Abstract: Methods, systems, and computer readable media for predicting early onset glaucoma via structural parameters obtained via time and spectral-domain optical coherence tomography (SD-OCT) are disclosed. SD-OCT technology measures the thicknesses of the layers of the retina that contain the cells that die in glaucoma before there is any functional loss. A multivariable predictive model may be used for the diagnosis of early glaucoma using a combination of optic nerve head (ONH), peripapillary retinal nerve fiber layer (RNFL), and macular ganglion cell-inner plexiform layer (GCIPL) parameters measured via SD-OCT. The model generates a glaucoma probability score for individual patient, which is valuable information in assisting clinicians in glaucoma diagnosis and treatment.

Abstract: Selection items which can be executed by an ophthalmologic application are displayed on a display portion on an ophthalmologic apparatus, and can be selected and executed by an operation portion on the ophthalmologic apparatus, thereby providing an ophthalmologic information process system and program which can reduce load on the operator and increase the overall throughput of examination. An ophthalmologic application transmits executable selection item information to the ophthalmologic apparatus and causes the ophthalmologic apparatus to display the information. Selection of one of the displayed selection items is executed by operation on the ophthalmologic apparatus. The behavior of the application is then controlled in accordance with the selection item.

Abstract: A Slit-lamp-or-Microscope-Integrated-OCT-Refractometer system includes an eye-visualization system, configured to provide a visual image of an imaged region in an eye; an Optical Coherence Tomographic (OCT) imaging system, configured to generate an OCT image of the imaged region; a refractometer, configured to generate a refractive mapping of the imaged region; and an analyzer, configured to determine refractive characteristics of the eye based on the OCT image and the refractive mapping, wherein the refractometer and the OCT imaging system are integrated into the eye visualization system.

Abstract: An image processing device for correcting at least a portion of a face image containing a person's face, includes an image acquisition unit that acquires a face image, a region extractor that extracts a pupil region containing a pupil from the face image, a determination unit that determines a presence or absence of halation in the pupil region, a first template acquisition unit that acquires a first template image which is a correction template image, a reference color acquisition unit that acquires a reference color corresponding to the person from the face image, a second template acquisition unit that generates a second template image using the first template image and the reference color, and a correction unit that composites the second template image with at least the region in the pupil region where the halation occurred to correct the halation.

Abstract: An applanation tonometer is disclosed for providing a measurement of intraocular fluid pressure inside the eye of a patient. The applanation tonometer includes a light-transmitting prism having a cornea contact tip at one end and a cornea alignment aid at the opposite end. The cornea alignment aid enables the patient to advise a vision professional when a light source of the tonometer is properly aligned with his cornea so that intraocular fluid pressure can be accurately measured. A light-blocking baffle is located at the opposite end of the prism, and a thin light-transmitting channel is formed through the baffle to lie on the longitudinal axis of the prism. In a preferred embodiment, the light baffle is at least one opaque disk, and the light-transmitting channel is a clear spot at the center of the opaque disk through which light is transmitted to the patient's cornea.

Abstract: An ophthalmologic apparatus of an embodiment includes an examination part, a moving mechanism, an information obtaining part, and a controller. The examination part is configured to include an optical system for optically examining an eye. The moving mechanism is configured to move the optical system. The information obtaining part is configured to obtain information for carrying out position matching of the optical system to the eye. The controller is configured to carry out first control for the moving mechanism based on the information obtained by the information obtaining part to move the optical system, determine whether information optically obtained by the optical system after the first control is appropriate to the examination or not, and when it is determined that this information is not appropriate, carry out second control for the moving mechanism in response to a prescribed trigger to move the optical system.

Abstract: A head mounted display system with at least one retinal display unit having a curved reflector positioned in front of one eye or both eyes of a wearer. The unit includes a first set of three modulated visible-light lasers co-aligned and adapted to provide a laser beam with selectable color and a first scanner unit providing both horizontal and vertical scanning of the laser beam across a portion of the curved reflector in directions so as to produce a reflection of the color laser beam through the pupil of the eye onto a portion of the retina large enough to encompass the fovea.

Abstract: A system for obtaining low-angle circumferential optical access to an eye of a subject. The system includes a light source to generate a beam of light; a beam steering mechanism to steer the beam of light a focusing lens to focus the beam of light; and a contact lens to direct the beam of light into the eye of the subject, the contact lens including a tapered reflective surface to direct the beam of light into the eye of the subject.

