Temporary gas injection into the eye to help stabilize the retina in adults with retinal detachment before vitrectomy surgery
| ISRCTN | ISRCTN29200092 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN29200092 |
| Secondary identifying numbers | 2024-3514 |
- Submission date
- 03/10/2025
- Registration date
- 10/10/2025
- Last edited
- 10/10/2025
- Recruitment status
- Recruiting
- Overall study status
- Ongoing
- Condition category
- Eye Diseases
Plain English summary of protocol
Background and study aims
Retinal detachment affecting central vision causes a decrease in visual acuity, often leaving permanent damage. The usual treatment for this type of detachment is an eye surgery called “vitrectomy”, which is done in the operating room.
There is a technique called pneumatic retinopexy, consisting of injecting an air bubble in the eye.
This gas injection allows the retina to start to reattach until the day of the operation by keeping the face downwards (see next image). This technique is often used when the detachment is partial, and/or when there is only one tear in the superior part of the retina. When retinal detachments are more complex (many tears, inferior detachment, etc.), the vitrectomy remains the operation of choice.
As of right now, we do not know whether pneumatic retinopexy before the operation can benefit visual acuity in the long run. This is the reason why it is not used routinely in clinical practice.
The objective of this research project is to determine whether pneumatic retinopexy done before the operation gives a better long-term vision for people with a retinal detachment.
Who can participate?
The study is for patients aged 30 - 90 years, experiencing a retinal detachment affecting the center of vision.
What does the study involve?
The study involves the injection of a gas bubble in the eye before performing the surgery to resolve the retinal detachment more permanently. Participants will be randomly assigned to group A or group B, with group A receiving the injection of gas and the group B not receiving the injection.
What are the possible benefits and risks of participating?
You may benefit personally from participating in this research project, but we cannot guarantee it. Furthermore, we hope that the results obtained will contribute to the advancement of scientific knowledge in this area and to the development of better treatments for patients.
1. Risks associated with the study procedure (group 1 only)
Injection of gas (pneumatic retinopexy)
• Temporary increase in intraocular after the procedure (expected and monitored, close to 100%)
• Progression of cataracts (20% risk)
• Formation of new retinal tears at the periphery of the retina (15% risk)
• Increase in the percentage of scars forming on the retina (4% risk)
• Passage of gas under the retina, which could further detach the retina (less than 1% risk)
• Infection in the eye (less than 0,1% risk)
Local anesthetic (0.5% tetracaine drops)
• Temporary burning or stinging sensation, redness, tearing (75% de risk)
• Reduced sensation of the cornea (expected effect), which can increase risks of corneal abrasion by rubbing (risk possible if eye rubbing)
• Allergic reaction (less than 1% risk)
If the surgeon decides to use sub-conjunctival anesthesia (an injection of 2% lidocaine on the surface of the eye), the risks of the injection are:
• Pain and pressure at the injection site (75% risk)
• Sub-conjunctival hemorrhage, a self-resolving benign bleeding which can be cosmetically notice, or swelling of the conjunctiva of the eye (30%)
• Perforation of the eye, infection in the eye (extremely rare, less than 0.01%)
And the risks associated with the anesthetic injected at the surface of the eye are:
• Allergic reaction or systemic reaction to the anesthetic (rare cases documented for this type of administration)
It is also uncomfortable to keep the head facing downwards until the surgery.
Where is the study run from?
The study is run in only one hospital, Hôpital Maisonneuve-Rosemont in Montreal, Quebec, Canada. All personnel work at this clinic and all patients will be recruited from the same clinic.
When is the study starting and how long is it expected to run for?
The study is starting in October 2025 and is expected to run until April 2026 depending on the amount of patients recruited.
Who is funding the study?
