Patent Application
20220387218
The invention relates generally to methods and systems for treating eye conditions with phacoemulsification (phaco) and excimer laser trabeculostomy (ELT).
Many people suffer vision loss due to cataracts or glaucoma. Cataracts are a common condition that occurs when light is blocked from entering the eye due to cloudiness or opacity in the lens of the eye. Patients suffering from glaucoma experience vision loss caused by damage to the optic nerve due to buildup of fluid in the anterior chamber of the eye.
The risk of developing cataracts, glaucoma, or both, increases with age; and many people over the age of 60 suffer from both vision-altering conditions. Moreover, patients diagnosed with cataracts at a young age have a higher risk of developing glaucoma later in life. Patients diagnosed with either condition undergo treatment ranging from medication to surgery.
The invention provides methods and systems for prophylactic treatment of glaucoma in patients being treated for cataracts. According to methods of the invention, a patient who presents for cataracts removal is evaluated and, if appropriate, prophylactically treated to prevent glaucoma. The invention takes advantage of the insight that patients with cataracts, especially at a younger age, are likely to develop glaucoma later in life or may be in the early stages of developing glaucoma. The invention comprises evaluating cataracts patients to determine whether an additional procedure as describe below would be beneficial to prevent the onset of glaucoma. Accordingly, methods of the invention comprise selecting patients being treated for cataracts for prophylactic treatment of glaucoma. Prophylactic glaucoma treatment is preferably an excimer laser trabeculostomy (ELT) procedure but may be any procedure known in the art.
Phacoemulsification treatment (Phaco) is a common method for removal of cataracts. Methods of the invention comprise administering phaco and ELT during the same surgical visit, thereby minimizing the amount of surgeries for a patient having multiple eye conditions. Because phaco and ELT are less invasive than traditional surgeries, the amount of recovery time for the patient is minimized. In fact, both phaco and ELT are performed through one small incision that is made in the eye.
Any cataracts treatment suffices for use in the invention. Phacoemulsification is a preferred cataracts treatment in which a small incision is made in the peripheral cornea and an ultrasonic probe is inserted. The incision is long enough to allow entry of the ultrasonic probe and additional instruments used for removal of the cataract. Typically, the incision is about ⅛ inch long. The ultrasonic probe breaks the cataract into small pieces which are then removed from the eye. The ultrasonic probe typically has a titanium or steel needle that vibrates at ultrasonic frequency to emulsify the cataract while a pump aspirates particles through the tip of the needle. To facilitate removal, the physician may use a chipping tool and an irrigator. A clear replacement intraocular lens (IOL) is then inserted through the incision.
Before closing the incision, methods of the invention allow for the performance of an excimer laser trabeculostomy for prophylactic treatment of glaucoma. In a preferred embodiment, the invention comprises use of an excimer laser to create perforations in the Schlemm's canal and/or the trabecular meshwork of the eye, thereby allowing drainage of fluid from the eye. ELT treats open-angle glaucoma at the site of occurrence by increasing the permeability of the trabecular meshwork. During ELT, the laser creates a direct connection between the front chamber of the eye and the Schlemm's canal by using a fiber probe in physical contact with the trabecular meshwork. The fiber probe comprises an optical fiber suitable for UV light that is embedded into a handheld laser applicator. In some examples, a FIDO LASER APPLICATOR manufactured by MLase AG is used as the fiber probe.
The ELT procedure comprises guiding a laser light to the trabecular meshwork in the iridocorneal angle via a small corneal incision. A goniolens may be used to achieve effective, precise positioning of an end of the fiber probe at the trabecular meshwork to create a passageway into Schlemm's canal. A physician uses the goniolens to intraoperatively observe quality criteria, including reflux hemorrhage and minor reflux bleeding.
