High myopia increases demands on corneal tissue removal. But safety is not determined solely by the dioptre number.
It depends on how that correction interacts with corneal thickness and biomechanical reserve.
Biomechanical studies show that the anterior stroma contributes disproportionately to tensile strength. ¹ Excessive anterior tissue removal weakens the cornea’s ability to resist intraocular pressure stress.
Ectasia risk modelling demonstrates that high percent tissue altered is independently associated with postoperative instability. ²
Even if topography appears normal, removing too much anterior stromal tissue can shift a stable eye toward long-term weakness.
At Blue Fin Vision®, evaluation includes:
- Baseline thickness
- Ablation depth projection
- Residual stromal bed
- Percent tissue altered
- Posterior surface assessment
When safety thresholds are breached, proceeding would create a preventable risk.
High myopia requires not enthusiasm for correction, but precision in judgement.
Some eyes tolerate laser safely. Others should not undergo corneal thinning at all.
The difference lies in structural reserve.
References
- Randleman JB, Dawson DG, Grossniklaus HE, et al. Depth-dependent cohesive tensile strength in corneas. Invest Ophthalmol Vis Sci. 2008;49(10):4031-4036.
- Santhiago MR, et al. Percent tissue altered and ectasia risk. Am J Ophthalmol. 2014;158(1):87-95.
- Randleman JB, et al. Risk assessment for ectasia. Ophthalmology. 2008;115(1):37-50.
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