Patent Application
20150057524
The present disclosure relates to systems and methods for intra-operative eye refractive measurement, and more particularly, to systems and methods using a smart intraocular pressure valve and tonometer for intra-operative eye refractive measurement.
Typical phacoemulsification surgical procedures include pre-surgical optical analysis of the eye. The pre-surgical analysis includes measurement of tissue and anatomical features when the eye is whole and eye pressure is at a natural or normal level. Based on the pre-surgical analysis, a surgical plan is created. The surgical plan takes into account the tissue and the size of different anatomical features of the eye. In addition, based on this, the refractive power of a replacement lens is also selected. However, during the surgical procedure, where tissue is removed and manipulated, the size of the different anatomical features may change, which may affect the fit of the earlier-selected replacement lens. Current state-of-the art cataract surgery relies on semi-empirical IOL formulae to prescribe refractive power of an IOL based on a patient's pre-op biometry data. The surgeon is often left with the difficult task of prescribing a single IOL refractive power based on differing IOL formulae answers. For the best surgical outcome, the surgeon must often make choices based on past experience, interpretation of various biometry measurements, data clustering, and trending for example.
In addition, since the surgical procedure typically occurs when the eye is at an elevated intra ocular pressure or IOP, any intraoperative measurements without normalizing IOP do not correspond to the size of the anatomical features as they will be when the eye is in its normal or natural state.
The present disclosure addresses one or more deficiencies in the prior art.
In an exemplary aspect, the present disclosure is directed to a system for capturing intraoperative biometry and/or refractive measurements. The system includes a sensor associated with the eye and configured to detect a pressure of the eye. The system also includes an intra-op diagnostics device including a control unit arranged to actuate the intra-op diagnostics device to capture the intraoperative biometry and/or refractive measurements when the sensor detects pressure within a pressure range.
In an aspect, the system also includes a plug, with the sensor being carried on the plug. The plug may be sized for implantation within the eye of the patient during the surgical procedure. In an aspect, the plug comprises a first transmission module in communication with the sensor, and the intra-op diagnostics device comprises a second transmission module in communication with the control unit. The first transmission module may be in communication with the second transmission module. The control unit may capture the intraoperative biometry and/or refractive measurements when the communication from the first transmission module indicates that the pressure is within the pressure range.
In an aspect, the plug comprises a valve configured to open and close to increase and decrease drainage from the eye to affect the pressure in the eye. In an aspect, the valve is configured to close when the pressure in the eye reaches the pressure threshold. In an aspect, the pressure threshold is defined in terms of IOP.
In an exemplary aspect, the present disclosure is directed to a method of capturing intraoperative biometry and/or refractive measurements. The method includes starting a surgical procedure in an eye, detecting pressure of the eye, intraoperatively capturing biometry and/or refractive measurements when the detected pressure of the eye is within a preset pressure range, and using the captured information during a portion of the remainder of the surgical procedure, and completing the surgical procedure.
In another exemplary aspect, the present disclosure is directed to a method of capturing intraoperative biometry and/or refractive measurements that includes receiving information relating to a pressure of an eye during a surgical procedure in the eye, comparing the information relating to the pressure to a pre-established threshold when the information is below the pressure threshold, capturing biometry and/or refractive measurements of the eye with an intra-op diagnostics device, and communicating information relating to the measurements to a health care provider.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory in nature and are intended to provide an understanding of the present disclosure without limiting the scope of the present disclosure. In that regard, additional aspects, features, and advantages of the present disclosure will be apparent to one skilled in the art from the following detailed description.
The accompanying drawings illustrate embodiments of the devices and methods disclosed herein and together with the description, serve to explain the principles of the present disclosure.
For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is intended. Any alterations and further modifications to the described devices, instruments, methods, and any further application of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one embodiment may be combined with the features, components, and/or steps described with respect to other embodiments of the present disclosure. For the sake of brevity, however, the numerous iterations of these combinations will not be described separately. For simplicity, in some instances the same reference numbers are used throughout the drawings to refer to the same or like parts.
The present disclosure relates generally to systems and methods for intraoperative biometry and/or refractive measurement in cataract surgery and phakic IOL implantation. Intra-op diagnostics may be used to perform actual refractive measurements on an aphakic eye. Such diagnostics were previously not possible to perform due to refractive distortions, introduced by cataract. Here however, intra-op diagnostics rely on direct refractive measurements rather than biometric measurements and complex IOL formulae that predict refractive error. During typical ocular surgical procedures, the eye is maintained at an elevated pressure or IOP in order to ensure that there is no collapse at the eye. Accordingly, during the procedure, or shortly thereafter, the pressure or IOP is permitted to decrease to a more natural or stabilized level. In some aspects, this may be around 30 mmHg or lower. Some systems and methods described herein include using a valve opened to allow pressure or IOP to gradually decrease. The valve may close when the pressure or IOP reaches a natural or desired level. At this time, the surgeon may capture biometry and/or refractive measurements using an intra-op diagnostics device. Since the measurements are taken when the pressure or IOP is close to the natural or desired level, the measurements reflect the size of the eye when it is in its natural condition, instead of its inflated or stretched condition. As such, when a lens is later selected and implanted, it fits properly when the eye is in its natural state having a natural pressure or IOP.
