Outflow facility studies in the perfused human ocular anterior segment.
We have recently developed a tissue model of the human aqueous outflow pathway involving placement of the eviscerated anterior corneoscleral shell, [with lens and uveal tissue removed but trabecular meshwork (TM) attached] onto a specialized perfusion apparatus. The TM and associated outflow tissues are perfused with culture medium at a physiologically-relevant perfusion pressure in a 5% CO2 environment at 37 degrees C. Under these conditions, the perfused outflow tissues are similar for several days, to the human and/or subhuman primate outflow system in vivo with regard to morphology as well as several functional parameters. Measured facility of outflow (0.271 +/- 0.018 microliters min-1 mmHg-1, n = 79) is similar to facility values obtained by tonography in living human beings. Moreover, outflow facility decreases in a linear fashion with increased perfusion pressure by 1.4% mmHg-1. Finally the removal of the TM results in a 41% decrease in measured outflow resistance. The ability to study viable human outflow tissue for at least several days and the opportunity to establish a model which serves as an alternative to animal testing, point to the potential importance of this technique in investigating the biology of the aqueous outflow system.
Erickson-Lamy
K
K
Howe Laboratory of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston 02114.
Rohen
J W
JW
Grant
W M
WM
D000869:Anterior Eye Segment / Q000502:physiology* / Q000648:ultrastructure; D001082:Aqueous Humor / Q000502:physiology*; D006801:Humans; D008854:Microscopy, Electron; D008875:Middle Aged; D008954:Models, Biological; D009924:Organ Culture Techniques; D010477:Perfusion / Q000295:instrumentation; D014129:Trabecular Meshwork / Q000502:physiology / Q000648:ultrastructure