Ability to maneuver without entering the eye a plus in some difficult cataract surgeries
Use of the femtosecond laser is enabling safe cataract surgery in difficult clinical situations, including eyes with white intumescent cataracts and those with zonular dialysis.
By Cheryl Guttman Krader; Reviewed by Robert J. Cionni, MD
Salt Lake City-The advent of femtosecond laser technology for cataract surgery is helping to improve the safety and efficacy outcomes in a variety of complex situations.
Robert J. Cionni, MD, presented videos to illustrate use of a proprietary femtosecond laser (LenSx, Alcon Laboratories) in two challenging cases. One eye had a white mature cataract and the second was a post-trauma case with marked zonular dialysis and a dense lens, explained Dr. Cionni, medical director, The Eye Institute of Utah, Salt Lake City.
The femtosecond laser was used in both cases to create the capsulotomy and corneal incisions, and it was used to perform lens fragmentation in the eye with zonular dialysis. The device could not be used with the white cataract, because the laser energy does not penetrate very deeply into the opaque lens material. However, its use for capsulotomy in the latter case was an advantage, Dr. Cionni noted.
“Typically, when performing capsulotomy in eyes with white intumescent cataracts, the fear is that the increased intralenticular pressure will cause the capsule to splay out,” Dr. Cionni said. “Using the [femtosecond] laser to open the capsule, without ever opening the eye, allows the natural anterior chamber pressure to counteract the intralenticular pressure and results in a beautiful capsulotomy without any radial tears.
“I have used the [femtosecond laser] system in this situation about a dozen times with consistently good results,” he said.
When operating on the eye with the white cataract, trypan blue was instilled to aid visualization of the capsule as Dr. Cionni inspected the laser cut to make certain it was complete. An ultrasonic chopper (Ultrachopper, Alcon) was used to divide the nucleus into quadrants, and the patient received a toric IOL with a good refractive result.
In the post-traumatic case, the ability to use the femtosecond laser to create the capsulotomy and fragment the lens without entering the eye offered advantages. Benefits included ensuring a complete and intact capsulorhexis and allowing for the surgery case to be completed with reduced zonular stress. The video from the femtosecond laser portion of the procedure showed how the laser not only was able to cut through the anterior capsule, but also through vitreous that had prolapsed from the original trauma.
In the operating room, the vitreous was removed with a bimanual anterior vitrectomy approach. The anterior chamber was filled with viscoelastic prior to removing the cut portion of the anterior capsule. Hydrodissection was performed to free the lens successfully. Instillation of ample viscoelastic enabled forward manipulation of the nuclear pieces created by the femtosecond laser fragmentation and safe removal.
“Notice the stability of the anterior chamber and uneventful cortex removal thanks to the use of hydro- and viscodissection,” said Dr. Cionni in his narration.
The case also involved placement of a capsular tension ring and sutured capsular tension segment that afforded a stable, well-centered capsular bag and allowed successful implantation of a multifocal IOL. Pupillary mydriasis was addressed with a single modified Siepser suture.
Robert J. Cionni, MD
Dr. Cionni is a consultant to Alcon Laboratories. This article is adapted from Dr. Cionni’s presentation during the Spotlight on Cataracts session at the 2012 annual meeting of the American Academy of Ophthalmology.