No capsule support? Anterior chamber versus posterior chamber IOL
Surgeons should be aware of variety of techniques in aphakic eyes that lack capsular support
Take-home message: When considering IOL implantation options when there is a lack of capsular support, cataract surgeons should use the approach with which they are most comfortable. They should also continue to learn about new available techniques.
Eugene, OR—A broad familiarity of techniques to implant an IOL in the absence of capsular support can be a valuable addition to the surgeon’s virtual toolkit, said Richard S. Hoffman, MD.
Available options for managing cases where there is a lack of capsule support include an anterior chamber (AC) IOL, a scleral-fixated posterior chamber (PC) IOL, an iris-fixated PC IOL, and intrascleral haptic capture, he noted.
“To date, no studies have shown that any one technique is superior to the others,” said Dr. Hoffman, clinical associate professor of ophthalmology, Casey Eye Institute, Oregon Health and Science University, Eugene.
Dr. Hoffman cited several studies that supported open-loop AC IOLs and that found this approach posed no greater threat than PC IOLs in the realm of visual outcomes in secondary IOL implantation.1-3
However, some complications with AC IOLs include pain, bullous keratopathy, angle-closure glaucoma, and chronic uveitis. A properly sized, modern Kelman-style open loop AC IOL may help avoid some of these complications and is easily inserted, has a polished finish, and flexible haptics, Dr. Hoffman said.
Dr. Hoffman recommended avoiding AC IOLs if a patient has glaucoma, a shallow anterior chamber, insufficient iris tissue, or corneal endothelial dystrophy.
If implanting a scleral-fixated IOL, Dr. Hoffman advised operating temporally to reduce astigmatism and using 9-0 Prolene or CV8 Gore-Tex. He did not recommend the use of 10-0 Prolene.
He said he also tries to avoid passing sutures at 9 o’clock and 3 o’clock. Two-point fixation is simpler, but four-point fixation allows for greater stability and less lens tilt. Four-point fixation can be associated with an increase in bleeding due to twice as many suture passes through the sclera, Dr. Hoffman said.
If using transscleral fixation, users should bury, cover, or rotate scleral knots to prevent conjunctival erosion and the risk for subsequent endophthalmitis, Dr. Hoffman said.
Some ways to avoid suture erosion with scleral-fixated IOLs include burying the knot in the scleral groove, rotating the knots, leaving the suture ends long, attempting multiple zig-zag scleral passes, covering the knot under the scleral flap, performing intrascleral haptic capture, or using a scleral pocket.
Another approach that surgeons could use is sutured iris fixation of PC IOLs. Some contraindications for this approach include large iris defects, iridoschisis, iris atrophy, aniridia, and a younger person who is particularly active, as too much activity could lead to suture tearing or suture slippage, Dr. Hoffman said.
Intrascleral haptic capture is another possible approach for lack of capsule support. Some complications intraoperatively include hyphema, haptic breakage, and a deformed haptic. Early complications include corneal edema, epithelial defects, and iritis, and late complications can include optic capture, IOL decentration, haptic extrusion, and possible reoperation.
Intrascleral haptic capture does have a learning curve, Dr. Hoffman explained. However, surgeons who have become familiar with the technique believe that it is easier to perform intrascleral haptic capture than suturing IOLs to the sclera.
As surgeons decide which approach is best for them, Dr. Hoffman had some advice.
“When approaching cases with no capsular support, surgeons should perform the procedure they are most comfortable with,” Dr. Hoffman said.
“However, surgeons should become familiar with the various available techniques as there may be instances where one procedure is better than another for a particular patient,” he added.
He also cited a study that reviewed the literature from 1980 to 2002 regarding IOL implantation in the absence of capsular support. The study supported the use of open-loop AC, scleral-sutured PC IOLs, and iris-sutured PC IOLS.
That study did not find sufficient evidence to suggest the superiority of one technique over another, Dr. Hoffman concluded.4
1. Lyle AW, Jin JC. Secondary IOL implantation: AC versus PC IOL. Ophthalmic Surg. 1993;24:375-381.
2. Donaldson KE, Gorscak JL, Budenz DL. AC and sutured PC IOLs in eyes with poor capsular support. J Cataract Refractive Surg. 2005;903-909.
3. Kwong YY, Yuen HK, Lam RF, et al. Comparison of outcome of primary scleral-fixated versus primary ac IOL implantation in complicated cataract surgeries. Ophthalmology. 2007;114:80-85.
4. Wagoner MD, Cox TA, Ariyasu RG, et al. IOL implantation in the absence of capsular support: A report by the AAO. Ophthalmology. 2003;110:840-859.