Authors: Chen Kaijian, Kan Qiuxia, Bai Ji, Zhang Guowei, Xu Duo, Liu Lina, Lang Min
Corneal biomechanical properties is important in the safety assessment of corneal refractive surgery. Corvis is a new device for measuring corneal biomechanics properties.
This study was to observe the correlation among corneal thickness, Corvis intraocular pressure and corneal biomechanical properties with Corvis.
A prospective observational study was performed. One hundred and fifty eyes of 75 patients with corneal thickness from 501 μm to 590 μm were divided into three groups according to the corneal thickness: low corneal thickness group (corneal thickness range from 501 μm to 530 μm), middle corneal thickness group (corneal thickness range from 531 μm to 560 μm), and high corneal thickness group (corneal thickness range from 561 μm to 590 μm); and 50 eyes of 25 patients for each group. The difference of intraocular pressure, corneal thickness and deformation amplitude (DA) among the three groups were analyzed by one-way ANOVA and the correlation among the groups were analyzed by liner regression.
The DA in the low corneal thickness group and middle corneal thickness group were significantly higher than that in the high corneal thickness group (P<0.05). The intraocular pressure was statistically different among the 3 groups (F=9.98, P<0.05). DA was negatively correlated with intraocular pressure and corneal thickness (r=-0.84, -0.33; both at P<0.01), with the linear regression DA=1.69-0.04×IOP (F=366.19, t=-19.14, P<0.01).
Corneal thickness cannot simply represent the corneal biomechanical properties in the safety assessment of corneal refractive surgery, IOP should be considered.