Pediatric Sutured Intraocular Lenses: Trouble Waiting to Happen EDWARD G. BUCKLEY
W
E KEEP FORGETTING THAT CHILDREN ARE NOT
just little adults, and that the age difference is more than just chronological. What may be quite effective for years in adults could be extremely problematic in children after decades. This becomes of special concern when we put things in and around the eye in a pediatric patient. Sure it can be done, but will it last, and what are the real long-term consequences, not 24 months but five, 10, and 20 years later? Authors need to be cautious in their recommendations, editors need to demand realistic discussions on these subjects, and readers need to be skeptical of outcomes that are not tempered with the dose of reality that the important issue is what happens over time. Intraocular lens (IOL) rehabilitation of the aphakic child is problematic if there is no capsular remnant to support the IOL in the sulcus. In this situation, a secondary IOL implant can be placed in the anterior chamber (AC), attached to the iris, or sewn into the posterior chamber sulcus. Pediatric patients who have undergone standard AC lens implants have had significant long-term complications such as corneal endothelial loss, corneal decompensation, iris sphincter erosion, pupillary ectopia, and glaucoma, making this procedure undesirable.1,2 Iris-claw lenses are also placed in the AC, but instead of being supported in the angle, they are attached to the iris with small polymethylmethacrylate (PMMA) clips that are part of the implant. They have been used in Europe successfully for over 20 years and have been reported as effective as other treatment modalities in children with minimal complications.3 Unfortunately, these lenses are not routinely available in the United States. The current preferred technique is to suture the IOL into the sulcus. Previous reports have shown that these secondary transscleral fixated IOL implants are well tolerated in the pediatric population4,5 but recent concern has been raised about the long-term safety of the suture material (10-0 polypropylene) that is used to fixate the IOL to the scleral wall.6 –11 These reports have indicated that over time the 10-0 polypropylene suture can degrade, resulting in spontaneous subluxation of the IOLs. The key See accompanying Article on page 121. Accepted for publication Aug 23, 2008. From the Department of Ophthalmology, Duke University Eye Center, Durham, North Carolina. Inquiries to Edward G. Buckley, Duke University, Department of Ophthalmology, P.O. Box 3802, Duke Eye Center, Erwin Road, Wadsworth Building, Durham, NC 27710; e-mail:
[email protected] 0002-9394/09/$36.00 doi:10.1016/j.ajo.2008.08.033
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point emphasized in these articles is that this happens years after implantation, typically four to five years or later. The investigators raise concern that past reports, which have indicated good results in both adults and children, have not had long enough follow-up after the surgery for this complication to occur. The issue of long-term viability of 10-0 polypropylene suture presents a particularly important concern for pediatric patients, because life expectancy is measured in decades. To address this issue, it has been recommended that a stronger thicker caliber suture material be used such as merislene or 9-0 polypropylene.6,9 In this issue of THE JOURNAL, Yen and associates have published their results on suturing the IOL to the undersurface of the iris instead of the scleral wall in pediatric patients.12 The rationale for using this technique is that it is supposedly simpler and faster than transscleral fixation. Noting the recent concern over late suture breakage after transscleral fixation, they comment that fixation to the iris may not result in late suture breakage because the iris is more floppy and less rigid than the scleral wall, which may create a “more forgiving” environment. Unfortunately none of the reported series using this technique, including Yen’s, have had follow-up long enough to address the late suture breakage issue, which typically takes five or more years to occur.13–15 While the issue of late suture breakage can only be speculated upon using this technique, early IOL dislocation is a significant problem. Five of 17 (29.4%) eyes in Yen’s study had an IOL dislocate during the first year after surgery and others have noted similar results.15 The etiology was unclear but presumed to be attributable to the IOL somehow tearing loose from the iris. Since the iris is constantly in motion, it would seem that over the lifetime of a child this would continue to be a significant concern. Intuitively, fixing the IOL to the undersurface of the iris seems destined for trouble. Instead of just the suture, you also have the soft floppy iris tissue to worry about. In my experience, the iris is more floppy in children with Marfan syndrome and ectopic lentis than in the normal population and certainly not like the stiff iris seen in the typical older adult whose IOL is implanted in this manner. I think the authors are overly optimistic about the long-term consequences of this technique in children and an honest review of the literature would seem to suggest caution with any type of sutured IOL in the pediatric population especially to the iris. Until we have a better solution, efforts to minimize the possibility of dislocation of the IOL both
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short- and long-term are needed. Short-term IOL dislocation is seen only with iris fixated lenses and appears to be attributable to surgical technique with either too little iris incorporated in the knot or too tight a knot resulting in the IOL tearing free from the iris. Late
dislocation of the IOL, which is possible with both techniques, is due to suture failure and this can be minimized with a stronger thicker material such as 9-0 polypropylene or mersilene. It is still anyone’s guess if it will last long enough in children.
