if not better than with lens-in-the-bag implantation. Further studies are needed to confirm these data. – by Michela Cimberle
- For more information:
- Marie-José Tassignon, MD, PhD, can be reached at Antwerp University Hospital, Wilrijkstraat 10, 2650 Edegem, Antwerp, Belgium; email: email@example.com.
Disclosure: Tassignon reports she has intellectual property in BIL ring caliper and bean-shaped rings (Morcher). She also reports she is a consultant for Théa and Carl Zeiss Meditec.