Corneal topography involves measuring subtle variations in a patient’s corneal curvatures. The cornea is the clear structure at the front of the eye, and it represents the most powerful fixed refractive surface of our visual system. Small variations in corneal curvature originating from genetic disease, or post-surgical complications, can affect vision negatively. Corneal scans using our Zeiss Atlas 9000 Corneal Topographer allows our doctors to view the cornea in a more detailed way than is afforded with only our biomicroscopes.
The information the corneal topographer provides is useful in monitoring disease, diagnosing disease, and fitting custom contact lenses. Corneal diseases that are best monitored with regular corneal topography include:
- Pellucid marginal degeneration
- Post-LASIK ectasia
- Corneal transplants (post-PKP)
- Ocular trauma
- Cornea degenerations
- Irregular astigmatism
- High refractive error
- Corneal edema
Patients with unexplained vision loss will sometimes present to our clinic with healthy eyes. If the patient has no cataracts, no retinal disease, and no history of amblyopia, where did the vision loss develop from? Sometimes the answer is in the cornea. Keratoconic eyes, as an example, tend to steepen greatly over time, and that steepness, instead of being centered on the visual axis, is notably decentered inferiorly. Unless keratoconus is especially advanced, it cannot be easily detected by merely looking at the eye, even under considerable magnification. The corneal topographer picks up the distortion of the cornea that is typical of this disease and leads to our ability to diagnose the cause of vision loss. At that point, our doctors can initiate a treatment plan to allow the patient to have better vision.
Custom contact lenses are lenses that are designed for corneas that fall outside standard parameter categories. These include lenses that are designed to fit post-LASIK/PRK eyes, post-corneal transplant eyes, and eyes with keratoconus. Using the Atlas 9000 allows us to better estimate the fit and vision that a contact lens will offer the patient, thus saving the number of return visits and lens modifications needed for a successful fit.