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

NCT06704503 | Recruiting DMC

• 1 other identifier: 2024-0939
• Study Type: observational
• Target: 120
• Locations: 1 country
• Sites: 2

Brief Summary

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.

Conditions

Accommodation

Outcome Measures

Primary Outcomes (13)

• Central corneal thickness changes during accommodation

  Central corneal thickness CCT(μm)

  Baseline, after accommodation(30 minutes after using pilocarpine)

• peripheral corneal thickness changes during accommodation

  peripheral corneal thickness(μm)

  Baseline, after accommodation(30 minutes after using pilocarpine)

• anterior chamber depth changes during accommodation

  anterior chamber depth ACD(mm)

  Baseline, after accommodation(30 minutes after using pilocarpine)

• anterior chamber Angle Angle changes during accommodation

  anterior chamber Angle Angle ACA(°)

  Baseline, after accommodation(30 minutes after using pilocarpine)

• anterior opening distance changes during accommodation

  anterior opening distance AOD(mm)

  Baseline, after accommodation(30 minutes after using pilocarpine)

• pupil size changes during accommodation

  pupil size PD(mm)

  Baseline, after accommodation(30 minutes after using pilocarpine)

• lens thickness changes during accommodation

  lens thickness LT(mm)

  Baseline, after accommodation(30 minutes after using pilocarpine)

• anterior and posterior surface curvature radius changes during accommodation

  anterior and posterior surface curvature radius(mm)

  Baseline, after accommodation(30 minutes after using pilocarpine)

• lens arch height changes during accommodation

  lens arch height LV(mm)

  Baseline, after accommodation(30 minutes after using pilocarpine)

• lens sagittal height changes during accommodation

  lens sagittal height(mm)

  Baseline, after accommodation(30 minutes after using pilocarpine)

• anterior chamber volume changes during accommodation

  anterior chamber volume(mm³)

  Baseline, after accommodation(30 minutes after using pilocarpine)

• posterior chamber volume changes during accommodation

  posterior chamber volume(mm³)

  Baseline, after accommodation(30 minutes after using pilocarpine)

• crystal equatorial diameter changes during accommodation

  crystal equatorial diameter(mm)

  Baseline, after accommodation(30 minutes after using pilocarpine)

Study Arms (3)

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.

Eligibility Criteria

• Age: 20 Years - 80 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• 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;

You may qualify if:

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

You may not qualify if:

• 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

Sponsors & Collaborators

• Second Affiliated Hospital, School of Medicine, Zhejiang University: lead

Study Sites (2)

Second Affiliated Hospital, Zhejiang University School of Medicine

Hangzhou, Zhejiang, 310009, China

NOT YET RECRUITING

Second Affiliated Hospital, Zhejiang University School of Medicine

Hangzhou, Zhejiang, 310009, China

RECRUITING

Biospecimen

Retention: SAMPLES WITHOUT DNA

Age 20-80 years old; Astigmatism ≤-1.50D; Best corrected visual acuity ≥4.9. Excluding people with 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;

Study Officials

• Wen Xu, Phd

  Second Affiliated Hospital, School of Medicine, Zhejiang University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Wen Xu, Phd

CONTACT

+86-13858185223; xuwen2003@zju.edu.cn

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Target Duration: 1 Day
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 17, 2024
• First Posted: November 26, 2024
• Study Start: November 27, 2024
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2028
• Last Updated: May 23, 2025

Record last verified: 2025-05

Locations

CN (2)