System and method for nomogram-based refractive laser surgery

Abstract

To provide a system and a method for nomogram-based refractive laser surgery.SOLUTION: A memory medium is provided for storing instructions or sets of instructions executable by a processor so that the processor can: identify a surgical parameter; correct the surgical parameter based on a nomogram specific for the refractive laser surgery system to provide a nomogram-based corrected surgical parameter; store the surgical parameter and the nomogram-based corrected surgical parameter in the memory media as data for a patient or for one or both eyes of the patient; and compare the surgical parameter and nomogram-based corrected surgical parameter to generate a graphical representation of the surgical parameter, a target outcome parameter associated with the surgical parameter, or both, and the nomogram-based corrected surgical parameter, to generate a warning based on a comparison of the nomogram-based corrected surgical parameter to the surgical parameter or an absolute value, or both.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure provides systems and methods for nomogram-based refractive laser surgery that may be performed on a patient's eye. [Background technology]

[0002] When light enters the human eye, it passes through the clear cornea in front of the pupil and iris, then through the lens behind the inner pupil, and finally to the retina at the back of the inner eye. As a result of refractive errors, light may not be properly focused on the retina, which can result in myopia, hyperopia, or astigmatism, for example. Refractive errors can be due to aberrations in the cornea, the lens, or both, but these are often most easily corrected by modifying the cornea, due to its easily accessible location on the outer surface of the eye. Corneal modifications are often performed using refractive laser surgery. One example of refractive laser surgery is laser-assisted in situ keratomileusis (LASIK), during which surgeons use advanced surgical systems that include an excimer laser to ablate specific areas of the cornea in a way that corrects the refractive errors in the eye. Another example of refractive laser surgery is small incision lenticule extraction (SMILE), during which surgeons use advanced femtosecond laser surgery systems to photoablate a portion of the cornea to create a lenticule, which is then removed to reshape the cornea to correct the refractive error in the eye. Summary of the Invention [Means for solving the problem]

[0003] The present disclosure provides a refractive laser surgery system including a processor having access to a memory medium storing instructions or sets of instructions executable by the processor to identify surgical parameters, correct the surgical parameters based on a nomogram specific to the refractive laser surgery system, provide nomogram-based corrected surgical parameters, store the surgical parameters and the nomogram-based corrected surgical parameters in the memory medium as data for a patient or for one or both eyes of the patient, compare the surgical parameters and the nomogram-based corrected surgical parameters, generate a graphical representation of the surgical parameters, a target outcome parameter associated with the surgical parameters, or both, and the nomogram-based corrected surgical parameters, and generate an alert based on a comparison of the nomogram-based corrected surgical parameters to the surgical parameters or absolute values, or both.

[0004] The refractive laser surgery system may further include the following additional features, which may be combined with each other in any possible combination unless expressly mutually exclusive: i) A nomogram specific to a refractive laser surgery system may be generated using historical surgical parameter data for the refractive laser surgery system, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data. ii) The system may further include a user interface, and the instructions or set of instructions may be further executable by the processor to cause the user interface to display a graphical representation or communicate a warning to the user and accept input from the user confirming that the corrected surgical parameters based on the nomogram are correct to allow the refractive laser surgery to be performed using the refractive laser surgery system to proceed, or to accept input from the user confirming that the corrected surgical parameters based on the nomogram are incorrect to prevent the refractive laser surgery from proceeding. iii) the refractive laser surgery system may further include an excimer or femto laser, and the instructions or set of instructions may include for the processor to calculate, using the corrected surgical parameters based on the nomogram, an ablation profile or photoablative profile for the cornea of ​​the patient's eye, and storing the ablation profile or photoablative profile in a memory medium as data for the patient or for one or both eyes of the patient; It may be further executable to compare the ablation profile or photoablation profile to surgical parameters to determine whether refractive laser surgery on the cornea of ​​the eye can safely proceed using the ablation profile or photoablation profile, and if refractive laser surgery can safely proceed, instruct an excimer laser to ablate the cornea in accordance with the ablation profile or instruct a femto laser to photoablate the cornea in accordance with the photoablation profile. iv) the processor may further have access to a memory medium storing historical surgical parameter data for the refractive laser surgery system, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data, and the instructions or set of instructions may be executable by the processor to create a nomogram specific to the refractive laser surgery system based on all or a set of the historical surgical parameter data for the refractive laser surgery system, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data, and store the nomogram in the memory medium. v) the instructions or set of instructions include instructions for the processor to compare historical surgical parameter data, historical target outcome parameter data associated with the historical parameter data, and historical actual outcome parameter data for the refractive laser surgery system to determine whether systematic deviations occur between the historical target outcome parameters and the historical actual outcome parameters based on the historical surgical parameters; It may further be feasible to develop a nomogram to correct the surgical parameters if systematic deviations occur. vi) The instruction or set of instructions may be further executable by the processor to generate a new nomogram using additional historical data after a predetermined time interval has elapsed. vii) The system may further include a diagnostic device, and the instructions or set of instructions may be further executable by the processor to cause the diagnostic device to determine the surgical parameters, actual outcome parameters associated with the surgical parameters, or both. viii) The system may further include a communications interface, and the instructions or set of instructions may be further executable by the processor to obtain, via the communications interface, surgical parameters, actual outcome parameters associated with the surgical parameters, or both, from diagnostic equipment external to the refractive laser surgery system. ix) The nomogram may include a correction table, a set of instructions which, when executed by a processor, arrives at the same values ​​that would be obtained using the correction table, or a function that calculates the appropriate corrections.

