Polarization sensitive optical coherence tomography for visualizing vitreous opacity

Abstract

A system for visualizing a target site in an eye using a polarization sensitive optical coherence tomography (PS-OCT) device includes a controller having at least one processor and at least one non-transitory tangible memory on which instructions are recorded. The target site is one or more vitreous opacity in vitreous fluid of the eye. The controller is configured to receive the PS-OCT data and determine, based on the PS-OCT data, at least one parameter corresponding to a birefringence characteristic of collagen fibrils in the vitreous humor. The at least one parameter includes a respective pitch of collagen fibrils. The controller is configured to determine a respective location of the one or more vitreous opacity when the at least one parameter exceeds a predefined range, and to generate a control signal adapted to direct the treatment beam at the respective location of the one or more vitreous opacity.

Description

Cross-reference to related applications

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 582,923, filed September 15, 2023, which is hereby incorporated in its entirety by reference. Background Technology

[0002] This disclosure relates to a system and method for visualizing vitreous opacities in the eye using polarization-sensitive optical coherence tomography (“PS-OCT”). A common condition affecting visual quality is the presence of vitreous opacities in the vitreous fluid of the eye, sometimes called floaters. Vitreous opacities can appear as spots or shadows of various shapes that seem to float in the patient’s field of vision and scatter light entering the eye. Vitreous opacities may be caused by microscopic collagen fibers within the vitreous fluid. Treatment for vitreous opacities can include vitrectomy or laser vitreolysis. Because the vitreous cavity and retina are deeper than anterior tissues such as the cornea and lens, effective visualization and treatment delivery of vitreous opacities are often challenging. Summary of the Invention

[0003] This document discloses a system and method for visualizing a target site in the eye using a polarization-sensitive optical coherence tomography (hereinafter “PS-OCT”) apparatus. The system includes a controller having a processor and a tangible, non-transitory memory on which instructions are recorded. The target site is one or more vitreous opacities (hereinafter “one or more”) in the vitreous fluid of the eye. The PS-OCT apparatus includes a source adapted to generate a PS-OCT source beam and a polarizer adapted to control the polarization of the PS-OCT source beam. The PS-OCT apparatus includes one or more polarization-sensitive detectors adapted to detect an interference pattern and generate PS-OCT data associated with the interference pattern, based in part on the reflected PS-OCT beam.

[0004] The controller is configured to receive PS-OCT data and determine, based on the PS-OCT data, at least one parameter (hereinafter referred to as "at least one") corresponding to the birefringence characteristics of collagen fibrils in the vitreous fluid. The parameter includes the corresponding spacing of the collagen fibrils. The controller is configured to determine the corresponding location of the vitreous opacity when the parameter exceeds a predefined range and generate a control signal adapted to guide the therapeutic beam to the corresponding location of the vitreous opacity.

[0005] Parameters may include the corresponding orientation of collagen fibrils. The PS-OCT device may include a beam splitter adapted to split the PS-OCT source beam into a sample beam propagating in a sample arm and a reference beam propagating in a reference arm, the reference arm having a reference mirror. A polarization beam splitter is adapted to split the reflected PS-OCT beam into two orthogonally polarized components. The reflected PS-OCT beam is a combination of the corresponding reflected beams of the sample beam and the reference beam.

[0006] The PS-OCT device may include: a first quarter-wave plate adapted to convert a sample beam into a polarized sample beam incident on a target region; and a second quarter-wave plate adapted to convert a reference beam into a polarized reference beam incident on a reference mirror. The two orthogonal polarization components include a vertical polarization component and a horizontal polarization component. A polarization-sensitive detector may include: a vertical detector adapted to receive the vertical polarization component; and a horizontal detector adapted to receive the horizontal polarization component. In some embodiments, the first quarter-wave plate is oriented at an angle of 22.5 degrees, and the second quarter-wave plate is oriented at an angle of 45 degrees.

[0007] The PS-OCT device may include a first channel and a second channel, which are adapted to detect signals from PS-OCT data in a first orthogonal polarization state and a second orthogonal polarization state, respectively. The signals are converted into Fast Fourier Transform (FFT) signals. A phase delay mode can be used to display the PS-OCT data. The phase delay mode is based on a delay factor (…). ), represented as In the formula, It is a calibration factor, and It is the corresponding amplitude of the Fast Fourier Transform signal from the first and second channels.

