RESUMEN
BACKGROUND: To develop and assess the usability of a smartphone-based visual acuity (VA) test with an automatic distance calibration (ADC) function, the iOS version of WHOeyes. METHODS: The WHOeyes was an upgraded version with a distinct feature of ADC of an existing validated VA testing app called V@home. Three groups of Chinese participants with different ages (≤20, 20-40, >40 years) were recruited for distance and near VA testing using both an Early Treatment Diabetic Retinopathy Study (ETDRS) chart and the WHOeyes. The ADC function would determine the testing distance. Infrared rangefinder was used to determine the testing distance for the ETDRS, and actual testing distance for the WHOeyes. A questionnaire-based interview was administered to assess the satisfaction. RESULTS: The actual testing distance determined by the WHOeyes ADC showed an overall good agreement with the desired testing distance in all three age groups (p>0.50). Regarding the distance and near VA testing, the accuracy of WHOeyes was equivalent to ETDRS. The mean difference between the WHOeyes and ETDRS ranged from -0.084 to 0.012 logMAR, and the quadratic weighted kappa (QWK) values were >0.75 across all groups. The test-retest reliability of WHOeyes was high for both near and distance VA, with a mean difference ranging from -0.040 to 0.004 logMAR and QWK all >0.85. The questionnaire revealed an excellent user experience and acceptance of WHOeyes. CONCLUSIONS: WHOeyes could provide accurate measurement of the testing distance as well as the distance and near VA when compared to the gold standard ETDRS chart.
RESUMEN
PURPOSE: The incidence and risk factors for diabetic retinopathy (DR) in southern China remain unclear. This project aims to explore the onset and progression of DR and their determinants through a prospective cohort in South China. METHODS: The Guangzhou Diabetic Eye Study (GDES) recruited patients with type 2 diabetic registered in the community health centers in Guangzhou, China. Comprehensive examinations were performed including visual acuity, refraction, ocular biometry, fundus imaging, blood and urine tests. RESULTS: A total of 2305 eligible patients were included in the final analysis. In total, 14.58% of the participants had any DR and 4.25% had vision-threatening DR (VTDR), among which 76 (3.30%), 197 (8.55%), 45 (1.95%) and 17 (0.74%) were classified as mild NPDR, moderate NPDR, severe NPDR and PDR, respectively. There were 93 (4.03%) patients with diabetic macular edema (DME). The presence of any DR was independently associated with a longer duration of DM, higher degree of HbA1c, insulin treatment, higher average arterial pressure, higher concentration of serum creatinine, presence of urinary microalbumin, older age, and lower body mass index (BMI) (all p < 0.001). For VTDR, seven factors were significant: older age, a longer duration of DM, higher concentration of HbA1c, use of insulin, lower BMI, higher concentration of serum creatinine, and high albuminuria (all p < 0.05). These factors were also independently associated with DME (all p < 0.001). CONCLUSION: The GDES is the first large-scale prospective cohort study of the diabetic population in southern China, which will help to identify novel imaging and genetic biomarkers for DR in this population.
