Bent Haptic Detected During IOL Insertion
CASE PRESENTATION
After injector insertion of a Sensar hydrophobic acrylic IOL (Advanced Medical Optics, Inc., Santa Ana, California), it is noticed that the leading (inferior) haptic is dislocated irretrievably from its normal position (Figure 1). The body of the optic is already out of the injector and unfolding in the anterior chamber before this is noted. The capsular bag is intact, and the case has proceeded uneventfully before this moment.
What options are available to ensure that the patient ends up with a well-centered lens?
Case presented by Larry Benjamin, DO, FRCS, FRCOphth
DAVID ALLEN, FRCOphth
Decentered IOLs can cause significant unwanted visual symptoms for patients. Although a small degree of decentration may be tolerated by an older patient with small pupils, it may be intolerable to a young myope with a pupil that dilates significantly in dim light. Attempts should always be made to ensure that the IOL optic is well centered at the end of surgery.
In this case, the first thing to do is nothing. Take time to consider the options, and if possible retain the haptics in the incision to help remove the IOL, if that is the decided course of action. When the optic unfolds (which it will do while you are considering the options), the configuration of the leading haptic will become clearer. If the capsulorrhexis is the correct size (ie, 0.5 to 1 mm smaller than the optic diameter) and well centered, one option with this three-piece IOL is rhexis capture of the optic, using the rhexis rather than the haptics to stabilize the optic. Depending on the configuration of the damaged haptic, either both haptics are placed into the capsular bag and then the optic is buttonholed anterior to the rhexis margin, or the haptics are placed in the ciliary sulcus and the optic buttonholed posteriorly into the capsule. In either case, the rhexis edge goes around each haptic/optic junction, holding the optic in place and preventing later decentration.
Alternatively, the IOL may have to be removed and replaced. Scissors can be used to cut the optic, but significant enlargement of the incision is often required to insert scissors into a viscoelastic-filled chamber. As this is an acrylic IOL, it is possible to refold it in the anterior chamber (Figure 2) and remove it through a slightly enlarged incision. Creating a small paracentesis opposite the incision allows instillation of viscoelastic anterior and posterior to the optic and insertion of a spatula or similar instrument, which is then placed under the optic. (In the case of a temporal incision this may be difficult in some patients because of the bridge of the nose.) With the spatula kept carefully aligned across the optic diameter, an IOL holder is introduced through the main incision. With the jaws of the holder slightly open, pressure on top of the optic against the counterpressure of the spatula results in gentle folding of the optic. Pronation of the holding hand during this maneuver then brings the folded optic horizontal, and the IOL can be withdrawn through the incision.
I. HOWARD FINE, MD
This presentation suggests that both haptics are still attached to the optic. Therefore, the only problem is the bend in the haptic. If the haptic were detached from the optic, the IOL would have to be removed and a new one placed, and the removal could take place by any of several previously described techniques.
However, with a bent haptic such as this, I would complete implanting the IOL into the anterior chamber and then draw the bent haptic out of the eye. Using insertion or folding forceps with round, parallel blades, the haptic can be gently pulled, holding it near its attachment to the optic with one hand. With the forceps in the other hand, the haptic is drawn out in such a way as to cause restitution in the bend to a normal haptic shape.
PMMA does have plastic memory. By stroking the haptic carefully in this way, so as to not break it, the haptic should resume its normal configuration. It can then be dialed into the capsular bag without problem.
MARK PACKER, MD, FACS
The haptic cannot be fixed, and the lens cannot be centered without the haptic; therefore, the IOL must be removed from the eye and a new IOL implanted. In order to remove the IOL, either the lens must be cut or the incision opened; the relatively stiff acrylic material cannot be safely refolded in the eye. This material resists cutting, so special scissors have been developed for precisely this situation (Packer-Chang IOL Cutter; MicroSurgical Technologies, Redmond, Washington). I have no financial interest in this instrument.
The first step in removing the IOL is to generously fill the capsule and anterior chamber with a dispersive viscoelastic to protect the corneal endothelium, iris, and capsular bag. It is necessary to grasp the IOL with forceps while it is cut. Toothed forceps may be used through the larger incision, and the scissors are manipulated through the paracentesis. They are designed to be introduced through a 1.2-mm incision. Alternately, Ahmed Micrograspers (MicroSurgical Technologies) can be used to hold the lens while it is cut.