[0008] Optical axis mode is suitable for displaying PS-OCT data. Optical axis mode is based on optical factor (…). ), represented as [ In the formula, and It is the corresponding phase of the Fast Fourier Transform signal from the first and second channels.

[0009] In some embodiments, the laser unit is adapted to selectively generate a therapeutic beam directed toward one or more vitreous opacities, the therapeutic beam comprising a plurality of ultrashort laser pulses. The plurality of ultrashort laser pulses may be defined with corresponding durations between about one femtosecond and about 50 picoseconds. The laser unit and the PS-OCT device may have a common aperture for guiding the therapeutic beam and the PS-OCT beam toward the target site, the common aperture being centered on a central axis. The therapeutic beam may travel at an off-axis angle deviating from the central axis, the off-axis angle being equal to or greater than 15 degrees.

[0010] This paper discloses a method for visualizing a target region in the eye using a polarization-sensitive optical coherence tomography (PS-OCT) device in a system having a controller having at least one processor and at least one non-transitory tangible memory. The method includes: generating a PS-OCT source beam via a light source in the PS-OCT device; and controlling the polarization of the PS-OCT source beam via a polarizer in the PS-OCT device. The target region is one or more vitreous opacities in the vitreous fluid of the eye. The method further includes: detecting an interference pattern, partially based on the reflected PS-OCT beam, via one or more polarization-sensitive detectors in the PS-OCT device, and generating PS-OCT data associated with the interference pattern.

[0011] The method includes: receiving PS-OCT data via a controller; and determining, based on the PS-OCT data, at least one parameter corresponding to the birefringence characteristics of collagen fibrils in the vitreous fluid. The parameter includes the corresponding spacing of the collagen fibrils. The method further includes: determining, via the controller, the corresponding location of one or more vitreous opacities when the at least one parameter exceeds a predefined range. The method also includes: generating a control signal via the controller, the control signal being adapted to guide a therapeutic beam to the corresponding location of one or more vitreous opacities.

[0012] The above-described features and advantages, as well as other features and advantages, of this disclosure will become apparent from the following detailed description of the best mode for implementing this disclosure, taken in conjunction with the accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a system for visualizing the eye using a PS-OCT device, which includes a controller;

[0014] Figure 2 It is a schematic diagram showing an eye with vitreous opacities;

[0015] Figure 3 It is a schematic diagram illustrating the birefringence effect of polarized light;

[0016] Figure 4 It is possible to be Figure 1 A schematic flowchart of the method executed by the controller;

[0017] Figure 5 This is a schematic magnified view of exemplary healthy collagen fibrils in the vitreous fluid of the eye;

[0018] Figure 6 This is a schematic magnified view of an example of unhealthy collagen fibrils in vitreous fluid;

[0019] Figure 7 It is used for applications Figure 4 A schematic diagram of an exemplary architecture for each part of the method;

[0020] Figure 8 This is a schematic diagram of an exemplary image generated using PS-OCT data in phase-delay mode; and

[0021] Figure 9 This is a schematic diagram of an exemplary image generated using PS-OCT data in optical axis mode.

[0022] Representative embodiments of this disclosure are shown by way of non-limiting example in the accompanying drawings and are described in more detail below. However, it should be understood that the novel aspects of this disclosure are not limited to the specific forms shown in the above-enumerated drawings. Rather, this disclosure will cover modifications, equivalents, combinations, sub-combinations, substitutions, groupings, and alternatives falling within the scope of this disclosure, such as those covered by the appended claims. Detailed Implementation

[0023] Referring to the accompanying drawings, similar reference numerals refer to similar parts. Figure 1 A system 10 is schematically illustrated for visualizing target sites in the eye 12 using data captured via a polarization-sensitive optical coherence tomography (OCT) apparatus 14. Optical coherence tomography is a non-invasive imaging technique that uses low-coherence interferometry to generate high-resolution images of ocular structures. Images generated by conventional OCT systems are intensity-based and can be used for many purposes, such as identifying and assessing eye diseases. However, they lack tissue-specific contrast. In other words, there is little difference between different types of tissue. This makes the interpretation of the images challenging.

