Molecular Background of Endothelial Cell Loss in Patients With Phakic Intraocular Lenses: a Tear and Aqueous Humour Analysis Study

NCT ID: NCT04174924

Last Updated: 2025-10-01

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 126 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2020-07-02
• Study Completion Date: 2025-05-01

Brief Summary

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.

Conditions

Cataract; Phakic Intraocular Lens Explantation

Study Design

• Observational Model Type: CASE_CONTROL
• Study Time Perspective: PROSPECTIVE

Study Groups

Phakic intraocular lens (pIOL) explantation

Patients with pIOLs where a combined pIOL explantation and cataract surgery is needed.

Phakic intraocular lens (pIOL) explantation

Intervention Type: PROCEDURE

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.

Cataract extraction

Healthy control group of patients scheduled for regular cataract surgery without comorbidities affecting an immune response.

No interventions assigned to this group

Interventions

Phakic intraocular lens (pIOL) explantation

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.

Intervention Type: PROCEDURE

Other Intervention Names

Cataract extraction

Eligibility Criteria

Inclusion Criteria

• Age over 18
• Cataract in one or both eyes, or indication for pIOL explantation
• Informed and having given informed consent.

Exclusion Criteria

• Insufficient understanding of the Dutch language to comply with study procedures
• Inability to complete follow-up or comply with study procedures
• Non-routine cataract surgery
• Cognitive or behavioral conditions that might interfere with surgery
• Patients with ocular comorbidities such as
• Women who are pregnant or nursing their child
• Immune-compromised patients (e.g., systemic corticosteroid use, leukaemia)
• Factors that increase the risk of complicated surgery

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Maastricht University Medical Center

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Maastricht University Medical Centre

Maastricht, Limburg, Netherlands

Countries

Netherlands

Other Identifiers

NL70342.068.19

Identifier Type: -

Identifier Source: org_study_id