Polarization-sensitive optical coherence tomography for visualizing vitreous opacities

Abstract

A system for visualizing an intraocular target site using a polarization-sensitive optical coherence tomography (PS-OCT) instrument includes a controller having at least one processor and at least one non-temporary tangible memory on which instructions are stored. The target site is one or more vitreous opacities in the vitreous fluid of the eye. The controller is configured to receive PS-OCT data and, based on the PS-OCT data, to identify at least one parameter corresponding to the birefringence characteristics of collagen fibrils in the vitreous fluid. The at least one parameter includes the spacing between each collagen fibril. If at least one parameter is outside a predetermined range, the controller is configured to identify the location of each of the one or more vitreous opacities and to generate a control signal adapted to guide a therapeutic beam to the location of each of the one or more vitreous opacities.

Description

TECHNICAL FIELD

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 582,923 filed on September 15, 2023, the entire disclosure of which is incorporated herein by reference. BACKGROUND ART

[0002] The present disclosure relates to systems and methods 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 humor of the eye, which is sometimes referred to as myodesopsia or eye floaters. Vitreous opacities appear as various forms of spots or shadows that seem to float in the patient's field of view, and can scatter light entering the eye. The source of vitreous opacities may be fine collagen fibers in the vitreous humor. Treatments for vitreous opacities may include vitrectomy or laser vitreolysis. Since the vitreous cavity and the retina are located deeper than anterior tissues such as the cornea and the lens, it is often difficult to achieve effective visualization of vitreous opacities and provide corresponding treatment. SUMMARY OF THE INVENTION MEANS FOR SOLVING THE PROBLEMS

[0003] This specification discloses a system and method for visualizing an intraocular target site using a polarization-sensitive optical coherence tomography (hereinafter "PS-OCT") instrument. The system includes a processor and a controller having tangible non-temporary memory on which instructions are stored. The target site is one or more vitreous opacities (hereinafter "one or more") in the vitreous fluid of the eye. The PS-OCT instrument includes a light source adapted to generate a PS-OCT light source beam and a polarizer adapted to control the polarization of the PS-OCT light source beam. The PS-OCT instrument includes one or more polarization-sensitive detectors adapted to detect interference patterns based in part on the reflected PS-OCT beam and to generate PS-OCT data relating to the interference patterns.

[0004] The controller is configured to receive PS-OCT data and, based on the PS-OCT data, identify at least one parameter (hereinafter, "at least one") corresponding to the birefringence characteristics of collagen fibrils in the vitreous fluid. The parameter includes the spacing between each collagen fibril. If the parameter is outside a predetermined range, the controller is configured to identify the location of each vitreous opacity and generate a control signal adapted to guide a therapeutic beam to each location of the vitreous opacity.

[0005] The parameters may include the orientation of each collagen fibril. The PS-OCT instrument may include a beam splitter adapted to split the PS-OCT light source beam into a sample beam propagating through a sample arm and a reference beam propagating through a reference arm, the reference arm having a reference mirror. The polarizing beam splitter is adapted to split the reflected PS-OCT beam into two orthogonal polarized components. The reflected PS-OCT beam is a combination of the reflected beams of the sample beam and the reference beam.

[0006] The PS-OCT instrument may include a first quarter-wave plate adapted to convert the sample beam into a polarized sample beam incident on the target site, and a second quarter-wave plate adapted to convert the reference beam into a polarized reference beam incident on the reference mirror. The two orthogonal polarization components include a vertical polarization component and a horizontal polarization component. The 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 instrument may include a first channel and a second channel 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 signals. A phase delay mode may be adapted to display the PS-OCT data. The phase delay mode is,

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[0008] The optical axis mode can be adapted to display PS-OCT data. The optical axis mode is,

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[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 multiple ultrashort laser pulses. The multiple ultrashort laser pulses may define durations ranging from approximately 1 femtosecond to approximately 50 picoseconds. The laser unit and PS-OCT instrument may have a shared aperture for guiding the therapeutic beam and PS-OCT beam toward the target site, the shared aperture centered on a central axis. The therapeutic beam may travel at an off-axis angle from the central axis, with the off-axis angle being 15 degrees or greater.

