Intraocular Lens CalculationNCT03856346
Intraocular Lens Power Calculation for Combined Phaco-vitrectomy Procedures
An observational study of Intraocular Lens Calculation and Combined Phaco-vitrectomy, run by Cantonal Hospital of St. Gallen at 1 site in Switzerland.
Trial summary
The aim of the study is to evaluate the degree of refractive error postoperatively in combined procedures and to calculate a new constant in order to improve current state of the art biometry calculations. Read more about this study
- Who is it for?
- Ages 18 to 99 yearsHealthy volunteers can take part
- Conditions the study is for
- Intraocular Lens Calculation, Combined Phaco-vitrectomy
- What is being tested?
- Biometry
- How many people
- 200 participants
- Where
- 1 siteSwitzerland
- Study dates
- 1 Jun 2019to 30 Sep 2020
- 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 99 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Patients who undergo a combined procedure with phacoemulsification and pars plana vitrectomy
Who may be able to join
- Patients who undergo a combined procedure with phacoemulsification and pars plana vitrectomy
Who cannot join
- Sulcus fixation of the IOL, sulcus suture of the IOL, or intra-scleral IOL fixation because of intraoperative posterior capsule rupture
- corneal disease, such as keratoconus, that interfered with refractive results
- IOL implantation with a toric IOL or multifocal IOL
- History of previous vitrectomy or corneal transplantation
- Other coexisting ocular disease such as proliferative diabetic retinopathy, advanced age-related macular degeneration, uveitis, acute retinal necrosis, Coat's disease, proliferative vitreous retinopathy, or trauma
- Intraocular tamponade using silicon oil
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Intraocular Lens Power Calculation for Combined Phaco-vitrectomy Procedures: Calculation of a New Constant for Biometry IOL-formulas
The aim of the study is to evaluate the degree of refractive error postoperatively in combined procedures and to calculate a new constant in order to improve current state of the art biometry calculations.
Read the detailed description
The IOL power calculation in combined phaco-vitrectomy has been performed similar to that in cataract surgery alone. In patients who undergo combined phaco-vitrectomy, deviations in refractive outcomes may be observed because of possible errors in measurement of axial length, changes in the properties of the vitreous cavity after removal of the vitreous, or intraocular tamponade. Most of the previous studies have reported variable degrees of myopic shift after phaco-vitrectomy for diabetic retinopathy, epiretinal membrane, and macular hole. Furthermore, use of intraoperative gas may increase further the risk of anterior displacement of the intraocular lens which may induce a higher myopic shift. However, these publications did not provide any quantification of the spherical deviations nor calculate any specific constant in order to improve currents state of art biometry calculations.
- Being tested
- Biometry
- Keywords
- Vitrectomy, Phacoemulsification, Biometry, IOL calculation, Cataract
- Medical subject headings
- Cataract
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
BiometryDiagnostic test
Biometry for phaco-vitrectomy procedures pre- and postoperatively
| Study group | Role | What they receive |
|---|---|---|
| Phaco-vitrectomy | Not described Receives: Diagnostic Test: Biometry |
What is being measured
The primary outcome is the main question the study is designed to answer.
Refractive prediction error (measured by subjective refraction, in diopters)
postoperative actual subjective refraction minus preoperative planned refraction in spherical equivalence (in diopters)
Measured: 6 weeks postoperatively
Absolute prediction error (measured by subjective refraction, in diopters)
absolute value of the difference between postoperative actual refraction and preoperative planned refraction (in diopters)
Measured: 6 weeks postoperatively
Changes in Axial Length (measured by biometry, in milimeters)
Change of axial length postoperatively (in milimeter)
Measured: 6 weeks postoperatively
Changes in corneal curvature (measured by corneal topography, in diopters)
change in corneal curvature (in diopters)
Measured: 6 weeks postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Feb 2019
- Study start1 Jun 2019 (estimated)
- Primary completion30 Jun 2020 (estimated)
- Study completion30 Sep 2020 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Intraocular Lens CalculationStudies of the same condition, open and under way.
