Clinical Research Directory

Inclusion Criteria: * (1) age between 40 and 80 years, regardless of gender, (2) meet the diagnostic criteria of T2DM based on the Standards of Medical Care in Diabetes (2021)11, and complete evaluation at the Endocrinology Department of Peking University Third Hospital, (3) meet the Diabetic Retinopathy Severity Scale (DRSS) score level of mild to moderate-severe NPDR (i.e. 35 ≤ DRSS level ≤ 60, as shown in eTables 1 \& 2 in the Supplement) based on the montages ultra-widefield (UWF) fundus photographs,12 without clinically significant macular edema (CSME, defined as one or more of the followings: retinal thickening at or within 500 μm of the center of the macula; hard exudates at or within 500 μm of the center of the macula, if associated with adjacent retinal thickening; or a zone or zones of retinal thickening one disc area in size, at least part of which is within one disc diameter of the center of the macula),13 (4) willing to sign the informed consent form. Exclusion Criteria: * (1) conjunctivitis, keratitis, blepharitis, episcleritis, scleritis, uveitis, severe dry eye disease, using anti-glaucoma eyedrops, or any condition causing conjunctival congestion or ciliary congestion, (2) pterygium, wearing contact lens in the past week, ocular surface burn, conjunctival tumors, or any condition causing significant conjunctival vascular deformities, (3) previously undergone intraocular surgeries involving manipulation of the conjunctiva, or corneal refractive surgery, (4) history of hematological disorder, dysthyroidism, rheumatic disorder, malignant tumor, (5) refractive media opacity resulting in poor visualization of fundus photographs, (6) difficulty in maintaining fixation or comprehension, making it challenging to cooperate with the examination, (7) difficulty in completing follow-up visits in 3 years.