Late in-the-bag intraocular lens dislocation

Authors: Kristianslund O, Dalby M, Drolsum L.

Geographical coverage: North America, Europe, and Asia

Sector: Cataract surgery

Sub-sector: Intraocular lens dislocation

Equity focus: Not reported

Study population: Patients with cataract

Review type: Effectiveness review

Quantitative synthesis method: Narrative synthesis

Qualitative synthesis method: Not applicable

Background:

In recent years, late in-the-bag intraocular lens (IOL) dislocation has emerged as a significant concern following cataract surgery, primarily affecting older patients. This condition is characterised by displacement of the IOL within the lens capsule occurring several years post-operation. Patients typically present 6–12 years after cataract surgery with symptoms such as blurred vision, glare, or diplopia. Predisposing factors include pseudoexfoliation syndrome (PEX) – reported in 31–83% of cases – as well as high myopia, prior vitreoretinal surgery, trauma, uveitis, and certain connective tissue disorders. Surgical intervention (IOL repositioning or IOL exchange) is often required to correct the dislocation. The current evidence base is limited, mostly comprising retrospective case series, underscoring the need for further high-quality research to optimise management approaches.

Objective:

To provide an updated overview of the literature on late in-the-bag IOL dislocation, specifically detailing the cumulative incidence of the condition, patient characteristics and risk factors, main surgical treatment options, potential surgical complications, and expected outcomes.

Main Findings:

The review analysed 40 clinical studies on late in-the-bag IOL dislocation, mostly retrospective, with only one RCT. Cumulative incidence was 0.5–3% over 10–25 years after cataract surgery, usually presenting 6–12 years post-op. Patients were generally older adults (65–85 years); main risk factors included pseudoexfoliation syndrome (31–83% of cases), high myopia, previous vitreoretinal surgery, ocular trauma, uveitis, and connective tissue disorders. No sex predominance was reported.

Two main surgical options were identified: IOL repositioning (using scleral sutures or capsular tension devices) and IOL exchange (removal and replacement of the lens). Both approaches yielded similar visual outcomes. IOL exchange was associated with a slightly higher risk of intraoperative complications, though overall prognosis was good.

Complications included cystoid macular oedema (0–24%), elevated intraocular pressure, and retinal detachment (3–8%). Most patients maintained good vision post-surgery unless limited by other eye diseases. No long-term difference in complication rates was observed between the two surgical methods.

Methodology:

The literature search was conducted through June 2020 in multiple databases, including PubMed, Embase, and the Cochrane Database of Systematic Reviews. The search strategy aimed to identify all relevant studies on surgical management of late in-the-bag IOL dislocation. This included not only RCTs but also observational clinical studies in which at least 50% of participants (minimum of 10 patients) had late in-the-bag IOL dislocation. The search was restricted to English-language publications; no date limits were applied. Reference lists of included studies were scanned for additional citations, though no specific efforts were made to retrieve unpublished data or grey literature.

The study selection and data extraction were performed by a single reviewer. Key information was compiled on study design, sample size, patient characteristics, risk factors, interventions used, and outcomes. Given the heterogeneous and mostly non-randomised nature of the evidence, a narrative synthesis approach was used to summarise findings qualitatively. Quality appraisal was carried out using Cochrane risk-of-bias tools appropriate to each study design: the RoB 2.0 tool for the lone RCT and the ROBINS-I tool for non-randomised studies. The results of individual studies were discussed in light of their methodological quality, but the review did not systematically correlate outcomes with risk-of-bias scoring in the text.

Applicability / External Validity:

The review highlighted that evidence mainly comes from specialised centres and small, retrospective case series, which limits generalisability. Variations in surgical technique and inclusion of only English-language studies may have excluded relevant data. Because late IOL dislocation often occurs long after cataract surgery, evolving surgical practices and lens designs may affect outcomes. The authors emphasise the need for prospective multicentre studies to compare surgical strategies and assess long-term results, which would improve guidance for managing this complication.

Geographical Focus:

No strict geographical criteria were used, but most studies appeared to come from North America, Europe, and some Asian centres. Since late IOL dislocation is a global issue, findings may still apply broadly. However, the review did not clarify regional variations or give detailed location data, so local patient factors should be considered when interpreting results.

Summary of Quality Assessment:

The overall confidence in this review’s conclusion is low due to the predominance of retrospective case series and just one RCT. The review used clear criteria and appropriate bias assessment tools but was limited by including only English-language studies, relying on a single reviewer, and not seeking unpublished data. Most studies lacked control groups and used varied follow-up times, limiting strong conclusions. While surgical techniques for late in-the-bag IOL dislocation appear similarly effective and PEX is a major risk factor, higher-quality studies are needed for definitive guidance.