Assessment of anterior scleral thickness in myopes and emmetropes using anterior segment optical coherence tomography

Purpose: To investigate the differences in anterior scleral thickness (AST) among the refractive statuses of Chinese adults aged 18-35. Methods: This study recruited 170 Chinese participants (mean age, 24.06 +/- 2.78 years), including myopes (spherical equivalent refraction [SER] -1.00 to -12.75 diopters [D]; n = 134), emmetropes (SER +/- 0.75 D; n = 36), and AST (superior, inferior, nasal, and temporal), which were investigated via swept-source optical coherence tomography. Semiautomated custom-designed software measured the scleral thickness from the scleral spur to 5 mm along four meridians. Results: The mean axial length and spherical equivalent refractive error were 25.12 +/- 1.44 mm and -3.93 +/- 3.09 D, respectively. The anterior sclera was thickest in the inferior region and thinnest in the superior region (753.9 +/- 88.7 mu m versus 613.6 +/- 58.4; p < 0.001). The AST in the temporal meridian was significantly thicker than that in the nasal meridian (727.5 +/- 60.8, 690.9 +/- 55 mu m; p < 0.001). There were no significant variations in AST in the myopes and emmetropes along the five latitude lines. AST along the inferior meridian at the 4-mm (r 2 = 0.0992; p < 0.001) and 5-mm (r 2 = 0.0888; p < 0.001) locations decreased significantly with increasing myopia. Conclusion: With increased myopia, AST at the 4-mm and 5-mm locations showed significant thinning in the inferior meridian. The results indicate that AST, especially along the inferior meridian, may act as a biologic marker to monitor the progression of myopia.