[0024] As described below, system 10 is configured to use polarization-sensitive optical coherence tomography (hereinafter referred to as "PS-OCT") to identify and treat one or more vitreous opacities 16 in eye 12 (see below). Figure 2 ). refer to Figure 2Vitreous opacities 16 may be located at various locations within the vitreous fluid 18 of the eye 12, as indicated by first vitreous opacity 16A, second vitreous opacity 16B, and third vitreous opacity 16C (see [reference]). Figure 2 Vitreous fluid 18 comprises approximately 98% water, hyaluronic acid, proteoglycans, and collagen fibers. Collagen forms uniform and parallel fibrils, and its density increases with age.

[0025] The main component of vitreous opacity 16 is collagen. Tissues containing collagen exhibit birefringence, a property of the material where the refractive index depends on the polarization orientation and propagation direction of light. For example... Figure 3 As shown, when polarized light 110 passes through a material 112 with birefringent properties (e.g., tissue with collagen fibers), the first polarization orientation 114 of the light slows down relative to the second polarization orientation 116, resulting in a phase delay 118. The magnitude of the phase delay 118 can be used to characterize the structure of the material 112.

[0026] refer to Figure 1 System 10 includes a controller C having at least one processor P and at least one memory M (or a non-transitory tangible computer-readable storage medium) on which instructions for executing a method 200 for visualizing vitreous opacities 16 in the eye 12 using an OCT device 14 are recorded. See below for further details. Figure 4 Method 200 is shown and described.

[0027] System 10 enables the identification of tissue-specific contrasts used to characterize vitreous opacities 16. Now refer to Figure 5 An exemplary view of relatively healthy collagen fibrils 310 in vitreous fluid 18 is shown. (Reference) Figure 5 Collagen fibrils 310 form an extended network by being organized into relatively aligned or parallel bundles (e.g., first bundle 312 and second bundle 314). The collagen fibrils 310 are both linked together and spaced apart by chondroitin sulfate chains 316. In a relatively healthy eye, the chondroitin sulfate chains 316 can be substantially orthogonal to the first bundle 312 and the second bundle 314.

[0028] Figure 6 This is a schematic exemplary view of relatively unhealthy collagen fibrils 410 in vitreous fluid 18. The location of vitreous opacity 16 can be characterized by the presence of aggregated cross-linked collagen fibrils 410. Figure 6As shown, collagen fibrils 410 aggregate at different points, with the bundles of collagen fibrils 410 (e.g., the first bundle 412 and the second bundle 414) being relatively misaligned. Various factors cause the collagen fibrils 410 to aggregate, including the loss of certain types (e.g., type IX) of collagen from the fibril surface. These factors can include age or various eye conditions (e.g., posterior vitreous detachment, myopic vitreous degeneration, etc.).

[0029] Now for reference Figure 1 System 10 includes a light source 20 adapted to generate a PS-OCT source beam 22. The light source 20 may be a swept-frequency laser or other suitable OCT source available to those skilled in the art. It should be understood that the PS-OCT device 14 may take many different forms and include multiple components and / or alternative components.

[0030] like Figure 1 As shown, the PS-OCT source beam 22 propagates through polarizer 24 to reach beam splitter 26. Polarizer 24 receives the incident PS-OCT source beam and emits a polarized PS-OCT source beam 30 with a known polarization. At beam splitter 26, the polarized PS-OCT source beam 30 is split into two components: a sample beam 32, which propagates through sample arm 34; and a reference beam 36, which propagates through reference arm 38. Beam splitter 26 is a non-polarized 50 / 50 beam splitter.

[0031] refer to Figure 1 In sample arm 34, sample beam 32 passes through a first quarter-wave plate 40, which converts sample beam 32 into polarized light with a known polarization state, so that the polarized sample beam 42 is incident on eye 12. Here, the first quarter-wave plate 40 can be at a 45-degree angle. Collimation unit 44 can be used to guide the polarized sample beam 42. (Reference) Figure 2 Incident beam ( Figure 1 The polarized sample beam 42 is reflected from the retina 50 and / or sclera 52 of the eye 12 and is diffracted, reflected and / or refracted by the vitreous turbidity 16 in the vitreous fluid 18. The reflected sample beam then travels back to the PS-OCT device 14, for example, through various combinations of optical devices (not shown).

