Ultra-wide-field fluorescein angiography (UWFA) can obtain very wide retinal images (up to 200°), and is a very helpful tool to detect peripheral retinal lesions which cannot be found by other imaging methods. Analyzing the characteristics of the UWFA images may improve our understanding, treatment outcomes and management strategies of ocular fundus diseases. However this technology is still in its premature stage, there is still a lot of work to be done to improve its clinical application and study the characteristics and clinical meanings of these peripheral retinal lesions.

Objective To observe the angiographic features of patients with retinal vein occlusion (RVO) by ultra-wide-field fluorescein angiography (UWFA) and compare with the conventional 7 standard field (7SF) imaging. Methods This is a retrospective clinical description study. Fifty-eight eyes of 56 RVO patients were included. There were 25 males (26 eyes) and 31 females (32 eyes). The age ranged from 25 to 69 years, with a mean age of (48.12±18.56) years. The course of disease was from 2 days to 25 months, with a mean course of (12.78±11.35) months. Thirty eyes were diagnosed with central RVO (51.72%), 26 eyes were diagnosed with branch RVO (44.83%) and 2 eyes were diagnosed with hemicentral RVO (3.45%). Retinal laser photocoagulation was performed in 11 eyes (18.97%). All patients received examinations of UWFA (British Optomap 200Tx imaging system) and optical coherence tomography (OCT). Using the protocol for obtaining 7SF images as described in the Early Treatment Diabetic Retinopathy Study, 7 circular regions with a range of 30 degrees were combined as the 7SF template to determine the observation area. This template was then overlaid on the UWFA image to identify the potential viewable area of 7SF. The visualized retinal area, retinal non-perfusion area, retinal neovascularization area, and laser spot area of UWFA and 7SF were quantified by a retinal specialist. In addition, the OCT images of the affected eye were observed and analyzed to confirm the existence of macular edema. Correlation analysis was done between retinal non-perfusion, retinal neovascularization and macular edema detected by UWFA. Results The results of UWFA and 7SF examination were the same. Compared with 7SF, UWFA showed 3.53 times more retinal visual area, 3.31 times more non-perfusion area, 1.94 times more neovascularization area, and 3.59 times more laser spots (t=72.13, 4.69, 1.76, 5.78;P=0.000, 0.005, 0.102, 0.000). Lesions of 11 eyes (18.97%) were found outside the range of 7SF images. By UWFA, non-perfusion area correlated with neovascularization and macular edema (χ2=12.13, 4.82;P=0.000, 0.028;C=0.42, 0.28). Non-perfusion area anterior to the equator have significantly correlations with macular edema (χ2=6.32, P=0.012, C=0.31), but non-perfusion posterior to the globe equator have no relevance with macular edema (χ2=2.88, P=0.090, C=0.22). Conclusions UWFA can detect more peripheral retinal lesions than 7SF images. By UWFA, non-perfusion area has correlation with neovascularization and macular edema.

Objective To observe the ocular fundus features and consistency of classification of diabetic retinopathy (DR) by ultra-wide-field fluorescein angiography (UWFA) and the simulated early treatment diabetic retinopathy study (ETDRS) 7 standard field (7SF) imaging. Methods This is a retrospective clinical description study. Ninety-six eyes of 55 DR patients were included. The ages ranged from 25 to 73 years, with a mean age of (41.34±15.07) years. UWFA examination (British Optos 200Tx imaging system) using the protocol for obtaining 7SF images as described in the ETDRS, 7 circular regions with a range of 30 degrees are spliced as 7SF templates to determine the observation range. This template was then overlaid on the UWFA image to identify the potential viewable area of 7SF. And the visualized area of the retina, retinal non-perfusion (NP) area, retinal neovascularization (NV) area, and pan-retinal photocoagulation (PRP) area of UWFA and 7SF were quantified by a retinal specialist. Results UWFA imaging and 7SF imaging have a high degree of consistency in judging DR classification (kappa=0.851, P=0.000). The retinal visual area, NP area, NV area and PRP area of the UWFA imaging were 3.16, 3.38, 2.22 and 3.15 times more comparing with the simulated 7SF imaging (t=213.430, 45.013, 22.644, 142.665;P=0.000, 0.000, 0.003, 0.000). The lesions of 8 eyes were found outside the range of simulated 7SF imaging, including peripheral NP in 5 eyes, NV areas in 3 eyes, respectively. Conclusion UWFA imaging and simulated 7SF imaging are consistent to judge DR classification, but UWFA can find more peripheral retinal lesions.