Open AccessCoupling blood flow and neural function in the retina: a model for homeostatic responses to ocular perfusion pressure challenge
Author(s) -
He Zheng,
Lim Jeremiah K. H.,
Nguyen Christine T. O.,
Vingrys Algis J.,
Bui Bang V.
Publication year - 2013
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.1002/phy2.55
Subject(s) - blood flow , retina , perfusion , retinal , intraocular pressure , hemodynamics , ischemia , medicine , ophthalmology , anesthesia , neuroscience , cardiology , biology
Retinal function is known to be more resistant than blood flow to acute reduction of ocular perfusion pressure ( OPP ). To understand the mechanisms underlying the disconnect between blood flow and neural function, a mathematical model is developed in this study, which proposes that increased oxygen extraction ratio compensates for relative ischemia to sustain retinal function. In addition, the model incorporates a term to account for a pressure‐related mechanical stress on neurons when OPP reduction is achieved by intraocular pressure ( IOP ) elevation. We show that this model, combining ocular blood flow, oxygen extraction ratio, and IOP mechanical stress on neurons, accounts for retinal function over a wide range of OPP manipulations. The robustness of the model is tested against experimental data where ocular blood flow, oxygen tension, and retinal function were simultaneously measured during acute OPP manipulation. The model provides a basis for understanding the retinal hemodynamic responses to short‐term OPP challenge.