Differential Effects of Corneal Biomechanics on Superficial and Deep Vessel Density and Their Association with Central Visual Function in Glaucoma Patients with Myopia

Background/Objectives: The purpose of this study was to investigate corneal biomechanical properties assessed with Corvis ST, structural features of myopia, and vessel density (VD) measured by optical coherence tomography angiography (OCT-A) and their associations with central visual function in myopic glaucoma patients. Methods: Forty-two eyes of 42 glaucoma patients with myopia without retinal lesions were subjected to analysis. Corvis ST was performed to measure the biomechanical properties of the eyeball. Superficial (retinal) and deep (choroidal) VDs in the peripapillary and macular regions were assessed using OCT-A, and retinal nerve fiber layer (RNFL) thickness was measured with OCT. The disc–foveal angle, disc torsion, and β-zone peripapillary atrophy (PPA) area were obtained from disc and retinal photography. Swedish interactive thresholding algorithm (SITA) 24-2 visual field (VF) testing was used to evaluate the function within the central 12 points. Results: A worse mean deviation (MD) from SITA 24-2 and higher whole-eye movement maximum from Corvis ST, representing deformable corneas, were associated with lower superficial peripapillary VD. A lower A1 deflection amplitude from Corvis ST, representing stiffer corneas, was associated with lower deep peripapillary VD. The sensitivity of the central 12 VF points was significantly associated with a larger disc–foveal angle, lower superficial peripapillary VD, and lower HC deformation amplitude from Corvis ST. Conclusions: Our preliminary findings suggest that more compliant corneas were associated with lower superficial VD, whereas stiffer corneas were associated with lower deep VD and central scotoma.