Macular HolesGEMNCT06079593
GaslEss Macular Hole Surgery
A study testing Gasless Macular hole surgery and Standard Macular hole surgery in people with Macular Holes, run by King's College Hospital NHS Trust.
Trial summary
Macular holes are a hole in the centre of the retina, the light-sensing layer in the back of the eye. They cause a central 'blind spot' in the vision, which can be very disabling for patients. Standard surgery involves injecting a large gas bubble inside the eye. This takes 4-8 weeks to leave the eye. Read more about this study
- Who is it for?
- Ages 18 to 100 years
- Conditions the study is for
- Macular Holes
- What is being tested?
- Gasless Macular hole surgery and Standard Macular hole surgery
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- No sites listed yet
- Study dates
- 1 Jan 2024to 31 Oct 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 to 100 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Requiring PPV to treat idiopathic (primary) FTMH.
- 18 years or older
- ETDRS BCVA letter score of 1 or better in the study eye
- Able to provide written informed consent
Who cannot join
- General:
- Hypersensitivity to hyaluronate or other components of Healon Pro® viscoelastic
- Any major illness or major surgical procedure within 4 weeks
- Any other condition that, in the opinion of the investigator, would prevent the participant from granting informed consent or complying with the protocol
- Study eye
- Previous vitreoretinal surgery, retinopexy, open-globe injury, or endophthalmitis
Show all 13Show fewer
- Presence of fibrotic retinal proliferation or central epiretinal membrane (within 1 disc diameter of the fovea)
- Aphakia
- Current or former myopia greater than 6 dioptres
- Current or previous posterior uveitis or choroiditis
- Presence of other ocular co-morbidity that, in the opinion of the investigator, is likely to impair BCVA postoperatively or affect FTMH closure
- Current ocular or periocular infection, other than mild or moderate blepharitis
- Lens or media opacity that preclude adequate retinal assessment and imaging
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: GaslEss Macular Hole Surgery (GEM): a Feasibility Study
Macular holes are a hole in the centre of the retina, the light-sensing layer in the back of the eye. They cause a central 'blind spot' in the vision, which can be very disabling for patients. Standard surgery involves injecting a large gas bubble inside the eye. This takes 4-8 weeks to leave the eye. During this time vision is greatly reduced in the eye. This limits patients' ability to drive and work. Gas causes clouding of the natural lens in the eye (cataract). The gas can also raise pressure inside the eye, causing pain and sometimes loss of vision. Patients cannot fly or have certain medicines until the gas absorbs.
Critically, most patients position face down for 50 minutes out of every hour for a week after surgery. This is to float the gas bubble onto the macula. Head positioning is particularly difficult. It very often causes pain in the neck, back, arms and legs. Rarely, blood clots can form in the legs and be life-threatening if they dislodge and travel to the lungs. Head positioning also places a large burden on those caring for the patient.
Read more
The gases are 'greenhouse' gases and cause damage to the environment, for about 3,200 years.
This study looks at a new surgical technique for treating macular holes. The new technique aims to make patients' recovery from surgery easier, and safer.
The purpose of this study therefore is to compare two treatments:
- Standard macular hole surgery with gas tamponade
- Novel macular hole surgery without tamponade Gathering feasibility data to inform a future fully powered trial
Read the detailed description
The investigators are testing a new surgical technique, that does not use the gas bubble and face down positioning. Instead, a licensed surgical gel and thin flap of retinal tissue seal the macular hole. Early small studies suggest the new technique is safe and works as well as standard surgery.
The investigators will invite 60 people with macular hole to take part in the study. Half will be randomly allocated to the new technique and half to standard surgery. All participants will return at regular intervals after surgery for review. The investigators will test their vision, examine their eyes, and ask participants to complete questionnaires about their treatment and vision.
The investigators aim to examine if the technique appears safe and works well at closing macular holes. It will also inform if a larger clinical trial is possible.
- Conditions
- Macular Holes
- Being tested
- Gasless Macular hole surgery, Standard Macular hole surgery
- Medical subject headings
- Retinal Perforations
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Gasless Macular hole surgeryProcedure or surgery
Pars plana vitrectomy to treat full thickness macular hole, with internal limiting membrane flap and ophthalmic viscosurgical device covering
Standard Macular hole surgeryProcedure or surgery
Pars plana vitrectomy to treat full thickness macular hole, with internal limiting membrane peel, and C2F6 tamponade
| Study group | Role | What they receive |
|---|---|---|
| Gasless Surgery | Experimental | Not described Receives: Procedure: Gasless Macular hole surgery |
| Standard surgery with gas tamponade | Active comparator | Not described Receives: Procedure: Standard Macular hole surgery |
What is being measured
The primary outcome is the main question the study is designed to answer.
