Two surgical methods effective for late in-the-bag IOL dislocation
Patients who underwent lens repositioning or lens exchange both experienced similar BCVA outcomes 6 months after surgery.
The frequency of late in-the-bag IOL dislocation has increased in recent years, and a prospective, randomized, parallel-group trial found both lens repositioning and lens exchange surgery were effective surgical options to treat dislocation.
There has been no clear consensus on which surgical method to use for late in-the-bag IOL dislocation, but both lens repositioning and lens exchange surgery provided adequate improvement in best corrected visual acuity 6 months after surgery and few serious complications, Olav Kristianslund, MD, told Ocular Surgery News.
“In our randomized trial we found that the two different operation methods, IOL repositioning and IOL exchange, had equal visual outcome 6 months after surgery. So, in most patients with late in-the-bag IOL dislocation, both these operation methods are good options,” he said.
Both effective methods
Kristianslund and colleagues randomized 104 patients to either IOL repositioning by scleral suturing or IOL exchange with retropupillary fixation of an iris-claw IOL. Each patient was given a preoperative examination, which included refraction and measurement of BCVA using the ETDRS visual acuity chart.
Fifty patients were randomized to IOL exchange with retropupillary fixation of an iris-claw IOL, and 54 were randomized to IOL repositioning by scleral suturing.
Both groups experienced a statistically significant improvement in BCVA 6 months after surgery. The mean BCVA at 6 months was 0.24 ± 0.29 logMAR in the repositioning group and 0.35 ± 0.54 logMAR in the exchange group; the between-group difference was not statistically significant.
In the repositioning group, 61% of patients achieved a BCVA of 20/40 or better, compared with 62% of exchange patients.
Secondary outcomes different
However, there were differences in the secondary outcomes between the two surgical methods, Kristianslund said.
“While the main outcome measure, best corrected visual acuity 6 months after surgery, was evaluated as equal between the two operation groups, the secondary outcome measure, postoperative endothelial cell density loss, was significantly more pronounced in the IOL exchange group. This may have been related both to surgical factors and to postoperative inflammation. It should be emphasized, though, that there was some uncertainty related to some missing data for this parameter,” he said.
The surgical time in the repositioning group was significantly longer compared with the exchange group. This is relevant because many patients undergoing late in-the-bag IOL dislocation are elderly and cannot lie on their backs for a significant amount of time during a lengthy procedure, he said.
Which method suits which patient?
The IOL exchange procedure resulted in more frequent occurrences of vitreous prolapse into the anterior chamber, “which is expected with removal of the whole IOL/capsule complex during this type of surgery,” Kristianslund said.
“Vitreous prolapse increases the risk of retinal detachment, but we were satisfied to register that no patients suffered from this complication. IOL exchange also had significantly more iris injuries, but these were only minor cases,” he said.
To determine which patient is best suited for either surgical method, Kristianslund said their characteristics are assessed to see if they are at higher risk for certain complications. Additionally, preoperative evaluations reveal patient factors that favor one of the operation methods over the other.
“In some patients only one of the methods is suitable, for example, related to IOL designs that preclude scleral suturing or large iris defects that make iris-claw IOLs unfavorable. Such factors were exclusion criteria in our study,” Kristianslund said. – by Robert Linnehan
- Kristianslund O, et al. Ophthalmology. 2016;doi:10.1016/j.ophtha.2016.10.024.
- For more information:
- Olav Kristianslund, MD, can be reached at Department of Ophthalmology, Oslo University Hospital, Ullevål, Kirkeveien 166 N-0407, Oslo, Norway; email: email@example.com.
Disclosure: Kristianslund reports his PhD scholarship is funded by the Norwegian ExtraFoundation for Health and Rehabilitation, which has no commercial interests in the research and had no role in the conduct or design of the study.