Apparatus and methods to adjust ocular blood flow

An apparatus to generate an indication of an ocular autoregulation (OA) index to characterize an autoregulation capability of an eye of a patient, the OA index characterized by at least two OA values, wherein an individual one of the at least two OA values includes an ordered pair relationship of an indication of ocular perfusion pressure (OPP) in the eye and an indication of blood flow in the eye, the apparatus comprising:

• a cover, sized and shaped to fit over the eye to define a cavity between the cover and an anterior surface of the eye;
• a pressure source, in communication with the cavity, configured to adjust fluid pressure in the cavity to affect the indication of OPP;
• and
• control circuitry, in communication with the pressure source, the control circuitry configured to:
• apply a first control signal to the pressure source to generate a first pressure in the cavity corresponding to a first indication of intraocular pressure (TOP) in the eye;
• receive the first indication of IOP in the eye and a first indication of systemic blood pressure in the patient to calculate a first indication of OPP and a first indication of blood flow in the eye associated with the first indication of OPP to form a first OA value;
• apply a second control signal to the pressure source to generate a different second pressure in the cavity corresponding to a second indication of IOP in the eye;
• receive the second indication of IOP in the eye and a second indication of systemic blood pressure in the patient to calculate a second indication of OPP and a second indication of blood flow in the eye associated with the second indication of OPP to form a second OA value;
• and
• calculate an OA index of the eye based upon the first OA value and the second OA value.