Dynamic Changes of Scleral Spur Length In Different Accommodation States

This study aimed to evaluate the scleral spur length in response to different accommodation stimuli states, as well as the correlation with Schlemm’s canal and trabecular meshwork. 74 children were recruited for this study. The 0D, -4D, and − 8.0 D accommodation state was stimulated by looking at a variable distance optotype. The ciliary muscle, scleral spur, Schlemm’s canal, and trabecular meshwork were imaged by swept-source optical coherence tomography. The scleral spur length increased with accommodation stimulation (p < 0.05). Method I was 127.97 ± 20.32 µm, 138.29 ± 20.11 µm, and 150.73 ± 21.75 µm at 0D, -4D and − 8D, respectively. Method II was 158.15 ± 19.97 µm, 168.47 ± 18.72 µm, and 179.79 ± 20.83 µm at 0D, -4D and − 8D, respectively. Method III was 221.56 ± 30.74 µm, 234.99 ± 30.11 µm, and 250.09 ± 29.87 µm at 0D, -4D and − 8D, respectively. Method III had the largest areas under ROC curves (0.798, 95% CI 0.721–0.875). Moreover, ciliary muscle 1, Schlemm’s canal, and trabecular meshwork length were significantly correlated with SSL (Method III) (p < 0.05). These findings suggest that the contractile ability and compliance of the scleral spur play an important role in maintaining the morphology of the SC. Moreover, the force of accommodation regulates the SC size by increasing the length of SS.