Abstract:
Examples of devices and method for quantifying opacities in ah eye are shown. Examples include analysis of still images or video images. In one example a cross section area of opacities within a visual axis are quantified. Opacities in the vitreous of an eye, such as “floaters” can vary in severity from little or no reduction in vision, to bothersome, to high reduction in visual function. It is desirable to be able to quantify a level of severity of visual obstruction within a patient&#39;s eye and proceed with a level of treatment to match the condition.

Description:
CLAIM OF PRIORITY 
       [0001]    This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 62/062,617, filed on Oct. 10, 2014 and to U.S. Provisional Patent Application Ser. No. 61/989,931, filed on May 7, 2014, both of which are hereby incorporated by reference herein in their entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    This invention relates to devices and methods for ophthalmological procedures. 
       BACKGROUND 
       [0003]    Opacities in the vitreous of an eye, such as “floaters” can vary in severity from little or no reduction in vision, to bothersome, to high reduction in visual function. It is desirable to be able to quantify a level of severity of visual obstruction within a patient&#39;s eye and proceed with a level of treatment to match the condition. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  shows an eye, including a number of opacities according to an embodiment of the invention. 
           [0005]      FIG. 2  shows an image of the vitreous of the eye from  FIG. 1 , according to an embodiment of the invention. 
           [0006]      FIG. 3  shows a block diagram of an ophthalmological diagnostic device according to an embodiment of the invention. 
           [0007]      FIG. 4  shows an example method of quantifying opacities according to an embodiment of the invention. 
           [0008]      FIG. 5A  shows a block diagram of another ophthalmological diagnostic device according to an embodiment of the invention. 
           [0009]      FIG. 5B  shows an example image according to an embodiment of the invention. 
           [0010]      FIG. 6  shows another example method of quantifying opacities according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown, by way of illustration, specific embodiments in which the invention may be practiced. In the drawings, like numerals describe substantially similar components throughout the several views. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized and structural, or logical changes, etc. may be made without departing from the scope of the present invention. 
         [0012]      FIG. 1  shows an eye  100  with a cornea  110  at the top, and a central retina area  112  within a bottom portion of the eye  100 . A number of opacities  122 - 130  are shown within a vitreous  114  of the eye. In one example, the number of opacities  122 - 130  are considered “floaters,” however examples of the present invention are equally effective at quantifying other types of opacities, such as blood clots, etc. within the eye  100 . 
         [0013]    The visual axis  140  is defined by the dashed lines shown. In one example, only select opacities are within the visual axis  140 . In the example of  FIG. 1 , opacity  130  is located entirely within the visual axis  140 . The opacity  130  includes a cross section that projects an area  131  onto the central retina area  112 . In the example of  FIG. 1 , the entire area  131  is within the visual axis  140 . In addition, opacity  126  is shown with a cross section that projects an area  127 . The area  127  is shown with only a portion of the area  127  within the visual axis  140 . Other opacities  124 ,  128  and  122  project a cross section, however in the example of  FIG. 1 , none of these cross sections is within the visual axis  140 . 
         [0014]      FIG. 2  shows an example image  200  of the vitreous  114  from  FIG. 1 . The central retina area  112  is shown, and effectively forms the visual axis  140 . Any cross section that overlaps the central retina area  112  is within the visual axis  140 . As discussed above, area  123  is projected from a cross section of opacity  122 , area  125  is projected from a cross section of opacity  124 , area  127  is projected from a cross section of opacity  126 , area  129  is projected from a cross section of opacity  128 , and area  131  is projected from a cross section of opacity  130 . As discussed above, area  131  and a portion of area  127  overlap the central retina area  112 , and are considered within the visual axis  140 . 
         [0015]    In one example, an image analysis system is used in conjunction with image  200  to detect the opacities, and their respective area projections. In one example, the image analysis system is used to detect a density of opacities. In one example, the image analysis system is used to determine the blockage of light transmission by individual opacities. For example, software can be used with a digital image to detect darker or lighter regions and/or gradients between regions. 
         [0016]    An appropriate algorithm can be used to quantify a cross section area of the opacities within the vitreous. Analysis of the image can also capture an amount of reflectance to calculate a level of opacity (translucence) of individual opacities. In the example of  FIG. 2 , the cross section area of all opacities would equal an area sum of regions  123 ,  125 ,  127 ,  129  and  131 . In one example, the image analysis system further defines the visual axis  140 . In one example the retina can be detected from features in the image. In another example, a user can define the visual axis  140  manually using movable boundaries and software. 