To achieve easier drainage of the aqueous humor in order to reduce IOP, a total of about 10 ELT sites or perforations, each with about a 200 μm diameter, are lasered into the trabecular meshwork and/or Schlemm's canal by means of photoablation. In comparison, stents and implants have smaller individual diameters that are between about 80 μm to about 120 μm. The photoablative excimer laser operates at a wavelength of 308 nm. In some examples, the excimer laser is an encapsulated xenon chloride (XeCl) excimer laser such as the EX TRA LASER manufactured by MLase AG. Because ELT is a non-thermal procedure, tissue reactions in the trabecular meshwork are not shown or activated post-operatively. The lack of heat generation in ELT allows for a nearly absent activation of postoperative tissue reactions and provides long-term stability of the pressure-reducing effects. Moreover, unlike the traditional glaucoma treatment method of shunt or stent placement, the stability of Schlemm's canal using ELT treatment remains unchanged.
Methods of the invention comprise treating a subject having one or more eye conditions and providing ELT as preventative treatment. Phacoemulsification ultrasound is applied to a subject having one or more eye conditions, and an excimer laser is applied to an eye of the subject to increase blood flow to an eye of the subject. Applying an excimer laser to the eye comprises applying shots of pulsed energy from the excimer laser. In some examples, about 10 shots of pulsed energy are applied to the eye. In an example, the one or more eye conditions comprise cataracts and glaucoma.
In some cases, applying an excimer laser prophylactically treats glaucoma. Methods of the invention further comprise administering anesthesia to the subject before applying the phacoemulsification ultrasound and the excimer laser. In some embodiments, methods of the invention further comprise post-operative analysis. For example, post-operative analysis comprises observing fluid flowing from Schlemm's canal in the eye.
Systems of the invention are used for treatment of a subject having one or more eye conditions. Systems of the invention are used to treat cataracts and preventatively treat glaucoma during the same surgical visit, thereby eliminating the need for multiple surgeries to treat the two conditions. By preventatively treating glaucoma, irreversible vision loss from glaucoma may be avoided. Systems include a phacoemulsification ultrasound system comprising an ultrasound probe for treating a cataract in an eye of a subject, and an excimer laser system comprising an excimer laser and a fiber probe for increasing blood flow to the eye of the subject. In some examples, increasing blood flow to the eye prophylactically treats glaucoma in the subject.
Moreover, methods of the invention provide treatment for both conditions and can decrease the amount of, or eliminate the need for, medications to manage the eye conditions. In an example, cataract medication is eliminated because phaco is effective in reversing vision loss due to cataracts. In an example, the IOP is lowered by the ELT procedure, and medication to treat glaucoma is reduced or eliminated because eye drops that lower IOP by decreasing the amount of fluid produced or increasing fluid flow output are unnecessary.
In an embodiment, a physician uses systems of the invention to perform phaco for the treatment of cataracts and ELT for the preventative treatment of glaucoma. An interactive user interface displays patient information, machine settings, and procedure information. The physician uses different instruments and probes depending on the treatment procedure. For example, the physician uses an ultrasonic handheld probe for phaco and a fiberoptic probe for ELT. The fiber probe comprises an optical fiber having a tip. In some embodiments, the tip comprises the optical fiber jacketed in stainless steel. In some cases, the tip is beveled. In certain embodiments, the fiber probe is disposable.
The physician is able to keep both hands free for use with the respective probes and other instruments during the procedure by using a foot pedal as the power source for each procedure. In some embodiments, the phacoemulsification ultrasound system further comprises a foot pedal to power application of ultrasound, irrigation, and aspiration to remove the cataract from the eye of the subject. In some embodiments, the excimer laser system further comprises a foot pedal to power the excimer laser and deliver a shot from the excimer laser to the eye of the subject. For example, the foot pedal is used by the physician to provide power to the fiber used for ELT, such as by providing laser shots.
Other instruments used by the physician include a goniolens, a chipping tool, and an irrigator. The user interface provides any suitable information. For instance, the user interface provides settings of the machine, such as number of laser shots administered with each tap of the foot pedal. The user interface displays patient information or procedure information.
In some embodiments, the patient is administered an anesthetic before surgery. In some examples, the anesthesia is topical. In some examples, the anesthesia comprises anesthetic drops. In some instances, general anesthesia is administered to the patient. In an example, the eye is anesthetized first with eye drops and then an injection of anesthetic is administered around the eye to prevent pain and excessive eye movement during surgery.