Université de Montréal Ophthalmology Research Fund (Canada)
Who are the main contacts
Shigufa K Ali, shigufa.kahn.ali.cemtl@ssss.gouv.qc.ca
Contact information
Scientific, Principal investigator
5415 Assomption Blvd, Montreal, Quebec
Montreal
H1T 2M4
Canada
| Phone | +1 514-252-3400 poste 4948 |
|---|---|
| cynthia.xin-ya.qian@umontreal.ca |
Public
5415 Assomption Blvd, Montreal, Quebec
Montreal
H1T 2M4
Canada
| Phone | +1 514-252-3400 poste 4948 |
|---|---|
| shigufa.kahn.ali.cemtl@ssss.gouv.qc.ca |
Study information
| Study design | Single center 2 arm open-label randomized controlled trial |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised controlled trial |
| Study setting(s) | Hospital |
| Study type | Treatment |
| Participant information sheet | No participant information sheet available |
| Scientific title | Preoperative C3F8 injection as a temporary macular tamponade in macula-off rhegmatogenous retinal detachments in candidates to pars plana vitrectomy |
| Study acronym | REMAC |
| Study objectives | The goal of this clinical trial is to learn if a gas injection in the eye before surgery can help long-term vision in retinal detachments affecting the center of vision in adult patients aged 30-90 years. The main question it aims to answer is: Does a gas injection in the eye before surgery improve long-term vision compared to surgery alone? Researchers will compare the gas injection followed by surgery to surgery alone to see if long-term vision is improved by the gas injection. Participants will either receive the gas injection followed by surgery as scheduled, or proceed to the surgery as scheduled. Patients receiving the gas injection will remain face-down until the surgery. |
| Ethics approval(s) |
Approved 23/09/2025, Research Ethics Committee of the CIUSSS Est-de-l'Île-de-Montréal (5415, boul. de l'Assomption Montréal (Québec), Montreal, H1T 2M4, Canada; +1 514 252-3400, extension 5708; cer.cemtl@ssss.gouv.qc.ca), ref: 2024-3514 |
| Health condition(s) or problem(s) studied | Rhegmatogenous Retinal Detachment - Macula Off |
| Intervention | Intervention: pneumatic retinopexy of C3F8 before vitrectomy surgery Control: vitrectomy surgery only The date of the vitrectomy is independent of the treatment arm. 1:1 randomization with randomization.net |
| Intervention type | Procedure/Surgery |
| Primary outcome measure | Visual acuity measured using ETDRS letters at 3 months |
| Secondary outcome measures | 1. Macular reattachment rate measured by the proportion of macular reattachment in both groups at 3 months 2. Presence of new tears measured using proportion of patients with new tears at 3 months 3. New or progression of proliferative vitreoretinopathy measured using rate of PVR developing or progression (using standard PVR grading) at 3 months. 4. Accordance of tamponade selection using accordance ratio of preoperative assessments and actual tamponade use at time of surgery. 6. Retinal displacement rate measured in proportion at 3 month 7. Number of total surgeries needed at 3 months |
| Overall study start date | 13/12/2023 |
| Completion date | 30/04/2026 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 30 Years |
| Upper age limit | 90 Years |
| Sex | All |
| Target number of participants | 78 |
| Key inclusion criteria | 1. Age 30-90 years old 2. Primary macula-off rhegmatogenous retinal detachment with a maximum 2 weeks (14 days) of central vision loss at presentation 3. Rhegmatogenous retinal detachment not suitable for pneumatic retinopexy alone without vitrectomy because of extension, multiple tears, inferior localization or multiple lattice |
| Key exclusion criteria | 1. Proliferative vitreoretinopathy grade B or C 2. Tractional or serous detachments 3. Presence of other ophthalmological diseases that have an effect on visual acuity (potential confounders): terminal glaucoma, neuropathy, history of posterior uveitis, previous macular pathology 4. Macula-split retinal detachments 5. Patients not able to maintain postoperative positioning 6. Patients who present with a central vision loss of more than 2 weeks (14 days) |
| Date of first enrolment | 03/10/2025 |
| Date of final enrolment | 30/01/2026 |
Locations
Countries of recruitment
- Canada
Study participating centre
Montreal
H1T 2M4
Canada
Sponsor information
Hospital/treatment centre
5415 Assomption Blvd, Montreal, Quebec
Montreal
H1T 2M4
Canada
| Phone | +1 514-352-3400 |
|---|---|
| bcrc.cemtl@ssss.gouv.qc.ca | |
| Website | http://www.maisonneuve-rosemont.org/pages/H/index.aspx |
"ROR" |
https://ror.org/03rdc4968 |
Funders
Funder type
University/education
No information available
Results and Publications
| Intention to publish date | 30/04/2027 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Available on request |
| Publication and dissemination plan | Planned publication in a peer-reviewed journal. |
| IPD sharing plan | De-identified individual participant data (IPD) may be made available upon reasonable request after publication of the primary results and with appropriate data-use agreements, including ethics board approval. |
Editorial Notes
06/10/2025: Trial's existence confirmed by Research Ethics Committee of the CIUSSS Est-de-l'Île-de-Montréal.
