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Diabetes MellitusNCT00155454

Intravitreal Long Acting Gas in the Prevention of Early Postoperative Vitreous Hemorrhage in Diabetic Vitrectomy

A study testing Intravitreal long acting gas (10% C3F8) in people with Diabetes Mellitus and Diabetic Retinopathy, run by National Taiwan University Hospital at 1 site in Taiwan.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Recurrent vitreous hemorrhage after vitrectomy for complications of diabetic retinopathy is a common occurrence. The hemorrhage may appear within the first few weeks after surgery or months later. Read more about this study

Who is it for?
Any age
What is being tested?
Intravitreal long acting gas (10% C3F8)
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
61 participants
Where
1 siteTaiwan
Study dates
Sep 2004to Dec 2012
Phase
Interventional
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

Who may be able to join

  • patients undergoing primary pars plana vitrectomy for complications of proliferative diabetic retinopathy were recruited for the prospective study

Who cannot join

  • (1) anticoagulant therapy had been used prior to surgery or during post-operative follow-up period; (2) positive medical history of blood diseases associated with abnormal blood coagulation.

Trial locations and contacts

1 site in 1 country.

Taiwan1 site
  • National Taiwan University Hospital

    Taipei

Other trials in Taiwan

About this study

Recurrent vitreous hemorrhage after vitrectomy for complications of diabetic retinopathy is a common occurrence. The hemorrhage may appear within the first few weeks after surgery or months later. This complication may delay visual rehabilitation significantly and sometimes requires additional procedures or surgery, jeopardizing previous successful operation. The causes of bleeding are diverse. While evidence suggests fibrovascular proliferation from the sclerotomy sites or in the vitreous base may be an important source of recurrent vitreous hemorrhage, other origins of hemorrhage exist including lysed clot from residual vitreous skirt, injured retinal vessels from surgery, and incompletely removed fibrovascular tissues. The latter three conditions may be the major sources of early postoperative vitreous hemorrhage. We have shown that peripheral retinal cryotherapy along with cryo treatment at the sclerotomy sites may effectively reduce the incidence of fibrovascular proliferation at the inner surface of sclerotomy sites and prevent the late-onset recurrent vitreous hemorrhage. However, many patients still experience disturbing vitreous hemorrhage within the first two to three weeks after post-operative transient clear-up of the vitreous. We hypothesize that gas bubble within the vitreous cavity may mechanically temponade the fragile retinal vessels, and concentrate the coagulation factors in the vitreous cavity, allowing the integrity of vessel walls gradually recovers and thus preventing the occurrence of early postoperative recurrent vitreous hemorrhage.

To test this hypothesis, a clinical study was undertaken to investigate the effect of long-acting gas infused into the vitreous cavity at the end of diabetic vitrectomy in the prevention of recurrent vitreous hemorrhage.

Read the detailed description

The study consisted of two parts. Part one was prospective clinical observational study; part two was case control study.

From January 2005 to May 2005, consecutive patients undergoing primary pars plana vitrectomy for complications of proliferative diabetic retinopathy were recruited for the prospective study. The selection criteria were: 1) anticoagulant therapy should not have been used prior to surgery or during post-operative follow-up period; 2) ther should be no medical history of blood diseases associated with abnormal blood coagulation. During operation, removal of the fibrovascular tissues as well as old and fresh blood was attempted as completely as could be safely done in all cases; blood clots adherent to the peripheral vitreous skirt was removed as much as possible; peripheral retinal cryotherapy (10 to 12 spots in one row), and sclerotomy sites cryo (2 spots, each 6 seconds, for 3 sclerotomy sites) were performed. For those cases without retinal detachment and breaks, fluid-gas exchange with 7.5% C3F8 was done at the end of the surgery; For those with preexisting breaks or iatrogenic breaks induced retinal detachment, fluid-gas exchange with 15% C3F8 was performed before cryotherapy. After surgery, patients without breaks were kept in a prone position overnight, and maintained head down during waking hours and lied on either side, during sleep for 3 weeks. Other patients assumed head positions depending on the location of breaks. Ophthalmological examinations were performed in the first 4 days after surgery, then weekly for 6 weeks and then monthly for 4 months. The preoperative, intraoperative and postoperative data were collected for each patient. These included age, gender, study eye, types and duration of diabetes mellitus, intraoperative diagnosis, and the use of scleral buckle, silicone oil temponade; data regarding the time, duration, frequency and treatment of recurrent vitreous hemorrhage and the duration of post-operation follow-up were also compiled. Results of ophthalmological examinations, including best corrected visual acuity, intraocular pressures, corneal conditions, anterior chamber reactions, lens status, intravitreal gas amount, and retina conditions were recorded. The amount of vitreous blood was assessed by indirect ophthalmoscopy with patients in both sitting and face-up position. The degree of vitreous opacity was recorded according to criteria set for grading vitreous opacity in uveitis.

Patients who had silicone oil infusion, failed to achieve retinal attachment for at least 3 months, or followed for less than a minimum of 5-month were excluded from the study.

Using the same inclusion and exclusion criteria, chart review from September 2004 to May 2005 for diabetic cases operated by the same surgeon with only cryo treatment but without long-acting gas infusion at the end of vitrectomy was done. Similar data as for the prospective study (except intravitreal gas amount) were collected. These cases served as control to compare the rate of recurrent vitreous hemorrhage and the change of best-corrected visual acuity between cases with intravitreal long-acting gas and those without.

Being tested
Intravitreal long acting gas (10% C3F8)
Keywords
Diabetic retinopathy, Vitrectomy, Postoperative vitreous hemorrahge, Intravitreal gas injection
Medical subject headings
Diabetes Mellitus, Diabetic Retinopathy, Vitreous Hemorrhage

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Intravitreal long acting gas (10% C3F8)Procedure or surgery

    At the end of surgery, fluid-gas exchange with 10% C3F8 were done in the eye of study group

Study groups in NCT00155454
Study groupRoleWhat they receive
Study groupExperimentalGroup 1 had intravitreal long acting gas (10% C3F8) injection in the vitreous cavity at the end of surgery
Receives: Procedure: Intravitreal long acting gas (10% C3F8)
Control groupSham comparatorGroup 2 did not receive intravitreal long acting gas (10% C3F8)
Receives: Procedure: Intravitreal long acting gas (10% C3F8)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Recurrent vitreous hemorrhage rate

    Initial time to vitreous clearing , percentage of prolonged vitreous clearing, and early versus late manifest postoperative recurrent vitreous hemorrhage in groups 1 and 2 were compared to determine the effects of long acting gas on prevention of early recurrent vitreous hemorrhage.

    Measured: Within 6 months after vitrectomy

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted12 Sep 2005 (estimated)
  2. Study startSep 2004
  3. Primary completionDec 2012
  4. Study completionDec 2012

Resources

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
Treatment
Allocation
Non-randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Outcomes assessor
Enrolment
61 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00155454
Sponsor's protocol ID
9461700621
Status last verified
Dec 2012
First submitted
8 Sep 2005
Last updated
27 Dec 2012
Results posted
No
Data monitoring committee
Yes

Questions about this trial

What is this clinical trial studying?

A study testing Intravitreal long acting gas (10% C3F8) in people with Diabetes Mellitus and Diabetic Retinopathy, run by National Taiwan University Hospital at 1 site in Taiwan.

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 1 inclusion and 1 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 27 Dec 2012. 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 Taiwan. 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. Some participants in this study may receive a placebo. 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?

Recurrent vitreous hemorrhage rate (time frame: Within 6 months after vitrectomy). 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 27 Dec 2012.

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