Patent Publication Number: US-2023157876-A1

Title: Vitreoretinal visualization for ophthalmic procedures

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to ophthalmic systems, and more particularly to vitreoretinal visualization for ophthalmic procedures. 
     BACKGROUND 
     Vitreoretinal eye procedures are performed in the vitreoretinal region of the eye. Examples of such procedures include: breaking up vitreous clumped pre-existing collagen fibers (“floaters”); vitreous traction of a flap tear (“horseshoe tear”) before in-office pneumatic retinopexy for limited retinal detachments; residual vitreoretinal traction after surgical vitrectomy; residual retinal tissue causing retinal detachment (or elevation) due to incomplete surgical retinectomy; selected small diabetic traction retinal detachments; and selected vitreomacular traction syndrome cases. 
     A doctor must be able to see the vitreoretinal region in order to successfully perform a procedure. Moreover, appropriate illumination is key to effective vitreoretinal visualization. Unfortunately, in some situations, known systems fail to provide illumination that yields effective visualization. 
     BRIEF SUMMARY 
     In certain embodiments, an ophthalmic system for visualizing an interior of an eye includes an illumination system and a visualization system. The illumination system illuminates the interior of the eye. The illumination system includes an annular illuminator that directs annular illumination, which has an illumination axis, towards the interior of the eye. The visualization system provides an image of the interior of the eye. The visualization system comprises visualization optical elements, which include an objective lens and oculars. The objective lens receives light reflected from the interior of the eye. The oculars, which have an ocular axis, transmit the reflected light to yield an image of the interior of the eye. 
     Embodiments may include none, one, some, or all of the following features. 
     The ophthalmic system includes a laser device that directs a treatment laser beam towards the interior of the eye. 
     The annular illuminator includes a laser source and annular optical elements. The laser source provides illumination light, and the annular optical elements modify the illumination light to yield the annular illumination. The laser source may provide the illumination light as a laser beam with a speckle pattern. The annular optical elements may include first and second axicons, where the first axicon transforms the illumination light into an annular distribution of light, and the second axicon modifies the annular distribution of light to yield the annular illumination. The annular optical elements may include an axicon and a spherical lens, where the axicon transforms the illumination light into an annular distribution of light, and the spherical lens modifies the annular distribution of light to yield the annular illumination. The annular optical elements may include an achromatic lens that focuses the annular illumination. 
     The annular illuminator includes a laser source and a spatial light modulator. The laser source provides an illumination light, and the spatial light modulator modifies the illumination light to yield the annular illumination. 
     The annular illuminator comprises an illumination ring, which includes lights disposed about the illumination ring. 
     The illumination axis is substantially coincident with the ocular axis. 
     The illumination axis is at an angle to the ocular axis. 
     The system comprises a slit lamp microscope. 
     In certain embodiments, an ophthalmic system for visualizing an interior of an eye includes an illumination system and a visualization system. The illumination system illuminates the interior of the eye. The illumination system comprises a multi-beam illuminator that directs illumination beams, which have an illumination axis, towards the interior of the eye. The multi-beam illuminator includes a laser source and one or more multi-beam optical elements. The laser source provides illumination light, and the multi-beam optical elements modify the illumination light to yield the illumination beams. The visualization system provides an image of the interior of the eye. The visualization system comprises visualization optical elements, which include an objective lens and oculars. The objective lens receives light reflected from the interior of the eye. The oculars, which have an ocular axis, transmit the reflected light to yield an image of the interior of the eye. 
     Embodiments may include none, one, some, or all of the following features. 
     The ophthalmic system includes a laser device that directs a treatment laser beam towards the interior of the eye. 
     The one or more multi-beam optical elements comprise a lenslet array that transforms the illumination light into the illumination beams. 
     The illumination beams are arranged into a circular pattern. 
     The illumination beams are arranged into a rectangular pattern. 
     The laser source provides a laser beam with a speckle pattern. 
     The illumination axis is substantially coincident with the ocular axis. 
     The illumination axis is at an angle to the ocular axis. 
