Diabetic MaculopathyNCT01549132
Retinal Oximtery Following Treatment for Diabetic Maculopathy
An observational study of Diabetic Maculopathy, run by East Kent Hospitals University NHS Foundation Trust.
Trial summary
The investigators believe that oxygen saturation measurements in the retina may provide more information on how well the retina is working and may detect problems in the retina earlier than the fundus fluorescein angiography (FFA). Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Diabetic Maculopathy
- How many people
- 45 participants
- Where
- No sites listed yet
- Study dates
- Apr 2012to Mar 2014
- 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 Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: • Patients will be selected from the Ophthalmology clinics with all sites at East Kent Hospitals University Foundation NHS Trust. These patients will be selected non-randomly by the ophthalmology clinician involved in their care based whether their clinical diagnosis fulfils the inclusion criteria. The ophthalmologists who are seeing patients in the ophthalmology clinics will identify the patients fulfilling the inclusion criteria for this study.
Who may be able to join
- Diabetic Retinopathy affecting the central retina (designated maculopathy)
- No contraindications to pupil dilation
- Ocular media sufficiently clear to enable retinal imaging
- Pupils which can be dilated (i.e not using miotic medication)
- Willingness to participate with the research study and formal consent obtained.
Who cannot join
- Narrow drainage angles or any other contraindication to being dilated.
- Dense cataracts or other ocular media opacities inhibiting a good view of the retina on fundoscopy
About this study
Official title: Non-invasive Retinal Oximetry Using Oxymap in Patients With Diabetic Maculopathy Receiving Laser/Intravitreal Anti-VEGF Therapy
The investigators believe that oxygen saturation measurements in the retina may provide more information on how well the retina is working and may detect problems in the retina earlier than the fundus fluorescein angiography (FFA). This may be useful to an ophthalmologist so that they may identify abnormal areas of the retina and commence or change the treatment so that they may prevent irreversible blindness.
Most patients with clinically significant macular oedema and/or ischaemic diabetic retinopathy could have either laser or Intravitreal Anti-VEGF injection treatment provided they are counseled about the risks. It is known the Anti-VEGF injections reduce oedema and it is believed that laser treatment of the retina in this condition improves the oxygen supply to the retina and sometimes reverses the damage. It will be useful to take pictures of these treated eyes using the Oxymap spectral retinal camera(s) to see whether the investigators can detect a change in the oxygen saturation in the retina before and after treatment using our oxygen saturation methods.
Read the detailed description
WHAT IS SPECTRAL IMAGING?
This is a way of studying in detail an area that is being imaged. This can be done because each picture of the same area is taken using different colours of light (wavelength). Different materials in the picture will absorb and reflect the different wavelengths of light from a hyperspectral camera differently. It is then possible to look at each point in the picture and work out what is in the picture. This has been used in satellites and aeroplanes to identify what is on the ground. For example, it can distinguish the different types of trees on the ground based on the different way they absorb and reflect different wavelengths of light.
USING SPECTRAL IMAGING IN MEDICINE. Spectral imaging was found to have uses in medicine because of its ability to distinguish one thing from another. A lot of Spectral imaging research has been done to measure the amount of oxygen in the blood. This is because oxygen is important to all living cells in the human body - without it cells would die or stop working. Oxygen is carried to living cells by blood in blood vessels known as arteries and the left over is carried away by veins. Most of the oxygen in the blood is transported by cells in the blood containing a chemical called haemoglobin. There are two main forms of haemoglobin called oxyhaemoglobin (haemoglobin binds to oxygen) and deoxyhaemoglobin (haemoglobin that is not bound to oxygen). The proportion of oxyhaemoglobin to the total amount of haemoglobin (both oxyhaemoglobin and deoxyhaemoglobin) is called the oxygen saturation and is presented as a percentage. The normal saturation in the artery is about 97% because it contains more oxyhaemoglobin and in the vein it is about 75% because it contains less oxyhaemoglobin. Importantly oxyhaemoglobin (HbO2) and deoxyhaemoglobin (Hb) have different spectral characteristics - i.e they absorb light differently at various wavelengths of light. This has been extensively documented in various publications using samples of blood. This property is the basis of pulse oximetry which is the measurement of the oxygen saturation (OS) in the finger tip using a saturation probe which is commonly used in the hospital.
The different spectral characteristics of Hb and HbO2 can also be used in spectral imaging to calculate the amount of each in the blood to perform oxygen saturation measurements in certain parts of the body. This has previously been used to study the oxygen supply in the skin and also to look at the oxygen supply in patients with diabetes which is a condition that is caused by a lack of a hormone called insulin causing high amount of sugar in the blood resulting in damage to the blood vessels.