[0032] On reference arm 38, reference beam 36 passes through second quarter-wave plate 54 and reference mirror 56. Second quarter-wave plate 54 converts the polarization state of the returning reference beam into a polarization state with two equal orthogonal polarization components. Here, second quarter-wave plate 54 can be at an angle of 22.5 degrees. Reference arm 38 may include dispersion compensator 55, positioned between quarter-wave plate 54 and reference mirror 56, for controlling beam dispersion.

[0033] refer to Figure 1 When the reflected sample beam (reflected from various parts of the eye 12) and the reflected reference beam (reflected from reference mirror 56) are combined at beam splitter 26, they form a reflected PS-OCT beam 60, which is guided to polarization beam splitter 62. The reflected PS-OCT beam 60 is a combination of the corresponding reflected beams of the sample beam and the reference beam. At polarization beam splitter 62, the reflected PS-OCT beam 60 is split into two orthogonal polarization components, such as a vertical polarization component 64 and a horizontal polarization component 66. The term "horizontal" refers to the X and Y directions in the XY plane, which can be defined as a plane approximately perpendicular to the apex of the cornea 68. The term "vertical" can refer to the Z direction in the Z plane, which is defined as a plane approximately perpendicular to the XY plane. It should be understood that the origin and orientation of the XYZ coordinate system can vary depending on the application.

[0034] refer to Figure 1 System 10 includes one or more polarization-sensitive detectors, such as a vertical polarization-sensitive detector 70 and a horizontal polarization-sensitive detector 72, which are adapted to receive the reflected PS-OCT beam 60. Figure 1 In the example shown, a vertical polarization-sensitive detector 70 is adapted to receive the vertical polarization component 64, and a horizontal polarization-sensitive detector 72 is adapted to receive the horizontal polarization component 66. The polarization-sensitive detectors detect the interference pattern of the reflected PS-OCT beam 60 and generate data associated with the interference pattern. This data can be transmitted to the controller C via the OCT processor 74.

[0035] refer to Figure 1 The controller C can be configured to process signals from the PS-OCT device 14 for playback on the display 76. The display 76 may include, but is not limited to, a high-definition or ultra-high-definition television, smart glasses, a projector, one or more computer screens, a laptop computer, a tablet computer, and may include a touchscreen. (Reference) Figure 1 The controller C can be configured to receive and send data via the user interface 78. The user interface 78 can be installed on a smartphone, laptop computer, tablet computer, desktop computer, or other electronic device.

[0036] Figure 1The various components of system 10 can communicate via network 80. Network 80 can be a bus implemented in various ways, such as a serial communication bus in the form of a local area network (LAN). The LAN can include, but is not limited to, a control area network (CAN), a control area network with flexible data rates (CAN-FD), Ethernet, Bluetooth, Wi-Fi, and other forms of data connection. Network 80 can be a wireless local area network (LAN) that uses a wireless distribution method to link multiple devices, a wireless metropolitan area network (MAN) that connects several wireless LANs, or a wireless wide area network (WAN). Other types of connections can be used.

[0037] Now for reference Figure 4 This shows that it can be generated by Figure 1 The flowchart illustrates method 200 executed by controller C. Method 200 does not need to be applied in the specific order listed herein, and some boxes may be omitted. Memory M may store the controller-executable instruction set, and processor P may execute the controller-executable instruction set stored in memory M.

[0038] from Figure 4 Starting at frame 202, controller C is configured to receive PS-OCT data captured by PS-OCT device 14. Proceed to... Figure 4 In box 204, controller C is configured to analyze PS-OCT data to determine at least one parameter corresponding to the birefringence properties of collagen fibrils 410 in the vitreous fluid. The parameters include the corresponding spacing of the collagen fibrils 410, such as... Figure 6 The corresponding spacing 418 between the first bundle 412 and the second bundle 414 is shown. Parameters may include the corresponding orientation 420 of the collagen fibrils 410, for example, whether the bundles are parallel or open. The corresponding orientation 420 may be represented by the angle between the corresponding bundles.

