Abstract
Purpose: :
To determine the relationship between peripheral retinal vascular nonperfusion and the presence of macular edema (ME) in patients with diabetic retinopathy (DR) using ultra-widefield fluorescein angiography (UWFA) imaging.
Methods: :
A retrospective review of 122 eyes of 70 treatment-naïve diabetic patients who underwent diagnostic UWFA using the Optos Optomap Panoramic 200A imaging system. Two independent, masked graders quantified the area of retinal ischemia using the UWFA images and Adobe software. Based on clinical examination, each patient was given a binary classification as either having ME or no ME. McNemar's Test and a two-sample test of proportions were used to determine the relationship between ME and ischemia for binary and proportional data, respectively. Linear and logistic models were constructed using generalized estimating equations to test relationships between independent variables, covariates and outcomes while controlling for inter-eye correlation, age, gender, hemoglobin A1c, mean arterial pressure, and dependence on insulin.
Results: :
76 eyes (62%) exhibited areas of peripheral nonperfusion. There was a significant direct correlation between ME and peripheral ischemia as seen on UWFA (p < 0.001). Additionally, patients with retinal ischemia had a 3.75 times increased odds of having ME compared to those without ischemia (CI 1.26 to 11.13, p < 0.02).
Conclusions: :
Retinal ischemia is significantly correlated with ME in treatment-naïve patients with DR. UWFA is a useful tool for detecting peripheral vascular nonperfusion which may have direct implications in the diagnosis, follow-up, and treatment such as targeted peripheral photocoagulation.
Keywords: diabetic retinopathy • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical