The sMap is such a cool instrument, and it tells us a lot of information.
Normal topographers map the corneal surface only, and give little (if any) data about the shape of the sclera. Since scleral lenses rest on the white part of the eye (the sclera), it makes sense that a scleral topographer could help improve our scleral lens fits. Scleral topographers are expensive, which is why most eye doctors do not offer this technology in their office. It would only make sense for clinics that are fitting scleral lenses at a high level to invest in this equipment.
This particular patient has severe keratoconus in the right eye (K max of over 70 diopters). He complains that a traditional scleral lens does not fit his eye perfectly and he has issues with redness and irritation. With the slit lamp, we observe a small area of elevation inferiorly and a slight area of increased elevation nasally. The nasal elevation is a result of a small pinguecula.
Corneal topography showing a keratoconus patient
A small pinguecula on the sclera can cause issues with a scleral lens fitting.
A small area of elevation is seen on the sclera (white part of the eye) . This was easily detected with the sMap.
The sMap images take 3 D images of all areas of the eye, and the information is used to create a custom fit scleral lens. We instill a drop of sodium fluorescein and have the patient look up, down, and straight ahead. Then, the sMap software stitches the images together to give us a 3D image of the shape of the sclera.
Notice how the 3:00 and 6:00 position are slightly "warmer" colors compared the the rest of the sclera. This is due to the elevation of the pinguecula nasally and the small area of elevation inferiorly.
sMap images of a patient looking up, down and straight ahead.
Notice the 3:00 position and the 6:00 position have more of a teal and yellow color compared to the other colors on the map.
This information will be used to create a custom scleral lens, which should vault over those areas perfectly. This results in an extremely accurate scleral lens fit.
So grateful to have this special technology in our office!
The end result is a beautiful scleral lens fit
The scleral lens fit is perfect.