Abstract: An illumination arrangement includes illumination optics defining an optical axis and a light source for generating at least one illumination beam path for illuminating an object field at a specific illumination angle with a viewing beam path. At least one mirror is provided in the illumination beam path for deflecting light from the light source and the mirror has a longitudinal extent along the optical axis. A light-emitting surface region of the light source is variable (x) perpendicular to the optical axis without movable components. The illumination optics are embodied in such a way for obtaining a desired illumination that an illumination pupil is imaged within the longitudinal extent of the mirror.

Abstract: An image processing apparatus includes an identifying unit configured to identify a region relating to the movement of blood cells on a fundus image captured by an ophthalmologic imaging apparatus that includes an adaptive optics system, and an acquisition unit configured to acquire information relating to a tissue that is positioned on a back side of a position where the movement of blood cells is recognized, when it is seen from an anterior eye part side, in the identified region.

Abstract: Combined equipment for non-contacting determination of axial length (AL), anterior chamber depth (VKT) and corneal curvature (HHK) of the eye, are also important for the selection of the intraocular lens IOL to be implanted, particularly the selection of an intraocular lens (IOL) to be implanted, preferably with fixation of the eye by means of a fixating lamp and/or illumination through light sources grouped eccentrically about the observation axis.

Abstract: Systems, methods and apparatuses for an intraocular imaging system are disclosed comprising an optical coherence tomography (OCT) system. The OCT system has an imaging range that may enable substantial portions of an eye or even a whole eye to be imaged. The OCT system may be coupled to an operation microscope, such that, for example, a surgeon can visualize ocular structures like the human crystalline lens and other ocular structures such as the cornea and/or vitreous while surgical instruments are in the field of view.

Abstract: A prism prescription value acquisition system that includes a calculation part for numerically transforming a fixation disparity amount (unit: angle), which indicates a degree at which the visual axis is shifted from the central fovea of the retina when a subject conducts visual fixation of a target, into a prism prescription value by multiplying the fixation disparity amount by a coefficient when the fixation disparity amount is within ±4 minutes. Herein, the prism prescription value is calculated according to the following equation: APver=kver*FDver, APhor=khor*FDhor providing that each of coefficients khor and kver satisfies the following conditions: 0.3?kver?0.7, 1.4?khor?2.0.

Abstract: Angle multiplexed optical coherence tomography systems and methods can be used to evaluate ocular tissue and other anatomical structures or features of a patient. The angle multiplexed optical coherence tomography system includes a light source, an optical assembly for obtaining a plurality of sample beams corresponding to respective anatomical locations of the eye of the patient, where individual sample beams are associated with a respective non-zero angle relative to a reference beam, and a detection mechanism that detects individual unique interference patterns respectively provided by the plurality of sample beams, for simultaneous evaluation of the anatomical locations.

Abstract: An ophthalmologic imaging apparatus that can follow up imaging for acquiring a cross sectional image by referring to a front image of an eye acquired in the past and scanning the same position as before with light, includes: a photographing part configured to photograph the eye and acquire a front image thereof; a cross sectional image forming part configured to scan the eye with light and form a cross sectional image thereof; a storage configured to store a first front image of the eye and a second front image acquired in follow up imaging executed with referring to the first front image; an information obtaining part configured to analyze the first and second front images and obtain misregistration information between these front images; and a calculator configured to calculate an evaluation value of an error in a scanning position in the follow up imaging based on the misregistration information.

Abstract: To prevent improper authentication, a authentication device includes a visual-line detecting unit configured to detect a visual line direction of a user, an authentication-permission visual-line direction setting unit configured to set an authentication permission visual-line direction, a biometric deciding unit configured to execute authentication by deciding whether a detected visual line direction is an authentication permission visual-line direction, and a display control unit configured to cause a display unit to display an image showing a type of a visual line direction in setting an authentication permission visual-line direction and configured to cause the display unit not to display the image in executing authentication.

Abstract: Methods for determining a prescription (Rx) for a person include providing aberrometric data characterizing wavefront errors of the person's eye, the aberrometric data being obtained using an wavefront sensor and comprising one or more coefficients characterizing the wavefront errors; determining a starting Rx for the person's eye based on the one or more coefficients and on predetermined information relating aberrometric data and subjective refraction data for a plurality of people's eyes; and reporting the starting Rx to an eye care professional.