[0039] Advance to Figure 4 In box 206, controller C can be configured to determine the corresponding location of vitreous opacity 16 when the parameter exceeds a predefined range (e.g., the corresponding spacing 418 is below a threshold). Figure 6 (Position 430 in the image). For example, the corresponding spacing 418 between the first beam 412 and the second beam 414 is approximately zero at position 430, which can be designated as vitreous opacity 16. In some embodiments, the controller C can generate multi-factor scores for each grid or segment of the spatial image of the vitreous fluid 18 based on PS-OCT data.

[0040] refer to Figure 7 The diagram illustrates the workflow for processing PS-OCT data. Figure 1 The PS-OCT device 14 may include a first channel 502 and a second channel 504 (in Figure 7As shown in the diagram, the first and second channels are adapted to detect corresponding signals from PS-OCT data in two orthogonal polarization states: a first orthogonal polarization state and a second orthogonal polarization state (e.g., vertical polarization state and horizontal polarization state). Reference Figure 7 The raw data from the first channel 502 and the second channel 594 is transmitted to the preprocessing unit 506, where multiple preprocessing steps are performed. These preprocessing steps may include filling, windowing, background suppression, filtering, etc.

[0041] The corresponding signal output by the preprocessing module 506 undergoes a fast Fourier transform, such as... Figure 7 As indicated by box 508 in the diagram. After the Fourier transform, the corresponding signals from the first channel 502 and the second channel 504 are each processed to obtain the OCT signal. and As shown in boxes 510 and 512, the Fast Fourier Transform signal from the first channel 502 can be represented as... In the formula, and These represent amplitude and phase, respectively. The Fast Fourier Transform signal from the second channel 504 can be represented as: In the formula, and These represent amplitude and phase, respectively. (Reference) Figure 7 The signal from PS-OCT data can be displayed using intensity mode 514, phase delay mode 516, and optical axis mode 518.

[0042] Phase delay mode 516 can be based on delay factor ( ), represented as Here, It is a calibration factor, and This represents the corresponding amplitude of the Fast Fourier Transform signal from channel 502 and channel 504. The relationship between the phase delay and the tissue birefringence (Δn) is as follows: In the formula, λ is the wavelength of light, and L is the imaging depth. In one embodiment, This is a factor calibrated based on surface reflection data to compensate for imperfect circular polarization in sample arm 34. As described above, refer to Figure 1 The sample arm 34 can be converted to a circular polarization state by adjusting the polarization controller in the beam path and inserting a quarter-wave plate 40.

[0043] Figure 8This is a schematic diagram of an exemplary PS-OCT image displayed in phase retardation mode 516. Arrow 620 highlights the contrast caused by collagen content (e.g., collagen content in vitreous fluid 18). Phase retardation mode 516 is visualized in the range of 0 to 90 degrees. As shown in Figure 615, the data is divided into individual blocks of 10 degrees each. Vertical axis 605 and horizontal axis 610 represent spatial dimensions.

[0044] Optical axis mode 518 can be based on optical factor ( ), represented as [ In the formula, and It is the corresponding phase of the fast Fourier transform signal from the first channel 502 and the second channel 504. Figure 9 This is a schematic diagram of an exemplary PS-OCT image displayed in optical axis mode 518. Arrow 720 highlights the contrast caused by collagen content (e.g., collagen content in vitreous fluid 18). Optical axis mode 516 visualizes the data in the range of 0 to 180 degrees. As shown in Figure 715, the data is divided into individual blocks of 20 degrees each. Vertical axis 705 and horizontal axis 710 represent spatial dimensions.

[0045] Intensity mode 514 can be based on intensity factor ( ), represented as Here, It is the corresponding amplitude of the fast Fourier transform signal from the first channel 502 and the second channel 504.

[0046] according to Figure 4 In box 208, method 200 includes generating a control signal for directing at least one therapeutic beam 82 to a corresponding location of the vitreous opacity 16 (e.g., Figure 6 At position 430 in the middle. According to box 210, the treatment beam 82 (see...) Figure 1 This can be delivered based on the control signal. (Return to reference) Figure 1 System 10 may include a laser unit 84 configured to selectively generate at least one treatment beam 82 via a laser source 86, the at least one treatment beam being directed toward the vitreous opacity 16. The treatment beam 82 may include a plurality of ultrashort laser pulses, each ultrashort laser pulse having a duration between approximately one femtosecond (10⁻¹⁰). -15 (seconds) and approximately 50 picoseconds (50 × 10) -12 Between seconds. Data from the control signal can be processed by the laser processor 88 and used to optimize the treatment beam 82 so as to at least partially vaporize or decompose the vitreous opacity 16.