Other embodiments described herein include valves or sensors that control pressure or IOP to match the eye's natural or desired state while capturing biometry and/or refractive measurements. The system may capture biometry and/or refractive measurements at a particular instant in time as the pressure or IOP reaches the natural or desired pressure or IOP or may capture it over a period of time. Some embodiments capture pressure or IOP measurements automatically, thus streamlining procedures and improving precision of adjustments.
The intra-op diagnostics device 102 includes a camera 106, a lens 108, a scanning laser generator 110, reflective units 112, and a control unit 114. The camera 106, the lens 108, the scanning laser generator 110, and the reflective units 112 are conventional and are not described further. The OCT device forming a part of the intra-op diagnostics device 102 is conventional and is not described further. Depending upon the embodiment, the control unit 114 may be specifically configured to cooperate with the plug 104 to control the pressure or IOP within the eye. The control unit 114 typically includes a processor and memory, with the processor being, for example only, an integrated circuit with power, input, and output pins capable of performing logic functions, or a controller that controls different components that perform different functions. To perform OCT functions, the control unit 114 also may include an optical fiber interferometer and high-speed analog to digital converter. The memory may be a semiconductor memory that interfaces with the processor. In one example, the processor can write to and read from the memory. For example, the processor can be configured to read data from the plug 104 and write that data to the memory. In this manner, a series of sensed or calculated pressure or IOP readings can be stored in the memory. The processor is also capable of performing other basic memory functions, such as erasing or overwriting the memory, detecting when the memory is full, and other common functions associated with managing semiconductor memory.
Some embodiments of the control unit 114 include a data transmission module 116 employing any of a number of different types of data transmission. For example, data transmission module 116 may be an active device such as a radio. Data transmission module 116 may also be a passive device such as an antenna and receiver.
The data transmission module 116 may communicate with the plug 104 and may pass signals representing information received from the plug 104 to the control unit 114 for processing. In some embodiments, the transmission module 116 comprises a receiver that receives wireless signals form the plug 104 representing, for example, information relating to the state of the plug 104 or pressure data relating to the actual measured pressure or IOP of the eye. In other embodiments, the transmission module 116 includes both a receiver and a transmitter for communicating with the plug 104. Depending on the embodiment, the data transmission module 116 and the plug 104 are configured for wired communication or wireless communication, and may communicate over Wi-Fi, Bluetooth, wireless local area network (WLAN), or wireless personal area networks (WPAN).
The plug 104 is configured to be associated with the eye and may be used to detect pressures or control the rate of drainage from the eye intraoperatively or at the conclusion of a surgical procedure. Detected pressures may be communicated to the control unit 114. Drainage control may be performed based upon signals from the control unit 114.
Typically, phacoemulsification surgery results in two small incisions being made into the eye. The larger of these receives the phacoemulsification handpiece tip to perform the phacoemulsification procedure. The smaller of these receives an assistance instrument, for example, a pick to move cataract pieces toward phaco tip, for example. As indicated previously, pressure or IOP is typically elevated during the surgical process in order to reduce a chance that the eye may collapse during the procedure. Therefore, when the surgical process ceases, the drainage from one or both of the incisions gradually decreases the pressure or IOP from its elevated surgical state toward the more natural normal state. With the incisions open, the pressure will fall below the natural or normal pressure or IOP level. Self-sealing structured incisions may reduce this occurrence, but some leakage may still occur at elevated IOP.
The plug 104 is sized and arranged to fit within one of the incisions and may operate as a restriction in the incision that reduces or inhibits drainage. Accordingly, intraoperatively, the phacoemulsification handpiece or the irrigation tube may be withdrawn, and the plug 104 may be inserted into the incision so that intraoperative biometry and/or refractive measurements may be obtained.
The plug 104 may comprise a pressure sensor and/or a flow control element, such as a valve. In embodiments employing a valve, the valve may comprise a passive valve, a pressure driven valve, an electronically controlled valve or other type of valve and may affect flow of fluid from the eye after a portion of the surgical procedure. It may include any number of valves and valve types in combination. Some embodiments also include one or more pumping systems that cooperate with one or more valves to maintain pressure or IOP stability. As will be described below, the valve 104 may operate under the control of the control unit 114 and may receive instructions from the control unit 114 to permit increased flow of fluid from the anterior chamber or to decrease flow to meet a desired flow rate and pressure.