     The system comprises a slit lamp microscope. 
     In certain embodiments, an ophthalmic system for visualizing an interior of an eye includes an illumination system, a visualization system, and a laser device. The illumination system illuminates the interior of the eye. The illumination system includes an annular illuminator that directs annular illumination, which has an illumination axis, towards the interior of the eye. The visualization system provides an image of the interior of the eye. The visualization system comprises a slit lamp microscope that has visualization optical elements, which include an objective lens and oculars. The objective lens receives light reflected from the interior of the eye. The oculars, which have an ocular axis, transmit the reflected light to yield an image of the interior of the eye. The laser device directs a treatment laser beam towards the interior of the eye. In the embodiments, the annular illuminator includes: a laser source that provides illumination light with a speckle pattern and annular optical elements that modify the illumination light to yield the annular illumination, the optical elements comprising a first axicon that transforms the illumination light into an annular distribution of light, a second axicon or a spherical lens that modifies the annular distribution of light to yield the annular illumination, and an achromatic lens that focuses the annular illumination; or a laser source that provides an illumination light and a spatial light modulator that modifies the illumination light to yield the annular illumination; or an illumination ring comprising lights disposed about the illumination ring. 
     In certain embodiments, an ophthalmic system for visualizing an interior of an eye includes an illumination system, a visualization system, and a laser device. The illumination system illuminates the interior of the eye. The illumination system comprises a multi-beam illuminator that directs illumination beams, which have an illumination axis, towards the interior of the eye. The multi-beam illuminator includes a laser source and one or more multi-beam optical elements. The laser source provides illumination light with a speckle pattern, and the multi-beam optical elements modify the illumination light to yield the illumination beams, which are arranged into a circular pattern or a rectangular pattern. The multi-beam optical elements comprise a lenslet array that transforms the illumination light into the illumination beams. The visualization system provides an image of the interior of the eye. The visualization system comprises a slit lamp microscope with visualization optical elements, which include an objective lens and oculars. The objective lens receives light reflected from the interior of the eye. The oculars, which have an ocular axis, transmit the reflected light to yield an image of the interior of the eye. The laser device directs a treatment laser beam towards the interior of the eye. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates an example of an ophthalmic system that provides vitreoretinal visualization for ophthalmic procedures, according to certain embodiments; 
         FIGS.  2  and  3    illustrate examples of illumination systems, according to certain embodiments, where  FIG.  2    illustrates an example of a coaxial illumination system and 
         FIG.  3    illustrates an example of an angled illumination system; 
         FIG.  4    illustrates an example of an ophthalmic laser system that may utilize an illumination system described herein, according to certain embodiments; 
         FIGS.  5 A through  5 C  illustrate examples of annular illuminators, according to certain embodiments, where  FIG.  5 A  illustrates an annular illuminator with one or more axicons,  FIG.  5 B  illustrates an annular illuminator with an illumination ring, and  FIG.  5 C  illustrates an annular illuminator with a spatial light modulator (SLM); 
         FIGS.  6 A and  6 B  illustrate examples of multi-beam illuminators, according to certain embodiments, where  FIG.  6 A  illustrates a multi-beam illuminator implemented as an angled illumination system, and  FIG.  6 B  illustrates a multi-beam illuminator implemented as a coaxial illumination system; and 
         FIG.  7    illustrates an example of a method for providing vitreoretinal visualization for ophthalmic procedures that may be performed by the system of  FIG.  1   , according to certain embodiments. 
     
    
    
     DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Referring now to the description and drawings, example embodiments of the disclosed apparatuses, systems, and methods are shown in detail. The description and drawings are not intended to be exhaustive or otherwise limit the claims to the specific embodiments shown in the drawings and disclosed in the description. Although the drawings represent possible embodiments, the drawings are not necessarily to scale and certain features may be simplified, exaggerated, removed, or partially sectioned to better illustrate the embodiments. 
