AstigmatismNCT04913883
Laser Correction of Astigmatism Using Vector Analysis
An observational study of Astigmatism, run by Assiut University.
Trial summary
To determine the effectiveness of correcting astigmatism by laser refractive surgery by a vectorial astigmatism outcome analysis that uses 3 fundamental vectors : target induced astigmatism vector ( TIA) , surgically induced astigmatism vector , and difference vector , as described by Alpins method. Read more about this study
- Who is it for?
- Ages 18 to 40 years
- Conditions the study is for
- Astigmatism
- How many people
- 50 participants
- Where
- No sites listed yet
- Study dates
- Jul 2021to Aug 2022
- 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 to 40 years
- All sexes
- Adult
Study population: Study will include 50 patients in different ages .
Who may be able to join
- At least 18 years of age .
- Stable eyeglass and contact lenses prescription for at least 2 to 3 years .
- Stable vision over at least the past year .
- No history or findings of active corneal disease .
- No significant dry eye .
- Not pregnancy or nursing .
- Refractive cylinder more than -1D (Diopter) .
Who cannot join
- Certain conditions make the method inadvisable :
- Residual , recurrent or active ocular disease such as uveitis , sever dry eyes , sever allergic eye disease , glaucoma visually significant cataract , and retinal disease .
- Previous corneal surgery or trauma within the corneal flap zone .
- Patent corneal vascularisation within 1mm of the corneal flap zone .
- Age less than 18 years old .
- Pregnancy or breast feeding .
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- Certain medical conditions such as autoimmune diseases (eg. lupus , rheumatoid arthritis), immunodeficiency states (eg. HIV) and diabetes may prevent proper healing after a refractive procedure.
- Systemic medications likely to affect wound healing such as retinoic acid and steroids .
- Keratoconus or other active eye disease .
Trial locations and contacts
No sites are listed yet.
About this study
Official title: Adjustment of Astigmatism for Laser Correction Using Vector Planning Calculator
To determine the effectiveness of correcting astigmatism by laser refractive surgery by a vectorial astigmatism outcome analysis that uses 3 fundamental vectors : target induced astigmatism vector ( TIA) , surgically induced astigmatism vector , and difference vector , as described by Alpins method.
Read the detailed description
Astigmatism is a condition of the eye where the cornea (clear window in front of the eye) has 2 different curvatures (much like an American football cut in half) so that, instead of being a single focal point, there ends up being two different focal points, neither of which is in focus.
As you can imagine, this makes whatever you are looking at blurred and fuzzy like a camera out of focus. Both objects up close and far away can look blurred and fuzzy with astigmatism. Many people with astigmatism also are nearsighted or farsighted.
There are several different treatment options if you have astigmatism with or without nearsightedness or farsightedness. Various treatment options available from an eye specialist include: Glasses, Contact Lenses and Laser Eye Surgery
Laser Eye Surgery:
Laser eye surgery, or laser vision correction, involves using lasers to reshape the front surface (cornea) of your eyes so that you can focus better. It can correct short-sightedness , long-sightedness and astigmatism.There are several different laser eye surgery options that can be used to help correct vision problems caused by astigmatism.Laser eye surgery corrects the refractive error in the cornea so that, instead of there being two focal points, there will be only one focal point that is in focus post-surgery.Laser vision correction can be used if you have astigmatism with or without nearsightedness or farsightedness.However, what laser eye procedures you are an ideal candidate for will vary based on your vision correction needs LASIK( Laser ASsisted In-situ Keratomileusis ),PRK ( Photorefractive Keratectomy ) and SMILE (Small Incision Lenticule Extraction ) . Unlike glasses or contacts, which just address astigmatism so you can see clearly with assistive devices, laser eye surgery is the only treatment to potentially resolve astigmatism so you no longer need glasses or contacts. To determine the effectiveness of correcting astigmatism by laser refractive surgery by a vectorial astigmatism outcome analysis that uses 3 fundamental vectors: target induced astigmatism vector (TIAT), surgically induced astigmatism vector, and difference vector, as described by the Alpins method.