[0005] The present disclosure further provides a method of performing refractive laser surgery on a cornea of ​​a patient's eye using a refractive laser surgery system including a processor and a memory medium having instructions or sets of instructions accessible and executable by the processor, the method including identifying surgical parameters, correcting the surgical parameters based on a nomogram specific to the refractive laser surgery system to provide the corrected surgical parameters, storing the surgical parameters and the corrected surgical parameters in the memory medium as data for the patient or for one or both eyes of the patient, comparing the surgical parameters and the corrected surgical parameters, generating graphical representations of the surgical parameters, target outcome parameters associated with the surgical parameters, or both, and the nomogram-based corrected surgical parameters, and generating an alert based on a comparison of the nomogram-based corrected surgical parameters to the surgical parameters or absolute values, or both.

[0006] The method may further comprise the following additional steps, which may be combined with each other in any possible combination unless expressly mutually exclusive: i) A nomogram specific to a refractive laser surgery system may be generated using historical surgical parameter data for the refractive laser surgery system, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data. ii) the method may further include causing a user interface of the refractive laser surgery system to display a graphical representation or communicate a warning to the user and accepting input from the user confirming that the corrected nomogram-based surgical parameters are correct to allow the refractive laser surgery to be performed using the refractive laser surgery system to proceed, or accepting input from the user confirming that the corrected nomogram-based surgical parameters are incorrect to prevent the refractive laser surgery from proceeding. iii) The method may further include calculating an ablation profile or photoablation profile for the cornea of ​​the patient's eye using the corrected surgical parameters based on the nomogram, and storing the ablation profile or photoablation profile in a memory medium as data for the patient, or for one or both eyes of the patient. iv) Comparing the ablation profile or photoablation profile to surgical parameters to determine whether refractive laser surgery on the cornea of ​​the eye can safely proceed using the ablation profile or photoablation profile. v) if the refractive laser surgery can safely proceed, instructing an excimer laser in the refractive laser surgery system to ablate the cornea according to the ablation profile or instructing a femto laser in the refractive laser surgery system to photoablate the cornea according to the photoablation profile. vi) The method may further include creating a nomogram specific to the refractive laser surgery system based on all or a set of historical surgical parameter data for the refractive laser surgery system stored in the memory medium, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data, and storing the nomogram in the memory medium. vii) the method may further include the steps of comparing historical surgical parameter data for the refractive laser surgery system, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data to determine whether a systematic deviation occurs between the historical target outcome parameters and the historical actual outcome parameters based on the surgical parameters, and creating a nomogram for correcting the surgical parameters if a systematic deviation occurs. viii) The method may further comprise the step of generating a new nomogram using additional historical data after a predetermined time interval has elapsed. ix) The method may further include determining, using diagnostic equipment of the refractive laser surgery system, the surgical parameters, actual outcome parameters associated with the surgical parameters, or both. x) The method may further include determining, using a diagnostic device external to the refractive laser surgery system, the surgical parameters, actual outcome parameters associated with the surgical parameters, or both, and communicating the surgical parameters, actual outcome parameters associated with the surgical parameters, or both, from the diagnostic device to the refractive laser surgery system. xi) The nomogram may include a correction table, a set of instructions which when executed by a processor arrives at the same values ​​that would be obtained using the correction table, or a function which calculates the appropriate corrections.

[0007] The above systems and methods may be used in any combination with each other and with all other systems and methods disclosed herein, unless expressly mutually exclusive.

[0008] Although the above systems and methods, as well as other systems and methods disclosed herein, are described with respect to performing surgery for illustrative purposes, they may be readily adapted for use during planning of surgery with a refractive surgery system. Generally, during the planning stage, if an unacceptable outcome is encountered, rather than terminating the surgery, the surgical plan is modified to avoid the unacceptable outcome, or the surgery is simply not performed if the unacceptable outcome cannot be avoided.

[0009] For a better understanding of the present disclosure, and its features and advantages, reference is now made to the following description which should be read in conjunction with the accompanying drawings, in which like numerals represent like elements and in which: [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram of selected elements of a refractive laser surgery system. [Diagram 2] FIG. 2 is a flow chart of selected elements of a method for planning or performing refractive laser surgery using a nomogram. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present disclosure provides systems and methods for nomogram-based refractive laser surgery.

