Washington, DC—If capsule bag fixation is not possible, cataract surgeons have several options for IOL optic capture depending on the particular surgical needs, explained Howard V. Gimbel, MD, MPH, professor and chairman, department of ophthalmology, Loma Linda University, Loma Linda, CA.
Washington, DC-If capsule bag fixation is not possible, cataract surgeons have several options for IOL optic capture depending on the particular surgical needs, explained Howard V. Gimbel, MD, MPH, professor and chairman, department of ophthalmology, Loma Linda University, Loma Linda, CA.
Optic capture can be defined as "haptics and optics on different sides of a tear-resistant opening in the capsule," he noted. Optic capture provides optic centration, IOL fixation away from the iris, and a barrier to vitreous migration through capsule openings, emphasized Dr. Gimbel during a symposium on phacoemulsification techniques at the American Society of Cataract and Refractive Surgery annual meeting.
In the case of large posterior capsule tears before IOL implantation, rhexis fixation is a possibility with the haptics and lens in the sulcus and the optic pushed through the anterior CCC.
If the lens has already been placed in the capsular bag and a large tear develops in the posterior capsule, the surgeon can pull the optic out of the capsule, so that it can be captured by the anterior CCC to ensure fixation. This prevents the lens from dropping into the vitreous, he said.
In pediatric cases, optic capture utilizing a posterior CCC has been successful in preventing visual axis opacification postoperatively without the need of vitrectomy, he said.
"This technique may be lens-dependent," he noted. "A three-piece lens should be used instead of a one-piece lens because a very narrow haptic/optic junction may be critical to getting a tight wrap of the capsule around the loop to prevent Elschnig pearls from getting behind the IOL and clouding the visual axis by spreading across the vitreous face."
In one case of secondary cataract in a patient treated for retinoblastoma, there has been no opacification of the visual axis even though the surgery was performed 12 years ago using this technique with no vitrectomy.
Optic capture with posterior CCC also is an option if there are large anterior capsule tears or multiple tears, and the surgeon is certain that IOL implantation in the bag is not possible.
"One can do a posterior capsulorhexis, place the lens in the sulcus, and push the optic through the posterior capsule to capture and stabilize the IOL without the risk of the lens swimming in the sulcus," he said.
In the case of a fused capsular membrane in postoperative cases, the surgeon can push the lens optic through the opening of the membrane if it is slightly smaller than the optic.
"We have used this technique for repositionings, removal and replacement, and unstable sulcus lenses even though they are centered," Dr. Gimbel noted.
If the lens has fallen into the vitreous after vitrectomy and is dangling, the surgeon can try to push the lens optic back through the anterior CCC or the membrane opening.
"If the membrane opening is of the right size, it will capture the lens and stabilize it without suturing," he said.
These techniques can help surgeons obtain IOL centration and stability in the absence of capsule bag fixation, he said.