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Internal Tamponade With Silicone Oil: Echographic Evaluation

  • M. Del Duca
Conference paper
Part of the FIDIA Research Series book series (FIDIA, volume 2)

Abstract

Silicone oil is used as an internal tamponade after vitrectomies. We also used this method for peeling off posterior epiretinal membranes with P.R. of recent occurrence. If there is a lens or vitreous opacity after vitrectomy, echography is necessary for the postoperative controls. Blood residuals or exudates in the early post-operatory period hinder exploration, as do cataracts which form during the months after the operation. The physical properties of silicone oil make the echographic interpretation more dif¬ficult. One of the features of silicone is the reduced speed of propagation of ultrasound in this media. We know from literature that the velocity value in silicone oil is about 983 meters a second. The ratio between the velocity in silicone oil and the theoretic velocity of ultrasound through the optic axis gives a coefficient which allows us to com-pare the magnitudes obtained echographically with silicone with real magnitudes:
$$ C = \frac{{V1}}{V} - \frac{{983}}{{1550}} = 0.63 $$
Another feature of silicone is that of having an ultrasound absorption coefficient, linked to features such as high viscosity, which is expressed in a reduction of the echo amplitudes calculated approximately as 1 db per mm using 8 MHz probes.

Keywords

Retinal Detachment Blood Residual Vitreous Opacity Recent Occurrence Postoperative Control 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Literature

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    Poujol J, Massim M (1979): L’examen echographique des jeux opèrèe deollement de retinè avec injection de silicone. Diagnostica ultrasoica in ophtalmologia. SIDUO VII H. Germet, 111–115.Google Scholar
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    Coleman J, Lizzi F, Jack R (1977): Ultrasonography of eye and orbit. Lea and Febiger, 1977, Philadelphia.Google Scholar
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    Hassani SN: Real time ophthalmic ultrasonography. Springer Verlag, New York Heidelberg Berlin.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1986

Authors and Affiliations

  • M. Del Duca
    • 1
  1. 1.Divisione Oculística C.T.O.Via NemesioRoma

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