Spectral imaging has only recently started to be used in imaging the eye. The main emphasis of Spectral imaging in ophthalmology has been on measuring the oxygen saturations in the retina (the layer at the back of the eye that allows us to see). This is called retinal oximetry. In essence, the principles of retinal oximetry are similar to that of pulse oximetry, i.e using the different spectral characteristics of Hb and HbO2 to calculate the oxygen saturation.
In diabetic retinopathy, the only way the investigators can study the blood supply is by performing a Fundus Fluorescein Angiogram (FFA). This is an invasive test which involves the injection of a dye into the arm, this dye is transported by blood to the eye and pictures of the blood vessels are taken with the dye in it. Also, importantly, there are side effects (sometimes life-threatening) to injecting this dye into the arm. If there is a problem with the blood supply in the retina then the dye will not fill up in the blood vessel and is seen in the pictures as a black area. The FFA provides information on the blood supply but not directly on the amount of oxygen in it. Loss of sight from diabetic retinopathy and age-related macular degeneration is believed to be caused by a reduction in the amount oxygen being supplied to the retina by the blood vessels.
The investigators believe that oxygen saturation measurements in the retina using spectral imaging could be a more useful test for an ophthalmologist because it may provide more information on how well the retina is working and may detect problems in the retina earlier than the FFA. This may be useful to an ophthalmologist so that they may identify abnormal areas of the retina and commence or change the treatment so that they may prevent irreversible blindness.
- Conditions
- Diabetic Maculopathy
- Keywords
- Clinically significant macular oedema, Retinal Oximetry, Spectral imaging, Retinal Laser therapy, Intravitreal Anti-VEGF Injection therapy
What is being measured
The primary outcome is the main question the study is designed to answer.
Retinal oximetry differences in patients with sight threatening diabetic macular oedema after treatment
Does retinal oxygen levels in small blood vessels as measured by spectral imaging photography using the oxymap device at the centre of the retina (macula) differ in diabetic retinopathy in sight threatening disease?
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Mar 2012 (estimated)
- Study startApr 2012
- Primary completionMar 2013
- Study completionMar 2014
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Diabetic MaculopathyStudies 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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 45 participants (actual)
Sponsor and investigators
- Lead sponsor
- East Kent Hospitals University NHS Foundation Trust
- Sponsor type
- Other government
- Responsible party
- Sponsor
- Investigators
- NISHAL PATEL, MD FRCOPHTH, Principal investigator, CONSULTANT OPHTHALMOLOGIST
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01549132
- Sponsor's protocol ID
- EKHT RETINAL RESEARCH UNIT
- Status last verified
- Sep 2023
- First submitted
- 6 Mar 2012
- Last updated
- 15 Sep 2023
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Sep 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Non-invasive Retinal Oximetry Using Oxymap in Patients With Diabetic Maculopathy Receiving Laser/Intravitreal Anti-VEGF Therapy
- ClinicalTrials.gov ID
- NCT01549132
- Acronym / sponsor ID
- EKHT RETINAL RESEARCH UNIT
- Conditions
- Diabetic Maculopathy
- Keywords
- Clinically significant macular oedema, Retinal Oximetry, Spectral imaging, Retinal Laser therapy, Intravitreal Anti-VEGF Injection therapy
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 45 participants (actual)
- Lead sponsor
- East Kent Hospitals University NHS Foundation TrustOther government
- Study start
- Apr 2012
- Primary completion
- Mar 2013 (actual)
- Study completion
- Mar 2014 (actual)
- First posted
- 9 Mar 2012 (estimated)
- 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 investigators believe that oxygen saturation measurements in the retina may provide more information on how well the retina is working and may detect problems in the retina earlier than the fundus fluorescein angiography (FFA). This may be useful to an ophthalmologist so that they may identify abnormal areas of the retina and commence or change the treatment so that they may prevent irreversible blindness.
Most patients with clinically significant macular oedema and/or ischaemic diabetic retinopathy could have either laser or Intravitreal Anti-VEGF injection treatment provided they are counseled about the risks. It is known the Anti-VEGF injections reduce oedema and it is believed that laser treatment of the retina in this condition improves the oxygen supply to the retina and sometimes reverses the damage. It will be useful to take pictures of these treated eyes using the Oxymap spectral retinal camera(s) to see whether the investigators can detect a change in the oxygen saturation in the retina before and after treatment using our oxygen saturation methods.
Detailed description
WHAT IS SPECTRAL IMAGING?
This is a way of studying in detail an area that is being imaged. This can be done because each picture of the same area is taken using different colours of light (wavelength). Different materials in the picture will absorb and reflect the different wavelengths of light from a hyperspectral camera differently. It is then possible to look at each point in the picture and work out what is in the picture. This has been used in satellites and aeroplanes to identify what is on the ground. For example, it can distinguish the different types of trees on the ground based on the different way they absorb and reflect different wavelengths of light.