A method of treating a subject having one or more eye conditions comprises applying phacoemulsification ultrasound to a subject having one or more eye conditions; and applying an excimer laser to the subject to preventatively treat glaucoma. A system for treatment of one or more eye conditions in a subject comprises a phacoemulsification ultrasound system and an excimer laser system. Methods and systems of the invention prophylactically treat glaucoma in the subject. The phaco system comprises an ultrasound probe for treating cataracts in the subject. The excimer laser system comprises an excimer laser and a fiber probe that applies pulsed shots of energy from the excimer laser to the eye.
The invention provides methods and systems for treatment of both cataracts and glaucoma during one surgical procedure. Methods of the invention treat a subject having cataracts and glaucoma with phacoemulsification (phaco) and excimer laser trabeculostomy (ELT). Phaco removes the cataract and inserts a clear replacement lens. ELT increases the flow of aqueous humor in the eye by perforating the trabecular meshwork with a laser. Phaco and ELT are administered during the same surgical visit, thereby minimizing the amount of surgeries for a patient having multiple eye conditions. Because phaco and ELT are less invasive than traditional surgeries, the amount of recovery time for the patient is minimized. In fact, both phaco and ELT are performed through one small incision that is made in the eye.
In some cases, the invention provides methods of treating a diagnosed eye condition and prophylactically treating a second eye condition during the same procedure. For example, a patient may be diagnosed with cataracts and require phaco surgery. Because certain of those patients with cataracts have a congenital risk of developing glaucoma, methods of the invention administer prophylactic ELT treatment during the same surgical procedure as phaco treatment. The ELT provides treatment of glaucoma increased outflow of aqueous humor on the eye. Thus, the patient diagnosed with cataracts will receive treatment for both eye conditions—cataracts and glaucoma—during the same surgical procedure.
A patient having one or more eye conditions is prepared for surgery. The method includes 120 administering anesthesia to the patient. Topical anesthesia is most commonly employed, typically by the instillation of a local anesthetic such as tetracaine or lidocaine. Alternatively, lidocaine and/or longer-acting bupivacaine anesthetic may be injected into the area surrounding (peribulbar block) or behind (retrobulbar block) the eye muscle cone to more fully immobilize the extraocular muscles and minimize pain sensation. A facial nerve block using lidocaine and bupivacaine may occasionally be performed to reduce lid squeezing. General anesthesia is recommended for children, traumatic eye injuries with cataract, for very apprehensive or uncooperative patients and animals. Cardiovascular monitoring is preferable in local anesthesia and is mandatory in the setting of general anesthesia. Proper sterile precautions are taken to prepare the area for surgery, including use of antiseptics like povidone-iodine. Sterile drapes, gowns and gloves are employed. A plastic sheet with a receptacle helps collect the fluids during phacoemulsification. An eye speculum is inserted to keep the eyelids open.
A physician 130 makes a small incision on the eye of the patient. Before the phacoemulsification or ELT procedures can be performed, a small incision is made in the eye to allow the introduction of surgical instruments. Through the small incision, treatment procedures are administered during one surgical procedure.
The procedure includes 140 applying phacoemulsification (phaco) treatment to the patient. Phacoemulsification is a modern cataract surgery in which the eye's internal lens is emulsified with an ultrasonic handpiece and aspirated from the eye. The physician removes the anterior face of the capsule that contains the lens inside the eye. The probe used during phaco is an ultrasonic handpiece with a titanium or steel needle. The tip of the needle vibrates at ultrasonic frequency and is used to sculpt and emulsify the cataract. A pump aspirates particles through the tip of the ultrasonic handpiece. In some techniques, a second fine steel instrument called a “chopper” is used from a side port to help with chopping the nucleus into smaller pieces. The cataract is usually broken into two or four pieces and each piece is emulsified and aspirated out with suction. The nucleus emulsification makes it easier to aspirate the particles. After removing all hard central lens nucleus with phacoemulsification, the softer outer lens cortex is removed with suction only.
