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Pre-chopping is effective for managing soft cataracts
The lens is dissected in two to four pieces, increasing mobility before the phaco tip is inserted into the eye.
NEW YORK — Pre-chopping is an effective means of managing softer cataracts, according to cataract/IOL subspecialist and teacher David Dillman, MD.
Dr. Dillman said he uses this technique, originally introduced in 1993 by Japanese ophthalmic surgeon Takayuki Akahoshi, MD, in about 25% of his cases. He described the benefits of the pre-chop technique here at the Ninth Annual Ocular Surgery News Symposium.
There are actually three separate pre-chopping techniques, said Dr. Dillman. He spoke about the one that is suited for soft cataracts, which he finds the most “stressful” to eliminate. Dr. Dillman uses an instrument called the Universal Prechopper (ASICO), which consists of two paddles attached at the nonpaddle end by a pair of hinged jaws, to dissect the lens into two to four pieces before introducing the phaco instrument into the eye.
“The basic idea is to get the pre-chopper kind of in the middle of the lens, and then separate the ‘paddles’ and split the lens into at least two pieces,” Dr. Dillman said. “This is preceded by excellent hydrodissection, so you have very good mobility. So before you ever put the phaco in the eye, there will be at least two free, loose and mobile pieces, which I find very comforting.”
Common sense approach
To do pre-chopping, Dr. Dillman pointed out surgeons need to understand several common sense matters. First, the lens has to be mature enough to have an identifiable endonucleus. Second, if resistance is met when the pre-chopping instrument is placed in the center of the endonucleus, the maneuver should be aborted.
“The ideal nucleus for pre-chopping is, for example, a grade two, with a posterior subcapsular cataract type of lens,” said Dr. Dillman. “As you try to put the pre-chopper into this endonucleus, if you encounter resistance you want to abort that case because the eye is kind of talking to you. If you listen to it, it is telling you, ‘I’m not quite as soft as you thought I was.’ Therefore, you’re going to put some stress on the zonules trying to put this pre-chopper into the eye. So, if it goes easily into the endonucleus, great. If there is resistance, then abort it and go to your routine phaco technique,” said Dr. Dillman.
Dr. Dillman stressed the importance of having an identifiable endonucleus. “If it is too soft, it is possible that you can go all the way through the endonucleus, especially if there is not much of a nucleus, and actually disrupt the posterior capsule,” he explained.
Pre-chopping technique
Dr. Dillman described his pre-chopping technique. “I put the Universal chopper into the center of the endonucleus and then open the jaws.” He said. “If I can see an intact posterior capsule, I know I was successful. But if I only went partially through and I don’t see the posterior capsule, then I take the pre-chopper and put it down to the bottom of the groove, making sure not to go any deeper because that would threaten the posterior capsule.”
The good news, he said, is that the learning curve for pre-chopping is short. It didn’t take him long to master the technique enough to consistently produce two pieces. “Once I learned that, I thought I’m going to go ahead and take the two halves and split them into quarters. But to be honest, the vast majority of the time if I can get it into two halves, then I’m content to go ahead and then just complete the case with my fastball technique, which is quick chopping,” said Dr. Dillman.
For Your Information:
- David M. Dillman, MD, can be reached at Dillman Eye Center, 600 N. Logan Ave., Danville, IL 61832; (217) 443-2244; fax: (217) 443-6779. Dr. Dillman has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.