Quantification of Vascular Tortuosity by Analyzing Smartphone Fundus Photographs in Patients with Retinopathy of Prematurity

ABSTRACT

Purpose@#To determine the usefulness of measuring the tortuosity of retinal arteries using smartphone fundus photographs to quantify plus disease in retinopathy of prematurity (ROP) patients. @*Methods@#Digital fundus photographs were taken with a smartphone of 116 eyes involving 58 premature infants. The tortuosity of retinal arteries named as the tortuosity index (TI) was measured with Image J software. Patients were classified into the treated and control groups and the TIs of the two groups were compared. A receiver operating characteristic curve was constructed and areas under the curve (AUC) were calculated to quantify the diagnostic utility of TI. @*Results@#Fundus photographs of 98 eyes of 50 premature infants were analyzed; 38 eyes of 20 infants were the treated group and 60 eyes of 30 infants were the control group. The TI was 1.231 ± 0.156 in the treated group before treatment, which was significantly larger than 1.062 ± 0.019 in the control group. After treatment of the treated group, the TI was 1.100 ± 0.093, which was significantly smaller than before treatment. The AUC was 0.926, and using a cut-off value of 1.095, the sensitivity and specificity of TIs for requiring treatment were 85.1% and 95.5%, respectively. @*Conclusions@#The tortuosity of retinal arteries was measured by analyzing smartphone fundus photographs to quantify plus disease in ROP patients. This method may be helpful for screening, follow-up, and treatment decisions for ROP patients.