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Twist technique to explant an IOL
This easy method allows the intact removal of an IOL through the original incision without special instruments.
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For more than 99% of patients, the IOL that is implanted at the time of cataract surgery will be in place forever. However, there are rare occasions when we need to explant or exchange an IOL, and ideally, we want to be able to do this via the same small incision that was used for the original procedure.
With modern cataract surgery, most ophthalmologists are using a phaco incision between 2 mm and 3 mm, with 2.4 mm and 2.8 mm widths being common. Because the optic diameter of most IOLs is 6 mm, we will need to find a way of cutting or compressing the IOL to remove it from a smaller incision. The first step is bringing the old IOL out of the capsular bag and into the anterior chamber where it can be manipulated.
Dissection of the IOL
Source: Uday Devgan, MD
To dissect the old IOL from the capsular bag, we need to create a gap between the optic face and the edge of the overlapping anterior capsular rim. Using a technique that I gleaned from Garry Condon, MD, I put a sharp 27-gauge needle on my dispersive viscoelastic and slide it under the edge of the capsulorrhexis. Once it is partially under the capsule edge, I inject a small aliquot of dispersive viscoelastic and then repeat the process. Once the gap has been widened, replace the needle with the standard 27-gauge blunt cannula and then viscodissect the posterior face of the optic free from the posterior capsule. Carefully separate the anterior and posterior capsule leaflets from each other using more viscoelastic. At this point, the IOL should be free from the capsular bag, and it can be brought into the anterior chamber.
Option of IOL cutting
The IOL can be cut into halves or even smaller pieces using specialty intraocular scissors made by multiple manufacturers. The incision should be widened to about 3 mm to facilitate removal of the IOL pieces. Some surgeons advocate only cutting it 80% through the optic so that the two halves are still attached to each other, which makes retrieving them from the eye easier. Others like to cut only halfway through the optic and then rotate the IOL out of the eye. If you are using sharp scissors in the eye, it may be advantageous to first insert the new IOL into the capsular bag to protect it. With the old IOL up in the anterior chamber, there will be enough space under it to insert the tip of the lens injector for the new IOL.
Option of IOL folding or rolling
Before IOL injectors were widely in use, the most common way of inserting an IOL was with folding forceps. The IOL was folded in half, grasped with special lens forceps and inserted into the eye. For a 6-mm optic, this requires an incision a little larger than 3 mm. We can also use these same forceps to fold the IOL optic within the anterior chamber. Making a paracentesis incision directly opposite the phaco incision allows us to insert a spatula with one hand and then the lens forceps with the other. The lens can then be folded and removed from the eye.
A better option for me is to roll the IOL optic using the twist technique. I first learned a variation of this technique from a lecture by Jack Chapman, MD, about a decade ago. One IOL haptic is brought out through the incision, and then straight tying forceps are used to grasp close to the edge of the optic. Importantly, do not grasp the center of the optic because we want to roll the IOL, not fold it. Once the edge is grasped (Figure 1a), the spatula is placed on top of the optic via a paracentesis that is 90° away (Figure 1b). The straight tying forceps can now be twisted to roll the IOL around the forceps.
In this illustrative case, the forceps are twisted by pronation of the right hand, and to maximize the rotational travel, the forceps are held with the right hand supinated before insertion into the eye. This will allow just about 360° of twisting (Figure 2c), and that will result in an IOL that is completely rolled around the forceps. The spatula is important to assist in rolling the IOL and to protect the corneal endothelium (Figure 2d). At this point, the IOL can be pulled straight out of the eye via the incision (Figure 3e) and then placed on the cornea to verify that it is intact and undamaged (Figure 3f).
If the original phaco incision was less than 2.8 mm in width, it is helpful to enlarge it to this size. This technique works well for single-piece and three-piece acrylic IOLs but is tougher with silicone IOLs, which tend to become slippery once coated with viscoelastic. This twist technique has been refined over the years and is now something that can be done quite easily in just a minute or two.
For the vast majority of your patients, explanting an IOL is something that you never have to think about. But in those rare cases, you may find that the twist technique is useful to explant an IOL, fully intact, through a small incision without requiring specialized instruments.
A full video of this technique can be found at CataractCoach.com, which is a free teaching website.
- For more information:
- Uday Devgan, MD, is in private practice at Devgan Eye Surgery, Chief of Ophthalmology at Olive View UCLA Medical Center and Clinical Professor of Ophthalmology at the Jules Stein Eye Institute, UCLA School of Medicine. He can be reached at 11600 Wilshire Blvd. #200, Los Angeles, CA 90025; email: devgan@gmail.com; website: www.CataractCoach.com.
Disclosure: Devgan reports he owns the CataractCoach.com website, which is free and noncommercial.