Embodiments including the controller 154 may be used to actively control the valve 152. Accordingly, in such embodiment, the valve 152 may be an active valve, such as an actuatable valve that may be controlled by signals from the controller 154. In some embodiments, the actuatable valve 152 may operate under the control of the controller 154. The valve 152 in this embodiment may comprise, for example, a microelectrical mechanical systems (MEMS) valve, a linear motor valve, a piezoelectric valve, an electromagnetic valve, a pneumatic piston valve, a diaphragm valve, electrical solenoid valve, or other such valve.
The controller 154 may be in communication with the control unit 114 via the transmission module 156. The transmission module 156 may be similar to the transmission module 122. The controller 154 may be constructed as the control unit 114 described above, may be a circuit, a PID controller, or some other type of controller arranged and configured to calculate the IOP from the pressures detected by the sensor or sensors 158. The sensor 158 may be similar to the sensor described above and is arranged to detect the pressure within the eye. In some embodiments, the pressure sensor 158 comprises multiple pressure sensors, including an atmospheric pressure sensor that enables calculation of IOP based off the pressure readings.
Turning now to
When the plug 150 includes only a mechanical valve, the valve 152 may be arranged to be open when the eye pressure exceeds a target or desired pressure. The valve 152 may include an indicator, whether visual or audible, that identifies when the valve changes from an open state to a closed state. When the valve changes states indicating that the IOP has reached a target pressure or passes through a target range surrounding a target pressure, the surgeon may control the intra-op diagnostics device 102 to take biometry and/or refractive measurements. In
When the plug 150 includes the active valve 152, the valve 152 may be open when the eye pressure exceeds a target or desired pressure and may be controlled to close when the pressure reaches a desired or target range. This may include detecting the pressure of the eye with the sensor 158, and based upon the sensed pressure, using the controller 154 to open and close the valve 152. When the valve 152 closes, as may be understood by a visual or audible indicator on the plug 150 itself, the surgeon may operate the intra-op diagnostics device 102 to capture biometry and/or refractive measurements. Since additional drainage may lower the IOP beyond the desired normal pressure, the surgeon may operate the intra-op diagnostics device 102 to capture the measurements within a preset time period after the valve closes. For example, the surgeon may operate to capture with measurements within about 30 seconds or less of the valve 152 closing. Accordingly, again with reference to
When the plug 150 includes the active valve 152, the controller 154, and the transmission module 156, information relating to the state of the eye or the state of the valve 154 may be transmitted to the intra-op diagnostics device 102. The intra-op diagnostics device 102 may then capture the intraoperative or post-operative measurements at the proper time. This may reduce the need for the surgeon to visually observe the valve 152 to determine its state. Accordingly, again with reference to
With reference to
At a step 304, the surgeon may insert the handpiece with attached irrigation tubing in the eye according to standard surgical procedures. With the instruments in the eye, at a step 306, the surgeon begins emulsifying the lens or the cataracts to prepare the eye for an implantable intraocular lens.
At a step 308, the surgeon may pause the surgical procure to take intraoperative biometry and/or refractive measurements in the eye. In some aspects, this may include removing the tubing from the eye and replacing it with a plug as described herein that may be capable of either passive or active measurement of the eye. As described with reference to the various embodiments herein, the plug may communicate with the control unit 114 of the intra-op diagnostics device 102. In some embodiments, at a step 310, the control unit or other controller may convert the measured pressure to IOP in order to provide a more accurate indication of the state of the eye at a particular time. This may aid when measuring the eye to provide a lens of proper fit. Converting the measured pressure to IOP may include detecting the atmospheric pressure and calculating the IOP based on both the atmospheric pressure and the measured pressure since IOP is a function of both atmospheric and eye pressure. While described as replacing the irrigation tube with the plug, in some aspects, the plug is placed in a separate incision. In such aspects, the fluidics of the phacoemulsification system can be used to deliver a fluid, such as a saline solution to the eye, through an irrigating/aspirating handpiece or infusion cannula inserted in one of incisions in the eye.
Since most surgeries are performed with the eye at an elevated IOP, in order to reduce any chance of collapse during the surgical procedure, it may be necessary to wait while the pressure gradually decreases due to leaking fluid during the paused surgical procedure. As the pressure decreases, the plug may be configured to communicate in real time the detected pressure so that the control unit 114 maintains a real-time indication of the pressure. When IOP is maintained by a phaco surgical console through the infusion cannula and tubing connecting the eye to fluidics system of the surgical console—a surgeon may merely request an appropriate or desired IOP value through a console interface and the console will maintain the IOP at this value.