[0012] Ophthalmic surgeons often find that there are consistent deviations from the desired refractive laser surgery outcomes based on the particular refractive laser surgery system used. These deviations are specific to the particular refractive laser surgery system and often do not exhibit a common profile across different systems, even if similarly constructed and configured. Surgeons often collect data regarding these deviations and use it to develop a nomogram or set of nomograms for the particular refractive laser surgery system. The surgeon then references the nomogram for the particular refractive laser surgery system and uses it to correct the surgical parameters, e.g., preoperative measurements of the eye, so that the actual surgical outcomes, typically actual outcome parameters, more closely approximate the expected surgical outcomes, typically target outcome parameters.

[0013] For example, a surgeon may determine based on a nomogram that for a patient with an actual spherical power of -8.0 diopters (D), a corrected spherical error of -8.75D should be entered to achieve zero refractive error (emmetropic) after refractive surgery with a particular individual system. For a patient with an actual spherical error of 4.0D using the same system, if the actual spherical power is 4.0D, the corrected spherical error may still be 4.0D, i.e., no correction of surgical parameters is required. However, for a patient with astigmatism with a cylinder error of -2.0D, if this same patient has a spherical error of 4.0D, the surgeon's nomogram may indicate that a corrected spherical error of 4.25D should be entered to achieve a target surgical outcome of zero spherical error when operating with the same laser refractive surgery system.

[0014] Current procedures using nomograms have many drawbacks: conditions during preoperative examinations (e.g. visual acuity test, refraction measurement), during surgical procedures (e.g. microkeratome, flap handling, surgeon experience) and postoperative care are very complex, often leading to variations in the predictability of the treatment outcome, and inaccurate input of surgical parameters into the patient record of the laser surgery system with corrections based on nomograms.

[0015] Thus, the present disclosure provides a refractive laser surgery system that generates nomograms based on actual surgical parameters and actual outcome parameters associated with refractive laser surgeries performed on a particular refractive laser surgery system. The refractive laser surgery system may apply these nomograms to correct surgical parameters when instructed to do so by a user, and may optionally modify other surgical parameters based on the nomogram-corrected surgical parameters. The refractive laser surgery system may then save the actual surgical parameters along with any nomogram-corrected surgical parameters in a file with which they are associated, typically the patient file or a file corresponding to one eye of the patient. The refractive laser surgery system may also visually report deviations in the nomogram-corrected surgical parameters resulting from the nomogram-based correction, and provide warnings if the deviations exceed a certain percentage of the original parameters, exceed an absolute value, or both. Such a report may be provided prior to surgery after the surgical parameters have been entered into the system, or the apparent validity of the surgical parameters or corrected surgical parameters based on a nomogram may be automatically checked during entry of the surgical parameters, e.g., to prevent the entry of surgical parameters without apparent validity.

[0016] Such refractive laser surgery systems may also generate additional nomograms representing actual surgical outcomes obtained with a particular refractive laser surgery system that further corrects the surgical parameters based on other factors, such as the patient's age and how the eye measurements were obtained.

[0017] The laser surgery systems described herein may automatically apply the nomogram-based corrected surgical parameters, or may eliminate the possibility of user input errors whenever the nomogram-based corrected surgical parameters are used by a refractive laser surgery system, such a system may first require the user to accept future nomogram-based surgical parameters.

[0018] Additionally, such refractive laser surgery systems may self-update the nomograms for their respective systems, self-validate whether additional nomograms may be generated, or both. Such self-updating, self-validating, or both may occur in response to a user's command, or at specific time intervals, such as monthly, weekly, or daily, or even after each use of the refractive laser surgery system to perform a refractive laser surgery on a patient or on an eye. Self-updating and self-validating may be able to correct for any additional deviations from expected system operation over time. The system may require the user to accept any self-updated nomograms or any new nomograms generated during self-validation before they are implemented in a refractive laser surgery.

[0019] Accordingly, the present disclosure provides a refractive laser surgery system, such as refractive laser surgery system 100 of Figure 1. A refractive laser surgery system according to the present disclosure may, but need not, include all of the elements of Figure 1. A refractive laser surgery system may include any combination of some of the elements shown in Figure 1. In addition, a refractive laser surgery system may include additional elements not shown in Figure 1, including, for example, a femto laser, a patient bed, or diagnostic equipment in addition to an excimer laser.

[0020] The refractive laser surgery system 100 of Figure 1 is shown in block diagram form and includes a processor 110 that is connected to and has access to memory media, collectively identified as memory 130, via a shared bus 120. The refractive laser surgery system 100 further includes an excimer laser 160, as well as a communications interface 140 and a user interface 150. In an alternative embodiment not shown in Figure 1, the excimer laser 160 may be replaced by a femto laser.

[0021] Processor 110 may be operable to execute instructions or sets of instructions stored in memory 130 to perform steps of the refractive laser surgery described herein that are not directly performed by a user. For example, processor 110 may be operable to generate a nomogram, use the target outcome parameters and the nomogram to generate corrected surgical parameters based on the nomogram, use the corrected surgical parameters based on the nomogram to further modify other surgical parameters, calculate an ablation profile or photoablation profile, control corneal ablation with an excimer laser according to the ablation profile or control corneal photoablation with a femto laser according to the photoablation profile, access information stored in memory 130 via shared bus 120 or cause information to be stored in memory 130, and perform any combination of any of these functions.

