Controlled unfolding of intraocular lenses
A method for controlled unfolding of an intraocular lens (IOL) includes inserting a folded IOL into an eye and heating a shape memory alloy (SMA) ring included with the IOL to a temperature that is at least a transition temperature of the SMA ring. The transition temperature is above a body temperature. Heating the SMA ring causes the SMA ring to unfold the IOL.
1. A method for the controlled unfolding of an intraocular lens (IOL), the method comprising:
inserting a folded IOL into an eye, wherein the IOL includes a shape memory alloy (SMA) ring having a transition temperature above a body temperature; and
heating the SMA ring to a temperature that is at least to the transition temperature, wherein the heating causes the SMA ring to unfold the IOL.
2. The method of claim 1 , wherein heating the SMA ring to a temperature that is at least the transition temperature includes:
inductively heating the SMA ring to at least the transition temperature.
3. The method of claim 2 , wherein the inductive heating is provided by an inductive coil.
4. The method of claim 2 , wherein the inductive heating is provided by a Helmholtz coil.
5. The method of claim 1 , further comprising:
monitoring the unfolding of the IOL during the heating of the SMA ring to determine a rate of unfolding; and
adjusting a rate of the heating of the SMA ring in response to the monitoring.
6. The method of claim 5 , wherein adjusting the heating of the SMA ring in response to the monitoring includes:
to increase the rate of the unfolding, increasing the rate of the heating.
7. The method of claim 6 , wherein adjusting the heating of the SMA ring in response to the monitoring includes:
to decrease the rate of unfolding being above a threshold, decreasing the rate of the heating.
8. The method of claim 1 , wherein the SMA ring is embedded in a support structure of the IOL.
9. The method of claim 1 , wherein the SMA ring is embedded in a sidewall of the IOL.
10. The method of claim 9 , wherein the SMA ring is an electrode of the IOL.
11. The method of claim 1 , wherein the SMA ring is an antenna of the IOL.
12. The method of claim 1 , further comprising:
folding the IOL into a desired geometry; and
loading the folded IOL into an inserter or injector for implantation.
13. The method of claim 12 , wherein the folding of the IOL is performed at a temperature below the transition temperature.
14. The method of claim 12 , wherein the folding of the IOL is performed at a temperature above the transition temperature.
15. The method of claim 1 , further comprising:
after unfolding the IOL, rinsing the IOL with a saline or viscoelastic gel; and
adjusting a position of the IOL in the eye.
16. The method of claim 1 , wherein heating the SMA ring includes:
heating the SMA ring from a starting transition temperature to a final transition temperature, wherein the SMA ring is completely unfolded when the temperature reaches the final transition temperature.
17. The method of claim 1 , wherein heating the SMA ring to a temperature that is at least the transition temperature includes:
heating the SMA ring to at least the transition temperature using one of laser pulses, ultrasound, or warm saline.
18. A method of unfolding an intraocular lens (IOL), the method comprising:
implanting a folded IOL into an eye, wherein the IOL includes a support structure and a shape memory alloy (SMA) ring included in the support structure, the SMA ring having a transition temperature above body temperature; and
inductively heating the SMA ring to a temperature that is at least to the transition temperature, wherein the heating causes the SMA ring to unfold the IOL.
19. The method of claim 18 , wherein inductively heating the SMA ring to a temperature that is at least to the transition temperature comprises:
inductively heating the SMA ring from a starting transition temperature to a final transition temperature, wherein the SMA ring is completely unfolded when the temperature reaches the final transition temperature.
20. The method of claim 18 , wherein the inductive heating is provided by an inductive coil.
21. The method of claim 18 , wherein the inductive heating is provided by a Helmholtz coil.
22. The method of claim 18 , further comprising:
monitoring the unfolding of the IOL during the heating of the SMA ring to determine a rate of unfolding; and
adjusting the heating of the SMA ring in response to the monitoring.
23. The method of claim 22 , wherein adjusting the heating of the SMA ring in response to the monitoring includes:
to increase the rate of unfolding, increasing the heating to increase a rate of unfolding.
24. The method of claim 22 , wherein adjusting the heating of the SMA ring in response to the monitoring includes:
to decrease the rate of unfolding, decreasing the heating to decrease a rate of unfolding.