Menu
Back to Journals » Clinical Ophthalmology » Volume 14
Vector Analysis of Astigmatism in Keratoconic Eyes After Combined Intrastromal Corneal Ring Segments Implantation and Collagen Cross-Linking
Authors Abozaid MA, Abdalla A
Received 10 December 2019
Accepted for publication 23 January 2020
Published 20 February 2020 Volume 2020:14 Pages 473—480
DOI https://doi.org/10.2147/OPTH.S241755
Checked for plagiarism Yes
Review by Single anonymous peer review
Peer reviewer comments 2
Editor who approved publication: Dr Scott Fraser
Video abstract presented by Mortada Ahmed Abozaid.
Views: 268
Mortada Ahmed Abozaid,1 Abdelsalam Abdalla2
1Faculty of Medicine, Sohag University, Sohag, Egypt; 2Faculty of Medicine, Assiut University, Assiut, Egypt
Correspondence: Mortada Ahmed Abozaid
Ophthalmology Department, Faculty of Medicine, Sohag University, Sohag, Egypt
Tel +20 932 309 244
Fax +20 932 325 531
Email mourtada_abdelaal@med.sohag.edu.eg
Purpose: To analyze astigmatic changes after intrastromal corneal ring segments (ICRSs) implantation accompanied by corneal collagen cross-linking (CXL) in keratoconic eyes using the Alpins vectorial method.
Patients and Methods: Twenty-eight eyes of 18 patients with keratoconus were included in this retrospective non-comparative study. All patients had combined femtosecond laser-assisted Keraring implantation and CXL, and completed at least 2 years of follow-up. Both manifest and corneal astigmatic changes were analyzed using the Alpins vectorial parameters based on 3 vectors; target induced astigmatism (TIA), surgically induced astigmatism (SIA) and difference vector (DV).
Results: Regarding analysis of manifest astigmatism, the TIA arithmetic mean was 5.22 D while the vector mean was 3.13 D Ax 173. The SIA arithmetic mean was 5.41 D while the vector mean was 2.38 D Ax 173. The DV arithmetic mean was 2.10 D while the vector mean was 0.75 D Ax 175. Regarding analysis of corneal astigmatism, the TIA arithmetic mean was 5.22 D while the vector mean was 3.13 D Ax 173. The SIA arithmetic mean was 5.23 D while the vector mean was 1.8 D Ax 12. The DV arithmetic mean was 4.28 D while the vector mean was 2.04 D Ax 157.
Conclusion: Vector analysis of manifest and corneal astigmatism in keratoconic eyes with previous ICRS and CXL reveals more accuracy and predictability of manifest refraction in calculating SIA.
Keywords: Alpins method, astigmatic correction in keratoconus, kerarings, vector analysis
This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License.
By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.