Evaluating the Effect of Optical Zones on Correction for SMILE: Vector Analysis

August 17, 2021 updated by: Tianjin Eye Hospital

Evaluating the Effect of Optical Zones on Myopia and Astigmatism Correction in SMILE: Vector Analysis

Evaluate the effect of the size of optical zones (OZ) on myopia and astigmatism correction in small incision lenticular extraction.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

To retrospectively study whether different surgical optical zone sizes affect the correction of diopter and astigmatism in myopia patients. Divided into 2 groups according to the diameter of the optical zone. The vector analysis method was used to analyze the changes and errors of astigmatism in TR and SIR after operation. Generalized Estimation Equation (GEE) model is used for multiple regression analysis to evaluate the potential factors related to the error value.

Study Type

Observational

Enrollment (Actual)

140

Contacts and Locations

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

Study Locations

  • China
      • Tianjin, China
        • TianJin eye hospital

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

Ages Eligible for Study

18 years to 45 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

age of patients between 18-45 years; spherical refraction of -3.00 to -6.00 diopters (D) with or without astigmatism (<-3.00 D); spherical equivalent, -3.00 to -6.00 D; corrected distant visual acuity (CDVA), >20/25

Description

Inclusion Criteria:

  • no ocular conditions
  • normal topography
  • central corneal thickness, >500µm
  • residual stromal thickness, >280 µm
  • pupil diameter, 2.78-4.9 mm (average, 3.76±0.43 mm);

Exclusion Criteria:

  • history of intraocular surgery
  • pupil diameter, >4.9 mm or <2.78mm
  • keratoconus or corneal ectasia

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
Intervention / Treatment
group A
small optical zone
Procedure: small incision lenticular extraction
In patients with the same degree of myopia, different optical zones were designed for operation
group B
large optical zone
Procedure: small incision lenticular extraction
In patients with the same degree of myopia, different optical zones were designed for operation

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
astigmatic changes
Time Frame: 2021.03
Observe the effect on changes in astigmatism by target induced astigmatism (TIA) versus surgically induced astigmatism (SIA)
2021.03
error value
Time Frame: 2021.04
Target refraction (TR) and surgically induced refraction (SIR) under different optical zones
2021.04

Collaborators and Investigators

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

Sponsor

Tianjin Eye Hospital

Investigators

  • Study Chair: yan wang, TianJin eye hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

August 1, 2020

Primary Completion (Actual)

December 31, 2020

Study Completion (Actual)

August 1, 2021

Study Registration Dates

First Submitted

August 11, 2021

First Submitted That Met QC Criteria

August 17, 2021

First Posted (Actual)

August 23, 2021

Study Record Updates

Last Update Posted (Actual)

August 23, 2021

Last Update Submitted That Met QC Criteria

August 17, 2021

Last Verified

August 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • TJYYLL-202034

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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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