[0010] This application discloses a method for visualizing an intraocular target site using a polarization-sensitive optical coherence tomography (PS-OCT) instrument in a system having a controller comprising at least one processor and at least one non-temporary tangible memory. The method includes generating a PS-OCT light source beam via a light source in the PS-OCT instrument and controlling the polarization of the PS-OCT light source beam via a polarizer in the PS-OCT instrument. The target site is one or more vitreous opacities in the vitreous fluid of the eye. The method includes detecting interference patterns based on a portion of the reflected PS-OCT beam via one or more polarization-sensitive detectors in the PS-OCT instrument and generating PS-OCT data associated with the interference patterns.

[0011] The method includes receiving PS-OCT data via a controller and, via the controller, identifying at least one parameter corresponding to the birefringence characteristics of collagen fibrils in the vitreous fluid based on the PS-OCT data. The parameter includes the spacing between each collagen fibril. If at least one parameter is outside a predetermined range, the method includes, via the controller, identifying the respective locations of one or more vitreous opacities. The method includes, via the controller, generating a control signal adapted to guide a therapeutic beam at the respective locations of one or more vitreous opacities.

[0012] The above-mentioned features and advantages of this disclosure, as well as other features and advantages, will be readily apparent from the following detailed description of the best mode for implementing this disclosure, in conjunction with the accompanying drawings. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a schematic diagram of a system for visualizing the eye using a PS-OCT device, which includes a controller. [Figure 2] Figure 2 is a schematic diagram showing an eye with vitreous opacity. [Figure 3] Figure 3 is a schematic diagram showing the birefringence effect on polarization. [Figure 4] Figure 4 is a schematic flowchart of the methods that can be performed by the controller in Figure 1. [Figure 5] Figure 5 is a schematic magnified view of an example of healthy collagen fibrils in the vitreous fluid of the eye. [Figure 6] Figure 6 is a schematic magnified view of an example of unhealthy collagen fibrils in vitreous fluid. [Figure 7] Figure 7 is a schematic diagram of an example architecture for applying part of the method shown in Figure 4. [Figure 8] Figure 8 is a schematic diagram of an example image generated using PS-OCT data in phase delay mode. [Figure 9] Figure 9 is a schematic diagram of an example image generated using PS-OCT data in the optical axis mode. [Modes for carrying out the invention]

[0014] Representative embodiments of this disclosure are shown in the drawings as non-limiting examples and described in further detail below. However, it should be understood that novel embodiments of this disclosure are not limited to the specific forms shown in the drawings listed above. Rather, this disclosure includes, for example, modifications, equivalents, combinations, secondary combinations, rearrangements, groupings and alternative forms that fall within the scope of this disclosure, such as those covered in the accompanying claims.

[0015] Referring to the drawings in which like reference numerals refer to like components, FIG. 1 schematically illustrates a system 10 for visualizing a target site within an eye 12 using data captured via a polarization-sensitive optical coherence tomography instrument 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 optical coherence tomography systems are based on light intensity, and are useful for many purposes such as identification and evaluation of ocular diseases. However, these lack tissue-specific contrast. In other words, there is little distinction between different types of tissues. This makes image interpretation difficult.

[0016] As described below, the system 10 is configured to identify and treat one or more vitreous opacities 16 (see FIG. 2) within the eye 12 using polarization-sensitive optical coherence tomography (hereinafter "PS-OCT"). Referring to FIG. 2, the vitreous opacities 16 may be at various positions in the vitreous humor 18 of the eye 12, which are indicated by a first vitreous opacity 16A, a second vitreous opacity 16B, and a third vitreous opacity 16C (see FIG. 2). The vitreous humor 18 comprises approximately 98% water, hyaluronic acid, proteoglycans, and collagen fibers. Collagen forms uniform, parallel fibers that increase in density with age.

[0017] The main component of the vitreous opacities 16 is collagen. Collagen-containing tissues have birefringent properties, which are optical properties of a material whose refractive index depends on the polarization direction and propagation direction of light. As shown in FIG. 3, when polarized light 110 passes through a material 112 having birefringent properties, such as a tissue with collagen fibers, a first polarization direction 114 of the light is retarded relative to a second polarization direction 116, resulting in a phase retardation 118. The magnitude of the phase retardation 118 can be used to characterize the structure of the material 112.