     Vitreoretinal visualization (i.e., visualization of the vitreous and/or retina) can be difficult because some targets, such as eye floaters, are almost transparent and absorb very little light. In addition, external illumination of the vitreoretinal area is limited by Purkinje images, which are reflections from the surfaces of the cornea and lens. Moreover, laser vitreoretinal procedures are typically real-time, see-aim-and-shoot procedures, so visualization should be in real-time, stereo, and in color. For example, when treating eye floaters, the doctor should have real-time visualization to see movement of the floaters in response to laser shots. In addition, the doctor should be able to see the lens and retina in stereo and in color, as they provide anatomic landmarks that prevent spatial disorientation. 
     These and other challenges render known vitreoretinal imaging techniques unsatisfactory in certain situations. Accordingly, certain embodiments presented here provide real-time, stereo, and color vitreoretinal visualization. The embodiments use different types of illumination, which can be implemented in a variety of ways, to enhance vitreous visualization. 
       FIG.  1    illustrates an example of an ophthalmic system  110  that provides vitreoretinal visualization for ophthalmic procedures, according to certain embodiments. Ophthalmic system  110  illuminates the interior of the eye in order to provide an enhanced image of the interior, such as the vitreoretinal region. The vitreoretinal region comprises at least a portion of the vitreous and/or the retina. 
     As an overview of system  110 , in the example, ophthalmic system  110  includes a visualization system  112 , an illumination system  114 , a treatment system  116 , and a computer  118 . Visualization system  112  includes optical elements  120 , such as oculars  122  and an objective lens  124 . Illumination system  114  includes a light source  130  and optical elements  132 . Treatment system  116  includes a laser device  134 . 
     Turning to the details of system  110 , visualization system  112  receives light reflected from an eye and provides an image of the interior of the eye from the reflected light. Optical elements  120  modify the light reflected from the eye to yield an image of the eye. Optical elements  120  may be included in a slit lamp stereo microscope. In general, an optical element is a component that can act on (e.g., transmit, reflect, refract, diffract, collimate, condition, shape, focus, modulate, and/or otherwise act on) light. Examples of optical elements include a lens, a lens array, a mirror, a prism, a diffraction grating, a spatial light modulator (SLM), and a polarizer. 
     Continuing with visualization system  112 , objective lens  124  collects and focuses the reflected light to yield an image of the eye, and oculars  122  magnify the image. Oculars  122  typically have left and right view paths with an ocular axis that coincides with a middle path midway between the left and right view paths. 
     Illumination system  114  provides light to illuminate at least a part of the vitreoretinal region, e.g., the vitreous and/or retina. Light source  130  generates illumination light, e.g., an illumination laser beam. In certain embodiments, light source  130  provides the illumination light as an illumination laser beam with an intrinsic speckle pattern. Light source  130  may be a laser beam source. Optical elements  132  modify the illumination light to yield any suitable illumination, e.g., one or more of the following types of illumination, and direct the illumination light along an illumination path towards the eye. The types of illumination include the following: 
     (1) Annular Illumination (AN): Annular illumination is light (e.g., white light-emitting diode (LED) light) provided as a tube or a hollow cone (such as a truncated cone), where light absent from the interior. Annular illumination has an axis, e.g., the axis of the tube or cone of illumination. If the axis of the annular illumination is substantially coincident with an axis of the eye (e.g., visual or optical axis), retinal reflections and Purkinje images may be reduced. 
     (2) Multi-Beam Illumination (MB): Multi-beam illumination is light provided as a plurality of light beams, e.g., a plurality of laser beams. Multi-beam illumination has an axis, e.g., an axis substantially in the center of the pattern of beams and parallel to the beams. Multi-beam illumination enhances visualization of targets, e.g., vitreous floaters. 
     (3) Speckle Pattern (SP): The mutual interference of a set of coherent wavefronts of light (such as laser light) produce a speckle pattern. The speckle pattern enhances visualization of vitreous of targets, e.g., vitreous floaters. The speckle pattern may be used with any suitable optical configuration, e.g., a single beam, a slit beam, and/or multiple beams. For example, non-pulsed dual aiming beams may have intrinsic speckle. The beams may be co-aligned and focused on the same image plane as the stereo microscope, illumination light, and treatment laser beam. 