Abstract: The present invention is directed to a method for designing a soft contact lens with semi-customized back surface including determining axial radius topography data for a plurality of eyes of a specific population; calculating an apical radius and a conic constant distribution from the axial radius data; determining apical radius and conic constant values for an individual subject; selecting a subset of base curves from a base curve library based on the individual subject's apical radius and conic constant values; and selecting a final base curve from the subset of base curves that fits the individual subject's needs based on one or more selection criteria.

Abstract: A non-stereo fundus image is used to obtain a plurality of glaucoma indicators. Additionally, genome data for the subject is used to obtain genetic marker data relating to one or more genes and/or SNPs associated with glaucoma. The glaucoma indicators and genetic marker data are input into an adaptive model operative to generate an output indicative of a risk of glaucoma in the subject. In combination, the genetic indicators and genome data are more informative about the risk of glaucoma than either of the two in isolation. The adaptive model may be a two-stage model, having a first stage in which individual genetic indicators are combined with respective portions of the genome data by first adaptive model modules to form respective first outputs, and a second stage in which the first outputs are combined by a second adaptive mode.

Abstract: An image processing apparatus comprising, boundary extraction means for detecting boundaries of retina layers from a tomogram of an eye to be examined, exudate extraction means for extracting an exudate region from a fundus image of the eye to be examined, registration means for performing registration between the tomogram and the fundus image, and calculating a spatial correspondence between the tomogram and the fundus image, specifying means for specifying a region where an exudate exists in the tomogram using the boundaries of the retina layers, the exudate region, and the spatial correspondence, likelihood calculation means for calculating likelihoods of existence of the exudate in association with the specified region, and tomogram exudate extraction means for extracting an exudate region in the tomogram from the specified region using the likelihoods.

Abstract: An optometry apparatus includes: a housing accommodating a concave mirror disposed on a reference axis; and a display disposed outside the housing and out of the reference axis for projecting a target light flux onto the concave mirror. The concave mirror is configured to reflect the target light flux output from the display toward an examinee's eye along the reference axis.

Abstract: A photorefraction ocular screening device for assessing vision and corresponding disorders associated with the human ocular system is provided. More specifically, the present invention provides for a photorefraction ocular screening device employing advanced methods of pupil detection and refractive error analysis. The photorefraction ocular screening device is comprised of an LED arrangement configured with a plurality of irradiation sources serving as visual stimuli, wherein the visual stimuli may be presented in varying illumination patterns to the pupils of an examinee for expanding the range of ocular responses that can be used to determine refractive error.

Abstract: A photorefraction ocular screening device for assessing vision and corresponding disorders associated with the human ocular system is provided. More specifically, the present invention provides for a photorefraction ocular screening device employing advanced methods of pupil detection and refractive error analysis. The photorefraction ocular screening device is comprised of an LED arrangement configured with a plurality of irradiation sources serving as visual stimuli, wherein the visual stimuli may be presented in varying illumination patterns to the pupils of an examinee for expanding the range of ocular responses that can be used to determine refractive error.

Abstract: An ophthalmic apparatus comprising: an illumination optical system including a light source and configured to illuminate an eye to be examined; an imaging optical system including an image sensor and configured to image the eye illuminated by the illumination optical system; an optical member insertion/removal unit configured to insert/remove an optical member in/from at least one of optical paths in the illumination optical system and the imaging optical system; and a notification unit configured to notify an insertion/removal state of the optical member with respect to the optical path based on a signal output from the image sensor in synchronism with insertion/removal of the optical member in/from the optical path.

Abstract: Various embodiments of a device for performing a gaze field sobriety test are disclosed. The device includes a housing. A light source is affixed in or on the housing. The light source generates light during at least a portion of the gaze field sobriety test. A speaker positioned in or on the housing generates sounds during at least a portion of the gaze field sobriety test. A power source is coupled to the speaker and the light source. An input is positioned on the housing. The input is selectable by a test administrator to initiate an audible sound through the speaker at a predetermined time interval during at least a portion of the gaze field sobriety test. The audible sound provides an indication to the test administrator during the gaze field sobriety test to assist in proper performance of the gaze field sobriety test.