[0018] Referring to Figure 1, the system 10 includes a controller C, which has at least one processor P and at least one memory M (or non-transitory tangible computer-readable storage medium) on which instructions for executing the method 200 of visualizing vitreous opacities 16 in the eye 12 using the PS-OCT device 14 are recorded. The method 200 is shown in Figure 4 and will be described later with reference thereto.

[0019] The system 10 enables identification of tissue-specific contrast used to characterize the vitreous opacities 16. Referring now to Figure 5, an exemplary diagram of relatively healthy collagen fibrils 310 in the vitreous humor 18 is shown. Referring to Figure 5, the collagen fibrils 310 form a widespread network by being organized into relatively aligned or parallel bundles (e.g., a first bundle 312 and a second bundle 314). The collagen fibrils 310 are interconnected and spaced apart by chondroitin sulfate chains 316. In a relatively healthy eye, the chondroitin sulfate chains 316 may be substantially orthogonal to the first bundle 312 and the second bundle 314.

[0020] Figure 6 is a schematic exemplary diagram of relatively unhealthy collagen fibrils 410 in the vitreous humor 18. The location of the vitreous opacity 16 can be characterized by the presence of aggregated cross-linked collagen fibrils 410. As shown in Figure 6, the collagen fibrils 410 are aggregated at various locations in a state where the bundles of collagen fibrils 410 such as the first bundle 412 and the second bundle 414 are relatively unaligned. The collagen fibrils 410 aggregate due to various factors, such as the loss of a specific type (e.g., type IX) of collagen from the fiber surface. These factors may include, in addition to age, various eye diseases such as posterior vitreous detachment and myopic vitreopathy.

[0021] Referring here to Figure 1, the system 10 includes a light source 20 adapted to generate a PS-OCT light source beam 22. The light source 20 may be a wavelength-swept light source laser or other suitable OCT light source available to those skilled in the art. It should be understood that the PS-OCT apparatus 14 may take many different forms and may include multiple and / or alternative components.

[0022] As shown in Figure 1, the PS-OCT light source beam 22 propagates through the polarizer 24 to the beam splitter 26. The polarizer 24 receives the incident PS-OCT light source beam and transmits a polarized PS-OCT light source beam 30 with a known polarization state. In the beam splitter 26, the polarized PS-OCT light source beam 30 is split into two components: a sample beam 32 propagating through the sample arm 34 and a reference beam 36 propagating through the reference arm 38. The beam splitter 26 is an unpolarized 50 / 50 beam splitter.

[0023] Referring to Figure 1, the sample beam 32 passes through a first quarter-wave plate 40 within the sample arm 34, which converts the sample beam 32 into a polarized state of known polarization, thereby polarizing the sample beam 42 to be incident on the eye 12. Here, the first quarter-wave plate 40 may be angled at 45 degrees. A collimation unit 44 may be used to guide the polarized sample beam 42. Referring to Figure 2, the incident beam (polarized sample beam 42 in Figure 1) is reflected by the retina 50 and / or sclera 52 of the eye 12 and diffracted, reflected and / or refracted by the vitreous opacity 16 in the vitreous fluid 18. The reflected sample beam then returns to the PS-OCT instrument 14 through various combinations of optical instruments (not shown), for example.

[0024] In the reference arm 38, the reference beam 36 passes through a second quarter-wave plate 54 and a reference mirror 56. The second quarter-wave plate 54 converts the polarization state of the returned reference beam into a polarization state having two equal orthogonal polarization components. Here, the second quarter-wave plate 54 may be angled at 22.5 degrees. The reference arm 38 may include a dispersion compensator 55 positioned between the quarter-wave plate 54 and the reference mirror 56 to control the chromatic dispersion of the beam.

[0025] Referring to Figure 1, when the reflected sample beam (reflected by a portion of the eye 12) and the reflected reference beam (reflected by the reference mirror 56) are combined in the beam splitter 26, a reflected PS-OCT beam 60 is formed, which is directed to the polarizing beam splitter 62. The reflected PS-OCT beam 60 is a combination of the reflected beams of the sample beam and the reference beam. In the polarizing beam splitter 62, the reflected PS-OCT beam 60 is split into two orthogonal polarization components, for example, 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 vertex of the cornea 68. The term "vertical" may 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 may be changed depending on the application.

