R E S E A R C H U P D AT E
New studies show cataract surgery incorporating IOLs or devices keeping the capsular bag open/expanded rather than having the “shrink wrap” effect of the capsule around the IOL optic (human eye shown on the right) may be more effective in preventing posterior capsule opacification (PCO). The arrows (top left) show the difference in fibrosis at the edge of the capsulorhexis between a rabbit eye with an open/ expanded-bag IOL, and an eye with a standard IOL. The Miyake-Apple views (bottom left) show the difference in PCO formation.
The Open/Expanded-Bag Intraocular Lens Concept A recent study from the Intermountain Ocular Research Center adds evidence that intraocular lenses (IOLs) and devices used in cataract surgery that keep the capsular bag open and expanded, instead of tightly collapsed around the IOL, are associated with improved bag clarity. Cataract surgeons use an anterior capsulotomy technique called capsulorhexis, which essentially “shrink wraps” the capsule around the IOL optic. The performance of a capsulorhexis with a diameter smaller than the diameter of the IOL optic was one of several techniques described in the early 2000s to reduce posterior capsule opacification (PCO), the most common cataract surgery complication that requires further intervention to correct. PCO, known as a secondary cataract, occurs when leftover lens epithelial cells (LECs) accumulate and proliferate in the lens capsule after surgery and cloud vision. New studies show cataract surgery incorporating IOLs or devices that keep the capsular bag open/expanded may be even more effective in keeping the bags clear and preventing PCO, according to recent presentations by Nick Mamalis, MD, and Liliana Werner, MD, PhD, co-directors of the Intermountain Ocular Research Center based at the Moran Eye Center.
In a video presentation at the 2023 American Society of Cataract and Refractive Surgery (ASCRS) conference, the center shared results from tests of several experimental openbag concept lenses showing improved bag clarity. “PCO preventative effects may be a result of a combination of mechanisms, such as better blockage of residual LECs at the equatorial region of the bag by the 360-degree haptic ring design feature of some lenses, maintenance of a more physiological shape and geometry of the capsular bag postoperatively, and possible roles of molecular factors on LEC proliferation,” Werner wrote in the October 2022 edition of the Journal of Cataract & Refractive Surgery. Werner wrote that aqueous flow within the inner compartment of the capsular bag is also being investigated as a possible factor. “Interactions between the capsular bag and IOLs fixated within it are complex and will continue to have an impact on IOL manufacturing as our knowledge of those interactions increases,” noted Mamalis in the video presentation. LEARN MORE Scan to view the award-winning ASCRS video, “The Key to Clarity: The Open/Expanded-Bag IOL Concept.”