     The types of illumination may be implemented in any suitable manner, and an implementation may have any suitable type of illumination, e.g., only Speckle Pattern SP, only Annular Illumination AN, only Multi-Beam Illumination MB, or any combination of SP, AN, and MB, such as SP and AN or SP and MB. Examples of implementations include the following. 
     (1) Coaxial Implementation: From the output of illumination system  114 , the light travels on an illumination path between the left and right view paths of oculars  122  such that the illumination path is coincident with (e.g., within +/−3 or 5 degrees of) the midway path. Illumination system  114  or at least the output of light may be located between the left and right view paths of oculars  122 . A coaxial illumination system  114  is described in more detail with reference to  FIG.  2   . 
     (2) Angled (or Oblique) Implementation: At the output of illumination system  114 , the light travels on an illumination path that is at an angle (e.g., greater than 3 or 5 degrees, such as 45 to 135 degrees or 70 to 110 degrees) to the midway path. An optical element, such as a mirror or beam splitter, directs the light to be coincident with the midway path. An angled illumination system may be used as the main illumination system or may augment the main illumination system using a beam splitter. An angled illumination system  114  is described in more detail with reference to  FIG.  3   . 
     Treatment system  116  includes laser device  134  that provides a treatment laser beam to treat the eye. Laser device  134  may include any suitable laser, e.g., a nanosecond, femtosecond, or picosecond laser with any suitable gain medium (e.g., Yb-doped fiber laser). The laser beam may have any suitable wavelength, e.g., in a range from 500 nm to 1100 nm. Any suitable repetition rate may be used, e.g., 3 Hz to MHz, and any suitable pulse energy may be used, e.g., an energy level sufficient to yield plasma in the eye tissue. Computer  118  provides instructions to systems  112 ,  114 ,  116  to perform visualization procedures. 
       FIGS.  2  and  3    illustrate examples of illumination systems  114  ( 114   a  and  114   b ), according to certain embodiments. In the examples, oculars  122  include left L ocular  122   a  and right R ocular  122   b , with left L view path  140   a  and right R view path  140   b , respectively. A midway path  142  is located midway between left L view path  140   a  and right R view path  140   b . When system  110  is used to view an eye, midway path  142  is typically substantially coincident with an axis of the eye. Each illumination system  114  ( 114   a  and  114   b ) has an illumination path  144  ( 144   a  and  144   b ), respectively. In certain embodiments, illumination system  114  may supplement an existing or additional illumination system  145 . In other embodiments, illumination system  114  may be the main illumination system. 
       FIG.  2    illustrates an example of a coaxial illumination system  114   a . In the example, illumination system  114  is located between left L view path  140   a  and right R view path  140   b  such that illumination path  144   a  is coincident with midway path  142 . Since the illumination and viewing paths are separated, the illumination source cannot be seen by the view path. 
       FIG.  3    illustrates an example of an angled illumination system  114   b . In the example, the light output of illumination system  114  is not located on midway path  142 . An optical element  146  directs the illumination light onto midway path  142 . 
       FIG.  4    illustrates an example of an ophthalmic laser system  10  that may utilize an illumination system  114 , according to certain embodiments. In the example, ophthalmic laser system  10  comprises oculars  20 , a laser delivery head  22 , an illumination system  114 ,  145 , a positioning device (such as a joystick  28 ), a base  30 , and a console  32 , coupled as shown. Laser delivery head  22  includes a laser fiber  34 , a zoom system  36 , a collimator  38 , a mirror  40 , and an objective lens  42 , coupled as shown. Console  32  includes a computer (such as a controller  50 ), a laser  52 , and a user interface  54 , coupled as shown. 
