Patients Undergoing Retina/Vitreous SurgeryCLOTNCT03863548
French Observational Study of Complications Associated With Anticoagulants and Antiplatelet Treatment in Retina/Vitreous Surgery
An observational study of Patients Undergoing Retina/Vitreous Surgery, run by Centre Hospitalier Universitaire Dijon at 1 site in France.
Trial summary
Anticoagulants and antiplatelet treatments are frequently prescribed treatments to prevent or treat thromboembolic complications and reduce morbidity and mortality related to cardiovascular risk factors. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Patients Undergoing Retina/Vitreous Surgery
- What is being tested?
- complication
- How many people
- 748 participants
- Where
- 1 siteFrance
- Study dates
- 8 Jan 2019to 19 Jul 2019
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients undergoing surgery
Who may be able to join
- person who has expressed willingness to participate
- person over 18 years of age
- person with a retinal-vitreous condition requiring scheduled surgery (epi-retinal membrane surgery, vitreous traction surgery, macular hole surgery).
Who cannot join
- person subject to legal protection (curatorship, guardianship)
- person deemed mentally incompetent
- pregnant, parturient or breastfeeding woman
- adult unwilling or unable to consent
- patient who has already participated in the study
- person with a physical or mental disability that does not allow participation.
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- a person who has participated in any study of an experimental medical product within the previous 3 months
- person who experiences any of the following during the ophthalmological examination:
- severe or proliferating diabetic retinopathy
- intra-vitreal hemorrhage
- tractional retinal detachment
- subretinal or retrohyaloidal hematoma.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: French Observational Study of Complications Associated With Anticoagulants and Antiplatelet Treatment in Retina/Vitreous Surgery (CLOT Study)
Anticoagulants and antiplatelet treatments are frequently prescribed treatments to prevent or treat thromboembolic complications and reduce morbidity and mortality related to cardiovascular risk factors. In retina/vitreous surgery, there are rare but potentially serious risks of hemmorrhagic complication resulting in irreversible loss of visual acuity. There is no clear consensus on how to proceed during the perioperative period with regard to the continuation or discontinuation of anticoagulant and antiplatelet treatments in these types of surgery. the purpose of the study is to identify complications at 1 month depending on the type of surgery with or without discontinuation of antithrombotic treatments. Practitioners are not asked to change their modus operandi. The hypothesis is that there is no excess risk of peri- or post-operative hemorrhage in retino-vitreous surgery in patients treated with antithrombotic compared to untreated patients and that therefore discontinuation of these treatments before surgery is not necessary.
- Being tested
- complication
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
complicationOther
collection of post-operative bleeding complications
| Study group | Role | What they receive |
|---|---|---|
| Continuation of antithrombotic drugs | operation carried out without stopping anticoagulants Receives: Other: complication | |
| Stop anti thrombotic drugs | operation performed with stopping the anticoagulants Receives: Other: complication |
What is being measured
The primary outcome is the main question the study is designed to answer.
Occurrence of intra-operative and postoperative hemorrhagic complications in retina/vitreous surgery
Measured: Through study completion, an average of 8 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Mar 2019
- Study start8 Jan 2019
- Primary completion19 Jul 2019
- Study completion19 Jul 2019
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 Patients Undergoing Retina/Vitreous SurgeryStudies of the same condition, open and under way.
- More trials run by Centre Hospitalier Universitaire DijonThe 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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 748 participants (actual)
Sponsor and investigators
- Lead sponsor
- Centre Hospitalier Universitaire Dijon
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03863548
- Sponsor's protocol ID
- LOUISON CFSR 2017
- Acronym
- CLOT
- Status last verified
- Feb 2026
- First submitted
- 4 Mar 2019
- Last updated
- 4 Feb 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Louison S, Gabrielle PH, Soudry A, Meillon C, Blanc J, Beal G, Arsene S, Le Mer Y, Berrod JP, Kodjikian L, Creuzot-Garcher C; CFCR Research net. Perioperative risk of bleeding with antithrombotic agents in macular surgery: a national, prospective, multicentre study. Acta Ophthalmol. 2020 Dec;98(8):e991-e997. doi: 10.1111/aos.14434. Epub 2020 Apr 12.