[0026] Referring to Figure 1, the 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. In the example shown in Figure 1, the vertical polarization-sensitive detector 70 is adapted to receive the vertical polarization component 64, and the 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 about the interference pattern. This data can be transmitted to the controller C via the OCT processor 74.

[0027] Referring to Figure 1, controller C may be configured to process signals from PS-OCT equipment 14 for broadcasting on display 76. Display 76 may, but is not limited to, a high-resolution or ultra-high-resolution television, smart eyewear, a projector, one or more computer screens, a laptop computer, a tablet computer, and a touchscreen. Referring to Figure 1, controller C may be configured to receive and transmit data through a user interface 78. The user interface 78 may be installed on a smartphone, laptop, tablet, desktop, or other electronic device.

[0028] Various components of system 10 in Figure 1 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. Local area networks may include, but are not limited to, Controller Area Network (CAN), Controller Area Network with Flexible Data Rate (CAN-FD), Ethernet, Bluetooth®, Wi-Fi, and other data connection forms. Network 80 may be a wireless local area network (LAN) connecting multiple devices using a wireless distributed scheme, a wireless metropolitan area network (MAN) or wireless wide area network (WAN) connecting several wireless LANs. Other types of connections may also be used.

[0029] Referring now to Figure 4, a flowchart of method 200 that can be executed by controller C in Figure 1 is shown. Method 200 does not need to be applied in the specific order described herein, and some blocks may be omitted. Memory M can store a controller executable instruction set, and processor P can execute the controller executable instruction set stored in memory M.

[0030] Starting from block 202 in Figure 4, controller C is configured to receive PS-OCT data captured by the PS-OCT instrument 14. Proceeding to block 204 in Figure 4, controller C is configured to analyze the PS-OCT data to identify at least one parameter corresponding to the birefringence characteristics of collagen fibrils in the vitreous fluid. The parameter includes the spacing between each collagen fibrils 410, for example, the spacing 418 between the first bundle 412 and the second bundle 414 shown in Figure 6. The parameter may include the orientation 420 of each collagen fibril 410, for example, whether the bundles are parallel or flared. Each orientation 420 may be represented by the angle between each bundle.

[0031] Proceeding to block 206 in Figure 4, controller C may be configured to identify each location of vitreous turbidity 16 (such as location 430 in Figure 6) when the parameters are outside a predetermined numerical range, for example, when each interval 418 is smaller than a threshold. For example, each interval 418 between the first bundle 412 and the second bundle 414 is approximately zero at location 430, which may be designated as vitreous turbidity 16. In some embodiments, controller C may generate a multifactor score based on PS-OCT data for each grid or segment of the spatial image of the vitreous fluid 18.

[0032] Referring to Figure 7, a workflow diagram for processing PS-OCT data is shown. The PS-OCT instrument 14 in Figure 1 may include a first channel 502 and a second channel 504 (shown in Figure 7), which are adapted to detect signals from PS-OCT data in two orthogonal polarization states, namely a first orthogonal polarization state and a second orthogonal polarization state (e.g., vertical and horizontal polarization states). Referring to Figure 7, the raw data from the first channel 502 and the second channel 594 is sent to a preprocessing unit 506, where several preprocessing steps are performed. These may include padding, windowing, background removal, filtering, and the like.

[0033] Each signal output by the preprocessing module 506 undergoes a Fast Fourier Transform, as shown in block 508 of Figure 7. After the Fourier Transform, the signals from the first channel 502 and the second channel 504 are processed individually, as shown in blocks 510 and 512, to obtain the OCT signals, E1 and E2, respectively. The Fast Fourier Transform signal from the first channel 502 is,

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[0034] Phase delay mode 516 is,

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[0035] Figure 8 is a schematic diagram of an exemplary PS-OCT image displayed in phase delay mode 516. Arrow 620 highlights the contrast due to collagen content (e.g., in the vitreous fluid 18). Phase delay mode 516 is visualized in the range of 0 to 90 degrees. As shown in legend 615, the data is divided into individual blocks of 10 degrees each. The vertical axis 605 and horizontal axis 610 indicate spatial dimensions.

