Publication:
Long-Term Follow-Up of Intrastromal Corneal Ring Segments in Paracentral Keratoconus with Coincident Corneal Keratometric, Comatic, and Refractive Axes: Stability of the Procedure

Loading...
Thumbnail Image
Full text at PDC
Publication Date
2017-11
Authors
Fernández-Vega Cueto, Luis
Lisa Fernández, Carlos
Merayo Lloves, Jesús Manuel
Alfonso, José F.
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
HINDAWI PUBLISHING CORPORATION
Citations
Google Scholar
Research Projects
Organizational Units
Journal Issue
Abstract
Purpose: To assess the long-term outcomes of implanting intrastromal corneal ring segments (ICRSs) to correct central keratoconus with a high corneal asphericity value. Methods: Forty-three eyes with central keratoconus with a corneal asphericity value ≥-1.00 were evaluated before and after implanting an inferior 210-degree arc-length Ferrara-type AFR5 ICRS (AJL Ophthalmic, Spain). Logarithm of the minimum angle of resolution uncorrected (UDVA) and best-corrected (CDVA) distance visual acuity, corneal asphericity, root mean square for coma-like aberrations [computed for the Zernike terms Z (3, 1) and Z (3, -1)], and residual refractive errors analyzed using vector analysis were recorded before and at all follow-up visits. The postoperative follow-up duration was 3 years in all cases. Result: Mean UDVA (logarithm of the minimum angle of resolution scale) rose from 1.18 ± 0.59 to a postoperative 0.53 ± 0.39 after ICRS implantation (P < 0.0001). Mean CDVA varied in turn from 0.36 ± 0.18 to 0.17 ± 0.10 (P < 0.0001). CDVA remained unchanged or improved in all eyes after surgery. Both UDVA and CDVA were stable over the postoperative period (P > 0.05). The spherical equivalent declined steeply after ICRS implantation (P < 0.0001). Both spherical equivalent and refractive cylinder were stable over the postoperative period. The corneal asphericity and root mean square values for coma-like aberrations exhibited statistically significant decreases 6 months after ICRS implantation (P < 0.0001) and were also stable over postoperative follow-up (P > 0.05). Conclusions: These results suggest that implanting a single, inferior, 210-degree arc-length Ferrara-type ICRS is a safe, effective, and stable procedure for treating patients with central hyperprolate keratoconus.
Description
Received 20 December 2016; Revised 3 April 2017; Accepted 27 July 2017; Published 29 August 2017
Keywords
Citation
Collections