[0022] The memory 130 may include persistent media, volatile media, or both, fixed media, removable media, or both, and magnetic media, semiconductor media, or both. The memory 130 is operable to store instructions, data, or both. The illustrated memory 130 includes a set or sequence of instructions, namely, an operating system 170, a nomogram calculator 180, and a nomogram-based correction calculator 190.

[0023] Operating system 170 may be a UNIX or UNIX-like operating system, the WINDOWS (Microsoft Corporation, Washington, US) family of operating systems, or any other suitable operating system.

[0024] Nomogram calculator 180 may perform any of the various methods and calculations described herein, optionally in combination with methods and calculations known in the prior art, to generate or update a nomogram specific to the individual refractive laser surgery system 100 and store such nomogram in memory 130.

[0025] The nomogram-based correction calculator 190 may perform any of the various methods and calculations described herein, optionally in combination with methods and calculations known in the prior art, to correct surgical parameters based on a nomogram or to change other surgical parameters based on the corrected surgical parameters based on a nomogram.

[0026] The nomogram-based correction calculator 190 may further perform any of the various methods and calculations described herein, optionally in combination with methods and calculations known in the prior art, to generate a comparison graph showing the surgical parameters and the surgical parameters after correction based on the nomogram.

[0027] The nomogram-based correction calculator 190 may further perform any of the various methods and calculations described herein, optionally in combination with methods and calculations known in the prior art, to compare the nomogram-based corrected surgical parameters with the original surgical parameters or with predetermined absolute values, and generate a warning regarding the nomogram-based corrected surgical parameters.

[0028] The nomogram-based correction calculator 190 may also perform any of the various methods and calculations described herein, optionally in combination with methods and calculations known in the prior art, and display or communicate to the user information regarding a comparison between the surgical parameters and the nomogram-based corrected surgical parameters, the absolute value of the nomogram-based corrected surgical parameters, or any warnings.

[0029] The memory 130 may also include sets or sequences of instructions in the form of a patient data resource (not shown). The patient data resource may store patient data, including surgical parameter and outcome parameter data, for the patient or for one or both eyes of the patient. The patient data resource may also perform any of the methods and calculations described herein, optionally in combination with methods and calculations known in the prior art, to store information regarding surgical parameters and nomogram-based corrected surgical parameters, and to otherwise use, update, and store patient data.

[0030] The memory 130 may further include a set or sequence of instructions in the form of an ablation tool or photodissection tool (not shown). The ablation tool or photodissection tool may perform any of the methods and calculations described herein, optionally in combination with methods and calculations known in the prior art, to generate an ablation profile or photodissection profile using the corrected surgical parameters based on the nomogram. The ablation tool or photodissection tool may further perform any of the methods and calculations described herein, optionally in combination with methods and calculations known in the prior art, to control the excimer laser 160 to ablate the cornea according to the ablation profile or control the femto laser to photodissect the cornea according to the photodissection shape.

[0031] The communications interface 140 may be connected to the processor 110, the memory 130, or both via a shared bus 120. The communications interface 140 may be operable to allow the refractive laser surgery system 100 to connect to a network (not shown in FIG. 1 ) or to other equipment, such as diagnostic equipment, particularly wavefront measuring equipment.

[0032] The user interface 150 may be coupled to the processor 110, the memory 130, or both via the shared bus 120. The user interface 150 may be operable to accept commands from a user and display information to the user. The commands may be entered via a keyboard, mouse, touchpad, microphone, voice recognition interface, foot pedals, or other input devices that may be part of the user interface 150. The information may be displayed on one or more screens, a heads-up display, or using other display devices that may be part of the user interface 150. The user interface 150 may further be operable to communicate information, such as alerts, to the user using other devices, such as speakers, lights, or buzzers, that may also be part of the user interface 150.

[0033] The excimer laser 160 or femto laser may be coupled to the processor 110, the memory 130, or both via the shared bus 120. The excimer laser 160 may be operable to ablate a portion of the cornea according to an ablation profile to correct refractive error in the eye. The femto laser may be operable to photoablate a portion of the cornea according to a photoablation profile to correct refractive error in the eye.

[0034] The present disclosure further provides a method of performing refractive laser surgery, such as the refractive laser surgery method 200 of FIG. 2. The refractive laser surgery system 100 described above may perform all or some of the steps of the method that are not performed by a user. The method may be performed by a user controlling the refractive laser surgery system, such as the refractive laser surgery system 100. A refractive laser surgery method according to the present disclosure may, but need not, include all of the steps of FIG. 2. A refractive laser surgery method may include any combination of some of the steps shown in FIG. 2, so long as the steps are performed in a useful order. Certain steps or combinations of steps, such as generating a nomogram and correcting surgical parameters based on the nomogram, may all be performed by the laser surgery system and do not require user input other than an optional start command. In addition, any of the refractive laser surgery methods may include additional steps not shown in FIG. 2, including, for example, forming a flap in the cornea using a femtosecond laser prior to corneal ablation with an excimer laser, or removing the lenticule after photoablation with the femtosecond laser.

