Any intraocular surgery within 6 months prior to study entry. Prior peeling of epiretinal membrane or inner limiting membrane. Any major surgical procedure within one month of study entry Prior irradiation of the head region of the eye under study. Any previous pharmacological treatment for DME, BRVO, CSR or MacTel (including corticosteroid intravitreal, subconjunctival or subtenon) or at any time during the last 90 days for any other condition.