Looming epidemic

There has been a sharp increase in the rate of late intraocular lens (IOL) dislocations in Sweden and other countries over the last decade, and the number of patients with the complication is likely to increase in coming years, said Ulf Stenevi MD, Sahlgrenska University Hospital, Mölndal, Sweden, at the XXXIII Congress of the ESCRS in Barcelona.

He noted that studies carried out in Sweden show that the rate of late IOL dislocation in that country – usually occurring several years after IOL implantation – began to increase markedly starting around 2004 and that the complication occurs in around a half a per cent to one per cent of patients. Research also suggests that other countries may be experiencing a similar trend.

The increase in late IOL and capsule subluxation appeared to follow, in a delayed fashion, the widespread introduction of phacoemulsification in the 1990s. If current trends continue, the incidence of IOL dislocations is likely to double in the next seven to eight years, given the increasing numbers of cataract procedures performed annually.

He noted that all authors agree that pseudoexfoliation is the most important risk factor for IOL dislocation. That is probably due to the weaker zonules and thinner, more brittle capsules in eyes with the condition. Other risk factors include concomitant eye disease, previous eye surgery, long axial length, and long phacoemulsification time.

He recommended referring patients at high risk for IOL dislocation to the most experienced surgeons available, and he suggested that extracapsular cataract surgery might be the best option in some cases.

CAPSULAR CONTRACTION

In a related presentation, Liliana Werner MD, PhD, John A Moran Eye Center, University of Utah, Salt Lake City, USA, noted that histopathological studies indicate that dislocation and subluxation occurs with a broad range of IOL designs and that capsular tension rings do not prevent the complication or the capsular contraction that can precipitate it.

In addition, a recent study conducted at the Moran Eye Center showed that histopathology detected pseudoexfoliation in 26 (65 per cent) of 40 consecutive explanted specimens, although the condition was noted in only 13 of the eyes involved at the time of cataract surgery, a mean of 8.5 years earlier.

Miad Pour Sadeghian MD, Goethe University Frankfurt, Germany, where the explantations were mainly performed by Prof Thomas Kohnen, noted that following the explantations most eyes received retropupillary Artisan® IOLs. The mean postoperative uncorrected visual acuity was 1.250 logMAR, compared to 1.476 logMAR upon admission, and their mean postoperative best corrected visual acuity was 0.733 logMAR.

Ulf Stenevi: ulf.stenevi@oft.gu.se

Liliana Werner: werner.liliana@gmail.com

Miad Pour Sadeghian,
C/O Thomas Kohnen:
kohnen@em.uni-frankfurt.de

Tags: myopic choroidal neovascularisation