In modern cataract surgery, foldable intraocular lenses (IOLs) have made it possible to perform IOL implantation through 2.2 to 4.0 mm incisions.1,2 The smaller incisions may heal more rapidly and theoretically lead to quicker visual recovery. However, implantation through incisions smaller than 3.2 mm requires an injector system, even with high-refractive-index silicone IOLs.3,4 Using a lens forceps, incisions are usually increased to 3.5 mm or larger to enable insertion of foldable polyacrylic IOLs with an optic diameter of 6.0 mm.
Recently, we developed a technique to roll up foldable IOLs using 2 pairs of forceps. A 1-piece soft polyacrylic IOL (AcrySof SA60AT, Alcon) was inserted through a 2.8 mm sclerocorneal incision without using an injector system. Using a slightly modified technique, 2 other IOLs (AF-1 YA-60BBR [Hoya] and Tecnis ZA9003 [AMO]) were successfully inserted through 2.8 to 3.2 mm incisions. In this article, we describe our technique for inserting soft polyacrylic IOLs through small incisions, which can be used in hospitals in which injector systems are not available.
A slit knife is used to make a superior sclerocorneal incision. Since the Legacy 20000 system with the MicroTip (Alcon Surgical) is used, a 2.8 mm incision is required. Continuous curvilinear capsulorhexis (CCC), hydrodissection, phacoemulsification, and cortical aspiration are performed conventionally, and the anterior chamber and capsular bag are filled with an ophthalmic viscosurgical device (OVD).
Intraocular Lens Roll Up
The SA60AT IOL is placed upside down on something flat and sterile (for example, the lid of an IOL container) to prevent it from moving. Using an acrylic IOL forceps with straight tips (forceps 1), the edge of the optic is grasped (Figure 1, A). Forceps 1 is rotated to fold the IOL edge (Figure 1, B). To facilitate insertion of the haptic, the folded edge should not contain the root of the trailing haptic. To roll up the IOL, another IOL forceps with straight tips (forceps 2) is used. By squeezing forceps 2 gently (Figure 1, C), the opposite edge of the optic meets the edge held with forceps 1. With continuous squeezing, the upper optic edge pushes down the folded edge. The tips of forceps 1 are opened to grasp both edges (Figure 1, D).
Intraocular Lens Insertion
A sclerocorneal incision of 2.8 mm is usually large enough for the SA60AT (Figure 2, A). The leading haptic, followed by the optic, is inserted through the sclerocorneal incision with the tips of forceps 1. The tip of forceps 1 outside the IOL should be located at the side of the optic to facilitate a smooth insertion (Figure 2, B). To avoid damage to the corneal endothelium, the tips of forceps 1 should be directed downward, not horizontally. The leading haptic is inserted under the edge of the CCC, and the optic is released. Before the tips are opened, forceps 1 should be rotated clockwise around the axis of the tips to keep the optic from turning upside down (Figure 2, C). The tips of forceps 1 are withdrawn from the incision, and a hook is used to rotate the IOL and insert the trailing haptic into the capsular bag (Figure 2, D).
Variation for Insertion of the YA-60BBR IOL
The YA-60BBR IOL is a 1-piece soft polyacrylic IOL with poly(methyl methacrylate) (PMMA) haptics. The roots of the haptics are hard and unfoldable. To roll up the optic so it is small enough, forceps 1 should grasp the optic edge so it contains the trailing haptic (Figure 3, A). The rest of the technique is the same as for the SA60AT IOL (Figure 3, B to D). For a smooth, safe insertion, the tip of forceps 1 outside the IOL should be located at the top of the optic when the leading haptic is inserted. The tips are then rotated clockwise while directed downward. A sclerocorneal incision of 2.8 mm is usually large enough for insertion of this IOL.
Variation for Insertion of the ZA9003 IOL
The ZA9003 is a 3-piece soft polyacrylic IOL. The optic is relatively thick and hard to fold. The roll-up technique is the same as for the SA60AT IOL (Figure 4, A to D), but the sclerocorneal incisions are 3.0 to 3.2 mm because of the characteristics of the optic. In addition, the haptics are relatively easy to break because they are thin and made of PMMA. When the leading haptic is inserted through the incision, one tip should be grasped with the second forceps and both forceps should proceed at the same time to prevent haptic damage (Figure 5).
