Recommendations for OCTA reporting in retinal vascular disease: A Delphi approach by International Experts

Purpose To develop a consensus nomenclature for reporting optical coherence tomography angiography (OCTA) findings in retinal vascular disease (e.g., diabetic retinopathy, retinal vein occlusion) by international experts. Design Delphi-based survey Subjects, Participants and/or Controls Twenty-five retinal vascular disease and OCTA imaging experts Methods, Intervention, or Testing A Delphi method of consensus development was used, comprising two rounds of online questionnaires, followed by a face-to-face meeting conducted virtually. Twenty-five experts in retinal vascular disease and retinal OCTA imaging were selected to constitute the OCTA Nomenclature in Delphi Study Group for retinal vascular disease. The four main areas of consensus were: definition of parameters of “widefield (WF)” OCTA, measurement of decreased vascular flow on conventional and WF-OCTA, nomenclature of OCTA findings, and OCTA in retinal vascular disease management and staging. The study endpoint was defined by the degree of consensus for each question: “strong consensus” was defined as ≥ 85% agreement, “consensus” as 80-84% and “near consensus” as 70-79%. Main Outcome Measures Consensus and near-consensus on OCTA nomenclature in retinal vascular disease Results A consensus was reached that a meaningful change in percentage of flow on WF-OCTA imaging should be an increase or decrease ≥30% of the absolute imaged area of flow signal and that a “large area” of WF-OCTA reduced flow signal should also be defined as ≥ 30% of absolute imaged area. The presence of new vessels (NV) and intra-retinal microvascular abnormalities (IRMAs), the foveal avascular zone (FAZ) parameters, the presence and amount of “no flow” area and the assessment of vessel density in various retinal layers should be added for the staging and classification of DR. Decreased flow ≥ 30% of the absolute imaged area should define an ischemic central retinal vein occlusion (CRVO). Several other items did not meet consensus requirements or were rejected in the final discussion round. Conclusions This study provides international consensus recommendations for reporting OCTA findings in retinal vascular disease, which may help to improve the interpretability and description in clinic and clinical trials. Further validation in these settings is warranted and ongoing. Efforts are continuing to address unresolved questions.