July 2008

 

CATARACT/ IOL

 

Causes of capsular contraction syndrome


by Matt Young EyeWorld Contributing Editor

   

Study traces possible causes related to the IOL haptics

Two continuous slices through an IOL during resting accommodation shows the IOL haptics posterior to the ciliary muscle plane; memory loss of IOL haptics have been implicated as a cause of capsular contraction syndrome Source: Liliana Werner, M.D., Ph.D.

New potential causes of capsular contraction syndrome (CCS) have been identified in a study published recently in the January 2008 issue of Clinical & Experimental Optometry. The causes include possible memory loss of the IOL haptics resulting from manipulations during IOL insertion and mounting the haptic on the optic. This “results in the deposition of fibrous material that may lead to anterior capsule opacification and phimosis,” wrote lead study author Ioannis Tsinopoulos, M.D., Second Department of Ophthalmology Medical School, Aristotle University, Thessaloniki, Greece. Other causes of the syndrome include IOL material, rectangular IOL edges, capsulorhexis size, and intracapsular ring implantation, Dr. Tsinopoulos wrote.

Pseudoexfoliation and retinitis pigmentosa also reportedly can exacerbate the syndrome. The new factors may add to ophthalmologists’ understanding of CCS and help prevent it.

Eight interesting cases

Researchers analyzed 243 eyes of 231 cataract patients and found eight cases that experienced CCS. These cases were implanted with a Premier lens (Bausch & Lomb, Rochester, N.Y.). “The IOL that was implanted in all eight cases described in the present report was a hydrophobic one-piece IOL with sharp edges, implanted with the use of the appropriate injector,” Dr. Tsinopoulos noted. “The intra-operative loss of the haptics’ memory appears to be the possible cause of ACO [anterior capsule opacification] that was observed post-operatively, while similar haptic dysfunction has not been previously reported.”

The memory loss was likely caused by intra-operative manipulations of the IOL to appropriately place it in the bag, Dr. Tsinopoulos reported. This resulted in one of the haptics—often the first implanted—being mounted on the optic right after implantation. This could be the reason for the phimosis and ACO. “We do not believe there is any specific data in the literature regarding the prevalence of ACO with this type of lens,” Dr. Tsinopoulos wrote. “As there was an even spread in the prevalence of ACO among the surgeons, it is unlikely that the development of the CCS can be attributed to intraoperative manipulations.”

One weakness of the study was that there was no actual proof that memory loss took place. Also, there is no evidence that this kind of problem exists with this IOL or other IOLs, Dr. Tsinopoulos acknowledged. “It is conceivable that the material of this specific IOL along with the haptic design and material may have contributed to the development of the capsule contraction syndrome,” Dr. Tsinopoulos reported. “This aspect of IOL design as well as IOL material selection may need to be further scrutinised by the IOL manufacturers.”

But how might memory loss have occurred? Pressure on the first of the haptics implanted could do this in the case of injector-inserted IOLs. Long haptics don’t do anything to help the situation. “Conse-quently, the next generation of this specific IOL has considerably shorter haptics and an overall diameter of 11.0 mm, thus making possible its implantation through a 2.75-mm incision,” Dr. Tsinopoulos noted. Still, ACO as a cause of CCS has been researched less—and there are plenty of other causes that still exist. There also are ways of preventing ACO, such as with a hydrophobic acrylic three-piece IOL compared with a silicone IOL, Dr. Tsinopoulos suggested. But Richard Gruen, M.D., Baltimore, suggested that it’s still difficult to prevent CCS. “It’s unpredictable,” Dr. Gruen said. “I’ve seen it in both the acrylic lenses and PMMA lenses, one piece and three piece.” It’s also hard to treat, he said. “You end up with a lot of work and a big mess,” he said. Dr. Gruen added, however, that he has been using capsular tension rings (CTRs) in patients with loose zonules and hasn’t had any cases of CCS since. He’s hoping that continues to be the case, but isn’t certain it will be. It’s hard to do a good study on CCS because it is rare, he said. If anterior capsule phimosis does occur, anterior capsulotomy using four radial incisions is a safe and effective way to manage the situation, Dr. Tsinopoulos noted. “It is imperative that Nd:YAG laser anterior capsulotomy be performed by an experienced practitioner due to the increased risk of creating pits compared to performing Nd:YAG capsulotomy in the posterior capsule,” Dr. Tsinopoulos also added.

Editors’ note: Dr. Tsinopoulos has no financial interests related to this study. Dr. Gruen has no financial interests related to his comments.

Contact Information

Gruen: 410-654-5700, Rgruen4036@aol.com

Tsinopoulos: galtsin@otenet.gr

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