An irrigation-aspiration probe or a bimanual system is used to aspirate out the remaining peripheral cortical matter, while leaving the posterior capsule intact. An intraocular lens implant (IOL), is placed into the remaining lens capsule. In some examples, the implant is a poly(methyl methacrylate) (PMMA) IOL, and the incision has to be enlarged. In some examples, the implant is a foldable IOL made of silicone or acrylic and is folded either using a holder, folder, or insertion device provided with the IOL. The IOL is inserted and placed in the posterior chamber in the capsular bag for in-the-bag implantations.
The procedure includes 150 applying excimer laser trabeculostomy (ELT) treatment to the patient. In the invention, ELT and cataract surgery are performed through the same corneal incision. In some examples, a physician creates about 10 ELT sites in an eye of the patient after completing phacoemulsification in that eye.
The obstruction of aqueous outflow at the trabecular meshwork and inner wall of Schlemm's canal is the primary cause of elevated TOP in open-angle glaucoma (OAG). The invention uses excimer laser to perforate the Schlemm's canal. Other lasers, such as ruby and argon lasers, cannot achieve a permanent perforation of the trabecular meshwork to create an internal, rather than external, outflow channel. Though the photothermal and photodisruptive lasers were initially successful in puncturing the meshwork, the effect was short-lived due to inflammatory and healing responses. Excimer laser trabeculostomy (ELT) reestablishes the natural aqueous outflow of the eye without inciting a healing response at the target tissue.
Ablation with excimer lasers causes almost no thermal damage, therefore minimizing inflammation and the formation of scar tissue. A 308-nm xenon-chloride ultraviolet excimer laser causes minimal thermal damage compared with visible or infrared lasers. Unlike argon and selective laser trabeculoplasty, ELT precisely excises tissue without causing thermal injury or scarring the surrounding tissue. ELT treatment thus creates a long-term opening that connects the anterior chamber of the eye directly to Schlemm's canal. To avoid the corneal absorption of laser radiation, an optical fiber is used to deliver the energy. The fiber probe, or fiberoptic probe, is advanced through the incision and across the anterior chamber of the eye to contact the trabecular meshwork. A goniscope or endoscope may be used by the physician to visualize placement of the fiber probe.
The physician applies pulsed photoablative energy. Typically, the physician creates 10 sites in one or two inferior quadrants. A small amount of bloody reflux from Schlemm's canal confirms each opening. The fiber probe is removed from the eye. Notably, the TOP decreases immediately after administering the ELT procedure. Topical antibiotics and steroid drops are used by the patient for 1 to 2 weeks post-operatively.
After applying phaco and ELT treatments, a physician 160 closes the incision. Secure closure of the incision is necessary to prevent endophthalmitis. Typically, a physician uses sutures to close the incision. Some physicians place a suture in the incision and other physicians reserve a suture for when there is persistent leakage. The number of sutures required also depends on the type of IOL implanted during the phaco procedure. For example, a foldable IOL requires few or no sutures because the foldable IOL may be inserted through an incision that is smaller than required for insertion of a PPMA IOL.
Methods of the invention include 170 analyzing post-operative results and 180 reporting results and scheduling post-operative follow-up with the patient after surgery. For example, the physician's analysis may include observing a small amount of bloody reflux from Schlemm's canal to confirm each opening. In turn, the physician may report the results to the patient, prescribe post-operative medication, such as topical antibiotics and steroid drops, and schedule a follow-up post-operative visit with the patient.
A processor generally includes a chip, such as a single core or multi-core chip, to provide a central processing unit (CPU). A processor may be provided by a chip from Intel or AMD.
Memory can include one or more machine-readable devices on which is stored one or more sets of instructions (e.g., software) which, when executed by the processor(s) of any one of the disclosed computers can accomplish some or all of the methodologies or functions described herein. A computer of the invention will generally include one or more I/O device such as, for example, one or more of a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device (e.g., a keyboard), a cursor control device (e.g., a mouse), a disk drive unit, a signal generation device (e.g., a speaker), a touchscreen, an accelerometer, a microphone, a cellular radio frequency antenna, and a network interface device, which can be, for example, a network interface card (NIC), Wi-Fi card, or cellular modem. The system 200 may be used to perform methods described herein. Instructions for any method step may be stored in memory and a processor may execute those instructions.
