Apparatus and methods to adjust ocular blood flow
An apparatus to treat, inhibit, or prevent an eye condition in a patient can include a cover, sized and shaped to fit over an eye of a patient to define a cavity between the cover and an anterior surface of the eye when the cover is located over the patient eye. The apparatus can include a pressure source, in communication with the cavity, capable of applying non-ambient pressure in the cavity. The apparatus can include control circuitry, in communication with the pressure source, configured to vary non-ambient pressure applied to the cavity to affect a targeted pressure relationship between an indication of a first physiological pressure level and a second physiological pressure level associated with the eye of the patient.
1. An apparatus to adjust an indication of ocular perfusion pressure (OPP) in an eye of a patient, the indication of OPP including a relationship between an indication of systemic blood pressure in the patient and an indication of intraocular pressure (IOP) in the patient 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, configured to receive the indication of systemic blood pressure and the indication of IOP, calculate the indication of OPP, and adjust the pressure source to change fluid pressure in the cavity to move the indication of OPP toward a target OPP in the patient eye.
2. The apparatus of claim 1 , wherein the control circuitry is configured to change the fluid pressure in the cavity toward the target OPP based at least in part on at least one of the indication of systemic blood pressure in the patient or the indication of IOP in the patient eye.
3. The apparatus of claim 2 , wherein the control circuitry is configured to change the fluid pressure in the cavity to move the indication of OPP toward the target OPP based on a difference between the indication of systemic blood pressure and the indication of IOP.
4. The apparatus of claim 2 , wherein the control circuitry is configured to change the fluid pressure in the cavity to move the indication of OPP toward the target OPP based on mean ocular perfusion pressure (MOPP).
5. The apparatus of claim 1 , wherein the control circuitry is configured to adjust the fluid pressure in the cavity to move the indication of OPP toward a target IOP level.
6. The apparatus of claim 5 , wherein the control circuitry is configured to adjust the fluid pressure in the cavity to move the indication of OPP toward a target IOP level based at least in part on at least one of the indication of IOP and the indication of OPP.
7. The apparatus of claim 1 , wherein the control circuitry is configured to receive an indication of blood flow in the patient eye associated with the indication of OPP to generate an ocular autoregulation (OA) value.
8. The apparatus of claim 7 , wherein the control circuitry is configured to adjust the fluid pressure in the cavity to move the indication of OPP toward a target level, wherein the target level includes a target OPP graph-point level and the control circuitry is configured to generate the OA value as an OA ordered pair including the target OPP graph-point level and the indication of blood flow corresponding to the target OPP graph-point level.
9. The apparatus of claim 8 , wherein the control circuitry is configured to process at least two OA ordered pairs to calculate an OA index.
10. The apparatus of claim 9 , wherein the OA index includes a slope of a best-fit line between at least two OA ordered pairs.
11. The apparatus of claim 1 , wherein the control circuitry is configured to adjust the fluid pressure in the cavity to move the indication of OPP toward a target SVP state including a transition SVP state to estimate CSFP level in the patient.
12. The apparatus of claim 11 , wherein the control circuitry is configured to receive an indication of systemic blood pressure including an indication of at least one of systolic blood pressure level or diastolic blood pressure level, and
wherein the control circuitry is configured to capture at least one of a first image of a blood vessel parameter corresponding to the systolic blood pressure level or a second image of the blood vessel parameter corresponding to a diastolic blood pressure level.
13. The apparatus of claim 1 , wherein the target OPP includes a target OPP range from about 30 mmHg to about 70 mmHg.
14. The apparatus of claim 1 , wherein the target OPP includes a target OPP range from about 40 mmHg to about 60 mmHg.
15. The apparatus of claim 1 , wherein the target OPP includes a target OPP range from about 45 mmHg to about 55 mmHg.
16. A method to adjust an indication of ocular perfusion pressure (OPP) in a patient eye using an apparatus, the apparatus comprising a cover, sized and shaped to fit over the eye to define a cavity between an interior surface of 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 OOP, and control circuitry, in communication with the pressure source, configured to adjust the pressure source to change fluid pressure in the cavity to move the indication of OPP toward a target OPP in the patient eye, the method comprising:
receiving an indication of systemic blood pressure in the patient and an indication of intraocular pressure (IOP) in the patient eye with the control circuitry;
calculating the indication of OPP from the received indications of systemic blood pressure and IOP with the control circuitry; and
adjusting the pressure source to change fluid pressure in the cavity to move the indication of OPP toward a target OPP in the patient eye.
17. The method of claim 16 , wherein adjusting the pressure source toward a target OPP includes applying negative non-ambient gauge pressure to the cavity.
18. The method of claim 16 , wherein adjusting the pressure source to move the indication of OPP toward a target OPP includes applying positive non-ambient gauge pressure to the cavity.
19. The method of claim 16 , wherein adjusting the pressure source to move the indication of OPP toward a target OPP includes adjusting pressure in the cavity based at least in part on at least one of the indication of systemic blood pressure in the patient or the indication of IOP in the patient eye.
20. The method of claim 16 , wherein adjusting the pressure source to move the indication of OPP toward a target OPP includes applying non-ambient pressure in the cavity to achieve a target OPP in a range of about 30 mmHg to about 70 mmHg.