         [0017]    In one example the image analysis system further quantifies an amount of the cross section area of the opacities that obstruct a retina. In the example of  FIG. 2 , the cross section area of opacities within the visual axis  140  would include all of region  131 , and the portion of region  127  that overlaps the central retina area  112 . In another example, any cross section area projected by an opacity that overlaps the central retina area  112  may be counted in its entirety, without accounting for what fraction is within the visual axis  140 . While less accurate, this example may be easier to implement with software. 
         [0018]    Using devices and methods described above, a cross section area of opacities that impinge on a patient&#39;s vision can be quantified and an appropriate treatment or lack of treatment can be chosen. Additionally, using devices and methods described above, a density of opacities that impinge on a patient&#39;s vision can be quantified and an appropriate treatment or lack of treatment can be chosen. 
         [0019]    In one example output, a color coded image or video can be calculated and displayed. Similar to a cloud cover weather map, very dense opacities may be color coded red to indicate a high level of obstruction, while more translucent opacities may be coded green, with yellow regions indicating an intermediate level of translucence. While these colors are used as an example, clearly other color schemes could be used. 
         [0020]    In one example the image  200  is a still image. In other examples, the image  200  includes a video image. Because opacities may only obstruct a patient&#39;s vision at one time or another depending on movement of the opacities within the eye and/or movement of the patient&#39;s eye itself, it may be useful to quantify an amount of obstruction over time using video analysis when the patient is moving their eye. Similar to the still photo example discussed above regarding  FIG. 2 , in a video example, each frame, or a sampled number of frames from the video file may be analyzed and the sum of each analyzed frame added together to determine a quantified amount of obstruction over time. 
         [0021]    Using the video example discussed above, it may be useful to have the patient move their eye in a controlled and repeatable manner in order to more consistently measure an amount of obstruction. 
         [0022]      FIG. 3  shows an ophthalmological diagnostic device  300  according to an embodiment of the invention. A patient&#39;s eye  302  is shown in relation to other block diagram elements of the device  300 . One of ordinary skill in the art, having the benefit of the present disclosure will recognize that any number of possible fixtures such as chin guides, forehead pads, etc. may be used to locate the patient&#39;s eye  302  within the device  300 . 
         [0023]    In one example the device  300  further includes an imaging device  310 . In one example, the imaging device  310  is an infrared imaging device. Although infrared is used as an example, other wavelengths of light and/or other imaging techniques may be used within the scope of the invention. In one example, the imaging device includes a scanning laser ophthalmoscope (SLO). Although a scanning imager is an example, the invention is not so limited. Non scanning imagers area also within the scope of the invention. The imaging device  310  acquires images of the vitreous within the patient&#39;s eye  302  along imaging direction  311 . 
         [0024]    The device  300  further includes at least one target  312  to align the patient&#39;s eye  302  at a desired angular orientation.  FIG. 3  shows four possible targets  312  as an example although, as described below, other examples are also within the scope of the invention. The targets  312  align the patient&#39;s eye  302  along the illustrated paths  320 - 326 . In one example, one or more mirrors can be used in conjunction with one or more targets to set a target distance, and an individual mirror can be moved to change an orientation of the target with respect to a straight-ahead gaze of the patient. 
         [0025]    Multiple selectable target locations A-D are also shown in  FIG. 3 . In one example a single target  312  is movable between the multiple selectable target locations to align the patient&#39;s eye  302  along a selected path  320 - 326 . In another example, multiple targets  312  are located at each target locations A-D, and a selected target  312  is activated, while other targets  312  are deactivated. For example, an LED light may be located at each target location A-D, and only a selected LED light is turned on at a time in order to orient the patient&#39;s eye  302  along a selected path  320 - 326 . 
         [0026]    Control circuitry  314  is further shown in  FIG. 3  to display the target at the multiple target locations A-D. In one example, the control circuitry  314  aligns the patient&#39;s eye  302  at a desired target location A-D and also signals the imaging device  310  to image the vitreous at each selected target location A-D. 
         [0027]    In one example, images are acquired with the eye stabilized by looking at a fixation target. The eye looks away, then back at the target (for example, a saccade), setting both the clear vitreous and opacities in motion for a few seconds. 
         [0028]      FIG. 4  shows an example method of quantifying opacities in an eye according to an example of the present invention. In operation  402  the vitreous cavity of an eye is imaged. In operation  404 , opacities are detected within the vitreous. In operation  406 , a cross section area of the opacities is quantified within the vitreous, and in operation  408 , an amount of the cross section area of the opacities that obstruct the central retina is quantified. 
         [0029]      FIG. 5A  shows an ophthalmological diagnostic device  500  according to an embodiment of the invention. A patient&#39;s eye  502  is shown in relation to other block diagram elements of the device  500 . One of ordinary skill in the art, having the benefit of the present disclosure will recognize that any number of possible fixtures such as chin guides, forehead pads, etc. may be used to locate the patient&#39;s eye  502  in relation to the device  500 . 
