Factors in late IOL dislocations

In what may be the largest study to date of late dislocations of intraocular lenses (IOLs) placed in the capsular bag during primary cataract surgery, use of intracameral cefuroxime was found to shorten the average interval between implantation and dislocation more than three years, or about one-third. Combining cefuroxime with phenylephrine to dilate pupils shortened the interval more than two additional years, Kari Krootila MD, PhD, told the American Society of Cataract and Refractive Surgery (ASCRS) 2018 Annual Symposium in Washington DC, USA. The retrospective study examined all patients implanted with in-the-bag IOLs during primary cataract surgery at the Helsinki University Hospital, Helsinki, Finland, who subsequently presented with late IOL dislocation from 1997 to 2017. Due to bilateral dislocations, the ongoing study involved 598 eyes in 534 patients at the time of the ASCRS presentation, Dr Krootila said. Overall, the average time from initial implant to late dislocation was 9.7 years. The study correlated the time to dislocation with common risk factors as well as substances introduced during the primary cataract procedure, said Dr Krootila, who is adjunct professor of ophthalmology and head of anterior segment surgery at the University of Helsinki and Helsinki University Hospital. Role of risk factors Phacodonesis at the primary cataract operation shortened the average time to dislocation by 2.2 years while pseudoexfoliation shortened it by one year, Dr Krootila reported. About half of patients who experienced a late dislocation had pseudoexfoliation, making it the most common risk factor. A few patients each had risk factors including trauma, glaucoma, retinitis pigmentosa and high myopia, while about one-third of patients had no known risk factor. Presence of diabetes or systemic connective tissue disease had no effect on time to dislocation, he added. For substances introduced at surgery, cefuroxime alone decreased the average interval to dislocation by about 3.2 years, from 10.9 ± 4.7 years to 7.7 ± 3.5 years (p<0.001). Adding lidocaine did not significantly decrease the interval further, while adding lidocaine and phenylephrine reduced the average interval another 2.2 years, to 5.5 ± 1.9 years (p<0.01). “Our observation is based solely on our clinical study and so far we have only speculations about the mechanism. I have also not seen any other clinical data supporting our finding, perhaps because our [study] is, to our knowledge, the largest so far regarding late dislocation of ‘IOL-in-the bag’,” Dr Krootila told EuroTimes. Further study is needed to understand the findings. Kari Krootila: kari.krootila@hus.fi

Tags: cataract and refractive, IOL