Safety and Efficacy by Multiple Injection of KH902 in Patients With Diabetic Macular Edema (DME)

Inclusion Criteria: * Signed the Informed Consent Form and willing to comply with study procedures; * 18 years old ≦ either gender ≦ 75 years old; * Confirmed diagnosed with Type 1 diabetes or Type 2 diabetes based on the diabetes diagnosis criteria; * Clinically significant DME: * Hard exudation within 500μm of the central foveal diameter accompanied with contiguous retina thickening; * The edema locates within 500μm of the central foveal diameter; * Retina thickening field \> 1DD and within the 1DD central fovea. * BCVA score of the study eyes between 78 and 19 letters, inclusively, and the BCVA score of fellow eyes ≥ 24 letters; * Previous treatment of antidiabetic drugs within three months preceding the screening, and blood-glucose concentration is predicted to be unchanged and stable during the whole study. Exclusion Criteria: * Uncontrolled glaucoma in either eye; * Currently active ocular inflammation or infection in either eye; * Macular edema in the study eye was caused by other diseases rather than diabetes; * Company with any other ocular conditions failing to prevent vision loss despite improving the macular edema; * Any other ocular diseases which may cause macular edema or vision alteration during study phase; * Retinal macular traction or macular epiretinal membrane in study eye; * Refractive error equate or exceed 8 diopters of myopia in study eye * Whole or regional retinal laser photocoagulation has been applied in study eye within 6 months preceding the screening; * Previous anti-VEGF drug treatment in study eye; * Intraocular or periocular injection of steroid drug within 6 months preceding the screening; * Previous ophthalmologic operation within 3 months preceding the screening and/or planning to receive an ophthalmologic operation during the study. * There is any potential for the study eye to receive the panretinal laser photocoagulation treatment during the study; * Previous vitrectomy in study eye. * Uncontrolled diabetes; * Hypertensive patients with poorly controlled blood pressure; * Uncontrolled systemic infectious diseases; * Systemic immune diseases; * History of allergy; * Any uncontrolled clinical disorders; * Pregnant or nursing women; * Adopt one or more adequate contraception methods.