| The two A.V.I. Lenses have high-resolution
aspheric optics so that sharp images are obtained even in the periphery
of the lens. They are smaller in size than the Volk Transequator or Quadraspheric
lenses. Since stereopsis is important in vitreous surgery, the lenses
have been designed to enable membrane dissection. The choice of contact
lenses over non-contact lenses was dictated by the need to neutralize
the optical interface of the cornea and to allow visualization of the
wilder field of view. The 68-degree or equatorial lens provides visualization
to the equator at higher magnification for epiretinal dissection and visualization
of the macula region. The 130-degree or peripheral lens is preferred for
vitreous base surgery, fluid air exchange and endophotocoalgulation. Thus
the surgeon can select either these lenses or planoconcave quartz or high
refractive index lens depending on the magnification and the field of
view desired. |
