Proposed Nomenclature for Landmarks in Anterior-Segment OCT: The APOSTEL-AS Panel Consensus

Anterior-segment optical coherence tomography (AS-OCT) has broad clinical and research utility. The utility of quantitative data derived from AS-OCT is, however, dependent on the quality and consistency of the cumulative evidence base.

To develop consensus-based nomenclature that supports standardized reporting of AS-OCT image acquisition and analyses as a foundation to improve research reproducibility.

A multistage consensus exercise was undertaken, in 2024, with an expert panel of ophthalmologists, optometrists, and vision scientists, informed by a scoping review to identify the range of AS-OCT applications and terminologies in use. Panel members were selected to represent the breadth of clinical areas identified within the review or key stakeholder groups (ie, ocular image acquisition, imaging analysis, consensus methodologies). Nominal group technique was used to seek consensus on existing and newly proposed terminologies for normal anatomical structures identifiable within cross-sectional swept-source and spectral-domain AS-OCT images. An ophthalmic histopathologist then reviewed the output for concordance with histological terminology. Data were analyzed from July 2024 to January 2025.

Expert consensus on nomenclature of ocular structures.

Agreement on nomenclature of ocular structures, with consensus defined as at least 80% expert agreement.

A multinational group of 14 experts (mean [SD] age, 46.1 [7.8] years; 10 male [71%]) participated in the consensus process. Scoping review findings resulted in the generation of 45 terms for the annotation of identifiable structures. After presentation of multiple image annotations representing these structures, consensus was reached for 31 terms across 7 images. There was consensus on the use of standardized descriptive terms from the Federative Committee on Anatomical Terminology (FCAT) alongside established eponymous terms. There was absence of consensus on annotations and visualization of structures within less optically accessible areas, such as the episcleral and scleral vasculature.

Results of this survey study describe international, multidisciplinary consensus on terminology for ocular structures identifiable in AS-OCT images and present representative annotated images for reference use. Future expansion of nomenclature and annotation are anticipated, facilitated by advances in imaging technology. Follow-up consensus exercises should consider consensus-based terminology and annotations of pathological structural changes.