Ignite Creation Date:
2024-10-26 @ 3:37 PM
Last Modification Date:
2024-10-26 @ 3:37 PM
Study NCT ID:
NCT06551480
Status:
COMPLETED
Last Update Posted:
None
First Post:
2024-08-09
Brief Title:
VCSEL Based Optical Swept Source Biometry
Sponsor:
None
Organization:
None
Study Overview
Official Title:
Pilot Study on VCSEL-based Optical Swept Source Biometry
Status:
COMPLETED
Status Verified Date:
2024-08
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
No
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
VBOB
Brief Summary:
Optical interferometric biometry is a non-invasive and highly precise method for measuring eye length and intraocular distances The method already exists as commercial devices eg IOLMaster Carl Zeiss Meditec AG A major cost factor of the devices available on the market is the laser used The use of a much cheaper laser could significantly reduce the price of these devices which would lead to greater availability of this technology in developing countries This would make it possible to replace the ultrasound methods used to date and thus enable contact-free measurements which in turn can reduce the spread of infectious diseasesThe study investigates the use of a thermally tunable vertical cavity surface emitting laser VCSEL for optical swept source biometry
Detailed Description:
1 Background
With 15 million operations per year cataract surgery is the most commonly performed eye surgery The number of operations worldwide is expected to increase by 25 between 2008 and 2015
The simplest operation is the implantation of a monofocal intraocular lens IOL It is the most commonly performed cataract procedure in developing countries eg 65 in India as well as in rural and poor areas in industrialized countries To prepare for the operation simple IOL calculation formulas are used that require knowledge of the axial eye length Today biometry is mainly performed by applanation ultrasound and simple keratometers However optical measurement by low coherence interferometry OCT is becoming increasingly important as it has the important advantage of being contact-free and thus avoiding complications that can be caused by possible infections In addition the method is extremely precise and does not depend on the skill of the doctor A major cost factor in the production of such devices is the laser used The use of a much cheaper laser diode could significantly reduce the price which would ensure availability even in developing countries
2 Rationale The suitability of electrically tuned VCSEL laser diodes as light sources for determining intraocular distances is to be investigated The results are to be compared with those of a commercial device in terms of signal quality and measurement accuracy Such a device would be contact-free which would help prevent infections would be significantly cheaper than currently available methods and would be able to determine intraocular distances very precisely
3 Study objectives The aim of the study is to demonstrate the usability of an electrically tuned VCSEL laser diode as a cost-effective alternative to the lasers used to date To this end the precision reproducibility and manageability of the measurement with the VCSEL laser diode will be investigated Test subjects and cataract patients will be examined The precision of the measurement with the device of intraocular distances will be compared with that of a commercial device IOLMaster500 from Carl Zeiss Meditec
4 Study Design
The study is a pilot study It takes the measurement principle of a commercially available device for measuring eye length as a starting point
The technology used is swept source Optical Coherence Tomography This swept source is to be implemented using the electrically tuned VCSEL laser diode Such laser diodes are able to change their central wavelength by changing the driver current Another advantage arises from the VCSEL technology used in the laser diode used This type of laser diode has a very narrow instantaneous line width and thus a very long coherence length which far exceeds that required for the biometry of the eye
In swept source OCT the attenuation of the signal in depth is much lower than in spectrometer-based systems In addition the sensitivity is higher than with time-domain partial coherence interferometry PCI biometry systems and they are much faster The reason is that the entire axial structure is encoded in parallel in the spectrum
41 Implementation and evaluation In the proposed study intraocular distances primarily the axial eye length and the anterior chamber depth of the participating subjects and patients are to be determined using the method described This is an exploratory pilot study to determine whether the VCSEL-based technology is suitable in terms of speed of measurement and sensitivity of the method to achieve a precise determination of the axial eye length in both healthy subjects and cataract patients with various degrees of cataract The measurements with the IOLMaster serve as a basis for comparison
Participants in the study are to be healthy subjects and cataract patients All participants will first undergo a routine examination Other risks will also be identified during the routine examination These examinations will be carried out at the Eye Clinic
The test subjects and patients are then measured using the measurement setup at the Center for Medical Physics and Biomedical Engineering
The routine examination at the eye clinic includes a slit lamp and eye length measurement The eye to be examined is selected by the investigator during the routine examination
42 Selection of the study population The participants are recruited via public notices 30 healthy subjects are selected between the ages of 19 and 85 years 30 cataract patients are selected between the ages of 19 and 85 years
43 Preliminary examination
Routine examination at the Eye Clinic of the Medical University of Vienna - - Measurement of eye length using IOL Masters
For cataract patients the degree of cataract is determined based on the Lens Opacities Classification Systems LOCS III
44 Withdrawal or replacement of study participants
The study participants will be excluded from the study under the following circumstances
If they so wish
If the study director believes that the study is not in the interest of the study participant