[0035] All steps of the refractive laser surgery methods described herein may be performed with any application of the refractive laser surgery systems described herein.

[0036] In the refractive laser surgery method 200, at step 205, surgical and outcome parameters are identified.

[0037] The surgical parameters may be measured characteristics of the eye on which the surgery is performed, such as the spherical power or, in the case of an astigmatic patient, the cylindrical power and the position of the cylindrical axis; physical facts about the patient, such as age or medical history or previous corneal surgery; settings of the refractive laser surgery system, such as the type of refractive surgery selected; other surgical steps and equipment, such as whether a microkeratome or femtosecond laser is used to create the corneal flap; or surgical environmental conditions, such as the temperature or time of day in the operating room.

[0038] An outcome parameter is a measurement of an ocular characteristic as a surgical outcome after a refractive laser surgery is performed. For example, the outcome parameter may be the optical zone, the spherical power, or, for an astigmatism patient, the cylindrical power and the position of the cylindrical lens axis. The outcome parameter has a target outcome parameter value, which is a value used with the refractive laser surgery machine's instructions or instruction set to determine how to perform the refractive laser surgery. The outcome parameter also has an actual outcome parameter value, which is a value measured in the eye after the refractive laser surgery. The actual outcome parameter value may be measured at any medically acceptable time after the refractive laser surgery for that parameter, including immediately after the refractive laser surgery, one week after the refractive laser surgery, one month after the refractive laser surgery, or three months after the refractive laser surgery.

[0039] The outcome parameter may be the same as the surgical parameter, for example, they may both be the spherical refractive power of the eye.

[0040] Two or more surgical parameters may be identified, particularly when they are known to affect each other or jointly affect an outcome parameter. For example, in a patient with astigmatism, both sphere and cylinder may be identified as surgical parameters, since a sphere at one cylinder may tend to be responsible for one surgical outcome, while the same sphere at another cylinder may tend to be responsible for another surgical outcome.

[0041] Similarly, more than one outcome parameter may be specified, particularly where multiple surgical parameters may affect multiple outcome parameters.

[0042] In some instances, both two or more surgical parameters and two or more outcome parameters may be identified. The method steps described herein are mostly described using one surgical parameter and one outcome parameter for simplicity. However, the same steps may equally be performed using two or more surgical parameters, two or more outcome parameters, or two or more of both.

[0043] The surgical parameters, outcome parameters, or both may be specified by a user or automatically by the refractive laser surgery system. For example, the refractive laser surgery system may simply iteratively identify every possible combination of surgical parameters, output parameters, or both, or it may identify all possible combinations that fall into every logical category, e.g., all of those for which data is available for a particular type of surgery. This identification process may be initiated by the user or may occur as part of a self-validation process that may occur automatically after a predetermined time interval or after each patient or after every use of the refractive laser surgery system.

[0044] Next, the historical surgical parameter data and historical outcome parameter data for a patient population is retrieved from the memory of the refractive laser surgery system at step 210. The patient population may be a group selected by the user, or it may be all past patients or all patients within a particular group, such as all past patients who have had a particular type of refractive laser surgery, all past patients within an age range, or all past patients who may or may not have had previous corneal surgery.

[0045] In step 215, the past surgical parameter data and the past target outcome parameter data are compared with past actual outcome parameter data (i.e., for the same patient or for the same eye of the same patient) associated with the past surgical parameter data to determine whether systematic deviations have occurred in the past between the target outcome parameters and the actual outcome parameters based on the surgical parameters.

[0046] If no systematic deviations occur, then no nomogram is generated and no correction is made to the surgical parameters, step 220. The memory of the refractive laser surgery system may be updated to reflect that no correction is required for the surgical parameters.

[0047] At step 225, a nomogram is created for correcting the surgical parameters if systematic deviations are indeed occurring. The nomogram may be in the form of a correction table, a set of instructions that, when executed by a processor, arrives at the same values ​​that would be obtained using the correction table, or a function that calculates the appropriate correction. The memory of the refractive laser surgery system may be updated to include the nomogram, reflect that nomogram-based corrections to the surgical parameters are required, and to include instructions or sets of instructions for nomogram-based correction of the surgical parameters.

[0048] For example, a nomogram may be created by calculating the distribution of target and actual outcome parameters or the difference between the target and actual outcome parameters for a group of refractive laser surgeries as a function of the surgical parameters. A fitted curve may be calculated for the distribution, for example a least squares error fit fitted curve. The fitted curve may be used to determine a statistically based correction to be applied to the surgical parameters to achieve an actual outcome parameter that is the same as, or within an acceptable variation from, the target outcome parameter.

[0049] In some more advanced nomograms, a confidence level for the distribution may also be set and used to calculate a confidence interval, which may determine whether a nomogram-based correction is applied to the surgical parameters and the extent of the nomogram-based correction. Generally, the lower the confidence interval, the less amount of nomogram-based correction is applied than when the confidence interval is higher.

