Condition category
Eye Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Vitreomacular traction (VMT) is disease of the macula (the small center of the retina that is the centre of our field of vision) causing reduced vision and distortion. The managment options for VMT include pars plana vitrectomy (a procedure that involves removal the gel from the eye), enzymatic vitreolysis (a technique that uses lasers to disrupt floaters) observation. Participants may have to undergo surgery to treat VMT. Intravitreal injections of a C3F8 gas (injections into the vitreal area of the eye) might avoid surgery. The aim of this study is to investigate if pneumatic vitreolysis with intravitreal injection of 0.3ml of 100% C3F8 gas can be a cost-effective and easy alternative to release the vitreomacular traction.

Who can participate?
Adults aged 18 and older who have symptomatic vitreomacular traction.

What does the study involve?
Participants receive the procedure which includes an injection into the eye with the 0.3ml of 100% C3F8 gas. They are asked not to lie flat on the back for five days. Participants are instructed to use eyedrops three times a day for three days. Participants are followed up the next day, one week and four weeks after surgery. If the treatment was successful the participants are referred back to the private ophthalmologist (eye surgeon). If the treatment wasn’t successful further treatment is offered.

What are the possible benefits and risks of participating?
Participants may benefit from having this procedure instead of having surgery. There is risks associated with an intravitreal injections including pain, bleeding, retinal tears, infections, loss of vision, loss of eyes (from severe injections), and need for further surgery.

Where is the study run from?
Eye Clinic, Cantonal Hospital Sankt Gallen (Switzerland)

When is the study starting and how long is it expected to run for?
September 2017 to March 2018

Who is funding the study?
Investigator initiated and funded (Switzerland)

Who is the main contact?
Dr Josef Guber

Trial website

Contact information



Primary contact

Dr Josef Guber


Contact details

Kantonsspital St.Gallen
Rorschacher Strasse 95
Haus 04
Sankt Gallen

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Outcome after gas injection for the treatment of vitreomacular traction


Study hypothesis

Intravitreal injection of 100% 0.3ml C3F8 Gas would release the vitreomacular traction.

Ethics approval

Not provided at time of registration

Study design

Interventional prospective study pre-post study design single center

Primary study design


Secondary study design

Non randomised study

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details to request a patient information sheet


Patients with symptomatic vitreomacular traction


Patients with symptomatic vitreomacular traction are included in this study. This procedure is performed by an experienced surgeon. The intervention takes about 10 minutes.

Injection Technique:
At the beginning a time-out is performed to confirm correct medication and correct eye. The participant is placed in near supine position. The procedure is performed in topical anesthesia only using lidocaine eyedrops. The eye and the eyelids are cleaned with Betadine and a drape is used to cover the face. An eyelid speculum holds the eye open. The location of injection is marked using an caliper: 3-3.5mm from the limbus for pseudophakes, 3.5-4.0 mm for phakic patients. The injection is performed with a short 30g needle tip usually in the superotemporal quadrant. At the end of surgery topical antibiotic is administer into the eye.

Participants have 0.3ml of C3F8 gas injected into the eye.
Participants are asked not to lie flat on the back for five days. A topical therapy with tobramycin eyedrops 3 times for three days is prescribed.

Participants are reviewed next day, after a week and after four weeks postoperatively. Each participant receive a complete ophthalmological examination including best-corrected visual acuity and spectral domain optical coherence tomography (SD-OCT) (Spectralis HRA OCT, Heidelberg Engineering, Heidelberg, Germany) prior to surgery as well as one week and four weeks after surgery respectively.

Intervention type



Drug names

Primary outcome measure

Release of vitreomacular traction will be checked by using an optical coherence tomography at one week and four weeks postoperatively.

Secondary outcome measures

Visual acuity and central retinal thickness is measured using a Snellen chart and an optical coherence tomography at one and four weeks postoperatively.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. All patients with a symptomatic vitreomacular traction
2. Aged 18 and older

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Presence of Epiretinal Membrane over the macula at baseline
2. Broad VMT/VMA >1500 microns at baseline
3. History of vitrectomy/injections
4. History of laser photocoagulation to the macula in the study eye
5. High myopia
6. Aphakia
7. History of retinal detachment/breaks/Vitreous hemorrhage
8. Diabetic retinopathy, ischaemic retinopathies, retinal vein occlusio

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Eye Clinic, Cantonal Hospital Sankt Gallen
Sankt Gallen

Sponsor information


Kantonsspital St.Gallen

Sponsor details

Haus 04
Rorschacher Strasse 95

Sponsor type

Hospital/treatment centre



Funder type


Funder name

Investigator initiated and funded

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer reviewed journal.

IPD sharing statement:
The datasets generated and/or analysed during the current study during this study will be included in the subsequent results publication.

Intention to publish date


Participant level data


Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

08/03/2019: The following changes were made to the trial record: 1. The recruitment end date was changed from 31/03/2018 to 31/12/2019. 2. The overall trial end date was changed from 31/03/2018 to 01/03/2020.