CataractMoBackNCT04174924
Molecular Background of Endothelial Cell Loss in Patients With Phakic Intraocular Lenses: a Tear and Aqueous Humour Analysis Study
An observational study of Cataract and Phakic Intraocular Lens Explantation, run by Maastricht University Medical Center at 1 site in Netherlands.
Trial 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… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Cataract, Phakic Intraocular Lens Explantation
- What is being tested?
- Phakic intraocular lens (pIOL) explantation
- Type of treatment
- Surgery or procedure
- How many people
- 126 participants
- Where
- 1 siteNetherlands
- Study dates
- 2 Jul 2020to 1 May 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: 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.
Who may be able to join
- Age over 18
- Cataract in one or both eyes, or indication for pIOL explantation
- Informed and having given informed consent.
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
Netherlands1 site
Maastricht University Medical Centre
Maastricht, Limburg, 6202 AZ
About this study
Official title: Molecular Background of Endothelial Cell Loss in Patients With Phakic Intraocular Lenses (MoBack-ECL): a Tear and Aqueous Humour Analysis Study
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.
Read more
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
- Being tested
- Phakic intraocular lens (pIOL) explantation
- Medical subject headings
- Cataract
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Phakic intraocular lens (pIOL) explantationProcedure or surgery
Also called Cataract extraction
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.
| Study group | Role | What they receive |
|---|---|---|
| Phakic intraocular lens (pIOL) explantation | Patients with pIOLs where a combined pIOL explantation and cataract surgery is needed. Receives: Procedure: Phakic intraocular lens (pIOL) explantation | |
| Cataract extraction | Healthy control group of patients scheduled for regular cataract surgery without comorbidities affecting an immune response. |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: up to 12 months after surgery
Secondary outcomes (2)
Correlation between inflammatory biomarkers (cytokines) in the aqueous humour and in tears
The following assay will be used: MSD multiplex pro-inflamatory kit.
Measured: 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.
Measured: up to 12 months after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Nov 2019
- Study start2 Jul 2020
- Primary completion1 Feb 2025
- Study completion1 May 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for CataractStudies of the same condition, open and under way.
- More trials run by Maastricht University Medical CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 126 participants (actual)
Sponsor and investigators
- Lead sponsor
- Maastricht University Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04174924
- Sponsor's protocol ID
- NL70342.068.19
- Acronym
- MoBack
- Status last verified
- May 2025
- First submitted
- 15 Nov 2019
- Last updated
- 1 Oct 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Oct 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Molecular Background of Endothelial Cell Loss in Patients With Phakic Intraocular Lenses (MoBack-ECL): a Tear and Aqueous Humour Analysis Study
- ClinicalTrials.gov ID
- NCT04174924
- Acronym / sponsor ID
- MoBack / NL70342.068.19
- Conditions
- Cataract, Phakic Intraocular Lens Explantation
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 126 participants (actual)
- Lead sponsor
- Maastricht University Medical CenterUniversity, hospital or other
- Study start
- 2 Jul 2020 (actual)
- Primary completion
- 1 Feb 2025 (actual)
- Study completion
- 1 May 2025 (actual)
- First posted
- 22 Nov 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Phakic intraocular lens (pIOL) explantation | – | Procedure: Phakic intraocular lens (pIOL) explantationPatients with pIOLs where a combined pIOL explantation and cataract surgery is needed. |
| Cataract extraction | – | –Healthy control group of patients scheduled for regular cataract surgery without comorbidities affecting an immune response. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- 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.
Key inclusion criteria (3 listed)
- Age over 18
- Cataract in one or both eyes, or indication for pIOL explantation
- Informed and having given informed consent.
Key exclusion criteria (8 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Phakic intraocular lens (pIOL) explantationAlso: Cataract extractionPhakic 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. | Procedure or surgery | Phakic intraocular lens (pIOL) explantation |
Primary outcome
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.
Time frame: up to 12 months after surgery
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.
2 secondary outcomes
Correlation between inflammatory biomarkers (cytokines) in the aqueous humour and in tears
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.
Time frame: up to 12 months after surgery
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Oct 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Cataract and Phakic Intraocular Lens Explantation, run by Maastricht University Medical Center at 1 site in Netherlands.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 1 Oct 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Netherlands. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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. (time frame: up to 12 months after surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Oct 2025.