         [0030]    In one example the device  500  further includes an imaging device  510 . In one example, the imaging device  510  is an infrared imaging device. Although infrared is used as an example, other wavelengths of light and/or other imaging techniques may be used within the scope of the invention. In one example, the imaging device includes a scanning laser ophthalmoscope (SLO). Although a scanning imager is an example, the invention is not so limited. Non scanning imagers area also within the scope of the invention. The imaging device  510  acquires images of the vitreous within the patient&#39;s eye  502  along imaging direction  511 . 
         [0031]    A projector  520  is further shown in the device  500  of  FIG. 5A . In one example, the projector is configured to project text onto at least a portion of the retina. In one example, the projector includes a scanning laser projector. In the example shown in  FIG. 5 , the projector  520  is a separate component of the device  500 , although the invention is not so limited. In one example, the projector  520  is integrated with the imaging device  510 . In one example, a scanning laser ophthalmoscope (SLO) is adapted to both project text onto at least a portion of the retina, and provide an imaging function sufficient to quantify obstructions in a patient&#39;s vitreous, such as floaters discussed in examples above. 
         [0032]      FIG. 5B  shows an example image  530  of the vitreous  538  using the device  500  of  FIG. 5 . The central retina area  540  is shown, and effectively forms the visual axis, similar to the visual axis  140  from  FIG. 1 . Any cross section that overlaps the central retina area  540  is within the visual axis. Projected areas  532 ,  534 ,  536 ,  542 , and  544  are caused by opacities within the vitreous. One technical challenge with evaluation of a patient with opacities is that some opacity locations within a vitreous do not significantly affect a patient&#39;s quality of vision, while other opacity locations may significantly impair quality of vision. However, quantifying an effect of opacities can be difficult because the opacities may move within the vitreous over time, and results of a test to quantify a quality of vision may change over time, and with motion of the eye and/or vitreous. It is desirable to quantify a quality of vision using a practical and repeatable test. 
         [0033]      FIG. 5B  illustrates an amount of text  550  that is projected within a patient&#39;s eye, onto at least a portion of the retina area  540 . In the example shown, the text is projected upside down to correspond to the way text would be imaged naturally when focused on the retina area  540 . Although text is used as an example, any collection of symbols that can be read or otherwise deciphered in order may be used. As illustrated in  FIG. 5B , a portion of the text  550  is obscured by projected area  532  from an opacity within the vitreous  538 . 
         [0034]    In one method of quantification of quality of vision, a patient reads the text  550  during evaluation over a period of time. Due to the size and location of the text  550 , in one example the patient must move their eye over time in order to read the text, or otherwise decipher symbols. The eye motion will cause the vitreous to move, and will cause the projected areas of any opacities to cause different obstructions of the text  550  over time. 
         [0035]      FIG. 6  shows a flow diagram of one example method of evaluation of quality of vision that provides a quantifiable result. In operation  602 , an imaging device is used to image a vitreous of an eye that includes some amount of opacities within the vitreous. In operation  604 , opacities are detected. In the examples discussed above, the detection is based on an amount of obstruction within a visual axis. In one example, the amount of obstruction is quantified based on area measurements of projected areas from opacities compared with a total retina area  540 , or other suitable repeatable area. 
         [0036]    In operation  606 , text is projected onto at least a portion of the retina, as described above in relation to  FIGS. 5A and 5B . In operation  608 , a reading proficiency of the projected text is quantified. In one example, reading proficiency is quantified as reading speed. Other possible factors for quantification may include, but are not limited to reading accuracy, symbol identification, etc. Combinations of speed and accuracy are also possible. In operation  610 , the amount of obstruction over time while reading the text is quantified based on area measurements of projected areas from opacities compared with a total retina area  540 , or other suitable repeatable area. 
         [0037]    By combining both a reading test and quantification of an amount of obstruction over time, a very accurate and repeatable test is provided to evaluate a quality of vision in a patient with opacities in their vitreous. The reading test is a very practical test of what a patient will experience in daily activity. The motion of the vitreous and any opacities caused by reading will provide quantifiable data for opacities that may not have factored in to a static test because at any single given time, selected opacities may be in a periphery of the vitreous. However, when evaluated over time, due to eye motion reading text, these opacities that would have been missed, are included in the overall evaluation of the patient. 