Feasibility: Screen failure
Proportion of those screened who are randomised
Measured: 36 months
Feasibility: Recruitment rate
Recruitment rate (participants per site per month)
Measured: 36 months
Feasibility: Participant retention
Proportion reaching month 6 milestone visit
Measured: 6 months
Feasibility: Cross-over
Proportion converting to standard vitrectomy with gas, due to inability to seal the FTMH, or detection of peripheral retinal breaks
Measured: 36 months
Secondary outcomes (9)
Efficacy Outcomes: Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA)
Mean change from baseline
Measured: 6 months
Efficacy Outcomes: Surgical success
Proportion with FTMH closure within 3 months, without further FTMH surgery
Measured: 3 months
Efficacy Outcomes: Area under the BCVA versus time curve (ETDRS letter score)
Measured: 6 months
Safety outcomes: Adverse events
Measured: 6 months
Safety outcomes: Intra- and post-operative complications
Measured: 6 months
Safety outcomes: Development or progression of lens opacity
Within 6 months of vitrectomy (proportion undergoing or listed for cataract surgery and mean change in Lens Opacities Classification System 2 [LOCS2] grading)
Measured: 6 months
Patient reported outcomes measures: Participant acceptability of the intervention
Assessed by the Macular Disease Treatment Satisfaction Questionnaire (MacTSQ; composite score)
Measured: 6 months
Patient reported outcomes measures: National Eye Institute 25-Item Visual Function Questionnaire (NEI VFQ25; composite score)
Measured: 6 months
Patient reported outcomes measures: Qualitative analysis
Analysis of participant feedback
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Oct 2023
- Study start1 Jan 2024 (estimated)
- Primary completion31 May 2026 (estimated)
- Study completion31 Oct 2026 (estimated)
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 Macular HolesStudies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- King's College Hospital NHS Trust
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute for Health Research, United Kingdom
- Responsible party
- Sponsor
- Investigators
- Timothy Jackson, PhD, FRCOphth, Principal investigator, King's College London & King's College Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06079593
- Sponsor's protocol ID
- 204994
- Acronym
- GEM
- Status last verified
- Dec 2023
- First submitted
- 6 Oct 2023
- Last updated
- 14 Dec 2023
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Murphy GSP, Wafa HA, Tarpey M, Wyatt D, Wang Y, Steel DH, Jackson TL. Gas versus GaslEss surgery for full thickness Macular hole (GEM): study protocol for a randomised, assessor-masked, surgical feasibility study. BMJ Open Ophthalmol. 2025 Dec 25;10(1):e002260. doi: 10.1136/bmjophth-2025-002260.
PubMed 41448786
Study at a glance
From the registry record, last updated by the sponsor on 14 Dec 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- GaslEss Macular Hole Surgery (GEM): a Feasibility Study
- ClinicalTrials.gov ID
- NCT06079593
- Acronym / sponsor ID
- GEM / 204994
- Conditions
- Macular Holes
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- King's College Hospital NHS TrustUniversity, hospital or other
- Collaborators
- National Institute for Health Research, United Kingdom
- Study start
- 1 Jan 2024 (estimated)
- Primary completion
- 31 May 2026 (estimated)
- Study completion
- 31 Oct 2026 (estimated)
- First posted
- 12 Oct 2023 (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.
Macular holes are a hole in the centre of the retina, the light-sensing layer in the back of the eye. They cause a central 'blind spot' in the vision, which can be very disabling for patients. Standard surgery involves injecting a large gas bubble inside the eye. This takes 4-8 weeks to leave the eye. During this time vision is greatly reduced in the eye. This limits patients' ability to drive and work. Gas causes clouding of the natural lens in the eye (cataract). The gas can also raise pressure inside the eye, causing pain and sometimes loss of vision. Patients cannot fly or have certain medicines until the gas absorbs.
Critically, most patients position face down for 50 minutes out of every hour for a week after surgery. This is to float the gas bubble onto the macula. Head positioning is particularly difficult. It very often causes pain in the neck, back, arms and legs. Rarely, blood clots can form in the legs and be life-threatening if they dislodge and travel to the lungs. Head positioning also places a large burden on those caring for the patient.
The gases are 'greenhouse' gases and cause damage to the environment, for about 3,200 years.