[0047] The laser source 86 can be a femtosecond laser or a picosecond laser, and can emit light with a wavelength of approximately 1050 nm. In one example, the laser source 86 is configured to deliver infrared radiation, i.e., a wavelength between approximately 700 nm and 1220 nm. It should be understood that the position of the laser source 86 relative to the light source 20 of the PS-OCT device 14 can vary. (See reference...) Figure 1 The position of the laser source 86 and the direction of the treatment beam 82 can be changed to target multiple locations of the vitreous opacity 16. For example, a second treatment beam 83 can be generated when the laser source is moved to position 87, such as... Figure 1 As shown. In some embodiments, the laser unit 84 can be moved relative to the central axis A, which can be accomplished by an operator-controlled input device 90 (e.g., keyboard, mouse, joystick).

[0048] In some embodiments, system 10 incorporates a common aperture 92 (see Figure 1 This is used for simultaneously imaging and delivering treatment to vitreous opacities 16. A common aperture 92 can be centered on a central axis A, and the treatment beam 82, perpendicular to this central axis, can be guided in an off-axis direction at an off-axis angle 94 between the treatment beam 82 and the central axis A. In some embodiments, the off-axis angle 94 can be equal to or greater than 15 degrees. The off-axis angle 94 can be equal to or greater than 30 degrees.

[0049] The healing beam 82 can be delivered with various patterns and settings based on the application at hand. It should be understood that the system 10 can employ various modulators or modifiers to adjust the healing beam. For example, as... Figure 2 As shown, the barrier 96 can be placed close to the eye 12 and is adapted to reduce the depth of field of laser delivery. This allows the treatment beam 82 to be highly focused. The barrier 96 can be a contact lens worn directly above the cornea 68 of the eye 12.

[0050] In summary, System 10 demonstrates a robust method for assisting physicians in identifying and treating one or more vitreous opacities 16 in an eye 12. System 10 is capable of generating tissue-specific contrast images of vitreous floaters in a non-invasive manner.

[0051] Figure 1The controller C includes a computer-readable medium (also called a processor-readable medium) that includes a non-transitory (e.g., tangible) medium involved in providing data (e.g., instructions) that can be read by a computer (e.g., by the computer's processor). Such a medium can take many forms, including, but not limited to, non-volatile and volatile media. Non-volatile media can include, for example, optical discs or magnetic disks, and other persistent storage. Volatile media can include, for example, dynamic random access memory (DRAM), which can constitute main memory. Such instructions can be transmitted via one or more transmission media, including coaxial cables, copper wires, and optical fibers, including wires containing a system bus connected to the computer's processor. Some forms of computer-readable media include, for example, floppy disks, floppy disks, hard disks, magnetic tapes, other magnetic media, CD-ROMs, DVDs, other optical media, physical media, RAM, PROMs, EPROMs, FLASH-EEPROMs, other memory chips or cartridges, or other media that can be read by a computer.

[0052] The lookup tables, databases, data repositories, or other data stores described herein can include various mechanisms for storing, accessing, and retrieving a variety of data, including hierarchical databases, a set of files in a file storage system, application databases in proprietary formats, relational database management systems (RDBMS), etc. Each such data store can be contained within a computing device employing a computer operating system (such as one of the aforementioned operating systems) and can be accessed via a network in one or more of various ways. File systems can be accessed from the computer operating system and can include files stored in various formats. RDBMS can employ Structured Query Language (SQL), as well as languages ​​used to create, store, edit, and execute stored programs, such as the PL / SQL language mentioned above.

[0053] The flowcharts shown illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each box in the flowchart or block diagram may represent a module, segment, or portion of code, including one or more executable instructions for implementing a specific logical function(s). It should also be noted that each box in the block diagram and / or flowchart illustrations, and combinations of boxes in the block diagram and / or flowchart illustrations, may be implemented by a system based on dedicated hardware or a combination of dedicated hardware and computer instructions that performs the specified function or action. These computer program instructions may also be stored in a computer-readable medium that can instruct a controller or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable medium produce an article of art including instructions for implementing the functions / actions specified in the flowchart and / or block diagram boxes.