Abstract: An adapter (60) for an apparatus (50) for measuring a first property of an eye is attachable to the apparatus (50), wherein, when the adapter (60) is attached to the apparatus (50), a second additional property of the eye is measurable.

Abstract: A slit lamp microscope capable of appropriately and easily carrying out the setting of the optical system is provided. In storage 102 of a slit lamp microscope 1, correspondence information 110 is stored in which standard setting conditions of an illumination system 8 and/or an observation system 6 are associated with each of multiple sites of an eye E. A searching part 121 searches the standard setting conditions corresponding to a site designated by an operation part 104 from the correspondence information 110. A setting-state acquiring part 122 acquires current setting states of the illumination system 8 and/or the observation system 6. A setting-state specifying part specifies, from among the current setting states acquired by the setting-state acquiring part 122, those differing from the standard setting conditions searched by the searching part 121. A controller displays information based on this specified result on the display 103.

Abstract: Systems and methods for improving the reliability of glaucoma diagnosis and progression analysis are described. The measurements made from one type of diagnostic device are adjusted based on another measurement using a priori knowledge of the relationship between the two measurements including the relationship between structure and function, knowledge of disease progression, and knowledge of instrument performance at specific locations in the eye. The adjusted or fused measurement values can be displayed to the clinician, compared to normative data, or used as input in a machine learning classifier to enhance the diagnostic and progression analysis of the disease.

Abstract: A system and method for drug screening for testing an iris for use of a chemical known to have a neurological effect that interferes with normal functioning of the iris and the voluntary muscles of the eye. The system and the method involve testing and documenting reactivity of the iris under known light conditions and can test for the presence of horizontal nystagmus. The identity of a subject can be confirmed by applying an iris pattern recognition model of a captured image of an iris of the eye compared with an image of an iris stored in a library of baseline color or a library of infrared eye images. The system and the method involves providing alarms when one eye pupil diameter exceeds or falls below the opposite eye pupil diameter and when horizontal gaze nystagmus has been determined to be present.

Abstract: The ophthalmic apparatus is aligned to an eye to be examined. The apparatus is used to examine the eye. It has two or more infrared or near infrared light sources for emitting light beams and a detector sensitive to infrared or near-infrared light with the capability of detecting the light reflected from the examinee's face. It registers the examination result of the eye examined. The ophthalmic apparatus is aligned to an eye to be examined. The light beam of one infrared or near infrared light source is directed to the face. The light beam of another infrared or near infrared light source is directed to pass the examinee. The direction of the light reflected from the examinee's face is detected and the examination result and the examined eye are registered to know whether the examined eye was the right eye or the left eye.

Abstract: A slit lamp microscope capable of appropriately and easily carrying out the setting of the optical system is provided. In storage 102 of a slit lamp microscope 1, correspondence information 110 is stored in which standard setting conditions of an illumination system 8 and/or an observation system 6 are associated with each of multiple sites of an eye E. A searching part 121 searches the standard setting conditions corresponding to a site designated by an operation part 104 from the correspondence information 110. A setting-state acquiring part 122 acquires current setting states of the illumination system 8 and/or the observation system 6. A setting-state specifying part specifies, from among the current setting states acquired by the setting-state acquiring part 122, those differing from the standard setting conditions searched by the searching part 121. A controller displays information based on this specified result on the display 103.

Abstract: A device for non-invasive monitoring of an eye position and ocular movements of a patient having: a housing body (2) having at least one through opening (2a); a plurality of light sources (3) housed in said housing body (2); a plurality of sensor means (4) housed in said housing body (2); deflector means (6) for invisible radiation (RL) supplied, in use, by said plurality of light sources (3) and reflected by said eye (O) under examination; support means (8) that can be adjusted for said housing body (2); at least one program data processing and control unit (9). The support means (8) can be adjusted in such a way that the through opening (2a) of the housing body (2) can be placed at the eye (O) under examination so that the invisible radiation hits the eye (O) frontally.

Abstract: An ophthalmic imaging apparatus having an automatic transition function for transiting from an anterior ocular observation state to a fundus observation state, an autofocus function performed during fundus observation, and an automatic image capturing function performed when fundus alignment is complete, the apparatus comprising: a first control unit configured to control the automatic transition function, the autofocus function, and the automatic image capturing function to be deactivated in response to a first user operation; and a second control unit configured to control the deactivated automatic transition function, autofocus function, and automatic image capturing function to be reactivated in response to a second user operation.

