---
title: Corneal ectasia risk factors in LASIK refractive surgery
description: "Corneal ectasia is a rare but serious complication after LASIK in which the cornea progressively thins and bulges. Understanding and screening for risk factors is essential to minimise this outcome. ## Pre‑existing Corneal Factors Candidates are carefully assessed for conditions…"
url: "https://bluefinvision.com/knowledge-base/topics/diagnostics-testing/corneal-ectasia-risk-factors-in-lasik-refractive-surgery/"
updated: "2025-12-15"
category: "Diagnostics & Testing"
---

# Corneal ectasia risk factors in LASIK refractive surgery

Corneal ectasia is a rare but serious complication after LASIK in which the cornea progressively thins and bulges. Understanding and screening for risk factors is essential to minimise this outcome.

## Pre‑existing Corneal Factors

Candidates are carefully assessed for conditions that weaken corneal structure.

- Forme fruste keratoconus, pellucid marginal degeneration, or suspicious topography patterns markedly increase risk.
- Thin baseline corneas and abnormal posterior elevation on tomography are important warning signs.
- Asymmetry between eyes, high corneal curvature, or irregular astigmatism also raise concern.
- A history of chronic eye rubbing, allergy, or atopy is taken seriously as it may reflect biomechanical vulnerability.

## Surgical Planning Factors

Safety margins during LASIK planning aim to preserve corneal strength.

- Excessive tissue removal, especially with high myopic corrections, can leave an inadequate residual stromal bed.
- Low residual stromal thickness and high percentage tissue altered (PTA) values are recognised predictors of ectasia.
- Poorly centered or uneven ablations may further destabilise the cornea.
- When risk factors are present, alternatives such as PRK, SMILE, ICL implantation, or no surgery may be recommended instead.