Loading...

Simulation of Transport Phenomena in Gas Injection in the Eye

Noohi, Parisa | 2012

547 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 43848 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Abdekhodaie, Mohammad Jafar; Goodarznia, Iraj
  7. Abstract:
  8. Retinal detachment is a disorder of the eye in which a part or entire retina detaches from underlying layers. It is a medical emergency and if it is not treated, all vision may be lost. Surgery is the only way to treat retinal detachment. Pneumatic retinopexy (PR) is an office-based procedure for repairing some retinal detachment. PR has three cardinal steps: applying laser or cryopexy around all breaks to seal them, injection of gas into the vitreous cavity and appropriate head position so that the bubble closes the retinal breaks.
    In this thesis, we are trying to model PR procedure and predict the behavior of intraocular gas. In general, once the gas is injected into the eye, because of concentration gradient between bubble and adjacent tissues, gases such as N2, O2 and CO¬2 diffuse into the bubble to equalize their partial pressures with blood gases and the injected gas diffuses out of the bubble and is absorbed. As this process occurs, the gas volume initially increases, reaches a maximum, and then decreases.
    By studying the gas behavior, intraocular gas volume and bubble - retina contact area can be predicted at any time. In addition, since positioning for 5-8 days to orient gas bubble at the site of the breaks is very difficult, due to the flap size and the gas-retina contact area, the presented model can determine the tolerance angle within which a patient can maneuver and still allow gas to completely cover the breaks.
    Quantifying factors that contribute to gas expansion is another benefit of modeling. By using quantified factors, we will be able to model “vitrectomy”. Moreover, in this project, we have considered two positions for the breaks; superior and posterior. Modeling these cases helps us to study the effect of aqueous humor flow on absorption of intraocular gas
  9. Keywords:
  10. Optimization ; Intraocular Gas ; Pheumatic Retinopexy (PR) ; Sulfurhexaflouride

 Digital Object List

 Bookmark

No TOC