Alpins method :
This method of astigmatism analysis enables the examination of results of astigmatism treatment by both refractive and corneal measurements. The approach uses vector analysis, which is used in this series for examining regular astigmatism. This can be further applied to irregular astigmatism by separately examining the 2 halves of the cornea by adding a second analysis between 181and 360 degrees and displaying both together on a 360 degree polar diagram as they would appear on an eye or topography map drawn between the two points . The length of this line represents the WTW ( White To White ) value [16].
- Conditions
- Astigmatism
- Medical subject headings
- Astigmatism
What is being measured
The primary outcome is the main question the study is designed to answer.
. Post operative Visual Acuity
To determine the effectiveness of correcting astigmatism by laser refractive surgery by a vectorial astigmatism outcome analysis by : CDVA and UCDVA, pentacam , 3 month, 6 month and 1 year after surgery.
- 3 months postoperative : assessment of visual acuity using corrected distance visual acuity (CDVA) , and uncorrected distance visual acuity (UCDVA) and pentacam measures .
- 6 months postoperative : assessment of visual acuity using corrected distance visual acuity (CDVA) , and uncorrected distance visual acuity (UCDVA) and pentacam measures .
- One year postoperative : assessment of visual acuity using corrected distance visual acuity (CDVA) , and uncorrected distance visual acuity (UCDVA) and pentacam measures .
Measured: one year
Secondary outcomes (1)
Postoperative Assessment
Wavefront Analysis of post operative corneal results , 3 months after surgery to assess visual acuity . wavefront analysis is that it measures the entire visual system, rather than just the corneal surface, as in corneal topography.
Measured: 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jun 2021
- Study startJul 2021 (estimated)
- Primary completionJul 2022 (estimated)
- Study completionAug 2022 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for AstigmatismStudies of the same condition, open and under way.
- More trials run by Assiut UniversityThe 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 only
- Time perspective
- Prospective
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Assiut University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Esraa Fathy Rateb Hassan, Assiut University
- Investigators
- Abdelnasser Awad, Professor, Principal investigator, Ophthalmology DepartmentKhaled Abdelazeem, Asst. Prof, Principal investigator, Ophthalmology DepartmentMohamed Anwer, Lecturer, Principal investigator, Ophthalmology Department
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04913883
- Sponsor's protocol ID
- Adjustment of Astigmatism
- Status last verified
- May 2021
- First submitted
- 25 May 2021
- Last updated
- 4 Jun 2021
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Alpins N. Astigmatism analysis by the Alpins method. J Cataract Refract Surg. 2001 Jan;27(1):31-49. doi: 10.1016/s0886-3350(00)00798-7.
PubMed 11165856
Study at a glance
From the registry record, last updated by the sponsor on 4 Jun 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Adjustment of Astigmatism for Laser Correction Using Vector Planning Calculator
- ClinicalTrials.gov ID
- NCT04913883
- Acronym / sponsor ID
- Adjustment of Astigmatism
- Conditions
- Astigmatism
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Assiut UniversityUniversity, hospital or other
- Study start
- Jul 2021 (estimated)
- Primary completion
- Jul 2022 (estimated)
- Study completion
- Aug 2022 (estimated)
- First posted
- 4 Jun 2021 (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.
To determine the effectiveness of correcting astigmatism by laser refractive surgery by a vectorial astigmatism outcome analysis that uses 3 fundamental vectors : target induced astigmatism vector ( TIA) , surgically induced astigmatism vector , and difference vector , as described by Alpins method.
Detailed description
Astigmatism is a condition of the eye where the cornea (clear window in front of the eye) has 2 different curvatures (much like an American football cut in half) so that, instead of being a single focal point, there ends up being two different focal points, neither of which is in focus.
As you can imagine, this makes whatever you are looking at blurred and fuzzy like a camera out of focus. Both objects up close and far away can look blurred and fuzzy with astigmatism. Many people with astigmatism also are nearsighted or farsighted.