     As an overview, ophthalmic laser system  10  includes a laser device  16  (e.g., laser  52 , laser fiber  34 , and laser delivery head  22 ) and a viewing portion (e.g., oculars  20 , objective lens  42 , mirror  48 , and illumination system  114 ,  145 ). Operator eye  12  utilizes the optical path from oculars  20  through mirror  40 , objective lens  42 , and mirror  48  to view patient eye  14 . A laser beam follows the laser path from laser  52  through laser delivery head  22  and mirror  48  to treat patient eye  14 . According to the overview, laser device  16  directs a laser beam comprising laser pulses towards a target within eye  14 . The viewing portion gathers light reflected from within eye  14  to yield an image of eye  14 . Controller  50  instructs laser device  16  to direct the laser pulses towards the target. 
     In more detail, in certain embodiments, oculars  20  allow operator eye  12  to view patient eye  14 . Laser delivery head  22  delivers a laser beam of laser pulses from laser  52  of console  32  to patient eye  14 . Laser fiber  34  of delivery head  22  transports the laser beam from laser  52  to the end of fiber  34 . Zoom system  36  includes optical elements that change the spot size of the laser beam that exits fiber  34 . Collimator  38  collimates the laser beam, and mirror  40  directs the beam through objective lens  42 , which focuses the beam. Zoom system  36  and collimator  38  are configured to direct a parallel laser beam to mirror  40 , in order to focus the laser beam onto the image plane of the viewing portion. Mirror  40  may be a dichroic mirror that is reflective for the laser beam wavelength and transmissive for visible light. 
     Illumination system  114 ,  145  may be an illumination system  114  as described herein or an existing illumination system  145  (e.g., a slit illuminator) to be supplemented by an illumination system  114  as shown in  FIGS.  2  and  3   . Base  30  supports laser delivery head  22  and illumination systems  114 ,  145 . Joystick  28  moves base  30  in the x-, y-, and z-directions. Console  32  includes components that support the operation of system  10 . Controller  50  of console  32  controls of the operation of components of system  10 , e.g., base  30 , laser delivery head  22 , illumination systems  114 ,  145 , laser  52 , and/or user interface  54 . Laser  52  supplies the laser beam. Laser  52  of laser device  16  may be similar to the laser of laser device  134  of  FIG.  1   . User interface  54  communicates information between the operator and system  10 . 
       FIGS.  5 A through  5 C  illustrate examples of annular illuminators  200  ( 200   a ,  200   b ,  200   c ) and visualization system  112 , according to certain embodiments. An annular illuminator  200  directs annular illumination towards the interior of an eye. In the examples, an annular illuminator  200  comprises a light source (e.g., laser source  210 ) that generates illumination light and annular optical elements that modify the illumination light to yield annular illumination. In certain embodiments, the light source may generate a laser beam, e.g., a laser beam with a speckle pattern. Visualization system  112  includes oculars  122 , which in turn include left L ocular  122   a  and right R ocular  122   b , with left L view path  140   a  and right R view path  140   b , respectively. A midway path  142  is located midway between left L view path  140   a  and right R view path  140   b.    
       FIG.  5 A  illustrates an annular illuminator  200   a  with annular optical elements comprising one or more axicons. In the example, annular illuminator  200   a  is implemented as an angled illumination system  114   b . In other examples, however, annular illuminator  200   a  may be implemented as a coaxial illumination system  114   a , such as coaxial axicon optics on a slit lamp. 
     In certain embodiments, the annular optical elements comprise one, two, or more axicons that yield the annular illumination. An axicon is a lens with a conical surface that transforms a laser beam into an annular distribution. An axicon typically has a long linear depth of focus, not a point focus. In the example, the annular optical elements include a laser source  210 , an optical fiber  214 , a lens  216 , a prism  218 , an axicon  220 , an axicon  222 , an objective lens  224 , and a beam splitter  226 , optically coupled as shown. In the embodiments, laser source  210  generates a laser beam, which optical fiber  214  delivers to lens  216 . Lens  216  directs the beam to prism  218 , which directs the beam to axicons  220  and  222 . Axicons  220  and  222  yield the annular illumination. In the embodiments, axicon  220  transforms the illumination light into an annular distribution of light, and axicon  222  modifies the annular distribution of light to yield the annular illumination. 
