• • Proportion of treated versus untreated eyes with improvement of visual acuity by 5 letters or more on the ETDRS chart at 24 months, no less than 3 months after the most recent treatment episode. An interim analysis of the primary and secondary outcome
• • Incidence of moderate or severe adverse effects related to treatment

• • Any change of visual acuity (treated versus untreated eyes) at 3 months and 24 months after treatment
• • Proportion of treated versus untreated eyes with reduction of macular thickness as demonstrated with OCT at 3 months and 24 months. Both absolute change and percentage change will be analysed.
• • Changes in semi-quantitative grading of cataract at 3 months and 24 months.

The trial will test the hypothesis that an intravitreal injection of triamcinolone is safe and efficacious for patients with clinically significant diabetic macular oedema that is recalcitrant to conventional laser therapy

Diabetic retinopathy is a common cause of severe loss of visual and the most common cause of legal blindness in individuals between the ages of 20 and 65 years in developed countries. Swelling of the central retina, or “macular oedema” is the commonest cause of visual loss in diabetic retinopathy.

Diabetic macular oedema is treated with laser coagulation to the macular area according to established guidelines which take into account the extent of the leak and its proximity to the centre of the macula, the “fovea”. This treatment does not, however, always work and is inherently destructive.

Intravitreal injection of crystalline steroids has been proposed as a new modality to treat clinically significant diabetic macular oedema.

To determine by means of a prospective, double-masked, randomised, placebo-controlled trial to determine whether an intravitreal injection of triamcinolone three months or more after focal or grid laser photocoagulation for clinically significant diabetic macular oedema will improve the visual acuity of eligible eyes. OCT will be used in addition to visual acuity testing as an objective measurement of macular oedema.

• Sutter FK, Simpson JM, Gillies MC. Intravitreal triamcinolone for diabetic macular edema that persists after laser treatment: three-month efficacy and safety results of a prospective, randomized, double-masked, placebo-controlled clinical trial. Ophthalmology. 2004 Nov;111(11):2044-9.
• Larsson J, Zhu M, Sutter F, Gillies MC. Relation between reduction of foveal thickness and visual acuity in diabetic macular edema treated with intravitreal triamcinolone. Am J Ophthalmol. 2005 May;139(5):802-6.

Inclusion Criteria:

• Clinically significant diabetic macular oedema involving the fovea in one or both eyes (phakic and/or pseudophakic) which persists at least 3 months after adequate macular photocoagulation.
• best corrected visual acuity in the affected eye(s) 6/9 or worse

Exclusion Criteria:

• Glaucoma which is uncontrolled or is controlled but with glaucomatous visual field defects
• Loss of vision due to other causes (e.g. age related macular degeneration, myopic macular degeneration)
• Significant macular ischemia (FFA)
• No useful vision in fellow eye
• Known allergies to triamcinolone acetate or steroids
• Patient is already under systemic treatment with > 5mg prednisolone (or equivalent) daily.
• Intercurrent severe disease such as septicaemia
• Any condition which would affect follow-up or photographic documentation (e.g. geographical, psycho-social, media opacities)