Even in complicated cases, cataract surgery with phacoemulsification and in-the-bag posterior chamber IOL implantation is the standard approach used today. After phacoemulsification of the lens and capsular bag cleaning, most surgeons relax a little, as the most difficult part of surgery seems to be over; I do the same. However, even IOL implantation can be challenging.
Many surgeons prefer one-piece acrylic IOLs, and there is a strong trend toward use of smaller incisions. This results in the use of smaller-sized IOL cartridges and one-handed injectors for wound-assisted IOL implantation. Therefore, forces inside the cartridge increase during IOL implantation. Sometimes a sudden release of the IOL can occur, causing damage to intraocular tissues. Potential causes of this complication include incorrect IOL positioning in the cartridge, mismatched IOL thickness and cartridge inner diameter, forcing of the plunger between the IOL and cartridge, a weak injector spring, and surgeon inexperience.
After performing more than 20,000 IOL implantations in my lifetime, this past year I experienced my own personal surgical nightmare. Phacoemulsification and aspiration of the cortical material were uneventful. I filled the anterior chamber and the capsular bag with an ophthalmic viscosurgical device (OVD), and my nurse loaded the 26.00 D IOL (AcrySof SA60AT; Alcon) into a D cartridge (Alcon) and placed it into a one-handed injector (ASICO). I inserted an instrument in the left sideport incision to stabilize the eye for wound-assisted IOL injection through a 2.2-mm incision and placed the injector with the cartridge at the entry of the limbal incision.
During implantation, I recognized that the leading haptic was not folded on top of the IOL optic and was emerging first, clockwiseóie, in the wrong direction (Figure 1). The implantation forces increased when I pushed the plunger, but I was focused on getting the leading haptic in the correct direction and did not realize there was a sudden decrease in resistance when the IOL optic was released from the cartridge. This caused the IOL to shoot toward the capsular bag, causing zonulolysis between the 7- and 12-oíclock positions and immediate collapse of the capsular bag (Figure 2).
To evaluate the situation, I increased the magnification on the operating microscope (Figure 3). There was no evidence of vitreous prolapse, and the IOL was anterior to the capsule, with the leading haptic in the ciliary sulcus and the trailing haptic in the anterior chamber angle. The posterior capsule seemed to be intact. I asked the nurse for a high-viscosity OVD (Healon 5; Abbott Medical Optics Inc.), which I injected through the temporal sideport incision. This OVD was used to stabilize the capsular bag and push the capsule equator toward the periphery.
Next, I used a preloaded capsular tension ring (CTR), placing the injector tip behind the IOL. I initiated injection from the temporal side to place the open ends of the CTR away from the damaged zonules (Figure 4). It is important to open the capsular bag with OVD in order to unfold the capsular bag equator in cases of severe zonulolysis; otherwise, the leading edge of the CTR could catch the capsular bag and/or go through the capsule, causing even more complications. I took care to ensure that the tip of the CTR injector stayed under the capsulorrhexis margin until it was released from the inserter. After uneventful implantation of the CTR, I felt it was safe to perform IOL implantation in the bag.
First, I moved the inferior haptic with a Sinskey hook from the ciliary sulcus into the capsular bag, and then I repositioned the second haptic from the iris surface into the bag. I then removed the OVD from behind the IOL (Figure 5) and from the rest of the capsular bag and anterior chamber. The IOL was well-centered, and there was no evidence of vitreous prolapse or instability of the capsular bag-IOL complex. The corneal incisions were hydrated with balanced saline solution (Figure 6).
Shortly after this event, I obtained a new device for IOL implantation: the Intrepid AutoSert for the Infiniti Vision System (both Alcon). This motorized implantation system gives the surgeon maximum control during IOL implantation, and it can be used with standard C and D cartridges for one-piece AcrySof lenses. The surgeon can individually select and control implantation speed via the footpedal. Sudden release of the IOL during implantation is not possible with this system, allowing the surgeon to focus on correctly positioning the cartridge in the surgical wound and the unfolding process of the IOL.
The lessons I learned from this case are these:
- Do not think it is over until the last moment;
- Be prepared for any possible complication (ie, have adequate OVD, CTR, iris hooks, etc.); and
- Stop the procedure if there is something wrong (eg, if increased injection forces are noted).
Gabor B. Scharioth, MD, PhD, is in private practice at the Aurelios Augenzentrum in Recklinghausen, Germany. Dr. Scharioth states that he has financial interest in Abbott Medical Optics Inc., Alcon, and Medicontur. He may be reached at tel: +49 2361306970; e-mail: gabor.scharioth@ augenzetrum.org.