February 2009

 

CATARACT/ IOL

 

Sutures for pediatric cataract patients


by Matt Young EyeWorld Contributing Editor

   
Image “B,” courtesy of optical coherence tomography (OCT), shows features of both foveal retinal detachment and retinoschisis; thus, suture break may lead to IOL subluxation, but not retinal detachment like this Source: J. Fernando Arevalo, M.D.

Ophthalmologists know cataract surgery can be challenging in children—especially in those without capsular support. What many may not know is that there could be some risk involved using 10-0 polypropylene sutures, according to research published in the December 2007 issue of Transactions of the American Ophthalmological Society. “Several recent reports have indicated that over time the 10-0 polypropylene suture can degrade, resulting in spontaneous subluxation of the intraocular lens,” wrote lead study author Edward G. Buckley, M.D., professor of ophthalmology and pediatrics, Duke Eye Center, Durham, N.C. “The key point emphasized in these articles is that this happens years after implantation, typically 4 to 5 years or later.”

Much research into this issue has focused on suture breakdown in a matter of months, which typically doesn’t happen. Hence, Dr. Buckley analyzed eyes with follow-up time of more than five years and, indeed, found a number of suture breaks. He also found other ophthalmologists revealing similar problems. Ophthalmologists may not recognize this problem as severe at first because a suture can be reattached. But over time, sutures could break down again and again, posing unwanted risks to these patients.

Not just needles in a haystack

Dr. Buckley analyzed 33 eyes of 26 pediatric patients that had transscleral sutured posterior chamber IOLs implanted as they had no capsular support. Post-op visual acuity was significantly improved as expected. Intraoperative and immediate post-op complications were minimal. But there were three patients (9%) that experienced a subluxed IOL after the 10-0 polypropylene suture broke. These breaks occurred at 3.5, 8, and 9 years after surgery—late, in other words, and just as other research has begun to suggest. “This is a significant number, which raises concern about the safety of our current approach,” Dr. Buckley reported. “There appeared to be no associated trauma or ocular predisposition for suture breakage to occur. The suture just failed. Fortunately, none of the patients suffered sustained loss of vision, but the potential is clearly evident.”

Dr. Buckley also surveyed more than 500 other pediatric ophthalmologists and found 10 more cases of broken sutures. “Some of these were associated with trauma, mainly sports, but many were spontaneous with no obvious etiology other than suture failure,” he wrote. Earlier research has given some hints that these sutures could fail. Scanning electron micrographs on sutures removed from iris-fixated lenses, for instance, have shown progressive surface cracks with flaking, Dr. Buckley noted. Other research found perpendicular cracks in one fixation suture after years of usage, with the diameter decreased toward both suture ends by more than 50%, he reported. The additional breakage cases that Dr. Buckley found suggest, according to him, that this is not an uncommon problem in the pediatric population, but many ophthalmologists have yet to see red flags.

“Because there were no significant complications associated with the broken suture other than that the IOL had to be reattached, the level of concern among pediatric surgeons that this was a serious problem going forward was minimal,” he reported.

But in the surveyed group, ophthalmologists that did report broken sutures simply reattached the IOLs with the same 10-0 polypropylene material, putting patients at risk again for potential dislocation, he suggested. Fortunately, the problem resulting from suture-break dislo-cation—at the moment—appears only to be the matter of reattachment. “A striking finding in both adults and children who have had a sutured IOL become subluxed is the apparent lack of significant consequences other than the necessity of needing to have it resutured,” Dr. Buckley found. “In this study, 3 children had a suture break that resulted in subluxation of the IOL with no associated problems and, in particular, no retinal damage.”

No patient lost vision resulting from the dislocation or subsequent resuturing procedure in this study, and pediatric ophthalmologists surveyed reported similar results. Nonetheless, 9-0 polypropylene could avoid this problem altogether. “The most likely alternative is to use 9-0 polypropylene suture, which has the same characteristics as 10-0 polypropylene but is sturdier and better able to resist degradation over time,” Dr. Buckley concluded. Dr. Buckley isn’t alone in reporting recent problems of suture breakage. The Polish journal Klinika Oczna reported in 2007 that complications of suture fixation of IOLs in children “included exposure of the scleral suture and the suture break,” according to lead study author Krystyna Kanigowska, Kliniki Okulistyki Instytutu Pomnik, Warsaw, Poland.

Once again, average follow-up time was long (average 9.1 years with a range of 8 to 11 years). Transsclerally sutured IOLs were fixated in 10 children (17 eyes) with ectopia lentis and in 16 children (21 eyes) with aphakia. Suture break and IOL dislocation was noted in three eyes. Once again though, these complications did not lead to retinal detachment.

Editors’ note: Drs. Buckley and Kanigowska have no financial interests related to their studies.

Contact information

Buckley: 919-684-3957, buckl002@mc.duke.edu
Kanigowska: 022 815 73 55

Sutures for pediatric cataract patients Sutures for pediatric cataract patients
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