[0050] At step 230, surgical parameters that are subject to correction based on the nomogram are determined for the patient undergoing the refractive laser surgery and stored as data for the patient in the memory of the refractive laser surgery system. The surgical parameters may be determined, for example, using a separate diagnostic device that may communicate information to the refractive laser surgery system via a communication interface, may be identified using a separate diagnostic device and entered into the refractive laser surgery system via a user interface, or may be determined using a diagnostic device that is part of the refractive laser surgery system. Target outcome parameters may also be determined for the patient and stored as data for the patient in the memory of the refractive laser surgery system. The target outcome parameters may be default outcome parameters for the type of refractive laser surgery, which may be recommended based on calculations performed by the refractive laser surgery, or which may be entered by a user via a user interface.

[0051] In step 235, the processor of the refractive laser surgery system compares the surgical parameters, the target outcome parameters, or both to the nomogram to generate nomogram-based corrected surgical parameters, which are entered as data for the patient into the memory of the refractive laser surgery system. The nomogram-based corrected surgical parameters may be the same as the surgical parameters, i.e., no changes may be made to their values ​​if the nomogram so indicates.

[0052] In step 240, a processor within the refractive laser surgery system may compare the nomogram-based corrected surgical parameters to the absolute values ​​and generate a warning or terminate the refractive laser surgery if the nomogram-based corrected surgical parameters are lower or higher than the absolute values, or the processor may compare the nomogram-based corrected surgical parameters to the surgical parameters and generate a warning or terminate the refractive laser surgery if the nomogram-based corrected surgical parameters differ from the surgical parameters by more than a predetermined amount, such as higher or lower, or any predetermined percentage thereof.

[0053] At step 245, the user is given the option, for example via a refractive laser surgery system user interface, to confirm that the nomogram-based corrected surgical parameters are correct. If the user confirms that the nomogram-based corrected surgical procedure is correct, the surgery continues. If the user confirms that the nomogram-based corrected surgical procedure is incorrect, the surgery ends at step 260.

[0054] At step 250, a processor within the refractive laser surgery system generates a graphical representation of the surgical parameters, outcome parameters, or both, and the corrected surgical parameters based on the nomogram. The graphical representation may be shown via a user interface. The graphical representation may be two-dimensional or three-dimensional and may include, for example, a graph or a collection of graphs representing the change in one surgical parameter, such as sphere power, at different values ​​of a second surgical parameter, such as cylinder power.

[0055] At step 255, the user is given the option to confirm, for example, via a refractive laser surgery system user interface, that the nomogram-based corrected surgical parameters are correct. If the user confirms that the nomogram-based corrected surgical procedure is correct, the surgery continues. If the user confirms that the nomogram-based corrected surgical procedure is incorrect, the surgery ends at step 260. In an alternative method, the nomogram-based corrected surgical parameters do not need to be confirmed for their correctness. Additionally, nomogram-based corrected surgical parameters that are either confirmed to be correct or confirmed to be incorrect may be used during surgical planning, in which case the surgery is not terminated but simply is not initiated with the nomogram-based corrected surgical parameters.

[0056] Steps 240 and 250 may occur during the same process step or at the same time, so that any warnings and graphical representations are presented to the user simultaneously. Steps 245 and 255 may occur during the same process step or at the same time, so that any confirmation that the nomogram-based corrected surgical parameters are correct occurs after both any warnings and graphical representations have been presented to the user.

[0057] At step 265, the refractive laser surgery system, either automatically or in response to user input, determines whether there are any additional surgical parameters that are subject to nomogram-based correction. If there are any such additional parameters, steps 235-255 are repeated for those parameters. If there are no such additional parameters, the refractive laser surgery system proceeds to step 270.

[0058] In step 270, an ablation profile or photosection profile is calculated by the processor using the at least one nomogram-based corrected surgical parameter and stored as data for the patient in the memory of the refractive laser surgery system.

[0059] The ablation profile and the photosection profile are calculated using the nomogram-based corrected surgical parameters, which may also be compared to safety-critical surgical parameters to determine whether the surgery is safe to proceed. The safety-critical surgical parameters may be the same surgical parameters as the nomogram-based corrected surgical parameters, or they may be different surgical parameters. Exemplary safety-critical surgical parameters include corneal stromal thickness and maximum ablation depth, which may be used with the ablation profile to determine the remaining corneal stromal thickness. If the comparison indicates that it is safe to proceed, and optionally, such a determination is confirmed by the user, the surgery continues. If the comparison indicates that it is not safe to proceed, or optionally, such a determination is not confirmed by the user, the refractive laser surgery ends at step 260.

[0060] This step, where the ablation profile or photosection profile is compared to the actual surgical parameters and not the nomogram-based corrected surgical parameters, is not possible in refractive laser surgery methods where only the nomogram-based corrected surgical parameters are provided to the refractive laser surgery system, presenting a way to improve patient safety by having the actual surgical parameters available in the refractive laser surgery system.

