The corneo-scleral junction assessed with optical coherence tomography

PURPOSE: To evaluate corneo-scleral junction (CSJ) using anterior segment optical coherence tomography (AS-OCT) and describe the pattern of cornea and sclera interfusion based on tissue reflectivity. METHODS: This prospective observational study enrolled candidates for vision correction. Eyes with previous ocular surgery or irregular corneas were excluded. Temporal and nasal CSJ width and reflectivity patterns were assessed with AS-OCT horizontal scans. Correlations between manual and automated variables and multivariate linear regression analyses with age and spherical equivalent were performed. RESULTS: 101 right eyes were analysed. Temporal CSJ was wider (median 1.62; 1.13 to 2.22 mm) compared to the nasal side (median 1.18; 0.73 to 1.80 mm) (p<.0001). The temporal CSJ width showed negative correlation with ipsilateral anterior chamber angle measurements and positive correlation with horizontal visible iris diameter (HVID). These relationships were not statistically significant for the nasal CSJ width. No significant correlations with age or refractive error were observed at both sides. The pattern of temporal CSJ reflectivity was mostly V- or U-shaped. The eyes with V-shaped temporal CSJ had significantly larger HVID than the eyes with irregular temporal CSJ. The nasal CSJ presented irregular reflectivity in 47% of cases. CONCLUSIONS: The temporal CSJ was wider and had regular (V or U-shaped) reflectivity patterns, while nasal CSJ was narrower and more irregular. The CSJ width was independent of age and refractive error and could not be predicted from other parameters. The HVID measurement accuracy may benefit from CSJ analysis based on AS-OCT.