Abstract: An ophthalmologic apparatus of an embodiment includes an examination part, a moving mechanism, an information obtaining part, and a controller. The examination part is configured to include an optical system for optically examining an eye. The moving mechanism is configured to move the optical system. The information obtaining part is configured to obtain information for carrying out position matching of the optical system to the eye. The controller is configured to carry out first control for the moving mechanism based on the information obtained by the information obtaining part to move the optical system, determine whether information optically obtained by the optical system after the first control is appropriate to the examination or not, and when it is determined that this information is not appropriate, carry out second control for the moving mechanism in response to a prescribed trigger to move the optical system.

Abstract: An image processing apparatus includes an extraction unit configured to extract a region where light is depolarized from a polarization-sensitive tomographic image of a subject, and a display control unit configured to display, on a display unit, a region determined as a region invading a predetermined layer of the subject, in a part of the region where light is depolarized.

Abstract: A fundus photographing apparatus includes: an illumination optical system for illuminating a fundus of a examinee's eye; and a photographing optical system for photographing the fundus illuminated by the illumination optical system. The photographing optical system includes: a first aperture diaphragm for forming an image of the aperture diaphragm in a position between a pupil and a posterior surface of a crystalline lens of the eye; and a second aperture diaphragm for forming an image of the aperture diaphragm not acting as a field diaphragm, in a position between the fundus of the eye and the image of the first aperture diaphragm.

Abstract: Systems and methods for sub-aperture correlation based wavefront measurement in a thick sample and correction as a post processing technique for interferometric imaging to achieve near diffraction limited resolution are described. Theory, simulation and experimental results are presented for the case of full field interference microscopy. The inventive technique can be applied to any coherent interferometric imaging technique and does not require knowledge of any system parameters. In one embodiment of the present invention, a fast and simple way to correct for defocus aberration is described. A variety of applications for the inventive method are presented.

Abstract: A method for adaptively determining a model of visual performance of a test subject comprising the step of exposing a test subject to a plurality of trials. Each trial comprises the steps of identifying the stimulus pattern to test, generating a stimulus pattern on a display, determining whether the stimulus pattern generated an OKR, updating the model to incorporate the OKR results, and determining whether the updated model is acceptable. The trials can be iteratively repeated until the model for visual performance is acceptable.

Abstract: Systems for performing sequential multiple function ophthalmic measurements using separate measurement instruments, by mechanical switching between the instruments. In prior art systems, the separate measurement instruments are stacked, and transfer between them is performed by means of a linear mechanical motion stage. The separate measurement instruments of the present application are mounted on a base which is rotatably pivoted around a joint at a location remote from the optical entry apertures of the instruments. The entrance apertures of the measurement instruments then traverse the eye being measured sequentially. A rotational motion around the pivoted joint is thus transformed into a linear motion at the eye of the subject, without the need for a linear motion stage. A Scheimpflug camera corneal thickness measurement is also described, in which the measurement head is tilted during the corneal scan such that the illuminating slit beam always impinges on the cornea normally.

Abstract: An ophthalmic device to measure weakness of Zinn's zonule of an examinee's eye having: an illuminating unit arranged to illuminate the examinee's eye including a lens; an imaging unit including an imaging element and arranged to capture an image of an anterior segment illuminated by the illuminating unit; and a determination unit arranged to process the image of the anterior segment captured by the imaging unit after applying a stimulus to guide the lens to move, the determination unit being further configured to obtain positional information of a characteristic point of the lens to detect mobility of the lens relative to the pupil when the lens returns to a pre-stimulus status, and determine the zonular weakness based on the detected mobility.

Abstract: A corneal endothelial cell photographing apparatus includes: a main unit that includes an illumination optical system, an imaging optical system, and a fixation optical system; a setting unit configured to preliminarily set illumination positions and an illumination order of the plurality of fixation lamps; a controller configured to obtain an endothelial image at a first fixation position, control the fixation optical system corresponding to a determination result for propriety of the endothelial image obtained at the first fixation position to light a fixation lamp corresponding to a second fixation position preliminarily set by the setting unit, and control the illumination optical system and the imaging optical system to obtain an endothelial image at the second fixation position; a monitor configured to display the endothelial image; and an operating unit configured to input a signal for operating at least the controller.

