Trc nw8 non mydriatic retinal camera

Each participant underwent visual acuity measurement, autorefractometry (HRK-7000A Auto Refractor; Huvitz, Inc., Anyang-si, South Korea), non-contact tonometry (TX-20 Full Auto Tonometer; Canon, Inc., Tokyo, Japan), slit-lamp examination, and fundus photography (TRC-NW8 non-mydriatic retinal camera, Topcon, Tokyo, Japan; D7500 DSLR camera, Nikon, Tokyo, Japan). Diagnosis and grading of HTNR were performed by two ophthalmologists specialized in retinal diseases using indirect fundoscopy and fundus photography; grading was based on Keith–Wagener–Barker and Mitchell–Wong classifications⁶ (link) (κ = 0.883). Differing diagnoses were reassessed and diagnosed by a senior chief ophthalmologist. The arteriovenous ratio was manually calculated using Image J 1.51 (National Institutes of Health, Bethesda, MD, USA). The diameters of arterioles and venules 1.5 papillary diameters to the optic disc were measured 10 times to obtain an average. The arteriovenous ratio cutoff point for determining retinal arteriole narrowing was set at ½. The distribution of retinopathy grades in each group was listed in Table 1.

In phase 1, retinal photographs were taken using three different retinal cameras in the development set: the AFP-210 nonmydriatic auto retinal camera (NIDEK Corporation, Aichi, Japan), TRC-NW8 nonmydriatic retinal camera (Topcon Corporation, Tokyo, Japan), and Nonmyd A-D (Kowa Co. Ltd., Shizuoka, Japan). In the development set, retinal photographs of all participants were taken, and blood tests were performed on the same day.
In phase 2, retinal photographs were taken at baseline using TRC-NW8 (Topcon Corporation, Tokyo, Japan) and KOWA VX-20 (Kowa, Chofu Factory, Japan) in the Korean Diabetic Cohort and Topcon 3D OCT-1000 Mark II (Topcon Corporation, Tokyo, Japan) in the UK Biobank.