A Multicentre Randomised Clinical Trial of Laser Treatment Plus Intravitreal Triamcinolone for Diabetic Macular Oedema

Overview

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.

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