When and How Should I Implant an Intraocular Lens in the Ciliary Sulcus?
Thomas A.
Oetting,
MS, MD
An intraocular lens (IOL) can often be securely placed using what remains of a damaged capsule for support.1 There are 4 typical situations: anterior capsular tear without extension, posterior capsular tear with intact anterior capsule, anterior capsular tear extending to a posterior capsular tear, and zonular dehiscence. First let us discuss how to place an IOL in the sulcus and then get to these 4 common situations.
The most important part of placing an IOL in the sulcus is getting both haptics in the sulcus.2 The most common problem is to have one haptic in the sulcus and the other in the bag, which results in a decentered IOL (Figure 33-1).
Figure 33-1. Decentered IOL. Superior haptic in the sulcus and inferior haptic in the bag.
One reason that it is hard to get both haptics in the sulcus is that the most common area of damage to the capsule is directly across from the wound. This area is vulnerable to radial tears as ophthalmic viscosurgical devices (OVD) are often running low as the capsulorrhexis passes this point, and this area is vulnerable as the phaco tip and chopper are active in this region. Unfortunately, this same area is where the leading haptic naturally flows during IOL insertion. If the capsule is damaged in this area, then the sulcus is poorly defined and the leading haptic can end up posterior to the anterior capsule rather than in the sulcus as intended.
When I am faced with capsule damage across from my wound, I will often inject the IOL into the eye and direct the leading haptic anterior to the iris in the anterior chamber to avoid the damaged capsule. I then will use Kelman McPherson forceps to place the trailing haptic into the sulcus. I then use an instrument like a Sinskey hook to rotate the IOL about 90 degrees so that the haptics are away from the damaged area. Then I take the Sinskey hook through a paracentesis, slide it over and hook onto the leading haptic, and pull the haptic inside the pupil and release the haptic just under the iris into the sulcus. Defining the sulcus with a viscous dispersive viscoelastic (eg, Viscoat [Alcon, Fort Worth, Tex]) will greatly ease placement of the haptics.
The second most common problem when placing an IOL in the sulcus is using the wrong IOL design or power. The best IOL for the sulcus has a large optic that is forgiving of mild decentration and permits a better view of the peripheral retina; long haptics with an overall length that will center the IOL even in large eyes; and smooth, thin haptics to reduce chaffing of the posterior leaf of the iris. Figure 33-23,4 shows a single-piece acrylic lens with large square-edged haptics that was placed in the sulcus, leading to iris transillumination defects and pigmentary glaucoma. I prefer acrylic to silicone IOLs for sulcus implantation because patients with capsule trauma are at increased risk for retinal detachment and the possible use of silicone oil. I like the Alcon MA50 3-piece IOL (Fort Worth, Tex) because it has wide haptics, a large yet injectable 6.5-mm optic, and it is acrylic.
Figure 33-2. Iris transillumination defects. Single-piece acrylic in the sulcus. (Courtesy of Drs. Anthony Kuo and Robert Noecker, University of Pittsburgh.)
As an IOL in the sulcus is more anterior than an IOL in the bag, the power of the IOL must be reduced. In our study of 30 sulcus-based IOLs, we found that the A-constant should be lowered by about 0.8 D.5 Other studies have had similar results, suggesting that we decrease the power of sulcus-based IOLs by 0.5 D to 1.0 D.6
It is very important to eliminate any vitreous in the area of IOL insertion. Vitreous streaming to the wound or to a paracentesis can cause IOL decentration. Careful bimanual anterior vitrectomy aided with Kenalog (Bristol-Myers Squibb, New York, NY) (not approved by the Food and Drug Administration for this indication) will greatly assist in the long-term stability of the IOL and retina (see Question 32).
There is no need to place a peripheral iridotomy when placing an IOL in the sulcus.
When the anterior capsule has a tear but the posterior capsule remains intact, one can often place an IOL in the bag. IOL insertion should be gentle, placing as little stress on the bag as possible. I prefer a single-piece acrylic in this case because the soft acrylic haptics, oriented 90 degrees away from the tear, create little tension on the bag, minimizing the risk of extension of the tear. My experience is that the single-piece acrylic is stable in the bag with a radial tear and remains centered (Figure 33-3). The disadvantage to placing this IOL in the bag with an anterior capsular tear is that should the radial tear advance to the posterior capsule during insertion, this IOL must be removed and exchanged for a 3-piece IOL suitable for the sulcus.
Figure 33-3. Single-piece acrylic IOL in the bag with a radial tear.
When the posterior capsule is torn and the anterior capsulotomy is intact, you have 2 options for the sulcus and one for the bag. One sulcus option is to simply place the IOL in the sulcus. The second, which I often use, is to place the haptics in the sulcus as described but then use a Kuglen hook to gently prolapse the optic back into capture by a well-centered anterior capsulotomy (Figure 33-4). This optic capture is very stable and seals off the vitreous from the anterior chamber. The final option applies to stable posterior capsule tears such as round holes from a direct phaco needle strike or those tears completed with a posterior capsulorrhexis, and that is to gently place a single-piece acrylic IOL into the bag (Figure 33-5).
Figure 33-4. Haptics in the sulcus and the optic is in the bag.
Figure 33-5. A single-piece acrylic in the bag. Round hole in the posterior capsule.
When the posterior and anterior capsules are both torn, it is best to seal off the area with Viscoat and to place the IOL in the sulcus as described above.
When the zonules are injured, my first thought is to try placing a capsular tension ring (CTR) with or without a suture. If the area of zonular loss is less than 3 clock hours, I would place a conventional CTR. If for some reason a CTR was not available, the IOL will usually remain in position in the sulcus with 3 clock hours or less of zonular dialysis. If the area of zonular loss is greater than 3 clock hours, I would suture a modified CTR (Cionni). If not available, I would be very cautious placing the IOL in a sulcus with this amount of zonular loss. I would try to place the IOL in the sulcus but have a very low threshold for iris suture fixation.
References
1. Amino K, Yamakawa R. Long-term results of out-of-the-bag intraocular lens implantation. J Cataract Refract Surg. 2000;26(2):266-270.
2. Oetting TA. Cataract Surgery for Greenhorns. MedRounds Publishing; 2005. Available at: http://www.medrounds.org/cataract-surgery-greenhorns. Accessed November 20, 2006.
3. Micheli T, Cheung LM, Sharma S, et al. Acute haptic-induced pigmentary glaucoma with an AcrySof intraocular lens. J Cataract Refract Surg. 2002;28(10):1869-1872.
4. LeBoyer RM, L Werner, Snyder ME, et al. Acute haptic-induced ciliary sulcus irritation associated with single-piece AcrySof intraocular lenses. J Cataract Refract Surg. 2005;31(7):1421-1427.
5. Maassen, J, Oetting T, Omphroy L. A constant for sulcus based MA60BM. Unpublished data presented at: University of Iowa Ophthalmology Resident Research Conference; Iowa City Iowa, May 19 2006. Available at http://webeye.ophth.uiowa.edu/dept/RESFELO/ResDay2006/abstracts/maassen.htm. Accessed Jan 3 2007.
6. Suto C, Hori S, Fukuyama E, Akura J. Adjusting intraocular lens power for sulcus fixation. J Cataract Refract Surg. 2003;29(10):1913-1917.