Identifier

etd-11152006-214523

Degree

Master of Science in Mechanical Engineering (MSME)

Department

Mechanical Engineering

Document Type

Thesis

Abstract

In this study, numerical computations of the ocular fluid dynamics in a human eye are presented with a perspective of understanding the mechanisms of increased flow resistance. In the present study, the TM is represented as a multilayered-graded porous structure with specific pore size and void fraction. The flow patterns and pressure distribution in anterior chamber are analyzed to delineate key flow mechanism; the shear stresses on the lens, iris and IW of SC are also examined to locate the maximum values. Inside the human eye, the largest pressure drop occurs across JCT and IW of SC. The highest pressure in SC is at the midpoint between two collector channels (CC). The pressure falls near CC which implies that the IW of SC will experience more pressure difference towards CC, and the canal may show a greater tendency to collapse close to the CC exits. The maximum velocity is found in the vicinity of IW pores. It is also seen that AH velocity funneling out of the IW pores is higher in the region underlying the collector. Analysis is also carried out for glaucomatous condition where the IOP is increased to a high value of 8000 Pa. The later part of thesis is dedicated to the drug delivery to the posterior segment of the eye. The main objective of this study is to characterize the spatio-temporal evolution of drug distribution following intravitreal injection into a vitreous substitute such as silicone oil and in the case of vitreous liquefaction caused due to aging. Both direct injection of drugs and injection of time released drugs are studied. The results show that the concentration distribution is highly dependent on the vitreous substitute, diffusion coefficient of the drug and the permeability of the retinal surface. For drugs with high diffusion coefficients, convection plays a small role whereas for the drugs with low diffusion coefficients and low viscosity vitreous fluids, convection is seen to play a more important role and can lead to high drug concentrations on the retina which can be potentially toxic. Time-released drug injection is shown to avoid conditions of retinal toxicity.

Date

2006

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Sumanta Acharya

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