[Wide-angle contact lenses of corundum monocrystal for pars plana vitrectomy].
BACKGROUND
A very light planoconcave (0.3 g) and biconcave (0.27 g) contact lens of corundum monocrystal is presented for simplification of pars plana vitrectomy.


METHODS
Corundum monocrystal is corrosion-resistant and extremely hard and mar-proof. It can be sterilised by all conventional procedures without changing its shape or transparency. Corundum monocrystal is transparent like glass and has a high refractive index of n = 1.76 like sapphire.


RESULTS
The high refractive index enables strong prismatic deflection and thus provides a good view of the peripheral retina. The lens is placed on the cornea over a drop of methylcellulose and requires no scleral fixation or irrigation system. An erect image is formed.


CONCLUSIONS
Compared to other systems, the two contact lenses have the advantage of easy handling with excellent optical quality.
Universitätsklinikum Benjamin Franklin, Freie Universität Berlin. fhoffman@zedat.fu-berlin.de
Friedrich
F
Hoffmann
Horst
H
Helbig
Helmut
H
Goersch
D000537:Aluminum Oxide; D003261:Contact Lenses; D006801:Humans; D055095:Optics and Photonics; D014821:Vitrectomy / Q000295:instrumentation*
D000537:Aluminum Oxide