Comparison of Corneal Layers and Anterior Sclera in Emmetropic and Myopic Eyes

The aim of this study was to compare the thickness of preocular tear film, corneal layers, and anterior sclera in patients with moderate to high myopia and emmetropia with anterior segment spectral domain optical coherence tomography.

This cross-sectional comparative study included 31 patients with high myopia and 31 emmetropic healthy controls. Patients with myopia had axial lengths ranging from 24 to 29 mm, whereas age-matched controls had axial lengths from 21 to 23.9 mm. Patients with myopia had refractive errors from -4.00 to -11.00 diopters spherical equivalent. Preocular tear film, corneal epithelium, Bowman layer, stroma, and Descemet membrane-endothelium complex were measured in the central cornea. Anterior scleral measurements were made at distances of 1, 3, and 5 mm from the limbus. Corneal-scleral thickness was measured with the anterior segment module of spectral domain optical coherence tomography.

No statistically significant differences (P > 0.05) between patients with myopia and controls emerged regarding the thickness of preocular tear film, corneal epithelium, Bowman layer, corneal stroma, and Descemet membrane-endothelium complex. The anterior scleral thickness values of 1, 3, and 5 mm from the limbus were similar in both patients with myopia and control participants (P > 0.05). There were no significant correlations between central cornea stromal thickness and anterior scleral thickness in myopic participants (P > 0.05).

The thickness of anterior wall structures and preocular tear film of patients with moderate to high myopia are not statistically different compared with those of healthy controls.