Dr. Reeder answers questions about Corneal Topography
1. Please describe the Corneal Topography technology and give a basic sense of how it works.
Corneal topography is an instrument that takes a map of the curvature of the front of the eye – the cornea. This instrument scans 780 points across the surface of the eye, measures the distance between the points, and tells us the high and low areas across the cornea. The reason this is important is that we need to know the shape and curvature of the cornea to determine treatment options. One option would be to reshape the cornea, or we can fit a lens that will match the shape and curve of the cornea. Corneal Topography is very useful tool to diagnose irregularities of the cornea and explain why someone has difficulty seeing. It’s also used to monitor changes that we make as we reshape the eye to improve vision.
2. Why is having a map of the cornea important, and how often do you use it?
We have felt in the last few years that it’s so valuable that we have every patient have this done prior to the exam with the doctor. In the past we used it only for people who were having a problem, and now we are diagnosing issues patients have and addressing them before they have symptoms. We are able to understand why a patient might have a vision problem at night, or why they can’t see as clearly with glasses as with contact lenses. An irregular surface of the cornea explains these problems.
3. What types of eye diseases and disorders can be discovered?
One of the most common eye diseases that is frequently discovered using corneal mapping, and this is why we started doing it on every patient, is keratoconus. Keratoconus affects 1 out of every 500 patients. Patients often don’t know they have a disease, they only know they can’t see as clearly as they used to with their glasses, or their eyes might be changing rapidly or getting worse in a short time. So we can see the early stages of keratoconus – it’s a thickening of a portion of the cornea that’s usually off center. The mapping topography of the cornea is really the best way to diagnose this problem because it give us the most detail.
4. What are the treatment options for keratoconus?
We have a whole family of specialty lenses, from large very comfortable scleral lenses that are custom made, to a hybrid lens that is rigid in the center with good optics and a soft skirt for best comfort. We even have soft lenses now that are made for irregular corneas that mask the abnormal pattern or irregularity.
We also are now able to offer our patients revolutionary cutting edge technology for treating keratoconus. We have been selected as one of six Specialty Contact Lens Practices to provide the Eyeprint Pro prosthetic scleral shell. The Eyeprint Pro is made from an imprint of the patients eye, and the lense is made to exactly match the irregularities of the eye. This new technology offers advanced treatment for all patients who suffer from corneal irregularities.
5. How do you determine the best treatment option?
We look at the high and low spots across the surface and the differential will determine what type of lens would be best for a patient. When we design a lens we want to make sure we clear the high spots and don’t impinge on the low spots.
6. Can you describe the patient experience during the exam?
They look into a target and there are quite a variety available, often the test consists of a series of rings that the patient looks through. In our office they look down a long road with a hot air balloon at the end. All we do is let the patient’s eyes relax and ask them to look at a target. Within a couple of minutes we are able to superimpose the rings 780 points across the surface of the cornea, and measure the high and low spots. Its very simple test. It takes about one minute per eye, there’s no air puff, the patient just looks at a single target. Then we analyze the measurement.
7. Do your patients appreciate this technology?
Patients appreciate that we use the latest technology to take the best care of their eyes and manage their vision problems. In most cases when we use corneal topography, we are educating patients about common problems, like a common astigmatism, and what that looks like on the cornea. But sometimes we alert a patient to a possible eye health condition like keratoconus, or if I have a patient who has had a corneal transplant we need to make sure that is monitored.
8. Can you share a particular story about a patient who you were able to treat using this corneal mapping technology?
One patient was having trouble seeing out of her glasses, and one eye was getting worse. She had had a lasik vision correction about 8-9 years earlier, and the problem was that there was a corneal distortion from the lasik surgery. We were able to see that and correct that with a contact lens. In that particular case the contact lens became a medical necessity due to the fact that the quality of vision was better with a contact lens compared to a spectacle prescription.