Method for eye lens removal using cavitating microbubbles
Inventors
Grubbs, Robert H. • Stoller, Marshall L • Han, Ying • Brodie, Frank L.
Assignees
California Institute of Technology • US Department of Veterans Affairs • University of California San Diego UCSD
Publication Number
US-11844724-B2
Publication Date
2023-12-19
Expiration Date
2040-01-03
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Abstract
A surgical method of cataract fragmentation and extraction via microbubble cavitation is described. In particular, gas-filled microbubbles are injected into a lens capsule of a subject's eye, and cavitation of the microbubbles is activated by applied ultrasound energy. The ultrasound energy can be applied from an external device. The cavitation fragments cataract tissues without damaging other tissue, such as the lens capsule. Fragmented lens material is then aspirated from the lens capsule. The method can be used alone or in conjunction with other methods, such as phacoemulsification.
Core Innovation
A surgical method for cataract fragmentation and extraction is presented using the cavitation of injected microbubbles activated by ultrasound energy. Gas-filled microbubbles are injected into a lens capsule containing the cataractous lens of a subject's eye, and ultrasound energy applied either externally or internally triggers cavitation of the microbubbles. This process fragments the cataract tissue effectively while preserving other tissues, such as the lens capsule, and the fragmented lens material is then aspirated from the capsule.
The invention addresses the safety drawbacks of conventional phacoemulsification methods, which rely on high-energy ultrasound to fragment and emulsify the lens but risk complications such as capsular bag rupture, damage to delicate ocular tissues, and loss of corneal endothelial cells leading to prolonged healing or corneal decompensation. Additionally, conventional methods require larger corneal incisions and involve costly equipment and disposables. The disclosed method reduces exposure to high-energy ultrasound by employing cavitating microbubbles that selectively fragment the cataract, improving safety, efficiency, and potentially reducing training complexity and costs.
Claims Coverage
The patent includes two independent claims that encompass methods for lens removal using microbubbles undergoing cavitation and a system for facilitating this process. The main inventive features focus on the use of gas-filled microbeads for cavitation-induced fragmentation, ultrasound energy application, and system components enabling safe and efficient cataract extraction.
Method for lens removal using microbubble cavitation
Injecting microbeads into the eye, applying energy sufficient to cause cavitation, fragmenting the lens material with the cavitation, and aspirating the fragmented material. The method may include repeating these steps until the entire lens is removed.
Composition of microbeads for targeted cavitation
Microbeads comprising a phospholipid shell with fluorinated alkane gas inside (such as perfluoropropane or butane), or alternatively, a block copolymer or polymer shell with fluorocarbon gas or air inside. Microbeads may be coated with targeting moieties such as polypeptides or acidic groups to bind lens material.
Integration with cataract surgery procedures and energy application
Performing capsulorhexis, hydrodissection, and artificial intraocular lens insertion. The microbeads may be injected with hydrodissecting liquid or as a liquid suspension used for irrigation. Ultrasound energy can be delivered externally through biological tissue or internally via an ultrasonic or phacoemulsification handpiece tip to activate cavitation. The method may include insertion of a phaco handpiece tip for emulsifying the lens material during or after cavitation, requiring less emulsifying energy than traditional methods.
System for lens removal using stabilized microbeads and activation instrument
A system comprising stabilized gas-filled microbeads smaller than 500 microns suitable for injection and cavitation upon ultrasound energy exposure, and a microbubble activation instrument configured to direct ultrasound energy to the microbeads to fragment lens material while preserving the lens capsule. The activation instrument may include an ultrasonic tip or phacoemulsification handpiece tip for insertion into the eye.
The independent claims provide comprehensive coverage of both the method employing cavitating microbeads activated by ultrasound energy for cataract fragmentation and the system facilitating this process, highlighting microbead composition, method integration with surgical steps, energy delivery modalities, and apparatus configurations to improve safety and efficiency in lens removal.
Stated Advantages
Improved safety and efficiency of cataract removal surgery by selectively fragmenting the cataract without damaging the lens capsule or surrounding delicate ocular tissues.
Reduced exposure to high-energy ultrasound lowers the risk of complications such as capsular bag rupture, corneal endothelial cell loss, wound burns, and damage to other eye structures.
Smaller corneal incisions are possible, enhancing surgical stability, reducing healing time, and enabling broader choices for artificial lenses.
Reduced equipment costs and possibly a shorter surgical training curve for ophthalmology residents due to the simplified and safer procedure.
Documented Applications
Cataract fragmentation and extraction surgery using microbubble cavitation activated by ultrasound energy, alone or in conjunction with phacoemulsification.
Use of gas-filled microbubbles injected into the lens capsule of a subject's eye for cataract removal.
Application of ultrasound energy externally or internally to activate cavitation for lens fragmentation.
Integration of microbubble cavitation with conventional surgical steps such as capsulorhexis, hydrodissection, aspiration, and intraocular lens implantation.
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