It takes four or five snips to transect the lens. A perfect hemisection will allow each piece to be withdrawn through the 2.8-mm incision used for IOL insertion. If the lens rotates as it is cut, a smaller piece may be cut off, in which case another cut must be undertaken and the thirds removed one at a time. A critical step is to reassemble the pieces of the IOL after they are extracted to make sure that no material has been left behind.1
Once the IOL is out of the eye, the capsule should be inspected for damage. If it is intact, folding and inserting a new IOL may proceed.
Generally, the cause of a crimped haptic is improper loading and folding. The plunger overrides the haptic-optic junction in the cartridge and puts pressure on the haptic, crimping it. Often the surgeon can feel unusual resistance to insertion as this occurs; in this case, the process should be stopped and the cartridge withdrawn from the eye and inspected. Specific to the Sensar, the relatively greater degree of force required to insert this lens may make this subtle difference in resistance less discernible. Fortunately, IOL exchange can be performed safely and efficiently without harm to the eye.
DAVID SPALTON, FRCOphth
This lens is irretrievably damaged and will not center. It must be explanted.
I would push the lens further into the anterior chamber so that it lies above the bag; fill the chamber with Viscoat (chondroitin sulfate, sodium hyaluronate; Alcon Laboratories, Inc., Fort Worth, Texas), a retentive or cohesive viscoelastic; and then explant the IOL. I use Duckworth & Kent (Baldock, Hertfordshire, England) explantation scissors, which have a serrated edge and cut all foldable IOL materials easily. I place a Sinskey hook though the sideport incision to support the distal rim of the IOL as I cut it because it tends to extrude from the scissors.
I like to divide the IOL completely into two hemispheres. Some surgeons make only a 90° cut and rotate the IOL out through the wound, but I think this can be more difficult and traumatic to the wound. I then remove the IOL through the unenlarged wound with Kelman forceps, ensuring that each hemisphere is rotated so that the haptic trails out. Otherwise, it can snag on the iris or capsular bag. A new lens is then injected.
LARRY BENJAMIN, DO, FRCS, FRCOphth
The IOL must be removed, as the damage to the shoulder of the haptic would mean increasing potential for decentration of the optic with time.
Various methods of lens removal are available: (1) refolding the IOL in the eye, (2) cutting the implant in half and removing each half in turn, (3) cutting the IOL through three-fourths of its length and rotating it out of the eye, and (4) enlarging the wound and removing the lens unfolded.
This particular type of implant is difficult to refold in the eye, so a decision was made to remove it with a cutting technique. The lens was cut through three-fourths of its diameter (Figure 3) and rotated out of the eye (Figure 4). It was then replaced with a new IOL uneventfully (Figure 5).
David Allen, BSc, FRCOphth, is a Consultant Ophthalmologist specializing in cataract surgery at Sunderland Eye Infirmary, UK. He states that he has received reimbursement for travel and lodging expenses from Alcon Laboratories, Inc., but also states that he has no direct financial interest in the products or companies mentioned. Mr. Allen may be reached at +44 191 5699071; david.allen@chs.northy.nhs.uk.
Larry Benjamin, DO, FRCS, FRCOphth, is in the Department of Ophthalmology at Stoke Mandeville Hospital, Aylesbury, UK. He is a member of the CRST Europe Editorial Board. Dr. Benjamin may be reached at larry.benjamin@btopenworld.com.
I. Howard Fine, MD, is a Clinical Professor of Ophthalmology at the Casey Eye Institute, Oregon Health & Science University, and he is in private practice at Drs. Fine, Hoffman, & Packer LLC, Eugene, Oregon. Dr. Fine states that he is a paid consultant to Advanced Medical Optics, Inc., and Bausch & Lomb. He receives research and travel support from Alcon Laboratories, Inc., STAAR Surgical Company, Eyeonics, Inc., and Rayner Intraocular Lenses Ltd. He is a member of the CRST Europe Global Advisory Board. Dr. Fine may be reached at +1 541 687 2110; hfine@finemd.com.
Mark Packer, MD, FACS, is a Clinical Associate Professor at the Casey Eye Institute, Department of Ophthalmology, Oregon Health, and Science University, and he is in private practice at Drs. Fine, Hoffman & Packer, LLC, Eugene, Oregon. He states that he is a consultant to Advanced Medical Optics, Inc. Dr. Packer is a member of the CRST Europe Global Advisory Board. He may be reached at +1 541 6872110; mpacker@finemd.com.
David Spalton, FRCS, FRCP, FRCOphth, is a Consultant Ophthalmic Surgeon at St. Thomas' Hospital, London. Dr. Spalton is a member of the CRST Europe Editorial Board. He may be reached at spalton@eyepractice.fsnet.co.uk.
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