[0054] The numerical values ​​of parameter items (e.g., quantities or conditions) in this specification (including the appended claims) should be understood to be modified by the term “about” in each corresponding instance, regardless of whether “about” actually appears before the numerical value. “About” indicates that the numerical value is slightly imprecise (the value is somewhat close to precise; about or fairly close to the value; almost close). If the imprecision provided by “about” is not otherwise understood in the art to have this common meaning, then “about” as used herein at least indicates the variation that may arise from common methods of measuring and using such parameter items. Furthermore, the disclosure of ranges includes the disclosure of each value throughout the range or of further subdivided ranges. Each value within a range and the endpoints of the range are thus disclosed as separate embodiments.

[0055] The specific details and accompanying drawings are supportive and descriptive of this disclosure, but the scope of this disclosure is defined solely by the claims. While some best modes and other embodiments for implementing the claimed disclosure have been described in detail, various alternative designs and embodiments exist to practice the disclosure as defined in the appended claims. Furthermore, the features of the embodiments shown in the drawings or the various embodiments mentioned in this specification are not necessarily to be construed as embodiments independent of each other. Rather, each feature described in one of these examples of embodiments may be combined with one or more other desired features from other embodiments to produce other embodiments not described in words or with reference to the drawings. Accordingly, such other embodiments fall within the scope of the appended claims.

Claims

1. A system for visualizing a target region in the eye using a polarization-sensitive optical coherence tomography (PS-OCT) device, the system comprising: A controller having at least one processor and at least one non-transitory tangible memory, wherein instructions are recorded in the at least one non-transitory tangible memory, the target site being one or more vitreous opacities in the vitreous fluid of the eye; The PS-OCT device includes a source adapted to generate a PS-OCT source beam and a polarizer adapted to control the polarization of the PS-OCT source beam. The PS-OCT device includes one or more polarization-sensitive detectors adapted to detect interference patterns and generate PS-OCT data associated with the interference patterns, partially based on reflected PS-OCT beams. The controller is configured to receive the PS-OCT data and, based on the PS-OCT data, determine at least one parameter corresponding to the birefringence characteristics of collagen fibrils in the vitreous fluid, the at least one parameter including the corresponding spacing of the collagen fibrils; and The controller is configured to determine the corresponding location of the one or more vitreous opacities when the at least one parameter exceeds a predefined range, and to generate a control signal adapted to guide a treatment beam to the corresponding location of the one or more vitreous opacities.

2. The system as claimed in claim 1, wherein, The at least one parameter includes the corresponding orientation of the collagen fibrils.

3. The system as described in claim 1, wherein, The PS-OCT device includes: A beam splitter adapted to split the PS-OCT source beam into a sample beam propagating in a sample arm and a reference beam propagating in a reference arm, the reference arm having a reference mirror; and A polarization beam splitter adapted to split the reflected PS-OCT beam into two orthogonal polarization components, the reflected PS-OCT beam being a combination of the corresponding reflected beams of the sample beam and the reference beam.

4. The system as described in claim 3, wherein, The PS-OCT device includes: A first quarter-wave plate, adapted to convert the sample beam into a polarized sample beam incident on the target region; and A second quarter-wave plate is adapted to convert the reference beam into a polarized reference beam incident on the reference mirror.

5. The system as described in claim 4, wherein, The two orthogonal polarization components include a vertical polarization component and a horizontal polarization component; and The one or more polarization-sensitive detectors include: a vertical detector adapted to receive the vertical polarization component; and a horizontal detector adapted to receive the horizontal polarization component.

6. The system of claim 4, wherein, The first quarter-wave plate is oriented at an angle of 22.5 degrees, and the second quarter-wave plate is oriented at an angle of 45 degrees.

7. The system as claimed in claim 1, wherein, The PS-OCT device includes a first channel and a second channel, which are adapted to detect signals from the PS-OCT data that are in a first orthogonal polarization state and a second orthogonal polarization state, respectively, and the signals are converted into fast Fourier transform signals.

