Products / Onefit MED

An intuitive and easy to use scleral lens that allows full customization of the fit for the highly irregular and medically indicated cornea.

Attributes

Onefit MED, with a standard diameter of just 15.6mm, is unique and simplifies the fitting process for a wide range of applications. Designed to allow the practitioner to fully customize the fit, adjustments are possible in four (4) separate zones of the lens (Central, Mid-Peripheral, Limbal and Edge). To easily find the exact location of the Mid-Peripheral and Limbal zones, the Dx lenses are etched with solid lines that can be observed at the slit lamp or OCT image. Onefit MED minimizes both lens thickness and tear layer, maximizing oxygen transmission to the cornea and stem cells. The design serves as its own platform from which Multifocal, Oblate and Front Toric geometries can be ordered.

Onefit MED is very predictable and the final lens parameters can be determined, as well as visualized, using the Onefit MED Fitting Tool.

Just like the rest of the Onefit Scleral Lens Platform, Onefit MED minimizes both lens thickness and tear layer required to support the lens, to optimize oxygen transmission to the cornea and stems cells, for long-term ocular health.

With a trial set composed of 20 lenses, practitioners can fit:

  • Irregular Corneas
  • Ectactic Corneas (moderate to severe)
  • Nipple & Oval Cones
  • Post-RK, Post-LASIK
  • Pellucid Marginal Degeneration
  • Ocular Surface Disease
  • Astigmatism
  • Presbyopia
  • Normal Prolate Corneas

Design Options for Onefit MED include:  Spherical, Multifocal, Toric, Toric PC, Oblate and Oblate Multifocal

Benefits provided by ALL Onefit lenses include superior comfort, stability of fit, vision that remains consistent throughout the wearing time, reduced glare and starbursts and reduced dryness.  Although designed for more advanced irregular patients, the attributes of this lens design also make it an ideal lens for athletes and active wearers, unhappy soft and soft toric lens wearers, and intolerant corneal GP wearers.  Onefit lenses offer the crisp vision of a GP while providing the comfort of a soft lens.

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Fitting Philosophy

Onefit MED is supported by the conjunctiva and the fluid layer under the lens, rather than by the cornea. It is designed to vault the entire corneal surface including the limbal area. The clearance over the cornea can be fully customized from center to periphery optimizes oxygen transmission to the tissue, especially over the limbus where the stem cells are located. Current published work indicates that fluid layer thickness is an important concern with scleral lenses. With an estimated DK value of 80, an excessively thick fluid layer under the lens can deprive the cornea and stem cells of sufficient oxygenation.

Keeping the Harvitt-Bonanno and Holden-Mertz criteria in mind, Onefit MED has been designed to maximize oxygen transmission when combining the lens and tear layer thickness.  Its unique geometry and design option reduces the thickness of the tear layer from the center out to the limbal area.  Optimum results in fit and corneal health are achieved by minimizing lens thickness (between 200-250 microns) combined with clearance of 150 to 175 microns at the apex of the cornea, or in the area where the cornea is steepest (e.g. host-graft corneal junction) with optimal limbal clearance at 40 microns. The lens peripheral edge should align with the conjunctiva. Onefit is manufactured in materials offering a minimum permeability of 100 DK.