[0036] Optical axis mode 518 is,

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[0037] Intensity mode 514 is,

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[0038] Block 208 in Figure 4 shows that method 200 includes generating a control signal to direct at least one treatment beam 82 to each location of the vitreous opacity 16 (e.g., location 430 in Figure 6). Block 210 shows that the treatment beam 82 (see Figure 1) may be delivered based on this control signal. Referring again to Figure 1, system 10 may include a laser unit 84 configured to selectively generate at least one treatment beam 82 directed toward the vitreous opacity 16 via a laser source 86. The treatment beam 82 may include a plurality of ultrashort laser pulses, each approximately 1 femtosecond (10⁻¹⁶). -15 (seconds) ~ approximately 50 picoseconds (50 x 10 -12 It has a duration of (seconds). Data from the control signal is processed through the laser processor 88 and can be used to optimize the treatment beam 82 to at least partially vaporize or decompose the vitreous opacity 16.

[0039] The laser source 86 may be a femtosecond or picosecond laser and may emit light with a wavelength of approximately 1,050 nm. In one example, the laser source 86 is configured to deliver infrared radiation with a wavelength of approximately 700 nanometers to 1220 nanometers. It should be understood that the position of the laser source 86 relative to the light source 20 of the PS-OCT instrument 14 may be changed. Referring to Figure 1, the position of the laser source 86 and the direction of the treatment beam 82 may be changed to target multiple locations of the vitreous turbidity 16. For example, as shown in Figure 1, the laser source may be moved to position 87 to generate a second treatment beam 83. 1. In some embodiments, the laser unit 84 may be movable with respect to the central axis A. This may be achieved through an operator-controlled input device 90, such as a keyboard, mouse, or joystick.

[0040] In some embodiments, the system 10 incorporates a shared aperture 92 (see Figure 1) for simultaneously generating an image of the vitreous opacity 16 and delivering treatment thereto. The shared aperture 92 may be centered on and perpendicular to the central axis A. The treatment beam 82 may be directed off-axis at an off-axis angle 94 between the treatment beam 82 and the central axis A. In some embodiments, the off-axis angle 94 may be 15 degrees or more. The off-axis angle 94 may be 30 degrees or more.

[0041] The treatment beam 82 can be delivered in various patterns and settings depending on the application at the time. It should be understood that various modulators or shapers may be used by the system 10 to adjust the treatment beam. For example, as shown in Figure 2, the barrier 96 may be positioned near the eye 12 and adapted to shallow the depth of field of the laser delivery. This causes the treatment beam 82 to be highly focused. The barrier 96 may be a contact lens that is directly fitted onto the cornea 68 of the eye 12.

[0042] In summary, System 10 provides a robust method to assist physicians in identifying and treating one or more vitreous opacities 16 within an eye 12. System 10 enables the non-invasive generation of tissue-specific contrast images of vitreous floats.

[0043] Controller C in Figure 1 includes computer-readable media (also called processor-readable media), which include non-temporary (e.g., tangible) media involved in providing data (e.g., instructions) that can be read by a computer (e.g., by the computer's processor). Such media can take many forms, including but not limited to non-volatile media and volatile media. Examples of non-volatile media include optical or magnetic disks and other persistent memory. Examples of volatile media include dynamic random access memory (DRAM), which can constitute main memory. Such instructions can be transmitted by one or more transmission media, such as coaxial cables, copper wires, and optical fibers, which include wiring including a system bus coupled to the computer's processor. Some forms of computer-readable media include, for example, floppy disks, flexible 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 a computer can read.

[0044] The lookup tables, databases, data repositories, or other data stores described herein may include various mechanisms for storing, accessing, and retrieving various types of data, including hierarchical databases, files within a file system, proprietary application databases, and relational database management systems (RDBMS). Each such data store may reside within a computing device employing a computer operating system, such as one of the aforementioned, and may be accessed over a network in one or more different ways. File systems may be accessible from a computer operating system and may contain files stored in various formats. RDBMS may use structured query language (SQL) in addition to languages ​​for creating, saving, editing, and executing stored procedures, such as the PL / SQL language described above.

