Standardization of Retinal Vasculitis Terminology With Consensus Definitions From a Delphi Panel

Retinal vasculitis is a sight-threatening condition associated with diverse ocular and systemic diseases. Variability in terminology and definitions across clinical practice and research has limited diagnostic consistency, communication among specialists, and comparability of studies.

To develop standardized, consensus-based definitions for retinal vasculitis and related terms to improve diagnostic clarity and harmonize communication among ophthalmologists and other medical specialties.

This was an international modified Delphi consensus study conducted using a structured consensus process guided by a comprehensive literature review, including systematic reviews and meta-analyses. Two rounds of Delphi surveys were performed, and consensus was predefined as at least 75% agreement. Included was an international expert panel of 27 specialists in ophthalmology, rheumatology, pathology, imaging, and research methodology. The specialists had recognized expertise in retinal and systemic vasculitis, retinal imaging, or consensus methodology. Study data were analyzed from March to September 2025.

Participation in a structured Delphi process evaluating proposed definitions and terminology related to retinal vasculitis and associated vascular inflammatory entities.

Consensus definitions for retinal vasculitis and related entities, with agreement using predefined consensus thresholds.

A total of 27 international experts participated in the Delphi process. After 5 executive committee members involved in developing preliminary definitions were excluded from voting to minimize bias, a total of 22 independent experts completed both Delphi rounds. All candidate statements exceeded the predefined consensus threshold in the first round (agreement range, 83.3%-95.5%), although some demonstrated variability in the strength of agreement. After refinement of definitions, consensus strengthened in the second round, with agreement levels ranging from 95.2% to 100%. The panel established consensus definitions for 8 terms: retinal vasculitis, vascular leakage, infectious retinal vasculitis, noninfectious retinal vasculitis, retinal perivasculitis, retinal vasculopathy, primary retinal vasculitis, and far-peripheral vascular leakage. These definitions were developed to distinguish vascular leakage from true vasculitis, clarify inflammatory and noninflammatory vascular disorders, and promote consistent terminology across clinical practice and research.

This international Delphi consensus established standardized nomenclature for retinal vasculitis and related vascular inflammatory entities. Adoption of these definitions may improve diagnostic accuracy, facilitate interpretation of imaging findings, enhance consistency across clinical studies, and support future research efforts, including the development of artificial intelligence-based classification systems for retinal vascular disease.