https://orcid.org/0000-0002-1017-3816
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Abstract
Purpose
To evaluate preoperative risk factors (mainly those related to corneal topography/tomography) for post-LASIK ectasia development.
Methods
A retrospective case review for post-LASIK ectasia for myopia or myopic astigmatism. The evaluated data included preoperative subjective refraction, method of flap creation, and topometric/tomographic parameters from Oculus Pentacam, including subjective curvature pattern, topometric, elevation, and pachymetric indices from the Belin Ambrosio display “BAD”, and the Pentacam Random Forest Index (PRFI). Moreover, preoperative ectasia detection indices were calculated (including Percentage of Tissue Altered “PTA” index, Randleman Ectasia Risk Score System “ERSS”, and Navarro Index for Corneal Ectasia “NICE”).
Results
Twenty-four eyes of 15 patients were enrolled. Concerning the risk factors, age was lower than 25 in 19 eyes (79%); flaps were created using a microkeratome in 17 eyes (70.8%); thinnest pachymetry was lower than 510μm in eight eyes (33%); total deviation from BAD was higher than 1.6 in 50%; Ambrósio’s relational thickness (ART) max was lower than 340 in 45.83%; PTA index was higher than 40% in 16%; ERSS was more than 3 points in 62.5%; NICE was higher than 8 points in three eyes (12.5%); PRFI index was more than 0.125 in 87.5%; two eyes (8%) had no identifiable risk factors.
Conclusion
Current ectasia risk assessment criteria were insufficient for detecting a relatively large number of cases. There is an unequivocal need for more information, which may be derived from biomechanical assessment and epithelial thickness mapping. Novel corneal tomography indices derived from artificial intelligence may increase accuracy in characterizing ectasia susceptibility.
Data Sharing Statement
Available from the corresponding author upon reasonable request.
Ethics Approval and Informed Consent
The study was approved by the Ethical Committee of Watany Eye Hospitals (registration code COR-2020-004) and the Ethical Committee of the Federal University of São Paulo/UNIFESP/SP 2020 (registration code 4.050.934). Both Ethical Committees granted a waiver of informed consent owing to the study’s retrospective nature. Patients’ data were kept anonymous with utmost confidentiality.
Consent for Publication
All the material included in this paper can be published, and the person(s) providing consent has been shown the article contents to be published.
Acknowledgments
We want to thank the surgeons from the Watany Eye Hospitals (WEH), Cairo, Egypt, for sharing with a considerate number of patients enrolled in the study: Dr. Fathy Fawzy Morkos, MD, FRCS (Glasg.), FRCOphth, Chairman WEH, Professor of Ophthalmology, Egyptian Military Medical Academy, and Prof. Dr. Abdallah K. Hassouna, MD, Ph.D., Vice - Chairman WEH, Professor of ophthalmology - Ain Shams University.
Author Contributions
All authors have made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis, and interpretation, or all these areas; took part in drafting, revising, or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.
Disclosure
Prof. Dr. Renato Ambrósio reports personal fees from Oculus, Alcon, and Mediphacos, during the conduct of the study; personal fees from Oculus, outside the submitted work. The authors report no other conflicts of interest in this work.