[0045] The flowcharts shown in the figures illustrate the architecture, functionality, and operation of feasible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, segment, or portion of code which includes one or more executable instructions for performing a specified logical function. It should also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, may be implemented by a system based on hardware for a specific purpose or a combination of hardware for a specific purpose and computer instructions that perform a specified function or action. These computer program instructions may also be stored in a computer-readable medium which can instruct a controller or other programmable data processing device to function in a specific way so that the instructions stored in the computer-readable medium produce a product which includes instructions that cause a block in the flowchart and / or block diagram to perform a specified function / action.

[0046] It should be understood that numerical values ​​indicating degree (e.g., quantity or state) in this specification, including the appended claims, are modified by “approximately” in each case, regardless of whether the term “approximately” actually precedes the numerical value. “Approximately” indicates that the stated numerical value allows for some degree of slight inaccuracy (somewhat close to the exact value, roughly the value, or reasonably close to it, nearly). Where the inaccuracy provided by “approximately” is not understood in this ordinary sense in the art, “approximately” as used herein indicates at least such degree of variation that may arise from ordinary methods of measurement and use. In addition, disclosures of ranges include disclosures of each value within the entire range and further subdivided ranges. In this specification, each value within a range and the endpoints of a range are disclosed as separate embodiments.

[0047] While the detailed description and drawings or figures are supplementary and illustrative to this disclosure, the scope of this disclosure is defined solely by the claims. Although several best modes and other embodiments for carrying out the claimed disclosure have been described in detail, there are various alternative designs and embodiments for carrying out the disclosure as defined in the accompanying claims. Furthermore, the characteristics of the embodiments shown in the drawings or the various embodiments referred to in this description should not necessarily be understood as independent embodiments. Rather, each characteristic described in one example of an embodiment may be combined with one or more other desirable characteristics from other embodiments, resulting in other embodiments not described in words or by reference to the drawings. Thus, such other embodiments are included within the framework of the accompanying claims.

Claims

1. A system for visualizing target areas within the eye using a polarization-sensitive optical coherence tomography (PS-OCT) device, The controller includes at least one processor and at least one non-temporary tangible memory on which instructions are recorded, wherein the target site is one or more vitreous opacities in the vitreous fluid of the eye. The PS-OCT device includes a light source adapted to generate a PS-OCT light source beam, and a polarizer adapted to control the polarization of the PS-OCT light source beam. The PS-OCT instrument includes one or more polarization-sensitive detectors adapted to detect interference patterns based partially on a reflected PS-OCT beam and to generate PS-OCT data relating to the interference patterns. The controller is configured to receive the PS-OCT data and, based on the PS-OCT data, to identify at least one parameter corresponding to the birefringence characteristics of the collagen fibrils in the vitreous fluid, wherein the at least one parameter includes the spacing between each of the collagen fibrils. The controller is configured to identify the location of each of the one or more vitreous opacities and to generate a control signal adapted to guide a therapeutic beam to each of the one or more vitreous opacities when the at least one parameter is outside a predetermined range.

2. The system according to claim 1, wherein the at least one parameter includes the orientation of each of the collagen fibrils.

3. The aforementioned PS-OCT device is A beam splitter adapted to split the PS-OCT light source beam into a sample beam propagating within a sample arm and a reference beam propagating within a reference arm, wherein the reference arm has a reference mirror, and the beam splitter A polarization beam splitter adapted to split the reflected PS-OCT beam into two orthogonal polarization components, wherein the reflected PS-OCT beam is a combination of the reflected beams of the sample beam and the reference beam, and The system according to claim 1, including the following:

4. The aforementioned PS-OCT device is A first quarter-wave plate adapted to convert the sample beam into a polarized sample beam incident on the target area, A second quarter-wave plate adapted to convert the reference beam into a polarized reference beam incident on the reference mirror, The system according to claim 3, including the system described in claim 3.

5. The two orthogonal polarization components include a vertical polarization component and a horizontal polarization component, and The system according to claim 4, wherein 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 according to 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 according to claim 1, wherein the PS-OCT instrument includes a first channel and a second channel adapted to detect signals from the PS-OCT data in a first orthogonal polarization state and a second orthogonal polarization state, respectively, the signals are converted into fast Fourier transform signals.

8. The system further includes a phase delay mode adapted to display the PS-OCT data, wherein the phase delay mode is [Math 1] Based on the delay coefficient (δ) expressed as, in the formula, F is the calibration coefficient and A １ A ２ The system according to claim 7, wherein is the amplitude of the fast Fourier transform signals from the first channel and the second channel, respectively.