If the study participant violates one of the requirements and points of the consent form In any case the study exclusion will be recorded with a detailed explanation If the study has to be terminated the data will be retained
Study participants who cannot complete the study will be replaced The data can however be used for analysis
45 Target variables
Axial eye length and anterior chamber depth standard deviation and mean over repeated measurements will be analyzed A comparison with the reference device will be established through Bland-Altman analysis
Measurements are taken per study participant with IOL Master Carl Zeiss Meditec AG and measurement setup with current tuned VCSEL diode
With 15 million operations per year cataract surgery is the most commonly performed eye surgery The number of operations worldwide is expected to increase by 25 between 2008 and 2015
The simplest operation is the implantation of a monofocal intraocular lens IOL It is the most commonly performed cataract procedure in developing countries eg 65 in India as well as in rural and poor areas in industrialized countries To prepare for the operation simple IOL calculation formulas are used that require knowledge of the axial eye length Today biometry is mainly performed by applanation ultrasound and simple keratometers However optical measurement by low coherence interferometry OCT is becoming increasingly important as it has the important advantage of being contact-free and thus avoiding complications that can be caused by possible infections In addition the method is extremely precise and does not depend on the skill of the doctor A major cost factor in the production of such devices is the laser used The use of a much cheaper laser diode could significantly reduce the price which would ensure availability even in developing countries
2 Rationale The suitability of electrically tuned VCSEL laser diodes as light sources for determining intraocular distances is to be investigated The results are to be compared with those of a commercial device in terms of signal quality and measurement accuracy Such a device would be contact-free which would help prevent infections would be significantly cheaper than currently available methods and would be able to determine intraocular distances very precisely
3 Study objectives The aim of the study is to demonstrate the usability of an electrically tuned VCSEL laser diode as a cost-effective alternative to the lasers used to date To this end the precision reproducibility and manageability of the measurement with the VCSEL laser diode will be investigated Test subjects and cataract patients will be examined The precision of the measurement with the device of intraocular distances will be compared with that of a commercial device IOLMaster500 from Carl Zeiss Meditec
4 Study Design
The study is a pilot study It takes the measurement principle of a commercially available device for measuring eye length as a starting point
The technology used is swept source Optical Coherence Tomography This swept source is to be implemented using the electrically tuned VCSEL laser diode Such laser diodes are able to change their central wavelength by changing the driver current Another advantage arises from the VCSEL technology used in the laser diode used This type of laser diode has a very narrow instantaneous line width and thus a very long coherence length which far exceeds that required for the biometry of the eye
In swept source OCT the attenuation of the signal in depth is much lower than in spectrometer-based systems In addition the sensitivity is higher than with time-domain partial coherence interferometry PCI biometry systems and they are much faster The reason is that the entire axial structure is encoded in parallel in the spectrum
41 Implementation and evaluation In the proposed study intraocular distances primarily the axial eye length and the anterior chamber depth of the participating subjects and patients are to be determined using the method described This is an exploratory pilot study to determine whether the VCSEL-based technology is suitable in terms of speed of measurement and sensitivity of the method to achieve a precise determination of the axial eye length in both healthy subjects and cataract patients with various degrees of cataract The measurements with the IOLMaster serve as a basis for comparison
Participants in the study are to be healthy subjects and cataract patients All participants will first undergo a routine examination Other risks will also be identified during the routine examination These examinations will be carried out at the Eye Clinic
The test subjects and patients are then measured using the measurement setup at the Center for Medical Physics and Biomedical Engineering
The routine examination at the eye clinic includes a slit lamp and eye length measurement The eye to be examined is selected by the investigator during the routine examination
42 Selection of the study population The participants are recruited via public notices 30 healthy subjects are selected between the ages of 19 and 85 years 30 cataract patients are selected between the ages of 19 and 85 years
43 Preliminary examination
Routine examination at the Eye Clinic of the Medical University of Vienna - - Measurement of eye length using IOL Masters
For cataract patients the degree of cataract is determined based on the Lens Opacities Classification Systems LOCS III
44 Withdrawal or replacement of study participants
The study participants will be excluded from the study under the following circumstances
If they so wish
If the study director believes that the study is not in the interest of the study participant
If the study participant violates one of the requirements and points of the consent form In any case the study exclusion will be recorded with a detailed explanation If the study has to be terminated the data will be retained
Study participants who cannot complete the study will be replaced The data can however be used for analysis
45 Target variables
Axial eye length and anterior chamber depth standard deviation and mean over repeated measurements will be analyzed A comparison with the reference device will be established through Bland-Altman analysis
Measurements are taken per study participant with IOL Master Carl Zeiss Meditec AG and measurement setup with current tuned VCSEL diode
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None