Dimensions of the limbus–ciliary sulcus region by OCT and correlation study in a large population

To assess the dimensions of the limbus-ciliary sulcus region measured by swept-source optical coherence tomography (SS-OCT) and conduct a correlation study in a large healthy population.Centro Internacional de Oftalmología Avanzada, Madrid, Spain.Cross-sectional study.The dimensions of the limbus-ciliary sulcus region were measured in the temporal and nasal quadrants using a SS-OCT. The limbus-sulcus distance (LSD), the posterior iris line-ocular surface to limbus distance (PIOLD), and the angle-to-sulcus distance (ASD) were measured. These distances were then assessed for correlations with factors such as age, sex, refractive error, anterior chamber angle (ACA), ciliary muscle thickness (CMT), conjunctival-Tenon capsule thickness (CTT), and anterior scleral thickness (AST).The mean age of the participants was 41.0 ± 18.2 years (range 5 to 86) and the mean refractive error -0.75 ± 3.3 diopters (range -10 to 7). The LSD could be measured in 93.2% of the participants (625 eyes out of 670 eyes), with a mean of 1.35 ± 0.12 mm (range 0.96 to 1.75) and 1.33 ± 0.12 mm (range 1.05 to 1.68) in the temporal and nasal quadrants, respectively, and a correlation of R = 0.616 (P < .001) between them. PIOLD measured 2.22 ± 0.31 mm (1.42 to 2.98), and ASD was 0.21 ± 0.05 mm (0.01 to 0.40). No correlation was observed between LSD with age, spherical error, sex, or ACA (P ≥ .247). However, LSD exhibited the highest correlation with AST (R = 0.466), followed by CTT (R = 0.309) and CMT (R = 0.259).The SS-OCT allowed for an accurate in vivo measurement of the dimensions of the limbus-ciliary sulcus region.