The goal of this clinical trial is to learn if drug TNTL works to treat non-proliferative diabetic retinopathy in adults. It will also learn about the safety of drug TNTL. The main questions it aims to answer are:

1. Does drug TNTL can improve visual acuity and reduce the degree of retinopathy?
2. What medical problems do participants have when taking drug TNTL? Researchers will compare drug TNTL to a placebo (a look-alike substance that contains no drug) to see if drug TNTL works to treat non-proliferative diabetic retinopathy.

Participants will:

1. Take drug TNTL or a placebo every day for 6 months
2. Visit the clinic once every 4 weeks for checkups and tests
3. Keep a diary of their symptoms and Change from baseline

Inclusion Criteria:

• Age range of 18 to 75 years old (including boundary values);
• Conform to the diagnosis of type 2 diabetes and diabetes retinopathy. diabetes retinopathy is classified as NPDR and mild and moderate patients;
• Patients with the best corrected visual acuity (BCVA) of the target eye is ≥ 34 points (ETDRS visual acuity chart, visual acuity equivalent to a score of 20/200, decimal 0.1);
• Patients who meet the syndrome differentiation criteria of Yin deficiency, internal heat, and eye meridian stasis in traditional Chinese medicine;
• During the screening period, glycated hemoglobin (HbA1c) should be ≤ 8.5%;
• Agree to participate in this clinical study and voluntarily sign the informed consent form.

Exclusion Criteria:

• Patients with no light perception in one eye;
• Patients with macular edema who require anti Vascular Endothelial Growth Factor(VEGF) treatment;
• People with other eye diseases, such as retinal artery or vein occlusion, non diabetes retinopathy, retinal detachment, uveitis, glaucoma, corneal ulcer, cataract affecting fundus examination, optic neuropathy and high myopia with fundus changes;
• Patients with acute complications of diabetes (such as diabetes ketoacidosis, hyperglycemia hyperosmolality syndrome, diabetes lactic acidosis, etc.) within one year before the screening period;
• People with other eye related complications of diabetes, such as iris neovascularization, angle neovascularization, and retinal neovascularization;
• acupuncture and moxibustion and other external treatment methods of traditional Chinese medicine were used to treat diabetes retinopathy within one week before enrollment;
• Patients who have used drugs clearly stated in the instruction manual to treat diabetes retinopathy, such as calcium dobesilate, pancreatic kallidinogenase, Qiming Granules, Shuangdan Mingmu Capsules, Compound Danshen Dropping Pills, Tongluo Mingmu Capsules, etc. within 2 weeks before enrollment;
• Patients who have undergone glaucoma, vitreous, retinal and other intraocular surgeries and procedures in the target eye within 3 months before enrollment;
• Patients who have undergone cataract surgery in the target eye within 3 months prior to enrollment and have not yet stabilized according to the researcher's assessment;
• Patients who have received intravitreal injections of anti VEGF antibodies and glucocorticoids in the target eye within 3 months prior to enrollment;
• Patients who have undergone total retinal laser photocoagulation treatment in the target eye;
• For those whose refractive media is turbid and difficult to evaluate fundus images in the target eye;
• Uncontrolled or controlled blood pressure with systolic blood pressure ≥ 160mmHg and/or diastolic blood pressure ≥ 100mmHg;
• When screening, alanine aminotransferase (ALT) or aspartate aminotransferase (AST) should be ≥ 1.5 times the upper limit of normal value;
• Patients with serious kidney disease (such as azotemia and uremia), diabetes foot, etc;
• When screening, individuals with severe primary diseases such as respiratory, cardiovascular, cerebrovascular, endocrine, digestive, and hematopoietic systems, or those with severe mental illnesses should be included;
• Suspected or confirmed history of alcohol or drug abuse;
• Pregnant women, lactating women, or women of childbearing age who are preparing to conceive; Female subjects of childbearing age or male subjects (with partners of childbearing age) who do not agree to voluntarily take effective contraceptive measures within one month after the last dose during the screening period;
• Individuals who are allergic to the drugs or their components used in this experiment;
• Participants who have participated in other clinical trials within the past month;
• The researchers believe that participants should not participate in the clinical trial.