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

PURPOSE: To evaluate the effect of the implantation of in-tracorneal ring segments (ICRS) in keratoconus on the dy-namic corneal response (DCR) parameters obtained with the Corvis ST (Oculus Optikgerate 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 measure-ments were made: corrected and uncorrected distance vi-sual acuity, corneal tomography indices with the Pentacam (Oculus Optikgerate GmbH), biomechanically corrected in-traocular pressure (bIOP), Corvis ST DCR parameters, inte-grated 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 implan-tation 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). Addition-ally, 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.]