9. The optical axis mode further includes an optical axis mode adapted to display the PS-OCT data, wherein the optical axis mode is [Math 2] Based on the optical coefficient (θ) expressed as, in the formula, Φ １ and Φ ２ The system according to claim 7, wherein is the phase of the fast Fourier transform signals from the first channel and the second channel, respectively.

10. The system according to claim 1, further comprising a laser unit adapted to selectively generate the therapeutic beam directed toward one or more vitreous opacities, wherein the therapeutic beam comprises a plurality of ultrashort laser pulses, each defining a duration of about 1 femtosecond to about 50 picoseconds.

11. The laser unit and the PS-OCT device have a shared aperture for guiding the therapeutic beam and the PS-OCT beam toward the target site, the shared aperture being centered on a central axis, according to claim 10.

12. The system according to claim 11, wherein the treatment beam travels at an off-axis angle from the central axis, and the off-axis angle is 15 degrees or more.

13. A method for visualizing an intraocular target site using a polarization-sensitive optical coherence tomography (PS-OCT) device in a system having a controller comprising at least one processor and at least one non-temporary tangible memory, The process involves generating a PS-OCT light source beam via a light source within the PS-OCT device, wherein the target area is one or more vitreous opacities in the vitreous fluid of the eye. Controlling the polarization of the PS-OCT light source beam via a polarizer in the PS-OCT device, The PS-OCT device detects interference patterns based on a partial reflection of the PS-OCT beam via one or more polarization-sensitive detectors, and generates PS-OCT data relating to the interference patterns. The PS-OCT data is received via the controller, The process involves, via the controller, identifying at least one parameter corresponding to the birefringence characteristics of the collagen fibrils in the vitreous fluid based on the PS-OCT data, wherein the at least one parameter includes the spacing between each of the collagen fibrils. If at least one of the parameters is outside a predetermined range, the controller is used to identify the location of each of the one or more vitreous opacities. The controller generates a control signal adapted to guide a therapeutic beam to each of the locations of the one or more vitreous opacities. A method that includes this.

14. The method according to claim 13, further comprising incorporating the orientation of each of the collagen fibrils into the at least one parameter.

15. The PS-OCT light source beam is split using a beam splitter into a sample beam propagating within a sample arm and a reference beam propagating within a reference arm, wherein the reference arm has a reference mirror. The method involves splitting the reflected PS-OCT beam into two orthogonal polarization components using a polarizing beam splitter, wherein the reflected PS-OCT beam is a combination of the reflected beams of the sample beam and the reference beam. The sample beam is converted into a polarized sample beam incident on the target area via a first quarter-wave plate, The first quarter-wave plate is used to convert the reference beam into a polarized reference beam that is incident on the reference mirror. The method according to claim 13, further comprising:

16. The method according to claim 13, further comprising orienting 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 involves selectively generating the therapeutic beam, which is directed toward one or more vitreous opacities via a laser unit, wherein the therapeutic beam comprises a plurality of ultrashort laser pulses. The laser unit and the PS-OCT device are configured to have a shared aperture for guiding the treatment beam and the PS-OCT beam toward the target site, wherein the shared aperture is configured to be centered on a central axis. The method according to claim 13, further comprising:

18. The method according to claim 13, further comprising incorporating a first channel and a second channel into the PS-OCT device for detecting signals from the PS-OCT data in a first orthogonal polarization state and a second orthogonal polarization state, respectively, wherein the signals are converted into fast Fourier transform signals.

19. The method further includes displaying the PS-OCT data in phase delay mode, wherein the phase delay mode is [Math 3] Based on the delay coefficient (δ) expressed as, in the formula, F is the calibration coefficient and A １ A ２ The method according to claim 18, wherein is the amplitude of the fast Fourier transform signals from the first channel and the second channel, respectively.

20. The method further includes displaying the PS-OCT data in optical axis mode, wherein the optical axis mode is [Math 4] Based on the optical coefficient (θ) expressed as, in the formula, Φ １ and Φ ２ The method according to claim 18, wherein is the phase of the fast Fourier transform signals from the first channel and the second channel, respectively.

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