Abstract: Disclosed herein is a method of calculating tear film lipid and aqueous layer thicknesses and/or corneal surface refractive index from interferometry data obtained from simultaneous measurements of the aqueous and lipid layers of the tear film along with a measurement of the corneal surface reflectance.

Abstract: Provided is a scanning laser ophthalmoscope capable of accurately superposing multiple photographed images. The scanning laser ophthalmoscope comprises an image generating unit that generates first images based on the light reflected from first laser light and second images based on the light reflected from second laser light. An associating unit associates the first images and the second images based on the first laser light and the second laser light parallelly scanned by the scanning unit. A displacement calculating unit calculates displacements between images regarding multiple first images. The position matching unit matches the positions of multiple second images based on the processing results from the associating unit and the displacements. The superposing unit superposes the multiple second images that have undergone the position matching. The display unit displays an image obtained by superposing the multiple second images.

Abstract: An image processing system includes: an obtaining unit configured to obtain a tomographic image of an eye to be examined; an analysis unit configured to execute analysis required to obtain information indicating a degree of curvature of a retina from the tomographic image of the eye to be examined according to an imaging mode upon capturing an image of the eye to be examined; and a display control unit configured to display three-dimensional shape data of a retinal layer generated to obtain the information on a display device.

Abstract: For appropriately obtaining the tomographic image and the layer thickness map are provided in a short period of time regardless of involuntary eye movement, when the tomographic image is to be obtained in a specific scan pattern, a 3D tomographic image is first obtained by 3D scan, and then a tomographic image of a desired part is extracted from the image in accordance with the specific scan pattern. Further, based on the obtained 3D tomographic image, a sector for layer thickness map display, a main scanning line, and a sub-scanning line, which are displayed on a fundus image, are set movable, and tomographic images taken along both the scanning lines after the movement are obtained. The sector having a center corresponding to the intersection between those scanning lines and the layer thickness map are recalculated and displayed so as to follow the intersection.

Abstract: Provided is an ophthalmologic apparatus which is capable of performing offset adjustment of an alignment position while performing transillumination observation by automatic alignment. The ophthalmologic apparatus includes an automatic alignment unit for automatically performing alignment between a measuring portion and an eye to be inspected, and an alignment position changing unit capable of moving an optical axis center position of the measuring portion to an arbitrary position in the transillumination observation.

Abstract: In one embodiment, a wavefront sensor is combined with a slit lamp eye examination device so that real time aberration values of an eye being examined can be viewed during a slit lamp eye examination session.

Abstract: A non-stereo fundus image is used to obtain a plurality of glaucoma indicators. Additionally, genome data for the subject is used to obtain genetic marker data relating to one or more genes and/or SNPs associated with glaucoma. The glaucoma indicators and genetic marker data are input into an adaptive model operative to generate an output indicative of a risk of glaucoma in the subject. In combination, the genetic indicators and genome data are more informative about the risk of glaucoma than either of the two in isolation. The adaptive model may be a two-stage model, having a first stage in which individual genetic indicators are combined with respective portions of the genome data by first adaptive model modules to form respective first outputs, and a second stage in which the first outputs are combined by a second adaptive mode.

Abstract: An ophthalmic optical power measurement device can include a light source configured to direct an input beam of light into the eye of a patient. The ophthalmic optical power measurement device can also include an aperture configured to receive an output beam that consists of light from the input beam that scatters from a location on the retina of the eye and exits through the pupil of the eye. The ophthalmic optical power measurement device can also include a detector configured to receive the output beam after it has passed through the aperture. A processor can be configured to determine the size of a spot created by the output beam on the detector, and to determine the optical power of the eye based upon the size of the spot.

Abstract: Some embodiments of the present inventive concept provide optical coherence tomography (OCT) systems for integration with a microscope. The OCT system includes a sample arm coupled to the imaging path of a microscope. The sample arm includes an input beam zoom assembly including at least two movable lenses configured to provide shape control for an OCT signal beam; a scan assembly including at least one scanning mirror and configured for telecentric scanning of the OCT signal beam; and a beam expander configured to set the OCT signal beam diameter incident on the microscope objective. The shape control includes separable controls for numerical aperture and focal position of the imaged OCT beam.