How the Europa Tangent Lens Improved the Fit for a Patient with Keratoconus
Visionary Optics’ new Europa Tangent lens design offers customized — yet streamlined — fitting. The Europa Tangent uses a three-zone fitting system, allowing changes to be made to the central, limbal, or scleral zone of the design without affecting other lens parameters (up to + 300 µm). Each step is done in 50 µm increments.
Other advantages of the lens design include contour-adjusting technology — limbal and landing curve enhancements derived from profilometry data — and a softer landing zone patterned after our free-form design.
A 62-year-old patient underwent a corneal transplant of her left eye decades ago and the graft has recurrent keratoconus. For many years, she wore a corneal gas permeable contact lens in her left eye that did not fit well but provided her with 20/25 vision. She had continuous trouble with the lens decentering and falling out, even if she simply coughed or sneezed.
The patient had ectasia and mild to moderate irregularity of her cornea. She also had significant steepening of her paralimbal cornea, causing the entire surface to become very elevated and creating challenges in fitting her for corneal gas permeable or scleral contact lenses. Her scleral elevation map showed no measurable toricity, with only a 200 µm difference between the superior and inferior quadrants, providing a spherical landing zone.
The patient’s optometrist, Greg DeNaeyer, O.D., FAAO, fit her with a Europa Tangent design, using a 16.0 mm lens and a hyper-Dk material to maximize oxygen to the cornea. He created a base curve of 54 diopters to give a sagittal depth of approximately 5500 µm, resulting in a steep, deep lens with a power of -11.75. An advantage of the Europa Tangent is that the landing zone remains compression-free, even when the design requires extreme sagittal depth. It also allows for fitting with a spherical landing zone, despite mild scleral shape asymmetry.
The patient is very happy with the comfortable and secure fit of the Europa Tangent lens, and she can now see with perfect 20/20 vision.
Learn more about the advantages of the Europa Tangent scleral lens.