[0061] In step 275, the processor uses the ablation profile to direct the excimer laser to ablate the cornea of ​​the patient's eye in accordance with the ablation profile to correct the refractive error of the patient's eye, or the processor uses the photoablation profile to direct the femto laser to photoablate the cornea of ​​the patient's eye in accordance with the photoablation profile to correct the refractive error of the patient's eye.

[0062] The outcome parameters are measured and stored as data for the patient in the memory of the refractive laser surgery system at step 280. The outcome parameters, like the surgical parameters, may be measured by diagnostic equipment external to or part of the refractive laser surgery system and, if desired, may be communicated to the refractive laser surgery system via a communication interface or user interface.

[0063] The outcome parameters may be measured at selected time points following refractive laser surgery, and may be measured more than once.

[0064] At step 285, the refractive laser surgery system determines whether a predetermined time interval has elapsed or whether a self-verification or self-update user input has been received. The predetermined time interval may be monthly, weekly, or daily, or even after every use of the refractive laser surgery system to perform refractive laser surgery on a patient or eye. If the predetermined time interval has elapsed or a self-verification or self-update user input has been received, the method returns to step 205. Otherwise, the method may end.

[0065] Alternative methods include those in which one or more nomograms are entered into the memory of the refractive laser surgery system and used as described in steps 230-285. Such methods may generate additional nomograms using steps 205-225, or they may rely solely on the entered nomogram.

[0066] Typical subsets of the method steps described above that may be performed individually include steps 205-255, steps 230-285, steps 230-265, or steps 270-280.

Claims

1. 1. A refractive laser surgery system, comprising: A memory medium, comprising: Identify surgical parameters, correcting the surgical parameters based on a nomogram specific to the refractive laser surgery system, and providing corrected surgical parameters based on the nomogram, the nomogram specific to the refractive laser surgery system being generated using historical surgical parameter data, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data for the refractive laser surgery system; storing the surgical parameters and the corrected surgical parameters based on the nomogram in the memory medium as data for the patient or for one or both eyes of the patient; a memory medium storing instructions or a set of instructions executable by the processor to compare the surgical parameters to the corrected surgical parameters based on the nomogram, generate a graphical representation of the surgical parameters, a target outcome parameter associated with the surgical parameters, or both, and the corrected surgical parameters based on the nomogram, and generate an alert based on a comparison of the corrected surgical parameters based on the nomogram to the surgical parameters or absolute values, or both. a processor having access to the refractive laser surgery system self-determines whether additional nomograms may be generated; The self-validation can correct for any incremental deviations from expected system behavior over time.

2. 2. The refractive laser surgery system of claim 1, wherein the nomogram specific to the refractive laser surgery system is generated using historical surgical parameter data for the refractive laser surgery system, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data.

3. and a user interface, the instructions or set of instructions being executed by the processor to: causing the user interface to display the graphical representation or communicate the alert to a user; Accepting input from the user confirming that the corrected surgical parameters based on the nomogram are correct to allow the refractive laser surgery to proceed with the refractive laser surgery system, or accepting input from the user confirming that the corrected surgical parameters based on the nomogram are incorrect to prevent the refractive laser surgery from proceeding. The refractive laser surgery system of claim 1 , further operable to:

4. and further comprising an excimer or femto laser, the instructions or set of instructions being, by the processor, calculating an ablation profile or light ablation profile for the cornea of ​​the patient's eye using the corrected surgical parameters based on the nomogram; storing the ablation profile or photoablation profile in the memory medium as data for the patient or for one or both eyes of the patient; comparing the ablation profile or photoablation profile to the surgical parameters to determine whether refractive laser surgery on the cornea of ​​the eye can safely proceed using the ablation profile or photoablation profile; If the refractive laser surgery can safely proceed, instruct the excimer laser to ablate the cornea according to the ablation profile or instruct the femto laser to photoablate the cornea according to the photoablative profile. The refractive laser surgery system of claim 1 , further operable to:

5. The processor may further have access to a memory medium storing historical surgical parameter data for the refractive laser surgery system, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data, and the instructions or set of instructions may be configured by the processor to: creating the nomogram specific to the refractive laser surgery system based on all or a set of the historical surgical parameter data for the refractive laser surgery system, the historical target outcome parameter data associated with the historical surgical parameter data, and the historical actual outcome parameter data; The nomogram is stored in the memory medium.

2. The refractive laser surgery system of claim 1 , operable to:

6. The instruction or set of instructions is executed by the processor: comparing historical surgical parameter data for the refractive laser surgery system, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data to determine whether systematic deviations occur between the historical target outcome parameters and the historical actual outcome parameters based on the historical surgical parameters; Developing the nomogram to correct the surgical parameters when systematic deviations occur.

6. The refractive laser surgery system of claim 5, further operable to:

7. 6. The refractive laser surgery system of claim 5, wherein the instructions or set of instructions are further executable by the processor to generate a new nomogram using additional historical data after a predetermined time interval has elapsed.

