The corneal deformation following an air puff may be influenced by several demographic and clinical factors. A significant correlation was found between IOP and CST data in previous studies.
16,17,21,31,32 In the present study, A1T, A1V, A2T, and A2V were significantly related to the IOP in both POAG and healthy controls. The DA and PD were inversely related to the IOP in all eyes and POAG eyes, which suggested that the corneal deformability decreased with increasing IOP.
17 Age has been reported to affect corneal biomechanical properties, with corneal stiffness increasing with age.
33,34 However, all corneal response parameters, except A2L, showed nonsignificant correlations with age, in agreement with the studies by Pedersen et al.,
35 Nemeth et al.,
21 and Ali et al.
33 We, as well as Valbon et al.,
20 consistently observed no relationship between the studied parameters and sex. Perez-Rico et al.
36 demonstrated that diabetes mellitus affects CST measurement process. In this study, subjects with diabetes mellitus were excluded. Lanza et al.
37 examined the association among CCT, corneal volume, corneal curvature, and corneal deformation parameters measured by CST and none of them were statistically significant. The most interesting observation was that no correlation was found between age, sex, IOP, CCT with A2L, HCT and CCR. These parameters may be worth studying further as independent biomarkers for ocular diseases. Studies have reported that the corneal deformation parameters are also influenced by corneal hydration, stiffness, the boundary condition related to the sclera, and the ocular muscles.
38 Thus, further studies are warranted to determine the relationship between these factors and CST parameters.