PubMed 32279459
Study at a glance
From the registry record, last updated by the sponsor on 4 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- French Observational Study of Complications Associated With Anticoagulants and Antiplatelet Treatment in Retina/Vitreous Surgery (CLOT Study)
- ClinicalTrials.gov ID
- NCT03863548
- Acronym / sponsor ID
- CLOT / LOUISON CFSR 2017
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 748 participants (actual)
- Lead sponsor
- Centre Hospitalier Universitaire DijonUniversity, hospital or other
- Study start
- 8 Jan 2019 (actual)
- Primary completion
- 19 Jul 2019 (actual)
- Study completion
- 19 Jul 2019 (actual)
- First posted
- 5 Mar 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.
Anticoagulants and antiplatelet treatments are frequently prescribed treatments to prevent or treat thromboembolic complications and reduce morbidity and mortality related to cardiovascular risk factors. In retina/vitreous surgery, there are rare but potentially serious risks of hemmorrhagic complication resulting in irreversible loss of visual acuity. There is no clear consensus on how to proceed during the perioperative period with regard to the continuation or discontinuation of anticoagulant and antiplatelet treatments in these types of surgery. the purpose of the study is to identify complications at 1 month depending on the type of surgery with or without discontinuation of antithrombotic treatments. Practitioners are not asked to change their modus operandi. The hypothesis is that there is no excess risk of peri- or post-operative hemorrhage in retino-vitreous surgery in patients treated with antithrombotic compared to untreated patients and that therefore discontinuation of these treatments before surgery is not necessary.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Continuation of antithrombotic drugs | – | Other: complicationoperation carried out without stopping anticoagulants |
| Stop anti thrombotic drugs | – | Other: complicationoperation performed with stopping the anticoagulants |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients undergoing surgery
Key inclusion criteria (3 listed)
- person who has expressed willingness to participate
- person over 18 years of age
- person with a retinal-vitreous condition requiring scheduled surgery (epi-retinal membrane surgery, vitreous traction surgery, macular hole surgery).
Key exclusion criteria (12 listed)
- person subject to legal protection (curatorship, guardianship)
- person deemed mentally incompetent
- pregnant, parturient or breastfeeding woman
- adult unwilling or unable to consent
- patient who has already participated in the study
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 |
|---|---|---|
| complicationcollection of post-operative bleeding complications | Other | Continuation of antithrombotic drugs, Stop anti thrombotic drugs |
Primary outcome
Occurrence of intra-operative and postoperative hemorrhagic complications in retina/vitreous surgery
Time frame: Through study completion, an average of 8 months
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 4 Feb 2026.
- Results publication: PubMed 32279459Louison S, Gabrielle PH, Soudry A, Meillon C, Blanc J, Beal G, Arsene S, Le Mer Y, Berrod JP, Kodjikian L, Creuzot-Garcher C; CFCR Research net. Perioperative risk of bleeding with antithrombotic agents in macular surgery: a national, prospective, multicentre study. Acta Ophthalmol. 2020 Dec;98(8):e991-e997. doi: 10.1111/aos.14434. Epub 2020 Apr 12.
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.
The record lists no contact. Use the official record to reach the sponsor.
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 Patients Undergoing Retina/Vitreous Surgery, run by Centre Hospitalier Universitaire Dijon at 1 site in France.
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 3 inclusion and 12 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 4 Feb 2026. 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 France. 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?
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?
Occurrence of intra-operative and postoperative hemorrhagic complications in retina/vitreous surgery (time frame: Through study completion, an average of 8 months). 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 NCT03863548, 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 Feb 2026.