- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT03394300
Accuracy of Intraocular Lens Power in High Myopia
Study Overview
Detailed Description
High myopia or pathological myopia is associated with elongation of axial length longer than 26 mm or refractive error at least-6 diopter.
High myopia is one of the most prevalent refractive condition globally with a higher risk of other eye conditions Moreover in high myopic eyes the incidence of cataract is significantly higher than in non myopic eyes and the progression is also faster.
Calculation of IOL in high myopic eyes remains a challenge often leading to unexpected postoperative hyperopia the main potential sources of errors in IOL calculation for high myopic eyes include AL measurement & IOL constants used &IOL power calculation formula used.
investigators suspect that the SRK I1 formula is inaccurate for myopic eyes, and that new formulas are needed, taking into account all those factors that make up the dioptric power of an eye.
Formulas for IOL power calculation had past four generations, first generation formulas were theoretical and based on the same fundamental constant with no respect to anterior chamber depth. Since then, Binkhorst, Holladay, Hoffer and Shammas had refined the existing theoretical formulas where each of them developed his regression formula based on analysis of their previous IOL cases .
This work was amalgamated in 1980 and yielded the Sanders Retzlaff Kraff I (SRKI) formula The second generation was designed by combining linear regression analysis and stepwise adjustment for long and short eyes according to anterior chamber depth .
The third and fourth generation formulas, started by Holladay in 1988, all aimed at better calculation of the IOL power in eyes with extreme axial length where another term had appeared which is IOL specific anterior chamber depth .
The accuracy of third and fourth generation formulas for IOL calculation in patients with high axial myopia had not been fully evaluated For that, the need for more studies conducted to evaluate such accuracy is crucial.
This study will be conducted to evaluate the accuracy of different formulas used for IOL power calculation in patients with high axial myopia undergoing cataract surgery
Study Type
Enrollment (Anticipated)
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Sampling Method
Study Population
Description
Inclusion Criteria:
- 1- patients with clear lense extraction or cataract & high myope with{ AL more than 26 mm.
2-their IOLpower is less than 15 diopter or their refraction before operation is more than -6.
Exclusion Criteria:
- Keratoconus patients or those with irregular cornea
- Patients with post operative complications like posterior capsule injury or vitrous loss.
- patients who had undergone previous intraocular surgery at anterior segment or posterior segment.
Study Plan
How is the study designed?
Design Details
- Observational Models: Case-Crossover
- Time Perspectives: Prospective
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
accuracy of iol power in high myopia
Time Frame: one year
|
biometry assment of IOLpower
|
one year
|
Collaborators and Investigators
Sponsor
Study record dates
Study Major Dates
Study Start (Anticipated)
Primary Completion (Anticipated)
Study Completion (Anticipated)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- 29110202500209
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
IPD Plan Description
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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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