Products / MSD Select

Msd fits most of pathologies and irregular corneas.

Attributes

msd™ Select mini scleral lenses provide a distinctive posterior surface incorporating reverse geometry with specially designed optical and posterior curves allowing for creation of a smooth, spherical second refractive surface to replace the irregular corneal surface. In either a 15.8mm (standard) or 18.0 diameter, the design and thin profile results in minimal lens edge/lid interaction providing excellent patient comfort and oxygen transmission to the cornea.

Msd fits most of pathologies (advanced keratoconus, post graft,etc.) and irregular corneas.

The msd™ Mini-Scleral Design is easy to fit and is suitable for patients with anterior segment pathology. Patients who will benefit from the design are those with advanced keratoconus and all corneal ectasias, dystrophies and degenerations, post- Lasik and post-surgical or any other compromised and/or irregular cornea condition.

The msd is a scleral lens manufactured in hyper Dk materials with a thinner profile that maximizes Dk/L to maintain corneal health. The design has a distinctive posterior lens surface that incorporates a reverse geometry design that allows easy manipulation of parameters for an optimized fit. The lens provides a smooth refracting surface by creating a tear layer between the cornea and back surface of the lens that eliminates much of the irregular and regular astigmatism caused by the corneal surface. The msd’s aspheric front surface optics reduces aberrations further improving vision. The proprietary mid-peripheral hinge in the msd lens design creates a unique tear pump providing enhanced tear exchange. The msd’s thinner profile and design results in minimal lens edge/lid interaction, providing excellent patient comfort.

Fitting Philosophy

A fundamental principle of GP contact lens fitting is to achieve a particular relationship between the posterior lens surface and the anterior cornea, thus creating a tear layer with specific characteristics. This is also true in fitting the msd lens with some differences when compared to corneal lens designs.

Corneal lenses are fitted by manipulating base curve and diameter in order to create the optimal lens/cornea relationship. When the cornea becomes highly irregular with steep and flat areas arbitrarily placed, the fit becomes very complicated and often impossible.

The underlying principle of the msd lens is not to rely on or use the highly irregular cornea but rather vault it as well as the limbus, and use the sclera as the landing area to properly position the posterior surface of the lens over the highly irregular cornea and recreate a smooth spherical second refractive surface. With this in mind, sagittal depth , as opposed to base curve and diameter, becomes the most comprehensive and easiest measurement in managing and optimizing the vaulting characteristics of msd lenses .

The msd is fit by selecting a lens with a sagittal depth (sag) that is greater than the height of the corneal surface and limbus upon which it is being fitted. The lens is available in sags from 3.6 mm to 5.8 mm in 100 micron increments (the difference in a 4.2 mm sag and 4.3 mm sag is 100 microns). There are four profile curves available to adjust the mid-peripheral curve over the limbus and the lens is available in a 15.8 mm and 18 mm. Using a simplified fitting process, the msd lens design can be made to fit nearly any eye shape.