8. The system of claim 7, further comprising: Phase delay mode, the phase delay mode being adapted to display the PS-OCT data, the phase delay mode being based on a delay factor ( ), represented as In the formula, It is a calibration factor, and It is the corresponding amplitude of the Fast Fourier Transform signal from the first channel and the second channel.

9. The system of claim 7, further comprising: Optical axis mode, the optical axis mode being adapted to display the PS-OCT data, the optical axis mode being based on optical factors ( ), represented as [ ], in the formula and It is the corresponding phase of the Fast Fourier Transform signal from the first channel and the second channel.

10. The system of claim 1, further comprising: A laser unit adapted to selectively generate the treatment beam, the treatment beam being directed toward the one or more vitreous opacities, the treatment beam comprising a plurality of ultrashort laser pulses defined for a corresponding duration between about one femtosecond and about 50 picoseconds.

11. The system of claim 10, wherein, The laser unit and the PS-OCT device have a shared aperture, which is used to guide the treatment beam and the PS-OCT beam toward the target area, with the shared aperture centered on the central axis.

12. The system of claim 11, wherein, The therapeutic beam travels at an off-axis angle that deviates from the central axis, the off-axis angle being equal to or greater than 15 degrees.

13. A method for visualizing a target region in the eye using a polarization-sensitive optical coherence tomography (PS-OCT) device in a system, said system having a controller having at least one processor and at least one non-transitory tangible memory, said method comprising: A PS-OCT source beam is generated via a light source in the PS-OCT device, and the target area is one or more vitreous opacities in the vitreous fluid of the eye; The polarization of the PS-OCT source beam is controlled via a polarizer in the PS-OCT device; Interference patterns are detected in part based on the reflected PS-OCT beam via one or more polarization-sensitive detectors in the PS-OCT device, and PS-OCT data associated with the interference patterns are generated. The PS-OCT data is received via the controller; The controller determines at least one parameter corresponding to the birefringence characteristics of collagen fibrils in the vitreous fluid based on the PS-OCT data, the at least one parameter including the corresponding spacing of the collagen fibrils; The controller determines the corresponding location of the one or more vitreous opacities when at least one parameter exceeds a predefined range; and A control signal is generated via the controller, the control signal being adapted to guide the treatment beam to the corresponding location of the one or more vitreous opacities.

14. The method of claim 13, further comprising: The corresponding orientation of the collagen fibrils is incorporated into the at least one parameter.

15. The method of claim 13, further comprising: A beam splitter is used to split the PS-OCT source beam into a sample beam propagating in the sample arm and a reference beam propagating in the reference arm, wherein the reference arm has a reference mirror; The reflected PS-OCT beam is split into two orthogonal polarization components using a polarization beam splitter. The reflected PS-OCT beam is a combination of the corresponding reflected beams of the sample beam and the reference beam. The sample beam is converted into a polarized sample beam incident on the target region via a first quarter-wave plate; and The reference beam is converted into a polarized reference beam incident on the reference mirror via a first quarter-wave plate.

16. The method of claim 13, further comprising: Orient the first quarter-wave plate at an angle of 22.5 degrees and the second quarter-wave plate at an angle of 45 degrees.

17. The method of claim 13, further comprising: The treatment beam is selectively generated via a laser unit, the treatment beam being directed toward the one or more vitreous opacities, and the treatment beam comprising multiple ultrashort laser pulses; as well as The laser unit and the PS-OCT device are configured to have a common aperture, which is used to guide the treatment beam and the PS-OCT beam toward the target area, with the common aperture centered on the central axis.

18. The method of claim 13, further comprising: The first and second channels are combined in the PS-OCT device to detect signals from the PS-OCT data that are in a first orthogonal polarization state and a second orthogonal polarization state, respectively, and the signals are converted into fast Fourier transform signals.

19. The method of claim 18, further comprising: The PS-OCT data is displayed in phase delay mode, which is based on a delay factor ( ), represented as In the formula, It is a calibration factor, and It is the corresponding amplitude of the Fast Fourier Transform signal from the first channel and the second channel.

20. The method of claim 18, further comprising: The PS-OCT data is displayed in optical axis mode, which is based on optical factors ( ), represented as [ In the formula, and It is the corresponding phase of the Fast Fourier Transform signal from the first channel and the second channel.

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