More than 100 IOLs have been inserted uneventfully using the roll-up technique. Surface scratches and tiny cracks sometimes observed on the IOL optic were no worse than those seen after conventional forceps-related manipulations. No patient has complained of glare or other symptoms. Enlargement of the incision (larger than 0.1 mm) was not observed after the insertion unless the technique was performed too forcibly.
Foldable IOLs are usually inserted with a forceps or an injector; however, IOL implantation through an incision smaller than 3.2 mm requires an injector system. When IOL forceps are used to fold an IOL in half, a relatively large incision is needed.3,4 In cataract surgery, smaller incisions may be associated with less postoperative inflammation.
Injector systems generally have at least 4 weak points. First, injectors are quite expensive and they have to be used with disposable (costly) cartridges, although some manufacturers provide cartridges at no charge. Second, different injectors and cartridges have to be used depending on the IOL manufacturer and surgeons have to learn how to use each one. Third, handling injector systems is sometimes complicated and may require a long time for inexperienced surgeons. Incorrect use of injectors can break IOLs. Fourth, cartridges require extra amounts of OVD. These weak points may explain why injector systems are not popular in certain circumstances; for example, in developing countries or even in industrialized ones that have strict limitations on national medical expenses. As a result, injector systems are not available in many countries. Therefore, the IOL roll-up technique is worth considering as it makes it possible to insert an IOL through a small incision comparable to that used by injector systems. (In regard to the SA60AT IOL, the disadvantages of injector systems are less of a problem because injector systems for the SA60AT are less complicated than those for other foldable IOLs and the SA60AT is hard to break because of its 1-piece structure.)
Wenzel et al.5 report a technique to insert a foldable IOL without an injector, but the technique requires a cartridge filled with OVD and a small cannula to push the IOL instead of an injector. Therefore, it should be seen as a variation of an injector system. Our technique is different as it uses only 2 pairs of forceps.
Recent improvements in cataract surgery make it possible to perform phacoemulsification through an incision 2.0 mm or smaller.1 However, a 3.0 mm incision is usually small enough since many popular phaco tips require incisions of 2.8 to 3.0 mm. We mainly perform cataract surgery with sclerocorneal incisions to avoid postoperative endophthalmitis.6 The need for ultrasmall incisions is relatively small compared with the need for corneal incisions. Using our technique, it is possible to insert foldable polyacrylic IOLs without enlarging sclerocorneal incisions. The modified roll-up technique for the ZA9003 IOL should be widely applicable because the 3-piece structure of the ZA9003 is popular and many similar foldable IOLs have been developed.
We have performed the IOL roll-up technique in more than 100 eyes and found it safe and effective. No IOL in the series has fractured, and the surface scratches that were observed on the optic were no worse than those seen after conventional forceps-related manipulations. Occasionally, a tiny crack was observed on the optic surface; this did not result in any clinical problem because the crack was small and located at the edge of the optic. No other complications associated with the IOL roll-up technique were observed.
The IOL roll-up technique is reproducible and easy to learn. We hope more IOLs with thin and soft optics will be developed as this would make our technique more useful.
1. Tsuneoka H, Hayama A, Takahama M. Ultrasmall-incision bimanual phacoemulsification and AcrySof SA30AL implantation through a 2.2 mm incision. J Cataract Refract Surg. 2003;29:1070-1076.
2. Tsuneoka H, Hayama A, Takahama M, Takashina H. 6.5 mm optic AcrySof implantation through a 3.0 mm incision. J Cataract Refract Surg. 2003;29:1869-1873.
3. Mamalis N. Incision width after phacoemulsification with foldable intraocular lens implantation. J Cataract Refract Surg. 2000;26:237-241.
4. Kohnen T, Koch DD. Experimental and clinical evaluation of incision size and shape following forceps and injector implantation of a three-piece high-refractive-index silicone intraocular lens. Graefes Arch Clin Exp Ophthalmol. 1998;236:922-928.
5. Wenzel M, Auer F, Bechmann M. Injection of an intraocular lens without an injector. J Cataract Refract Surg. 2003;29:2461.
6. Nagaki Y, Hayasaka S, Kadoi C, et al. Bacterial endophthalmitis after small-incision cataract surgery; effect of incision placement and intraocular lens type. J Cataract Refract Surg. 2003;29:20-26.