---
title: What is corneal ectasia?
description: "Corneal ectasia is a progressive thinning and bulging of the cornea that leads to irregular shape and distorted vision. It can occur as part of conditions like keratoconus or, more rarely, after corneal surgery. ## Causes and Mechanism In ectasia,…"
url: "https://bluefinvision.com/knowledge-base/topics/conditions-diseases/what-is-corneal-ectasia/"
updated: "2025-12-15"
category: "Conditions & Diseases"
---

# What is corneal ectasia?

Corneal ectasia is a progressive thinning and bulging of the cornea that leads to irregular shape and distorted vision. It can occur as part of conditions like keratoconus or, more rarely, after corneal surgery.

## Causes and Mechanism

In ectasia, the collagen framework that normally maintains corneal strength becomes weakened so the cornea stretches forward under normal eye pressure, causing increasing myopia and irregular astigmatism.

- Primary ectasias include keratoconus and pellucid marginal degeneration, often linked to genetic and environmental factors such as eye rubbing.
- Post‑surgical ectasia is an uncommon complication after laser vision correction when residual corneal thickness is insufficient.
- Early signs may be subtle, detected only on topography or tomography.
- Symptoms include ghosting, glare, and frequent prescription changes.

## Management

Treatment aims to stabilise the cornea and improve visual quality, using spectacles, rigid or custom contact lenses, corneal cross‑linking, or transplant in advanced cases.

- Corneal cross‑linking strengthens collagen bonds and can slow or halt progression, especially when done early.
- Specialist lenses (RGP, scleral, hybrid) often give clearer vision than glasses by masking surface irregularity.
- Severe scarring or thinning may require lamellar or full‑thickness transplantation.
- Patients are advised to avoid eye rubbing and manage allergies to reduce mechanical stress.