The Effect of Intracorneal Ring Segments Implantation for Keratoconus on In Vivo Corneal Biomechanics Assessed With the Corvis ST

Abstract

PURPOSE: To evaluate the effect of the implantation of intracorneal ring segments (ICRS) in keratoconus on the dynamic corneal response (DCR) parameters obtained with the Corvis ST (Oculus Optikgeräte GmbH). METHODS: This prospective clinical study included patients who underwent ICRS implantation for keratoconus over a period of 1 year. On the day of the surgery and at least 1 month after ICRS implantation, the following measurements were made: corrected and uncorrected distance visual acuity, corneal tomography indices with the Pentacam (Oculus Optikgeräte GmbH), biomechanically corrected intraocular pressure (bIOP), Corvis ST DCR parameters, integrated inverse concave radius (1/R), deformation amplitude ratio (DA ratio), stiffness parameter at first applanation (SP-A1), stress–strain index (SSI), and highest concavity radius (HRC). RESULTS: Fifty-one eyes of 40 patients were included with a median follow-up time of 3 months (interquartile ratio [IQR]: 2 to 6 months). Statistical analysis showed that ICRS implantation did not affect corneal biomechanical measurements evaluated with the Corvis ST, which was demonstrated by non-significant changes in the SP-A1 ( P = .637), 1/R ( P = .647), HRC ( P = .177), DA ratio ( P = .735), and SSI ( P = .501). Additionally, the results showed that bIOP measurements were not significantly affected by ICRS implantation ( P = .113). CONCLUSIONS: ICRS implantation does not affect corneal biomechanical measurements in early follow-up. [ J Refract Surg . 2022;38(4):264–269.]