An observational study in Cataract and Phakic Intraocular Lens Explantation, sponsored by Maastricht University Medical Center. Completed at 1 site in Netherlands. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-10-01.
Sponsored by Maastricht University Medical Center · Observational
Rationale: The number of highly myopic patients is increasing. Especially in East and Southeast Asia, up to 90% of adolescents are currently myopic. Long-term treatment of high myopia can be obtained by three types of surgery: laser refractive surgery, phakic intraocular lens (pIOL) implantation, and refractive lens exchange Implantation with a pIOL is the preferred treatment for high myopes, resulting in increasing patient numbers implanted due to the increasing numbers of patients with high myopia.
Long-term results show that implantation of a pIOL induces an accelerated decrease in corneal endothelial cells (EC). Although some risk factors for increase EC loss have been identified, the underlying mechanism is currently unknown. It is hypothesized that the aqueous flow in the anterior segment of the eye (i.e. anterior chamber) is disturbed, causing an altered nutritional flow in the anterior chamber. Another hypothesis is that the pIOL causes chronic subclinical inflammation in the anterior chamber resulting in increased EC loss. Currently there is insufficient proof to confirm or reject either hypothesis. If one of these hypotheses can be confirmed, it is likely to induces significant changes in clinical practice.
Objective: The primary objective of the study is to explore the role of inflammation in the anterior chamber on endothelial cell loss in patients implanted with iris-fixated pIOLs. The secondary objective is to identify whether there is a correlation between biomarkers in aqueous humour and biomarkers in tears, both related to the accelerated progression of EC loss.
Study design: Two strategies are incorporated in the design of this study. The first part will retrospectively evaluate EC loss in patients with iris-fixated (IF) phakic intraocular lenses (pIOLs). The second part is prospective and will compare EC measurements, cytokines in aqueous humour and in tears from patients scheduled for IF-pIOLs explantation and compare them to patients with routine cataract surgery.
Study population: Patients over 18 years of age, undergoing regular cataract surgery, and patients undergoing pIOL explantation in combination with cataract surgery. A total number of 126 patients is needed, equally divided over two groups.
1,701 studies on the registry are indexed under Cataract; 230 are open to participants now.
This study's enrollment of 126 is above the median of 81 across 484 observational studies indexed under Cataract.
Browse Cataract studies →Maastricht University Medical Center is the lead sponsor of 835 studies on the registry; 122 are open to participants now.
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Two groups will be included to compare endothelial cell loss due to inflammation in affected (i.e. iris-fixated [IF] phakic intraocular lens [pIOL] implanted) versus healthy (i.e. scheduled for regular cataract surgery) eyes.
Exclusion Criteria:
Patients with pIOLs where a combined pIOL explantation and cataract surgery is needed.
Procedure: Phakic intraocular lens (pIOL) explantation
Healthy control group of patients scheduled for regular cataract surgery without comorbidities affecting an immune response.
Phakic intraocular lens (pIOL) explantation is a surgical procedure to remove the pIOL which needs to be done after cataract formation. Cataract extraction is a surgical procedure to remove a lens in the eye that has become cloudy over time, affecting vision in that eye.
Also known as: Cataract extraction
Difference in pro- inflammatory cytokine levels between patients undergoing a pIOL explantation in combination with a cataract surgery compared to patients only undergoing cataract surgery in aqueous humour.
Cytokines of interest are IFN-γ, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, TNF-α, MMP9. Detection will be in pg/mL.
Time frame: up to 12 months after surgery
Correlation between inflammatory biomarkers (cytokines) in the aqueous humour and in tears
The following assay will be used: MSD multiplex pro-inflamatory kit.
Time frame: up to 12 months after surgery
Progress of EC loss after combined IF-pIOL explantation and cataract surgery compared to cataract surgery as a single procedure.
Progress will be measured with non-contact specular microscopy which will be the same for all patients.
Time frame: up to 12 months after surgery
Plan to share: No
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This study is completed, as verified in May 2025. You cannot join it, but the record below documents what was studied.
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Maastricht University Medical Center