This study looks at a new surgical technique for treating macular holes. The new technique aims to make patients' recovery from surgery easier, and safer.
The purpose of this study therefore is to compare two treatments:
- Standard macular hole surgery with gas tamponade
- Novel macular hole surgery without tamponade Gathering feasibility data to inform a future fully powered trial
Detailed description
The investigators are testing a new surgical technique, that does not use the gas bubble and face down positioning. Instead, a licensed surgical gel and thin flap of retinal tissue seal the macular hole. Early small studies suggest the new technique is safe and works as well as standard surgery.
The investigators will invite 60 people with macular hole to take part in the study. Half will be randomly allocated to the new technique and half to standard surgery. All participants will return at regular intervals after surgery for review. The investigators will test their vision, examine their eyes, and ask participants to complete questionnaires about their treatment and vision.
The investigators aim to examine if the technique appears safe and works well at closing macular holes. It will also inform if a larger clinical trial is possible.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Gasless Surgery | Experimental | Procedure: Gasless Macular hole surgery |
| Standard surgery with gas tamponade | Active comparator | Procedure: Standard Macular hole surgery |
Who may qualify
- Ages
- 18 to 100 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Requiring PPV to treat idiopathic (primary) FTMH.
- 18 years or older
- ETDRS BCVA letter score of 1 or better in the study eye
- Able to provide written informed consent
Key exclusion criteria (13 listed)
- Hypersensitivity to hyaluronate or other components of Healon Pro® viscoelastic
- Any major illness or major surgical procedure within 4 weeks
- Any other condition that, in the opinion of the investigator, would prevent the participant from granting informed consent or complying with the protocol
- Study eye
- Previous vitreoretinal surgery, retinopexy, open-globe injury, or endophthalmitis
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 |
|---|---|---|
| Gasless Macular hole surgeryPars plana vitrectomy to treat full thickness macular hole, with internal limiting membrane flap and ophthalmic viscosurgical device covering | Procedure or surgery | Gasless Surgery |
| Standard Macular hole surgeryPars plana vitrectomy to treat full thickness macular hole, with internal limiting membrane peel, and C2F6 tamponade | Procedure or surgery | Standard surgery with gas tamponade |
Primary outcome
Feasibility: Screen failure
Time frame: 36 months
Proportion of those screened who are randomised
Feasibility: Recruitment rate
Time frame: 36 months
Recruitment rate (participants per site per month)
Feasibility: Participant retention
Time frame: 6 months
Proportion reaching month 6 milestone visit
Feasibility: Cross-over
Time frame: 36 months
Proportion converting to standard vitrectomy with gas, due to inability to seal the FTMH, or detection of peripheral retinal breaks
9 secondary outcomes
Efficacy Outcomes: Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA)
Time frame: 6 months
Efficacy Outcomes: Surgical success
Time frame: 3 months
Efficacy Outcomes: Area under the BCVA versus time curve (ETDRS letter score)
Time frame: 6 months
Safety outcomes: Adverse events
Time frame: 6 months
Safety outcomes: Intra- and post-operative complications
Time frame: 6 months
Safety outcomes: Development or progression of lens opacity
Time frame: 6 months
Patient reported outcomes measures: Participant acceptability of the intervention
Time frame: 6 months
Patient reported outcomes measures: National Eye Institute 25-Item Visual Function Questionnaire (NEI VFQ25; composite score)
Time frame: 6 months
Patient reported outcomes measures: Qualitative analysis
Time frame: 6 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Dec 2023.
- Derived from this study: PubMed 41448786Murphy GSP, Wafa HA, Tarpey M, Wyatt D, Wang Y, Steel DH, Jackson TL. Gas versus GaslEss surgery for full thickness Macular hole (GEM): study protocol for a randomised, assessor-masked, surgical feasibility study. BMJ Open Ophthalmol. 2025 Dec 25;10(1):e002260. doi: 10.1136/bmjophth-2025-002260.
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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.
Timothy Jackson, PhD, FRCOphth principal investigator
King's College London & King's College Hospital
Questions about this trial
What is this clinical trial studying?
A study testing Gasless Macular hole surgery and Standard Macular hole surgery in people with Macular Holes, run by King's College Hospital NHS 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 4 inclusion and 13 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: opening soon, as of the sponsor's last update on 14 Dec 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact George Murphy, MB BCh BAO, FRCOphth ((+)44 2032991297 ext 31297, george.murphy4@nhs.net), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Feasibility: Screen failure (time frame: 36 months). The study lists 4 primary outcomes in all. 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 NCT06079593, 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 14 Dec 2023.