A Multicentre Randomised Clinical Trial of Laser Treatment Plus Intravitreal Triamcinolone for Diabetic Macular Oedema
This study is likely to identify an improved and economical treatment for diabetic macular oedema, one of the commonest causes of blindness both in Australia and the rest of the world.The specific aims of the study are to test the following hypotheses:
- That intravitreal triamcinolone followed by laser treatment results in a greater improvement in visual acuity than placebo followed by laser treatment of eyes with macular oedema secondary to diabetes;
- That intravitreal triamcinolone followed by laser treatment results in greater degree of resolution of macular oedema than placebo followed by laser treatment of eyes with macular oedema secondary to diabetes;
- That intravitreal triamcinolone followed by laser treatment results in a reduced requirement for further laser treatment to control diabetic macular oedema than placebo followed by laser treatment;
- That intravitreal triamcinolone followed laser has a manageable and acceptable safety profile in eyes with diabetic macular edema.
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Phase II/III Multicentre Randomised Clinical Trial of Laser Treatment Plus 4 mg Intravitreal Triamcinolone Injection to Reduce Diabetic Macular Oedema|
- The proportion of eyes showing an improvement of visual acuity by 10 letters on a LogMAR chart compared with the pre-injection level 24 months after treatment [ Time Frame: 24 month ]At 24 months, improvement of ≥10 LogMAR letters was seen in 15/42 (36%) eyes treated with IVTA plus laser compared with 7/42 (17%) eyes treated with laser only (p=0.047, odds ratio 2.79, 95% CI, 1.01, 7.67).
- Number of laser treatments required for the treatment of macular oedema during the course of the study. [ Time Frame: 24 month ]At least 1 retreatment was required in the second year of the study in 29/42 (69%) of IVTA plus laser treated eyes compared with 19/42 (45%) laser only eyes (p=0.187).
- Change in retinal thickness demonstrated on optical coherence tomography (OCT) [ Time Frame: 24 month ]There was no difference in the mean CMT (346.8μm ± 114.9SD vs 372.6μm ± 154.2SD, comparing IVTA plus laser vs laser only, p=0.349) or mean logMAR visual acuity (56.1 ± 15.7SD vs 54.5 ± 16.1SD letters, p=0.439).
- The incidence of moderate or severe side effects related to the procedure of intravitreal injection or related to the drug [ Time Frame: 24 month ]Cataracts were removed from 17/28 (61%) of phakic IVTA plus laser-treated eyes vs. 0/27 (0%) laser only eyes (p<0.001). Treatment for elevated intraocular pressure was required in 27/42 (64%) of the IVTA plus laser eyes compared with 10/42 (24%) laser only eyes (p<0.001)
|Study Start Date:||April 2005|
|Study Completion Date:||May 2009|
|Primary Completion Date:||May 2009 (Final data collection date for primary outcome measure)|
Drug: Triamcinolone acetate
A 25 fold increase in the risk of going blind on diagnosis of diabetes is one of the most daunting threats that people with diabetes face. Stimulated by several uncontrolled, anecdotal reports, we are already conducting a randomized clinical trial of intravitreal triamcinolone for the treatment of diabetic macular edema which is refractory to conventional laser treatment. The analysis of the 3 month data from this study has already unequivocally demonstrated that the treatment very significantly reduces or eliminates macular oedema in the short term and results in improved visual acuity. Thus intravitreal triamcinolone may represent the most significant development in the prevention of blindness in people with diabetes since the introduction of laser treatment. It is also a highly cost-effective intervention that can be administered by general ophthalmologists. The next question to be answered, which will be addressed directly by the present study, is whether there is a significant, synergistic beneficial effect when intravitreal steroids are combined with current therapy (laser).
This study represents the second major project to be undertaken by the Australian Retinal Collaboration (ARC). The ARC aims to set the highest attainable standards for investigator-initiated clinical research in retinal diseases in Australia. Having enrolled and treated more than the target of 120 patients, we are currently completing an RCT of laser induced chorioretinal anastomosis for central retinal vein occlusion, an innovative Australian concept for a severe and otherwise untreatable disease. The proposed study is likely to identify an improved and economical treatment for one of the commonest causes of blindness both in Australia and the rest of the world. Intravitreal triamcinolone is also an intervention which has generated intense interest internationally, and one for which members of the ARC are acknowledged pioneers.
Successful implementation of the study proposed, which is feasible, is highly likely to have an immediate and direct effect on the prevention of vision impairment and blindness in people with diabetes
Please refer to this study by its ClinicalTrials.gov identifier: NCT00148265
|Australia, New South Wales|
|Save Sight Institute, Sydney/Sydney Eye Hospital Campus, University of Sydney|
|Sydney, New South Wales, Australia, 2000|
|Principal Investigator:||Mark C Gillies, MBBS, PhD||Save Sight Institute, Deaprtment of Clinical Ophthalmology, University of Sydney|
|Principal Investigator:||Ian L McAllister, MBBS||Lions Eye Institute, The University of Western Australia|
|Principal Investigator:||Tien Wong, MBBS, PhD||Royal Victoria Eye & Ear Hospital, Department of Ophthalmology, University of Melbourne|
|Principal Investigator:||Jennifer Arnold, MBBS||Marsden Eye Centre Parramatta|