Our latest toy – the SMap 3D topographer
Recently our practice purchased a SMap 3D topographer. Up until now we have only been able to measure the curvature of the cornea, however this new exciting instrument provides us with a three-dimensional image of the entire front surface of the eye, including the cornea and the surrounding white portion of the eye (the sclera). These images are then used to create a customized scleral contact lens such that the back-surface curvatures of this scleral lens match the front surface curvatures (both corneal and scleral) of the eye. My colleagues Andrew Huhtanen and Jillian Campbell have been doing all the customized fittings with the SMap 3D topographer and so I’ll let them tell you more about this amazing instrument. Over to you Andrew and Jill ….
The SMap has been very exciting for us, as we are just one of a handful of practices with this new technology in Australia!
For many years, we have been able to measure the curvature of the cornea, the clear “window” of the eye. We use this measurement, called corneal topography, to determine the best contact lens shape and curvature. With the new SMap technology, we now have the ability to measure not only the corneal curvature but also the curvature of the white portion of the eye - the sclera.
This has been particularly useful for fitting mini-scleral contact lenses, which rest directly on the sclera and do not touch the cornea at all. Every year we fit hundreds of patients with mini-scleral contact lenses, using a variety of different lens designs. Most patients have fairly predictable scleral curvature and they can be fit with standard lens designs. However, there are some patients whose eyes are more ‘irregular’, making standards design more difficult to fit. Using the new SMap, we can now take a ‘scleral map’ of the white part of the eye and then design a more customized, computer-generated contact lens to closely match all the hills and valleys of the sclera!
In addition to patients with an ‘irregular-shaped’ sclera, some patients have advanced corneal diseases such as keratoconus and pellucid marginal degeneration. For those of you who don’t know, these conditions cause the cornea to become very pointy, making the corneal shape very irregular and uneven. In the past, these patients have been very challenging to fit with contact lenses, due to the very asymmetrical shaped corneas. These patients can now benefit from a more customized contact lens design, to improve the overall fit of the contact lens.
We are excited to have this amazing technology which improves our ability to achieve an even fit across both the cornea and sclera. With the use of the SMap 3D topographer, we have been able to fit these challenging, cone-like eyes with better accuracy, providing excellent comfort, vision and optimal corneal health.