Does Intravitreal Injection of Triamcinolone Acetonide Impairs the Adrenal Function

The use of intravitreal corticosteroids in the management ocular inflammatory diseases has recently gained widespread acceptance. The purpose of this study is to determine if the use of intravitreal triamcinolone is associated with suppression of endogenous cortisol production, as generally admitted for patients treated with oral or parenteral corticosteroid therapy.

The normalcy of hypothalamic- pituitary- adrenal axis (HPA axis) of enrolled subjects will will be assessed before intravitreal injection of 4mg of triamcinolone and again after one day, one week and two weeks. Patients with abnormal HPA axis will be re-tested after four weeks and later until the HPA axis function return to normal. The HPA axis will be assessed with low dose (1mcg) intravenous corticotropin(ACTH) stimulation test, in which cortisol levels will be sampled before , 30 minutes and 60 minutes after 1mcg ACTH IV injection.