In an embodiment, the foot pedal is used for the phaco procedure. In the first position, the phaco foot pedal provides irrigation only. In the second position, the phaco foot pedal provides irrigation and aspiration. In the third position, the phaco foot pedal provides irrigation, aspiration, and phaco power.
In an embodiment, the foot pedal is used for the ELT procedure. Each depression of the foot pedal may result in one shot from the laser. For example, when the foot pedal is depressed to the first position, as shown in
The eye further includes a trabecular meshwork 2140, which is a narrow band of spongy tissue that encircles the iris 2120 within the eye. The trabecular meshwork has a variable shape and is microscopic in size. It is of a triangular cross-section and of varying thickness in the range of 100-200 microns. It is made up of different fibrous layers having micron-sized pores forming fluid pathways for the egress of aqueous humor. The trabecular meshwork 2140 has been measured to about a thickness of about 100 microns at its anterior edge, known as Schwalbe's line, which is at the approximate juncture of the cornea and sclera.
The trabecular meshwork widens to about 200 microns at its base where it and iris 2120 attach to the scleral spur. The passageways through the pores in trabecular meshwork 2140 lead through very thin, porous tissue called the juxtacanalicular trabecular meshwork that abuts the interior side of a structure called Schlemm's canal 2150. Schlemm's canal 2150 is filled with a mixture of aqueous humor and blood components and branches off into collector channels which drain the aqueous humor into the venous system. Because aqueous humor is constantly produced by the eye, any obstruction in the trabecular meshwork, the juxtacanalicular trabecular meshwork or in Schlemm's canal prevents the aqueous humor from readily escaping from the anterior eye chamber which results in an elevation of intraocular pressure within the eye.
The eye has a drainage system for the draining aqueous humor. The aqueous humor flows from a posterior chamber behind the lens 2110 through the pupil into the anterior chamber 2135 to the trabecular meshwork 2140 and into Schlemm's canal 2150 to collector channels and then to aqueous veins. The obstruction of the aqueous humor outflow which occurs in most open angle glaucoma (i.e., glaucoma characterized by gonioscopically readily visible trabecular meshwork) typically is localized to the region of the juxtacanalicular trabecular meshwork located between the trabecular meshwork 2140 and Schlemm's canal 2150, more specifically, the inner wall of Schlemm's canal. When an obstruction develops, such as at the juxtacanalicular trabecular meshwork or at Schlemm's canal, intraocular pressure gradually increases over time, leading to damage and atrophy of the optic nerve, subsequent visual field disturbances, and eventual blindness if left untreated.
A laser probe according to the invention is used to treat glaucoma. The delivery tip of the laser probe 2160 is guided through a small incision, typically about ⅛ inch or smaller, in the cornea 2125 of the eye and across the anterior chamber 2135 to a position transverse to the Schlemm's canal 2150. The probe is guided very flat through the anterior chamber to avoid perforating the cornea in the visual field. The laser probe is coupled to a laser source and transmits laser energy from the laser source to the trabecular meshwork 2140 and Schlemm's canal 2150, resulting in photoablation of tissue including at least the trabecular meshwork 2140 and, in some instances, the Schlemm's canal 2150. The photoablation from the laser energy creates perforations in the meshwork and Schlemm's canal, thereby improving fluid drainage into the Schlemm's canal 2150 and reducing intraocular pressure in the eye.
References and citations to other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been made throughout this disclosure. All such documents are hereby incorporated herein by reference in their entirety for all purposes.
While the present invention has been described in conjunction with certain embodiments, one of ordinary skill, after reading the foregoing specification, will be able to effect various changes, substitutions of equivalents, and other alterations to the compositions and methods set forth herein.
This application is a continuation patent application of U.S. application Ser. No. 16/389,404, filed Apr. 19, 2019, the entire contents of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16389404 | Apr 2019 | US |
| Child | 17842933 | US |