There are several different treatment options if you have astigmatism with or without nearsightedness or farsightedness. Various treatment options available from an eye specialist include: Glasses, Contact Lenses and Laser Eye Surgery
Laser Eye Surgery:
Laser eye surgery, or laser vision correction, involves using lasers to reshape the front surface (cornea) of your eyes so that you can focus better. It can correct short-sightedness , long-sightedness and astigmatism.There are several different laser eye surgery options that can be used to help correct vision problems caused by astigmatism.Laser eye surgery corrects the refractive error in the cornea so that, instead of there being two focal points, there will be only one focal point that is in focus post-surgery.Laser vision correction can be used if you have astigmatism with or without nearsightedness or farsightedness.However, what laser eye procedures you are an ideal candidate for will vary based on your vision correction needs LASIK( Laser ASsisted In-situ Keratomileusis ),PRK ( Photorefractive Keratectomy ) and SMILE (Small Incision Lenticule Extraction ) . Unlike glasses or contacts, which just address astigmatism so you can see clearly with assistive devices, laser eye surgery is the only treatment to potentially resolve astigmatism so you no longer need glasses or contacts. To determine the effectiveness of correcting astigmatism by laser refractive surgery by a vectorial astigmatism outcome analysis that uses 3 fundamental vectors: target induced astigmatism vector (TIAT), surgically induced astigmatism vector, and difference vector, as described by the Alpins method.
Alpins method :
This method of astigmatism analysis enables the examination of results of astigmatism treatment by both refractive and corneal measurements. The approach uses vector analysis, which is used in this series for examining regular astigmatism. This can be further applied to irregular astigmatism by separately examining the 2 halves of the cornea by adding a second analysis between 181and 360 degrees and displaying both together on a 360 degree polar diagram as they would appear on an eye or topography map drawn between the two points . The length of this line represents the WTW ( White To White ) value [16].
Study design
- Observational model
- Case only
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Age groups
- Adult
- Study population
- Study will include 50 patients in different ages .
Key inclusion criteria (7 listed)
- At least 18 years of age .
- Stable eyeglass and contact lenses prescription for at least 2 to 3 years .
- Stable vision over at least the past year .
- No history or findings of active corneal disease .
- No significant dry eye .
Key exclusion criteria (9 listed)
- Residual , recurrent or active ocular disease such as uveitis , sever dry eyes , sever allergic eye disease , glaucoma visually significant cataract , and retinal disease .
- Previous corneal surgery or trauma within the corneal flap zone .
- Patent corneal vascularisation within 1mm of the corneal flap zone .
- Age less than 18 years old .
- Pregnancy or breast feeding .
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
. Post operative Visual Acuity
Time frame: one year
To determine the effectiveness of correcting astigmatism by laser refractive surgery by a vectorial astigmatism outcome analysis by : CDVA and UCDVA, pentacam , 3 month, 6 month and 1 year after surgery. * 3 months postoperative : assessment of visual acuity using corrected distance visual acuity (CDVA) , and uncorrected distance visual acuity (UCDVA) and pentacam measures . * 6 months postoperative : assessment of visual acuity using corrected distance visual acuity (CDVA) , and uncorrected distance visual acuity (UCDVA) and pentacam measures . * One year postoperative : assessment of visual acuity using corrected distance visual acuity (CDVA) , and uncorrected distance visual acuity (UCDVA) and pentacam measures .
1 secondary outcome
Postoperative Assessment
Time frame: 3 months
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Jun 2021.
- Background: PubMed 11165856Alpins N. Astigmatism analysis by the Alpins method. J Cataract Refract Surg. 2001 Jan;27(1):31-49. doi: 10.1016/s0886-3350(00)00798-7.
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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.
Abdelnasser Awad, Professor principal investigator
Ophthalmology Department
Khaled Abdelazeem, Asst. Prof principal investigator
Ophthalmology Department
Mohamed Anwer, Lecturer principal investigator
Ophthalmology Department
Questions about this trial
What is this clinical trial studying?
An observational study of Astigmatism, run by Assiut University.
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 7 inclusion and 9 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: status not confirmed, as of the sponsor's last update on 4 Jun 2021. Status can change between updates, so confirm with the study contact before making plans.
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?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Esraa Fathy, Resident (01000323696, essraarateb94@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
. Post operative Visual Acuity (time frame: one year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04913883, which also lists 1 linked publication.
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 4 Jun 2021; AzTrials last refreshed its copy on 27 Oct 2026.