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[Wide-angle contact lenses of corundum monocrystal for pars plana vitrectomy]
Friedrich Hoffmann1, Horst Helbig, Helmut Goersch
1Universitätsklinikum Benjamin Franklin, Freie Universität Berlin. fhoffman@zedat.fu-berlin.de
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.
Material And 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.
Conclusion:
Compared to other systems, the two contact lenses have the advantage of easy handling with excellent optical quality.
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