- 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
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Cantonal Hospital of St. Gallen
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Josef Guber, Cantonal Hospital of St. Gallen
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03856346
- Sponsor's protocol ID
- Phaco-vity-biometry study
- Status last verified
- Apr 2019
- First submitted
- 5 Feb 2019
- Last updated
- 2 May 2019
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 May 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Intraocular Lens Power Calculation for Combined Phaco-vitrectomy Procedures: Calculation of a New Constant for Biometry IOL-formulas
- ClinicalTrials.gov ID
- NCT03856346
- Acronym / sponsor ID
- Phaco-vity-biometry study
- Keywords
- Vitrectomy, Phacoemulsification, Biometry, IOL calculation, Cataract
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Cantonal Hospital of St. GallenUniversity, hospital or other
- Study start
- 1 Jun 2019 (estimated)
- Primary completion
- 30 Jun 2020 (estimated)
- Study completion
- 30 Sep 2020 (estimated)
- First posted
- 27 Feb 2019 (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.
The aim of the study is to evaluate the degree of refractive error postoperatively in combined procedures and to calculate a new constant in order to improve current state of the art biometry calculations.
Detailed description
The IOL power calculation in combined phaco-vitrectomy has been performed similar to that in cataract surgery alone. In patients who undergo combined phaco-vitrectomy, deviations in refractive outcomes may be observed because of possible errors in measurement of axial length, changes in the properties of the vitreous cavity after removal of the vitreous, or intraocular tamponade. Most of the previous studies have reported variable degrees of myopic shift after phaco-vitrectomy for diabetic retinopathy, epiretinal membrane, and macular hole. Furthermore, use of intraoperative gas may increase further the risk of anterior displacement of the intraocular lens which may induce a higher myopic shift. However, these publications did not provide any quantification of the spherical deviations nor calculate any specific constant in order to improve currents state of art biometry calculations.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Phaco-vitrectomy | – | Diagnostic Test: Biometry |
Who may qualify
- Ages
- 18 to 99 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Patients who undergo a combined procedure with phacoemulsification and pars plana vitrectomy
Key inclusion criteria (1 listed)
- Patients who undergo a combined procedure with phacoemulsification and pars plana vitrectomy
Key exclusion criteria (6 listed)
- Sulcus fixation of the IOL, sulcus suture of the IOL, or intra-scleral IOL fixation because of intraoperative posterior capsule rupture
- corneal disease, such as keratoconus, that interfered with refractive results
- IOL implantation with a toric IOL or multifocal IOL
- History of previous vitrectomy or corneal transplantation
- Other coexisting ocular disease such as proliferative diabetic retinopathy, advanced age-related macular degeneration, uveitis, acute retinal necrosis, Coat's disease, proliferative vitreous retinopathy, or trauma
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| BiometryBiometry for phaco-vitrectomy procedures pre- and postoperatively | Diagnostic test | Phaco-vitrectomy |
Primary outcome
Refractive prediction error (measured by subjective refraction, in diopters)
Time frame: 6 weeks postoperatively
postoperative actual subjective refraction minus preoperative planned refraction in spherical equivalence (in diopters)
Absolute prediction error (measured by subjective refraction, in diopters)
Time frame: 6 weeks postoperatively
absolute value of the difference between postoperative actual refraction and preoperative planned refraction (in diopters)
Changes in Axial Length (measured by biometry, in milimeters)
Time frame: 6 weeks postoperatively
Change of axial length postoperatively (in milimeter)
Changes in corneal curvature (measured by corneal topography, in diopters)
Time frame: 6 weeks postoperatively
change in corneal curvature (in diopters)
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 May 2019.
- Individual participant dataSharing planned: No
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Intraocular Lens Calculation and Combined Phaco-vitrectomy, run by Cantonal Hospital of St. Gallen at 1 site in Switzerland.
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 1 inclusion and 6 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 2 May 2019. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
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 Josef Guber, MD (+41 71 494 17 54, josef.guber@hotmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Refractive prediction error (measured by subjective refraction, in diopters) (time frame: 6 weeks postoperatively). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 2 May 2019.