Trc nw8 fundus camera

A comprehensive ophthalmic examination was performed in all the participants at baseline and at 1, 3–6, and 12 months after PRP including best corrected visual acuity (BCVA), intraocular pressure, slit-lamp examination, dilated fundoscopy, 45° CFP (TRC-NW8 fundus camera, TOPCON, Tokyo, Japan), OCT (HRA-OCT, Heidelberg Engineering, Germany), and OCTA (Optovue, Fremont, California, USA). FFA (Spectralis HRA, Heidelberg Engineering, Jena, Germany) was performed at baseline and 3–6 and 12 months after PRP. AL was obtained by using ocular biometry (LS900 Haag-Streit Diagnostics, Köniz, Switzerland) at baseline to correct the retinal magnification of each OCTA image.
Demographic and systemic parameters including the age, sex, duration of diabetes, blood pressure, body mass index (BMI), waist-hip ratio (WHR), glycated hemoglobin (HbA1c), creatinine, and creatinine clearance rate (Ccr) within 1 week before initiating PRP were recorded.

Each participant underwent ophthalmic examination by retinal photographs taken of both eyes. Fundus photographs (45°) were taken using a “nonmydriatic” TRC NW8 fundus camera (Topcon Corporation, Tokyo, Japan), without pupil dilation, in seven fields per eye. Two qualified assessors, blinded to all participant information, graded the photographs independently. Discrepancies of the grading results between these two assessors were graded by a third ophthalmologist to confirm the final results. The level of retinopathy was defined according to the modified Early Treatment of Diabetic Retinopathy Study (ETDRS) severity scale [8 (link)]. In the present study, DR was defined as an ETDRS scale score ≥ level 20, which is defined as very mild DR. The classification was based on the grading of the worst eye.

The clinical images were collected at Xi’an No.1 Hospital. Ten normal eyes from ten participants were included in this study. We captured both high quality fundus images using a DF-camera (Topcon TRC-NW8 fundus camera, FOV of 45^o) and low quality fundus images using a HF-camera (iExaminer plus ‘Panoptic’, FOV of 25^o, Welch -Allyn Inc., Skaneateles Fall, NY, USA)10 ). The low quality images showed a smaller FOV, lower resolution, and poorer contrast due to the hardware limitations, greatly increasing the difficulties of image analysis. Informed consent for research use of data was sought and obtained from each study participant before participation. The study was approved by the Ethics Committee of Xi’an Jiaotong University. The methods were carried out in accordance with the approved guidelines.