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Author Spotlight: Advancements in Refractive Surgical Correction for Presbyopia and Exploring Postoperative Visual Acuity
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Ectasia risk factors in refractive surgery.
Marcony R Santhiago1, Natalia T Giacomin1, David Smadja2
1Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil.
Clinical Ophthalmology (Auckland, N.Z.)
|May 5, 2016
Summary
Preoperative screening for laser in situ keratomileusis (LASIK) ectasia should assess corneal topography and percentage of tissue altered (PTA). These factors, along with age and residual stromal bed, help predict post-LASIK ectasia risk.
Area of Science:
- Ophthalmology
- Corneal Surgery
- Refractive Surgery
Background:
- Post-laser in situ keratomileusis (LASIK) ectasia is a sight-threatening complication.
- Accurate preoperative risk assessment is crucial for patient safety.
- Identifying reliable risk factors can improve screening protocols.
Purpose of the Study:
- To review preoperative risk factors for post-LASIK ectasia.
- To introduce a new metric, percentage of tissue altered (PTA), for ectasia risk detection.
- To emphasize the importance of comprehensive screening.
Main Methods:
- Review of existing literature on LASIK ectasia risk factors.
- Analysis of intrinsic biomechanical properties (corneal topography/tomography, age).
- Analysis of alterable biomechanical properties (tissue altered, remaining tissue), including PTA calculation.
Main Results:
- Abnormal corneal topography is the most significant identifiable risk factor.
- High percentage of tissue altered (PTA) is the most robust risk factor in normal topography cases.
- PTA offers a more individualized biomechanical alteration measure than RSB or CCT.
- Other factors include low residual stromal bed (RSB), thin cornea, high myopia, and age.
Conclusions:
- Comprehensive screening using tools like the Ectasia Risk Score System is recommended.
- Corneal topography and PTA are key metrics for preoperative ectasia risk assessment.
- Age remains an overlooked yet critical risk factor.
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