     The annular optical elements may include other or additional optical elements. For example, the annular optical elements may include an element that collimates light prior to axicons  220  and  222 . As another example, the annular optical elements may include an element that yields a Bessel beam before, between, or after axicons  220  and  222 . As another example, the annular optical elements may include an axicon transforms the illumination light into an annular distribution of light, and a spherical lens modifies the annular distribution of light to yield the annular illumination. 
     Objective lens  224  focuses the illumination light, and may comprise, e.g., a lens such as an achromat. An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration. Achromatic lenses are corrected to bring two wavelengths (typically red and blue) into focus on the same plane. Beam splitter  226  directs the come of light towards the eye. 
       FIG.  5 B  illustrates an annular illuminator  200   b  with annular optical elements comprising an illumination ring  230 . In the example, annular illuminator  200   b  includes a ring substrate  232  and a plurality of light emitters  234 . Ring substrate  232  supports light emitters  234  and may have any suitable diameter, e.g., 10 to 20 millimeters, such as similar to the diameter of the cornea, e.g., 12 mm. Light emitters  234  emit light to yield the annular illumination. Light emitters  234  may be individual light sources, e.g., LED lights (such as white or green), or may be light outputs, e.g., the output of optical fibers delivering light from a light source. Annular illuminator  200   b  may be implemented as a coaxial illumination system  114   a  or in some cases as an angled illumination system  114   b.    
       FIG.  5 C  illustrates an annular illuminator  200   c  with annular optical elements comprising a spatial light modulator (SLM)  230 . In the example, annular illuminator  200   c  is implemented as a coaxial illumination system  114   a . In other examples, annular illuminator  200   c  may be implemented as an angled illumination system  114   b.    
     In the example, annular illuminator  200   c  includes a laser source  210 , SLM  230 , and an objective lens  224 , coupled as shown. Laser source  210  generates a laser beam. SLM  230  modulates the laser beam to yield annular illumination. SLM  230  may be any suitable SLM, e.g., a reflective and/or transmissive SLM or a phase-controlled SLM, such as a phase-controlled programmable liquid crystal on silicon (LCoS or LCOS) SLM. Objective lens  224  focuses the illumination light. 
       FIGS.  6 A and  6 B  illustrate examples of multi-beam illuminators  250  and visualization system  112 , according to certain embodiments. A multi-beam illuminator  250  directs a plurality of substantially parallel illumination beams towards the interior of an eye. In the examples, multi-beam illuminators  250  ( 250   a ,  250   b ) include a light source (e.g., a laser source  210 ) and multi-beam optical elements (e.g., a beam multiplier  252  and an objective lens  224 ), optically coupled as shown. Visualization system  112  includes oculars  122 , which in turn include left L ocular  122   a  and right R ocular  122   b , with left L view path  140   a  and right R view path  140   b , respectively. A midway path  142  is located midway between left L view path  140   a  and right R view path  140   b.    
     In certain embodiments, the light source generates illumination light. In certain embodiments, the light source may be laser source  210  that generates a laser beam, e.g., a laser beam with a speckle pattern. Multi-beam optical elements modify the illumination light to yield the illumination beams. Beam multiplier  252  modulates (e.g., multiples) the laser beam to yield the illumination beams, and objective lens  224  focuses the beams. In certain embodiments, beam multiplier  252  or other multi-beam optical element collimates the laser beam to yield substantially parallel illumination beams. 
     Beam multiplier  252  may comprise any suitable optical element that yields more beams from fewer beams (e.g., multiple beams from one beam), e.g., a lenslet array (e.g., a wafer optics lenslet array) or a SLM. The intersections (e.g., laser spots) of the beams with a plane orthogonal to the direction of the beams may have any suitable pattern, e.g., a rectangular or a polar array. A rectangular array comprises rows of spots, where the rows may be (but are not necessarily) equidistant from each other. The spots of the rows may or may not align into columns. A polar array comprises concentric ovals, such as concentric circles. 
       FIG.  6 A  illustrates multi-beam illuminator  250   a  implemented as an angled illumination system. In the example, the light output of illuminator  250   a  is not located on midway path  142 . A beam splitter directs the illumination light onto midway path  142 . 
