Risk and protective factors of late in-the-bag intraocular lens dislocations: systematic review

To identify and review published articles addressing risk and protective factors of late in-the-bag (ITB) intraocular lens (IOL) dislocations.

Prevention of this complication is of great importance considering the great number of cataract cases and its vision-threatening capacity.

A structured search on PubMed (MEDLINE) using both Medical Subject Headings and key words was conducted. In addition, the reference lists of the resulting articles were screened for further publications. Articles were eligible if they included 20 or more patients. Hazard and odds ratios were analyzed if they were calculated in the original study. The relative frequency of risk factors was recorded if hazard or odds ratios were not available. The threshold for clinical significance was set at 10%. Risk-of-bias in individual studies was evaluated using the revised Cochrane risk-of-bias tool in randomized trials (RoB 2.0) and the Cochrane risk-of-bias in nonrandomized studies of intervention tool.

Database search identified 3474 records, and no further records were obtained from the reference lists. After exclusion of records not related to the topic, 177 articles were assessed for eligibility. Of these, 39 were considered eligible and read in full. 3 studies were prospective, while all other investigations were retrospective. In total, 18 614 cases of late ITB dislocations were analyzed across all studies. The risk of bias within studies was considerable because only 3 studies were prospective and statistical significance of risk factors was assessed in only 5 studies.

Typical patient age of this condition is between 70 and 85 years, and there seems to be a slight male predominance. Risk factors with a good level of evidence include preoperative trauma and zonular dehiscence, previous vitrectomy, retinitis pigmentosa, pseudoexfoliation, high myopia, glaucoma/previous glaucoma surgery, corneal endothelial damage, and uveitis. Hydrophilic, quadripode, and haptic-angulation IOLs are further risk factors. Capsular tension rings, Nd:YAG capsulotomy, 3-piece IOLs, and IOLs with large optic diameters protect from ITB dislocations. Typically, no risk factors can be identified in approximately one-fourth of patients.