Corneal Topography

What is Corneal Topography?

Corneal topography is an advanced, non-invasive imaging technique that creates a detailed, three-dimensional “map” of the surface curvature of your cornea – the clear, dome-shaped front window of your eye. Think of it like taking a topographical map of a mountain range, but for your eye!

This sophisticated technology measures thousands of points across your cornea, revealing subtle variations in its shape and elevation that are impossible to see with the naked eye or even a standard eye examination. The result is a precise, color-coded map that helps your eye care professional understand the unique contours of your eye.

Why is Corneal Topography Important?

Understanding the precise shape of your cornea is crucial for many aspects of eye health and vision correction:

• Customized Vision Correction: A perfect fit for contact lenses (especially specialty lenses like rigid gas permeable (RGP) or scleral lenses) depends on knowing your corneal shape.
• Diagnosing Corneal Conditions: It’s essential for detecting and monitoring conditions like keratoconus (a progressive thinning and bulging of the cornea), pellucid marginal degeneration, or post-surgical corneal irregularities.
• Pre- and Post-Surgical Assessment: Vital for planning refractive surgeries like LASIK, PRK, or cataract surgery, and then assessing the results to ensure optimal vision.
• Astigmatism Management: Provides a highly accurate assessment of the type and amount of astigmatism, leading to more precise spectacle and contact lens prescriptions.
• Troubleshooting Vision Issues: Helps to identify corneal irregularities that might be causing blurry vision or glare, even when your prescription seems correct.

What Conditions Can Be Managed with Corneal Topography?

Corneal topography is an invaluable tool for the diagnosis, management, and monitoring of various eye conditions and procedures:

• Keratoconus and Ectasias: The primary diagnostic tool for these progressive corneal thinning disorders. It allows for early detection and tracking of progression, which is vital for timely interventions like corneal collagen cross-linking.
• High or Irregular Astigmatism: Helps to accurately measure and manage complex astigmatism, leading to better vision correction.
• Contact Lens Fitting: Crucial for fitting complex contact lenses such as rigid gas permeable (RGP) lenses, scleral lenses, and orthokeratology (Ortho-K) lenses, ensuring optimal comfort and vision.
• Pre-LASIK/PRK Assessment: Essential for determining if a patient is a suitable candidate for refractive surgery and for planning the laser treatment.
• Post-Surgical Complications: Used to identify and manage corneal irregularities that can occur after surgery, such as decentered ablations or corneal ectasia.
• Corneal Scars/Trauma: Helps to map the extent and impact of corneal scarring from injury or infection.

What to Expect During Corneal Topography?

The corneal topography procedure is quick, simple, and entirely painless. There’s no contact with your eye.

1. Positioning: You will be asked to sit comfortably and place your chin on a chin rest and your forehead against a headrest, just like during a regular eye exam.
2. Focusing: You will look straight ahead at a target inside the topography instrument.
3. The Process: A series of illuminated rings (often called “Placido rings”) will be projected onto your cornea. The camera then captures the reflection of these rings. Distortions in the rings’ reflection reveal the precise shape and curvature of your cornea.
4. Quick Capture: The image capture takes only a second or two. Often, several images will be taken to ensure accuracy.
5. No Drops: No eye drops are usually required for this test.
6. Results: The data is immediately processed by a computer to generate the color-coded topographic map, which your optometrist will then interpret and discuss with you.

At our Dalby and Chinchilla practices, we use the latest corneal topography technology to provide you with the most accurate and personalized eye care. If you have any questions, please don’t hesitate to ask our friendly team!