Improved prediction of nasal step defects in glaucoma through wide-field optical coherence tomography

The purpose of this study was to evaluate the clinical utility of 12 × 12 mm wide-field optical coherence tomography (WF-OCT) for assessing structure-function correspondence in glaucoma, specifically analyzing nasal step visual field (VF) defects.

We conducted a retrospective comparative study, classifying participants into 5 groups based on VF defect pattern: healthy controls, nasal step, arcuate scotoma, paracentral scotoma, and preperimetric glaucoma. The structure-function relationship was assessed using the Garway-Heath (G-H) map, the 12 × 9 mm Hood map, and 12 × 12 mm WF-OCT. Predictive accuracy within each VF defect group was categorized as correct, incorrect, or unknown, with a targeted subgroup analysis specifically evaluating diagnostic performance for nasal step defects.

When comparing the G-H map, the Hood map, and WF-OCT, no significant differences were observed in the control, arcuate scotoma, paracentral scotoma, and preperimetric glaucoma groups (p > .05 for all comparisons). In contrast, significant differences were found for nasal step defects: the G-H map and WF-OCT correctly identified nasal step defects in 94.4% and 96.3% of cases, respectively, with no significant difference between them (p = 1.000), whereas the Hood map classified 98.1% of nasal step cases as unknown because of insufficient scan coverage (p < .001).

While demonstrating comparable sensitivity to the G-H map in nasal step detection, WF-OCT successfully addresses the geographical limitations of the Hood map. By providing direct topographical visualization alongside conventional peripapillary assessments, WF-OCT offers a valuable modality for evaluating peripheral glaucomatous damage.