         [0038]    In one example to encourage controlled eye movement, the text  550  is projected in an area larger than the retina area  540 , as shown in  FIG. 5B . An area of the text can be chosen in a repeatable size to control an amount of eye movement to provide a repeatable test. In one example, the text  550  is moved over time to different locations over the retina area  540  to encourage controlled eye movement. By controlling the locations of the text  550 , the eye motion is controllable to provide a repeatable test. 
         [0039]    To better illustrate the method and device disclosed herein, a non-limiting list of embodiments is provided here: 
         [0040]    Example 1 includes an ophthalmological diagnostic device. The device includes a vitreous imager, an image analysis system configured to detect opacities within a vitreous, and a retina analysis system configured to quantify an amount of obstruction of the retina from the opacities. 
         [0041]    Example 2 includes the ophthalmological diagnostic device of example 1, wherein the vitreous imager is configured to capture still photo images. 
         [0042]    Example 3 includes the ophthalmological diagnostic device of any one of examples 1-2, wherein the vitreous imager is configured to capture and record video images. 
         [0043]    Example 4 includes the ophthalmological diagnostic device of any one of examples 1-3, wherein the retina analysis system is configured to quantify an amount of obstruction of the retina per unit of time over a duration of at least a portion of a video. 
         [0044]    Example 5 includes the ophthalmological diagnostic device of any one of examples 1-4, further including a number of controlled targets to direct a patient&#39;s eye in a controlled way during a video image capture. 
         [0045]    Example 6 includes the ophthalmological diagnostic device of any one of examples 1-5, wherein the vitreous imager includes an infrared spectrum imager. 
         [0046]    Example 7 includes a method including imaging a vitreous of an eye, detecting opacities within the vitreous, quantifying a cross section area of the opacities within the vitreous, and quantifying an amount of the cross section area of the opacities that obstruct a retina. 
         [0047]    Example 8 includes the method of example 7, wherein imaging the vitreous of the eye includes infrared imaging. 
         [0048]    Example 9 includes the method of any one of examples 7-8, wherein imaging the vitreous of the eye includes still photographic imaging. 
         [0049]    Example 10 includes the method of any one of examples 7-9, wherein imaging the vitreous of the eye includes video imaging. 
         [0050]    Example 11 includes the method of any one of examples 7-10, wherein quantifying the amount of the cross section area of the opacities that obstruct the retina includes quantifying an amount of obstruction over time in a video. 
         [0051]    Example 12 includes the method of any one of examples 7-11, further including directing a patient to look from one direction to another in a controlled manner during video imaging. 
         [0052]    Example 13 includes an ophthalmological diagnostic device, comprising a vitreous imager, an image analysis system configured to detect opacities within a vitreous, a projector to project text onto a retina, and a retina analysis system configured to quantify an amount of obstruction of the retina from the opacities. 
         [0053]    Example 14 includes the device of example 13, wherein the projector includes a scanning laser projector. 
         [0054]    Example 15 includes the device of any one of examples 13-14, wherein the projector is integrated with the vitreous imager. 
         [0055]    Example 16 includes the device of any one of examples 13-15, wherein the projector is configured to move a projection location to different portions of the retina. 
         [0056]    Example 17 includes the device of any one of examples 13-16, further including a testing system to quantify a patient&#39;s reading proficiency of the projected text. 
         [0057]    Example 18 includes the device of any one of examples 13-17, wherein the testing system uses a number of factors to quantify a patient, the factors chosen from a group consisting of; an amount of obstruction of the retina from the opacities over time; a reading speed of the projected text; an amount of movement of the projected text; and an amount of movement of the vitreous. 
         [0058]    Example 19 includes an evaluation method, comprising imaging a vitreous of an eye, detecting opacities within the vitreous, projecting text onto a retina of the eye, quantifying a reading proficiency of the projected text, and quantifying any obstruction of the retina from the opacities while the reading proficiency is being quantified. 
         [0059]    Example 20 includes the method of claim  19 , wherein projecting text onto a retina of the eye includes moving text to different locations over the retina during the evaluation method. 
         [0060]    Example 21 includes the method of any one of examples 19-20, wherein quantifying a reading proficiency includes quantifying a reading speed. 
         [0061]    Example 22 includes the method of any one of examples 19-21, wherein a quantified evaluation score includes a factor of amount of obstruction over time. 
         [0062]    Example 23 includes the method of any one of examples 19-22, wherein a quantified evaluation score includes a factor of an amount of vitreous movement. 
         [0063]    Example 24 includes the method of any one of examples 19-23, wherein a quantified evaluation score includes a factor of an amount of projected text movement. 
         [0064]    Example 25 includes the method of any one of examples 19-24, wherein projecting text onto the retina of the eye include scanning text onto a retina of the eye using a laser. 
         [0065]    The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein. 
         [0066]    In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. 
         [0067]    The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. §1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.