       FIG.  6 B  illustrates multi-beam illuminator  250   b  implemented as a coaxial illumination system. In the example, illuminator  250   b  is located between left L view path  140   a  and right R view path  140   b  such that the illumination path is coincident with midway path  142 . 
       FIG.  7    illustrates an example of a method for providing vitreoretinal visualization for ophthalmic procedures, such as a laser vitreolysis procedure, that may be performed by system  110  of  FIG.  1   , according to certain embodiments. The method begins at step  410 , where illumination system  114  generates light. The light may be a laser beam, e.g., a laser beam with a speckle pattern. 
     Illumination system  114  modifies the light at step  412 . Optical elements of system  114  modify the light to yield annular or multi-beam illumination. Illumination system  114  directs the light towards the interior of the eye at step  416  to illuminate at least a part or all of the vitreoretinal region, e.g., the vitreous and/or retina. The illumination may be directed coaxially or at an angle. 
     Visualization system  112  captures light reflected from the interior of the eye at step  418 . Optical elements of visualization system  112  provide an image of the eye from the reflected light at step  420 . Oculars  122  may provide the image to a user of system  110 . Treatment system  116  directs a treatment laser beam towards the eye at step  422 . The user may instruct treatment system  116  to direct the treatment laser beam towards a target identified in the image. The method then ends. 
     Certain embodiments of the optical visualization systems may have advantages over digital imaging systems. Doctors are more familiar with optical systems. In addition, digital imaging processing involves certain estimates and ambiguity that optical processes do not. Moreover, live optical systems are more reliable and require less complex software development and less regulatory approval. 
     A component (such as computer  118 ) of the systems and apparatuses disclosed herein may include an interface, logic, and/or memory, any of which may include computer hardware and/or software. An interface can receive input to the component and/or send output from the component, and is typically used to exchange information between, e.g., software, hardware, peripheral devices, users, and combinations of these. A user interface is a type of interface that a user can utilize to communicate with (e.g., send input to and/or receive output from) a computer. Examples of user interfaces include a display, Graphical User Interface (GUI), touchscreen, keyboard, mouse, gesture sensor, microphone, and speakers. 
     Logic can perform operations of the component. Logic may include one or more electronic devices that process data, e.g., execute instructions to generate output from input. Examples of such an electronic device include a computer, processor, microprocessor (e.g., a Central Processing Unit (CPU)), and computer chip. Logic may include computer software that encodes instructions capable of being executed by an electronic device to perform operations. Examples of computer software include a computer program, application, and operating system. 
     A memory can store information and may comprise tangible, computer-readable, and/or computer-executable storage medium. Examples of memory include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., a Compact Disk (CD) or Digital Video or Versatile Disk (DVD)), database, network storage (e.g., a server), and/or other computer-readable media. Particular embodiments may be directed to memory encoded with computer software. 
     Although this disclosure has been described in terms of certain embodiments, modifications (such as changes, substitutions, additions, omissions, and/or other modifications) of the embodiments will be apparent to those skilled in the art. Accordingly, modifications may be made to the embodiments without departing from the scope of the invention. For example, modifications may be made to the systems and apparatuses disclosed herein. The components of the systems and apparatuses may be integrated or separated, or the operations of the systems and apparatuses may be performed by more, fewer, or other components, as apparent to those skilled in the art. As another example, modifications may be made to the methods disclosed herein. The methods may include more, fewer, or other steps, and the steps may be performed in any suitable order, as apparent to those skilled in the art. 
     To aid the Patent Office and readers in interpreting the claims, Applicants note that they do not intend any of the claims or claim elements to invoke 35 U.S.C. § 112(f), unless the words “means for” or “step for” are explicitly used in the particular claim. Use of any other term (e.g., “mechanism,” “module,” “device,” “unit,” “component,” “element,” “member,” “apparatus,” “machine,” “system,” “processor,” or “controller”) within a claim is understood by the applicants to refer to structures known to those skilled in the relevant art and is not intended to invoke 35 U.S.C. § 112(f).