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.]

Automated summary

This study evaluated the effect of ICRS implantation on dynamic corneal response parameters in patients with keratoconus. The results showed that ICRS implantation did not significantly affect corneal biomechanical measurements and intraocular pressure.