Background/Aim To analyse ultrawide-field fluorescein angiography (UWF-FA) images of diabetic retinopathy using a novel software that automatically calculates microaneurysm (MA) and non-perfusion area.
Methods Two hundred UWF-FA images of treatment-naïve diabetic retinopathy (38 proliferative diabetic retinopathy and 162 non-proliferative diabetic retinopathy) from 120 patients (mean age 54.22; 80 male) were analysed using novel software to determine the number of MAs, area of capillary non-perfusion (ischaemic index) and number of neovascularisations. Each result was compared according to its retinal regions.
Results For the total retina, the mean number of MAs was 292.02 (±175.57) and the ischaemic index was 59.42% (±14.78%). Most MAs were located in the mid-peripheral retina (80.54%); however, the density of MAs was highest in the posterior pole (p<0.001). The ischaemic index was highest in the peripheral retina (89.19%), followed by mid-periphery (50.65%) and posterior pole (1.85%). Patients with diabetic macular oedema (DME) presented more MA and a greater ischaemic index (p<0.001, each) than those without DME.
Conclusion The automated software allowed prompt and quantitative analysis of UWF-FA images of DMR. MAs were most frequent in the nasal and mid-peripheral retina, with their density being highest in the posterior pole and nasal retina. Ischaemic index increased with distance from the posterior pole, showing strong correlation with central foveal thickness in all retinal areas except the posterior pole.
- diagnostic tests/investigation
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Contributors GS: conception and design of the work; acquisition, analysis and interpretation of data; drafting the work; revising the work. YJK: conception and design of the work; analysis and interpretation of data; revising the work. YSS: conception and design of the work; producing the software. BP: conception and design of the work; producing the software. J-GK: conception and design of the work; revising the work; final approval of the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval Approval of the Institutional Review Board of Asan Medical Center (IRB number: 2017–0798) was granted before initiation of the study, which was performed in compliance with the tenets of the Declaration of Helsinki.
Provenance and peer review Not commissioned; externally peer reviewed.
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