The feasibility of Ultra-widefield SS-OCTA to guide laser photocoagulation in retinal vascular diseases.

PURPOSE

This study aimed to evaluate the feasibility of ultra-widefield swept-source optical coherence tomography angiography (UWF SS-OCTA) in guiding laser photocoagulation for retinal vascular diseases.

METHODS

A total of 285 eyes from 195 patients with retinal vein occlusion (RVO) and diabetic retinopathy (DR) were retrospectively evaluated at the Medical Retina Department of Zhongshan Ophthalmic Center, Sun Yat-sen University, from July 24 to October 27, 2023. All patients underwent UWF SS-OCTA (VG200, Intalight Imaging, Ltd., Luoyang, China) examination with a single scan using the widefield AngioMosaic protocol. A subset of patients also underwent fluorescein fundus angiography and fundus photography based on clinical discretion. Retinal non-perfusion area (NPA), a key biomarker for guiding laser photocoagulation, along with other findings such as existing laser spots, were analyzed to guide treatment.

RESULTS

The UWF SS-OCTA produced a 29×24 mm single-scan angiographic image and generated a 220° field-of-view montage. Images of the retinal superficial vascular complex (RSVC) could distinctly depict NPA, retinal neovascularization, and intraretinal microvascular abnormalities, while enhanced angio mode images of the choroidal capillary layer (CCL) effectively demonstrated the location of existing laser spots. Utilizing the UWF SS-OCTA findings, initial photocoagulation therapy was performed in 34.3% of RVO patients and 15.8% of DR patients, and supplementary photocoagulation was applied in 13.9% of RVO and 13.6% of DR cases.

CONCLUSION

UWF SS-OCTA images of the RSVC and the CCL with the enhanced angio mode, provide a non-invasive, efficient, and precise method for guiding retinal photocoagulation, representing a viable alternative to conventional invasive techniques.