8. The refractive laser surgery system of claim 1, further comprising a diagnostic device, wherein the instructions or set of instructions are further executable by the processor to compare past surgical parameter data for the refractive laser surgery system, past target outcome parameter data associated with the past surgical parameter data, and past actual outcome parameter data to determine whether a systematic deviation occurs between the past target outcome parameters and the past actual outcome parameters based on the surgical parameters and / or actual outcome parameters associated with the surgical parameters.

9. 2. The refractive laser surgery system of claim 1, further comprising a communications interface, wherein the instructions or set of instructions are further executable by the processor to obtain, via the communications interface, the surgical parameters, actual outcome parameters associated with the surgical parameters, or both, from diagnostic equipment external to the refractive laser surgery system.

10. 2. The refractive laser surgery system of claim 1, wherein the nomogram includes a correction table, a set of instructions that when executed by the processor arrives at the same value that would be obtained using the correction table, or a function that calculates the appropriate correction.

11. 1. A method of operating a refractive laser surgery system including a processor and a memory medium accessible by the processor and storing an instruction or set of instructions executable by the processor, comprising: the processor identifying surgical parameters; the processor correcting the surgical parameters based on a nomogram specific to the refractive laser surgery system and providing corrected surgical parameters, the nomogram specific to the refractive laser surgery system being generated using historical surgical parameter data, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data for the refractive laser surgery system; storing, by the processor, the surgical parameters and the corrected surgical parameters in the memory medium as data for a patient or for one or both eyes of the patient; the processor comparing the surgical parameters to the corrected surgical parameters, generating a graphical representation of the surgical parameters, a target outcome parameter associated with the surgical parameters, or both, and the corrected surgical parameters based on the nomogram, and generating an alert based on a comparison of the corrected surgical parameters based on the nomogram to the surgical parameters or absolute values, or both; Including, the refractive laser surgery system self-determines whether additional nomograms may be generated; A method in which the self-validation can correct for any incremental deviations from expected system behavior over time.

12. 12. The method of claim 11, wherein the nomogram specific to the refractive laser surgery system is generated by the processor using historical surgical parameter data for the refractive laser surgery system, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data.

13. causing a user interface of the refractive laser surgery system to display the graphical representation or communicate the alert to a user; the processor accepting input that the corrected surgical parameters based on the nomogram are identified as correct, allowing the refractive laser surgery to proceed with being performed using the refractive laser surgery system, or accepting input that the corrected surgical parameters based on the nomogram are identified as incorrect, allowing the refractive laser surgery to proceed; The method of claim 11 , further comprising:

14. the processor calculating an ablation profile or a light section profile for the cornea of ​​the patient's eye using the corrected surgical parameters based on the nomogram; the processor storing the ablation profile or photodissection profile in the memory medium as data for the patient, or for one or both eyes of the patient; the processor comparing the ablation or photosection profile to the surgical parameters so that a user can determine whether refractive laser surgery on the cornea of ​​the eye can safely proceed using the ablation or photosection profile; if the refractive laser surgery can safely proceed, instructing an excimer laser in the refractive laser surgery system to ablate the cornea according to the ablation profile or instructing a femto laser in the refractive laser surgery system to photoablate the cornea according to the photoablative profile; The method of claim 11 , further comprising:

15. generating the nomogram specific to the refractive laser surgery system based on all or a set of: historical surgical parameter data for the refractive laser surgery system stored in the memory medium, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data; storing the nomogram in the memory medium by the processor; The method of claim 11 , further comprising:

16. the processor comparing historical surgical parameter data for the refractive laser surgery system, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data to determine whether systematic deviations occur between the historical target outcome parameters and the historical actual outcome parameters based on the surgical parameters; generating the nomogram for correcting the surgical parameters when systematic deviations occur; The method of claim 11 , further comprising:

17. 20. The method of claim 16, further comprising the step of the processor generating a new nomogram using additional historical data after a predetermined time interval has elapsed.

18. 17. The method of claim 16, further comprising the step of the processor comparing past surgical parameter data for the refractive laser surgery system, past target outcome parameter data associated with the past surgical parameter data, and past actual outcome parameter data to determine whether systematic deviations occur between the past target outcome parameters and the past actual outcome parameters based on the surgical parameters and / or actual outcome parameters associated with the surgical parameters.

19. the processor comparing historical surgical parameter data, historical target outcome parameter data associated with the historical surgical parameter data, and historical actual outcome parameter data for the refractive laser surgery system to determine whether systematic deviations occur between the historical target outcome parameters and the historical actual outcome parameters based on the surgical parameters and / or actual outcome parameters associated with the surgical parameters; the processor communicating the surgical parameters, actual outcome parameters associated with the surgical parameters, or both from a diagnostic device to the refractive laser surgery system; 20. The method of claim 16, further comprising:

20. 12. The method of claim 11, wherein the nomogram includes a correction table, a set of instructions that when executed by the processor arrives at the same values ​​that would be obtained using the correction table, or a function that calculates the appropriate correction.

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