Study to Evaluate Efficacy and Safety of Entelon 50mg in Patients With Non-Proliferative Diabetic Retinopathy

Inclusion Criteria: 1. 19 years ≤ age 2. Those who are diagnosed as Type 2 diabetes mellitus 3. Those whose blood sugar level has been well adjusted to less than 9% of HbA1c with dietary and oral blood sugar lowering durgs for 3 months based on the time of screening 4. Those who agree to use an effective method of contraception 5. Those who provide written consent voluntarily to participate in this clinical trial Inclusion criteria for the study eye 1. Those with 0.5(20/40 Snellen lines) or more visual acuity 2. Those with 300 micrometers or less central macular thickness 3. Those who are diagnosed as mild to moderate NPDR(DRSS levels 35-47) Exclusion Criteria: 1. Those who are diagnosed as proliferative diabetic retinopathy 2. Those with macular edema 3. Diabetic subjects who have difficulty in controlling blood sugar 4. Those whose blood pressure is not well controlled at the time of the screening(\>140/90mmHg) 5. Those who, have had stroke or myocardial infarction or arrhythmia that should be treated within 6 months prior to the time of screening 6. Subjects with severe renal disorder or severe liver disorder 7. Those who have a history of malignant tumors within 5 years prior to the time of screening 8. Those who are required to receive Kallidinogenase, Vaccinium myrtillus extract, Sulodexide, or Calcium dobesilate during the clinical trial period 9. Those who have an allergy to investigational product or any of its excipients 10. Those who have an allergy to fluorescein 11. Those who have galactose intolerance, lapp lactase deficiency, or glucose-galactose malabsorption 12. Those who have difficulty to get OCT test or Fundus photo test 13. Pregnant or lactating woman 14. Those with medication of other investigational product within 3 months prior to the time of randomization 15. Patients who are considered to be ineligible for study participation by the investigator Exclusion criteria for the study eye 1. Those who have a visual defect that can affect the evaluation determined by an investigator 2. Those who have a opacity that can affect the evaluation determined by an investigator 3. Those who have eye diseases that can affect the evaluation determined by an investigator 4. Those with 25mmHg or more intraocular pressure on a study eye 5. Those who are on medication of intravitreal injection of steroid or anti VEGF treatment or get laser photocoagulation within 6 months prior to the first administration 6. Those who have a history of a vitrectomy 7. Those who have a major ophthalmic surgery history within 3 months prior to the time of first administration for investigational products 8. Those who have a history of yttrium aluminum garnet capsulotomy within 2 months prior to the time of first administration for investigational products 9. Those with a phakia