Abstract
Abstract: :
Purpose: The anterior segment perfusion model is valuable to study processes that influence conventional outflow in human eyes. While inflow and outflow facility in this system approximates magnitude of fluid flow in vivo, at least two physiological factors are not currently represented. The aim of the present study was to examine the potential to include diurnal inflow variations and ocular pulse in the anterior segment perfusion model. Methods: To simulate diurnal fluctuations in aqueous humor secretion, a programmable syringe pump was used to modify inflow into the perfusion chamber. Two pumps, a syringe pump and a pulsatile blood pump, were used in tandem to simulate the magnitude and frequency of intraocular pressure pulses found in vivo. A fixed resistor (steel eye) was connected to pump(s) and a pressure transducer to test and optimize these two physiological variables. Results: A sinusoidal, 24 hour pattern of flow was successfully delivered, with a minimum flow rate of 1.5 µl/min and a maximum of 3.4 µl/min. Intraocular pulsations were replicated in vitro with spikes in intra–chamber pressure having a magnitude of 2.7 mmHg every second. Conclusions: Results show that two physiologically relevant mechanical forces can be delivered to the anterior chamber perfusion system at a magnitude and interval consistent with those experienced in vivo.
Keywords: anterior segment • outflow: trabecular meshwork • aqueous