The Changes Under Different Accommodation of Anterior Eye and 3D Crystal Reconstruction.

May 19, 2025 updated by: Second Affiliated Hospital, School of Medicine, Zhejiang University

To Study the Changes Under Different Accommodation of Anterior Eye in People of Different Ages and 3D Crystal Reconstruction.

Accommodation is defined as a dynamic change in the overall refractive power of the eye during near fixation. Despite extensive investigations, the exact nature of human accommodation remains controversial. And recent alternative theories question the original concept of accommodation.Different experts have put forward different hypotheses. The age-related changes that underlie presbyopia are also not fully understood.Because of these unanswered questions, the topic of regulation and presbyopia remains a focus of research.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Accommodation is the process by which the eye changes the shape and diopter of the lens to obtain a clear image of an object at different distances. Despite extensive research on regulation, the exact nature of human regulation remains controversial. Age-related changes in presbyopia are also not fully understood. Some studies have shown that a hardening of the lens and an increase in the thickness and diameter of the lens with age can lead to presbyopia. Others believe that the main cause is external lens factors, such as age-related changes in the Angle of lens suspension ligament attachment, reduced ciliary body movement, etc. Due to these unanswered questions, the topic of regulation and presbyopia remains the focus of research. In living humans, modulation studies utilize different imaging modes, and ultrasound biomicroscopy (UBM) and Optical Coherence Tomography(OCT) are particularly important in studying anterior segments and modulation. However, UBM is a contact inspection and requires highly skilled technicians. And UBM cannot image the entire anterior segment in a single capture. Anterior segment OCT (AS-OCT), on the other hand, is non-invasive and provides higher resolution imaging, allowing us to capture the morphology of the anterior segment structures in different populations and the changes of the anterior segment structures in response to regulatory stimuli. Studies have shown that with age, reduced anterior chamber depth, pupil contraction, increased lens thickness, increased lens arch height, and loss of posterior ciliary muscle contraction may be biomarkers of early presbyopia. In this study, anterior segment OCT was used to explore whether there were differences in the structural morphology of the anterior segment in people of different ages, and what changes occurred in the structure of the anterior segment after initiation of regulation.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
120

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
    • Zhejiang
      • Hangzhou, Zhejiang, China, 310009
        • Recruiting
        • Second Affiliated Hospital, Zhejiang University School of Medicine
        • Contact:
      • Hangzhou, Zhejiang, China, 310009
        • Not yet recruiting
        • Second Affiliated Hospital, Zhejiang University School of Medicine
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

Age 20-80 years old; Astigmatism ≤-1.50D; Best corrected visual acuity ≥4.9;Excluding other systemic underlying diseases; Have a history of eye surgery; Patients with intraocular lens or aphakia; Patients with strabismus and amblyopia; Pregnant or lactating women; People with mental disorders or neurological diseases who cannot cooperate with the examination;

Description

Inclusion Criteria:

· Patients with astigmatism ≤-1.50D and best corrected visual acuity ≥4.9

Exclusion Criteria:

  • Patients with other systemic diseases
  • Patients with a history of eye surgery
  • Patients with intraocular lens or aphakia
  • Patients with strabismus and amblyopia
  • Pregnant or lactating women
  • People with mental disorders or neurological diseases who cannot cooperate with the examination

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Group A was 20-40 years old
They were divided into three groups according to age: A, B, and C.Group A was 20-40 years old.
Group B was 40-60 years old
They were divided into three groups according to age: A, B, and C. Group B was 40-60 years old.
Group C was 60-80 years old
They were divided into three groups according to age: A, B, and C. Group C was 60-80 years old.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Central corneal thickness changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
Central corneal thickness CCT(μm)
Baseline, after accommodation(30 minutes after using pilocarpine)
peripheral corneal thickness changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
peripheral corneal thickness(μm)
Baseline, after accommodation(30 minutes after using pilocarpine)
anterior chamber depth changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
anterior chamber depth ACD(mm)
Baseline, after accommodation(30 minutes after using pilocarpine)
anterior chamber Angle Angle changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
anterior chamber Angle Angle ACA(°)
Baseline, after accommodation(30 minutes after using pilocarpine)
anterior opening distance changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
anterior opening distance AOD(mm)
Baseline, after accommodation(30 minutes after using pilocarpine)
pupil size changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
pupil size PD(mm)
Baseline, after accommodation(30 minutes after using pilocarpine)
lens thickness changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
lens thickness LT(mm)
Baseline, after accommodation(30 minutes after using pilocarpine)
anterior and posterior surface curvature radius changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
anterior and posterior surface curvature radius(mm)
Baseline, after accommodation(30 minutes after using pilocarpine)
lens arch height changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
lens arch height LV(mm)
Baseline, after accommodation(30 minutes after using pilocarpine)
lens sagittal height changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
lens sagittal height(mm)
Baseline, after accommodation(30 minutes after using pilocarpine)
anterior chamber volume changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
anterior chamber volume(mm³)
Baseline, after accommodation(30 minutes after using pilocarpine)
posterior chamber volume changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
posterior chamber volume(mm³)
Baseline, after accommodation(30 minutes after using pilocarpine)
crystal equatorial diameter changes during accommodation
Time Frame: Baseline, after accommodation(30 minutes after using pilocarpine)
crystal equatorial diameter(mm)
Baseline, after accommodation(30 minutes after using pilocarpine)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Second Affiliated Hospital, School of Medicine, Zhejiang University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Wen Xu, Phd, Second Affiliated Hospital, School of Medicine, Zhejiang University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 27, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 17, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 24, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 26, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 23, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 19, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2024-0939

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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