Abstract
Abstract: :
Purpose: To develop new computational models to solve the problems related to fluid flow in the eye based on a confocal method of using microbeads to track fluid movement in the living rabbit eye. Methods: New Zealand white rabbits were anesthetized and a 27-gauge needle was introduced into the anterior chamber, avoiding contact with tissue, to inject a 5 µl aliquot (1.031 x 10 6 beads/ml water) of saline containing 2.6 µm diameter microbeads over 5 mins. To visualize the beads moving in the aqueous flow, the objective of the confocal microscope was positioned over a thin layer of optical coupling material. SVHS real time video was analyzed for 17 locations within the chamber and each frame was digitized. Vectors represented fluid velocity at any given position and a distance-weighted average was calculated for points extrapolated outside the 17 locations. The anterior chamber was modeled as a 3-dimensional rectangular space. Results: From the 3-dimensional data set, a vector flow model and a virtual bead tracking model were developed. In the vector flow model, velocity and direction were displayed by color representation, and in the bead tracking model the direction and velocity of individual beads were represented as a spectrum of colors and the aqueous was transparent. Both models revealed that flow was not altogether uniform, at times moving with components of horizontal and vertical flow. The paths of individual beads were shown color coded for both velocity and direction and were likewise complex. Conclusions: Anterior chamber fluid dynamics were found to be more complex than previously suggested. Modeling flow may be useful for examining the effects of pharmacological treatment on outflow or secretion.
Keywords: 317 anterior chamber • 503 outflow: trabecular meshwork • 514 pharmacology