A Pilot Study of Peribulbar Triamcinolone Acetonide for Diabetic Macular Edema

Detailed Summary

The study involves the enrollment of patients over 18 years of age with diabetic macular edema involving the center of the macula who have not already been given maximal laser treatment. Patients with one study eye will be randomly assigned (stratified by prior laser) with equal probability to one of five treatment groups: 1. Focal laser photocoagulation (modified ETDRS technique) 2. Posterior peribulbar injection of 40 mg triamcinolone (Kenalog) 3. Anterior peribulbar injection of 20 mg triamcinolone 4. Posterior peribulbar injection of 40 mg triamcinolone followed after one month by laser 5. Anterior peribulbar injection of 20 mg triamcinolone followed after one month by laser For patients with two study eyes (both eyes eligible at the time of randomization), the right eye (stratified by prior laser) will be randomly assigned with equal probabilities to one of the five treatment groups listed above. If the right eye was assigned to laser only, then the left eye will be assigned to one of the four triamcinolone groups above with equal probability (stratified by prior laser). If the right eye was assigned to receive triamcinolone, then the left eye will receive laser only. Triamcinolone acetonide will be the corticosteroid utilized in this study. The triamcinolone acetonide preparation to be used is Kenalog. Kenalog is manufactured by Bristol Myers Squibb and is approved by the Food and Drug Administration for intramuscular use for a variety of indications. Peribulbar injections of Kenalog have been used for a wide variety of ocular conditions, particularly uveitis and post-cataract extraction cystoid macular edema, for many years. Two different triamcinolone regimens will be assessed in the study: 40 mg injected posteriorly and 20 mg injected anteriorly. There is no indication of which treatment regimen will be better. Although the injection behind the eye is more common than the injection near the front of the eye, the injection near the front of the eye has less risk of injuring the eye. However, it is possible that the injection near the front of the eye may increase eye pressure more frequently. Little is known about which of the two injections decreases macular edema and improves vision more often. Patients enrolled into the study will be followed for three years and will have study visits 1 month, 2 months, 4 months, 8 months and annually after receiving their assigned study treatment. For the first 8 months of the study, patients should only be retreated with their randomized treatment. However, if the patient's visual acuity has decreased by 15 letters or more, then any treatment may be given at the investigator's discretion. After completion of the 8-month visit, treatment is at investigator discretion. The primary objective of this study is to obtain estimates of efficacy and safety outcomes for each of the treatment groups. These estimates will provide a basis for the sample size estimation and hypothesis generation in a phase III trial.

Study Details

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Interventions