Features of the Biomechanical Parameters of the Fibrous Capsule of the Eye in Patients after Radial Keratotomy

Abstract

Objective: to identify the features of biomechanical parameters of the fibrous capsule of the eye in patients after radial keratotomy (RK). Materials and methods. 87 eyes were examined after radial keratotomy, the average age was 59.8 ± 0.83 years. With glaucoma 47 eyes, without — in 40 eyes. Patients were divided into three groups: 17 eyes with a central corneal thickness (CCT) of less than 530 microns; 30 eyes with a CCT of 530–580 microns; 40 eyes with a CCT of more than 580 microns. The control group consists of myopic patients without glaucoma, without PES, over 45 years old. Corneal tomography and biomechanical parameters were measured using Pentacam (Oculus) and CorVis ST, respectively. Results. in the eyes after RK, the corneal stiffness (DA ratio, R) is higher in comparison with the control and increases with an increase in CCT. The stiffness of the fibrous capsule of the eye (SP-A1) after RK is reduced in comparison with the control and increases with an increase in CCT. The SSI analysis showed a higher stiffness of the eyeball than in the control, regardless of the CCT. BGF is higher in the eyes after RK compared to the control with the maximum value for thin corneas. Hyperopic shift (HS) after RK is distinctive for eyes with glaucoma. With a CCT of more than 580 microns, HS is a clinical glaucoma detector, with thin corneas, it is not. Conclusion. The eye after RC is characterized by an increase in the stiffness of the cornea, a decrease in the stiffness of the fibrous capsule of the eye, a general increase in the stiffness of the eyeball and HS.

Keywords

• radial keratotomy
• central corneal thickness
• tonometry
• corneal-compensated pressure
• biomechanical properties of the fibrous capsule of the eye
• hyperopic shift