THE AUTHOR INDICATES NO FINANCIAL SUPPORT OR FINANCIAL CONFLICT OF INTEREST. THE AUTHOR WAS INVOLVED IN design and conduct of study; data collection; analysis, management, and interpretation of data; and preparation, review, and approval of manuscript.
REFERENCES 9.
1. Epley KD, Shainberg MJ, Lueder GT, Tychsen L. Pediatric secondary lens implantation in the absence of capsular support. [erratum appears in J AAPOS 2002;6:50]. J AAPOS 2001;5:301–306. 2. Hiles DA. Peripheral iris erosions associated with pediatric intraocular lens implants. J Am Intraocul Implant Soc 1979;5:210 –212. 3. Van der Pol BA, Worst JG. Iris-claw lenses in children. Doc Ophthalmol 1996;92:29 –35. 4. Buckley EG. Scleral fixated (sutured) posterior chamber intraocular lens implantation in children. J AAPOS 1999;3: 289 –294. 5. Bardorf CM, Epley KD, Lueder GT, Tychsen L. Pediatric transscleral sutured intraocular lenses: efficacy and safety in 43 eyes followed an average of 3 years. J AAPOS 2004;8:318 –324. 6. Buckley E. Hanging by a thread: The long-term efficacy and safety of transscleral sutured intraocular lenses in children (An American Ophthalmology Society Thesis). Trans Am Ophthalmol Soc 2007;105:294 –311. 7. Kim J, Kinyoun JL, Saperstein DA, Porter SL. Subluxation of transscleral sutured posterior chamber intraocular lens (TSIOL). Am J Ophthalmol 2003;136:382–384. 8. Vote BJ, Tranos P, Bunce C, Charteris DG, Da Cruz L. Long-term outcome of combined pars plana vitrectomy and
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scleral fixated sutured posterior chamber intraocular lens implantation. Am J Ophthalmol 2006;141:308 –312. Price MO, Price FW Jr, Werner L, Berlie C, Mamalis N. Late dislocation of scleral-sutured posterior chamber intraocular lenses. J Cataract Refract Surg 2005;31:1320 – 1326. Asadi R, Kheirkhah A. Long-term results of scleral fixation of posterior chamber intraocular lenses in children. Ophthalmology 2008;115:67–72. Kanigowska K, Gralek M, Karczmarewicz B. Transsclerally fixated intraocular artifical lenses in children-analysis of long-term postoperative complications. Klin Oczna 2007; 109:283–286. Yen KG, Reddy AK, Weikert MP, et al. Iris-fixated posterior chamber intraocular lenses in children. Am J Ophthalmol 2009;147:121–126. Dureau P, Meux P, Edelson C, Caputo G. Iris fixation of foldable intraocular lenses for ectopia lentis in children. J Cataract Refract Surg 2006;32:1109 –1114. Condon G, Masket S, Kranemann C, Crandall A, Ahmed I. Small incision iris fixation of foldable intraocular lenses in the absence of capsule support. Ophthalmology 2007;114: 1311–1318. Kopel A, Carvounis P, Hamill M, Weikert M, Holz E. Iris-sutured intraocular lenses for ectopic lentis in children. J Cataract Refract Surg 2008;34:596 – 600.
OPHTHALMOLOGY
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