USING SPECTRAL IMAGING IN MEDICINE. Spectral imaging was found to have uses in medicine because of its ability to distinguish one thing from another. A lot of Spectral imaging research has been done to measure the amount of oxygen in the blood. This is because oxygen is important to all living cells in the human body - without it cells would die or stop working. Oxygen is carried to living cells by blood in blood vessels known as arteries and the left over is carried away by veins. Most of the oxygen in the blood is transported by cells in the blood containing a chemical called haemoglobin. There are two main forms of haemoglobin called oxyhaemoglobin (haemoglobin binds to oxygen) and deoxyhaemoglobin (haemoglobin that is not bound to oxygen). The proportion of oxyhaemoglobin to the total amount of haemoglobin (both oxyhaemoglobin and deoxyhaemoglobin) is called the oxygen saturation and is presented as a percentage. The normal saturation in the artery is about 97% because it contains more oxyhaemoglobin and in the vein it is about 75% because it contains less oxyhaemoglobin. Importantly oxyhaemoglobin (HbO2) and deoxyhaemoglobin (Hb) have different spectral characteristics - i.e they absorb light differently at various wavelengths of light. This has been extensively documented in various publications using samples of blood. This property is the basis of pulse oximetry which is the measurement of the oxygen saturation (OS) in the finger tip using a saturation probe which is commonly used in the hospital.
The different spectral characteristics of Hb and HbO2 can also be used in spectral imaging to calculate the amount of each in the blood to perform oxygen saturation measurements in certain parts of the body. This has previously been used to study the oxygen supply in the skin and also to look at the oxygen supply in patients with diabetes which is a condition that is caused by a lack of a hormone called insulin causing high amount of sugar in the blood resulting in damage to the blood vessels.
Spectral imaging has only recently started to be used in imaging the eye. The main emphasis of Spectral imaging in ophthalmology has been on measuring the oxygen saturations in the retina (the layer at the back of the eye that allows us to see). This is called retinal oximetry. In essence, the principles of retinal oximetry are similar to that of pulse oximetry, i.e using the different spectral characteristics of Hb and HbO2 to calculate the oxygen saturation.
In diabetic retinopathy, the only way the investigators can study the blood supply is by performing a Fundus Fluorescein Angiogram (FFA). This is an invasive test which involves the injection of a dye into the arm, this dye is transported by blood to the eye and pictures of the blood vessels are taken with the dye in it. Also, importantly, there are side effects (sometimes life-threatening) to injecting this dye into the arm. If there is a problem with the blood supply in the retina then the dye will not fill up in the blood vessel and is seen in the pictures as a black area. The FFA provides information on the blood supply but not directly on the amount of oxygen in it. Loss of sight from diabetic retinopathy and age-related macular degeneration is believed to be caused by a reduction in the amount oxygen being supplied to the retina by the blood vessels.
The investigators believe that oxygen saturation measurements in the retina using spectral imaging could be a more useful test for an ophthalmologist because it may provide more information on how well the retina is working and may detect problems in the retina earlier than the FFA. This may be useful to an ophthalmologist so that they may identify abnormal areas of the retina and commence or change the treatment so that they may prevent irreversible blindness.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- • Patients will be selected from the Ophthalmology clinics with all sites at East Kent Hospitals University Foundation NHS Trust. These patients will be selected non-randomly by the ophthalmology clinician involved in their care based whether their clinical diagnosis fulfils the inclusion criteria. The ophthalmologists who are seeing patients in the ophthalmology clinics will identify the patients fulfilling the inclusion criteria for this study.
Key inclusion criteria (5 listed)
- Diabetic Retinopathy affecting the central retina (designated maculopathy)
- No contraindications to pupil dilation
- Ocular media sufficiently clear to enable retinal imaging
- Pupils which can be dilated (i.e not using miotic medication)
- Willingness to participate with the research study and formal consent obtained.
Key exclusion criteria (2 listed)
- Narrow drainage angles or any other contraindication to being dilated.
- Dense cataracts or other ocular media opacities inhibiting a good view of the retina on fundoscopy
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
Retinal oximetry differences in patients with sight threatening diabetic macular oedema after treatment
Time frame: 1 year
Does retinal oxygen levels in small blood vessels as measured by spectral imaging photography using the oxymap device at the centre of the retina (macula) differ in diabetic retinopathy in sight threatening disease?
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Sep 2023.
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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.
NISHAL PATEL, MD FRCOPHTH principal investigator
CONSULTANT OPHTHALMOLOGIST
Questions about this trial
What is this clinical trial studying?
An observational study of Diabetic Maculopathy, run by East Kent Hospitals University NHS Foundation Trust.
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 5 inclusion and 2 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: finished, as of the sponsor's last update on 15 Sep 2023. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Retinal oximetry differences in patients with sight threatening diabetic macular oedema after treatment (time frame: 1 year). 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 15 Sep 2023; AzTrials last refreshed its copy on 7 Nov 2026.