Do you have an incredibly complicated cornea?
A more custom gas permeable lens might be the answer!
With traditional gas permeable lenses (also known as RGPs, rigid gas permeable lenses, or hard lenses), a doctor must use a fitting set to help identify the best fit for your eye. This involves the doctor analyzing images of your eye and using a fitting guide from the manufacturer of the contact lens.
After reviewing your images, the doctor selects an initial lens to apply to your eye. After that, they might put some yellow dye into your eye and check the fit of the lens with a blue light. Depending on what they see, they will remove the lens, and re-apply a new lens with a different shape and re-assess this lens.
This process will be repeated over and over again until the doctor identifies the best fitting lens for your eye. Once the doctor selects the best fitting lens, they will often do more testing such as an over-refraction (the test where they ask "which is better 1 or 2?"). This will tell the doctor what prescription to put into the lens. It will also tell us what your best potential visual acuity is.
This is important because the doctor and patient must understand what your best vision will be so that all expectations are met prior to ordering a contact lens. In some cases, the contact lens fitting can be very challenging.
For patients who require a hard contact lens that have severe issues such as advanced keratoconus, corneal scarring, corneal transplants, corneal surgeries, and other corneal issues, special gas permeable lenses may be required for an optimal fit.
For some of these challenging corneas, we offer a technology that is not available in most eye clinics. It is called the EyePrint GP or EPGP lens. This revolutionary type of lens involves taking an impression of the eye (see photo below - note: this is NOT the patient in the case report).
Once we take an impression of the eye, it is sent to the lab. The lab uses proprietary 3D technology to assess the entire cornea and conjunctival surface like you see in the photo. For this particular patient, she suffered from calcium deposits on her cornea which were scraped off by her ophthalmologist.
You can see the scar tissue that remains on the cornea. She also has a very high amount of irregularity at the limbus or conjunctival area nasal and temporally, shown with the blue arrows. The lab will use 3 million data points to design a custom gas permeable lens for this patient.
We are very excited to get the lens into our office and see how well her vision improves.
We are grateful to have such amazing technology in our practice to help even some of the most complicated patients.