At a step 310, the control unit 114 may monitor the pressure or IOP until it reaches a pre-established target threshold. The target threshold may be a value or range set to correspond with the normal or natural pressure or IOP for the patient determined in pre-surgical measurements. In other embodiments, the target threshold may be set to correspond with a particular pressure or range that may or may not be unique to the individual's normal pressure. In other embodiments, the control unit 114 does not monitor the target threshold, but the plug provides a visual indication when the target threshold is reached.
At a step 312, when the target pressure is reached, the intra-op diagnostics device 102 may be activated to capture intraoperative biometry and/or refractive measurements. This may be accomplished automatically when the control unit 114 detects that the threshold has been reached, or may accomplished manually when the surgeon receives an indication that the threshold has been reached and then activates the intra-op diagnostics device 102. This indication may be a visual indication, an audible indication, or a tactile indication, for example. The intra-op diagnostics device may take a single measurement or may take multiple measurements over a period of time. In some embodiments, the measurements may be averaged. As described above, in some instances, the measurements may take place for a specific time period. In other embodiments, the pressure may be monitored until the pressure falls below the desired target. In other embodiments, the control unit 114 is programmed to take a designated number of measurements, such as two, three, or four measurements, for example. The example shown in
Based on the measurements, the surgeon may select a lens for implantation, at a step 314. The selected lens may have refractive power to best fit the eye refractive properties when the eye is at a normal pressure or IOP. At a step 316, the surgeon may implant the lens in a manner known in the art. This may include removing the plug and restoring the instruments for the surgical procedure. Some embodiments will not require removal of the plug, for example, where the infusion cannula 222 is employed. In some instances, the infusion cannula 222 may be left in place through the surgical procedure. At a step 318, when the implantation process is complete, some surgeons may once again take intraoperative biometry and/or refractive measurements. This may be done to ensure that the lens fits properly and the tissue is disposed as desired after the surgery.
At a step 404, the control unit 114 receives information relating to a pressure of an eye during a surgical procedure. Many of the details of the method are described throughout and not all variations are repeated here. As described above, this may be communicated from a plug, the surgical console, the handpiece, or the infusion cannula for example. In addition, these may sent over wire or wireless connection. At a step 406, the control unit 114 compares the information relating to the pressure to the threshold pressure. To do this, the control unit 114 may compare the actual pressure or may compare the IOP, which is a function of the pressure. To obtain the IOP, the system may also measure atmospheric pressure and calculate the IOP based on measured pressure in the eye and based on the measured atmospheric pressure. Based on the comparison, the control unit 114 may control aspects of the system, including, for example, the valve of the plug or other aspects of the plug.
When the control unit 114 determines that the pressure (whether actual or IOP) is below the pressure threshold (whether actual or IOP), the control unit actuates the intra-op diagnostics device to capture biometry and/or refractive measurements of the eye at a step 408. As described above, this may be a single capture or may be a capture in succession over a length of time. In some embodiments, this may continue at regular intervals until the measured pressure falls below the pre-established threshold, which may include falling below a threshold range of pressures. At a step 410, the control unit 114 communicates information relating to the measurements to a health care provider. The health care provider may then make adjustments to the treatment plan, may select a lens sized to fit the eye based on the information, or may take other action.
Although described with the plug being inserted into the incision, other embodiments and other surgical methods include the plug being maintained separately through a separate perforation in the eye globe. In this embodiment, the irrigation tube and the handpiece may be maintained within the eye and the measurements may be captured with those elements within the eye.
The system and methods disclosed herein provide multiple advantages over prior systems and methods as set forth above. In addition, the systems and methods herein include integration of the pressure or IOP sensor/valve with an intra-operative biometry and/or refraction device via wireless communication, improved accuracy of intra-operative biometry through improved accuracy of IOP or pressure target point, decreased dependence on surgical skills due to automation of the procedure, and faster pressure or IOP measurement and adjustment then through manual adjustment and applanation pressure or IOP measurement. In addition, the systems and methods disclosed herein provide actual aqueous pressure measurement inside the eye instead of mechanical resistance of cornea measurement via applanation tonometer.
Persons of ordinary skill in the art will appreciate that the embodiments encompassed by the present disclosure are not limited to the particular exemplary embodiments described above. In that regard, although illustrative embodiments have been shown and described, a wide range of modification, change, and substitution is contemplated in the foregoing disclosure. It is understood that such variations may be made to the foregoing without departing from the scope of the present disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the present disclosure.
