46 results about "Fovea centralis" patented technology

Methods for analyzing retinal tomography maps to detect patterns of optic nerve diseases such as glaucoma, optic neuritis, anterior ischemic optic neuropathy are disclosed in this invention. The areas of mapping include the macula centered on the fovea, and the region centered on the optic nerve head. The retinal layers that are analyzed include the nerve fiber, ganglion cell, inner plexiform and inner nuclear layers and their combinations. The overall retinal thickness can also be analyzed. Pattern analysis are applied to the maps to create single parameter for diagnosis and progression analysis of glaucoma and optic neuropathy.

A gaze direction determining system and method is provided. A two-camera system may detect the face from a fixed, wide-angle camera, estimates a rough location for the eye region using an eye detector based on topographic features, and directs another active pan-tilt-zoom camera to focus in on this eye region. A eye gaze estimation approach employs point-of-regard (PoG) tracking on a large viewing screen. To allow for greater head pose freedom, a calibration approach is provided to find the 3D eyeball location, eyeball radius, and fovea position. Both the iris center and iris contour points are mapped to the eyeball sphere (creating a 3D iris disk) to get the optical axis; then the fovea rotated accordingly and the final, visual axis gaze direction computed.

ABSTRACT OF THE DISCLOSURE The newly discovered retinal ganglion cell photoreceptor melanopsin absent in the central fovea of the eye but distributed throughout the remaining human retinal body provides both non-visual biological / physiological input inducing circadian entrainment, and visual input affecting perceived brightness; this perceived brightness is not the object brightness commonly associated with luminance and perceived color of an object in central view, but the perception of brightness of a whole space or task background. Discussed are improvements to circadian lighting systems based on melanopsin stimulation whereby ambient and / or device background lighting may be temporally tuned over a range of prescribed color temperatures from a first subset of lighting having a higher melanopic content to a second subset of lighting having a lower melanopic content or vice versa in accordance with a desired circadian cycle, and in a manner where net light output is of a constant perceived brightness and color throughout temporal tuning.

Two problems arise when measuring length at the eye by short-coherence interferometry. First, the measurement focus and coherence window usually do not coincide. Second, the scanning process along the eye axis is time-consumin g. Both result in poor signal quality and inaccurate measurements. The present application is directed to a short-coherence interferometer in which a right-angle mirror and focusing optics jointly carry out a periodic back-and-forth movement in such a way that the measurement beam focus which is generated by the focusing optics and imaged on the eye by relay optics is moved synchronously with the coherence window from the cornea along the optic axis of the eye to the fovea centralis. Further, different path lengths are generated in the measurement beam path and reference beam path by means of a plurality of reflectors, so that the scanning process is limited to distances which are smaller than the optical length of the eye. The present invention is advantageously implemented using on a fiber-optic interferometer. According to the invention, the reference interferometer arm and measurement interferometer arm are combined with the arms of a fiber-optic interferometer.

Lenses and methods are provided for improving peripheral and / or central vision for patients who suffer from certain retinal conditions that reduce central vision or patients who have undergone cataract surgery. The lens is configured to improve vision by having an optic configured to focus light incident along a direction parallel to an optical axis at the fovea in order to produce a functional foveal image. The optic is configured to focus light incident on the patient's eye at an oblique angle with respect to the optical axis at a peripheral retinal location disposed at a distance from the fovea, the peripheral retinal location having an eccentricity between −30 degrees and 30 degrees. The image quality at the peripheral retinal location is improved by reducing at least one optical aberration at the peripheral retinal location. The method for improving vision utilizes ocular measurements to iteratively adjust the shape factor of the lens to reduce peripheral refractive errors.

The invention discloses an SD-OCT image macular fovea centralis center positioning method. The method comprises the following steps: segmenting an inner boundary film layer and a Bloom film layer of an SD-OCT image; extracting each column of pixels between the inner boundary film layer and the Bloom film layer as features; training a random forest classifier to segment a fovea centralis non-vascular region, and calculating the geometric center position of the fovea centralis non-vascular region as the rough center position P1 of the macular fovea centralis; a retina thickness image is generated within a certain range with P1 as the center; judging whether the retina in the area is sunken or not, and if yes, taking the position at the minimum thickness value as a new foveal fovea central position P2; if not, the P2 is still the position of the P1; and searching a central concave high-reflection region around the position P2, if the high-reflection region exists, taking the central position of the high-reflection region as a final central concave central position P3, and otherwise, taking the P3 as the position P2. Compared with the conventional method for positioning only accordingto the thickness change of the retina, the robustness and the precision of the method are greatly improved.

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.

A process for performing retinal phototherapy or photostimulation includes generating a laser light that creates a therapeutic effect to retinal and / or foveal tissues exposed to the laser light without destroying or permanently damaging the retinal or foveal tissue. The laser light is applied to a first treatment area of the retina. After a predetermined interval of time, within a single treatmentsession, the laser light is reapplied to the first treatment area of the retina. During the interval of time between the laser light applications to the first treatment area, the laser light is applied to one or more additional areas of the retina that is spaced apart from the first treatment area and one another. The laser light is repeatedly applied to each of the areas to be treated until a predetermined number of laser light applications to each area to be treated has been achieved.

The invention relates to a method for realizing flexible central fovea imaging based on a rotary biprism imaging system. The method comprises the steps of S1, constructing a rotary biprism imaging system; S2, constructing a fitness function, and defining a definition and calculation method of a fitness value; S3, determining a region of interest and the number of sub-images, and solving a prism rotation angle by using a particle swarm optimization algorithm; S4, sequentially adjusting the rotation angles of the prisms according to the result of the particle swarm optimization algorithm, and collecting images; S5, carrying out distortion correction on the collected images; S6, splicing the distorted and corrected images to obtain a large field of view; and S7, performing super-resolution reconstruction on the region of interest to further improve the resolution of the central fovea region. According to the invention, central fovea imaging with flexible adjustment of the region of interest can be realized, and acquisition of an overall large field of view is considered. Besides, central fovea imaging can be realized only by using the single rotary biprism imaging system, so that the complexity of equipment is greatly reduced, and the method has excellent practical value.

Several new vector-promoter combinations to overcome the limitations associated with AAV-mediated cone transduction in the fovea are provided. The delivery modality relies on a cone-specific promoter and result in high-level transgene expression compatible with optogenetic vision restoration. Methods of expressing a polynucleotide of interest in the cone photoreceptors of a subject comprising subretinal delivery of a therapeutically effective amount of a recombinant AAV9-derived vector comprising a VP1 capsid protein as set forth in SEQ ID NO: 11 and the polynucleotide of interest under the control of the pR1.7 promoter as set forth in SEQ ID NO: 12 are also provided.

Intraocular injection of adeno-associated viral (AAV) vectors has been an evident route for delivering gene drugs into the retina. Currently, the vectors need to be injected into the subretinal spacein order to provide gene delivery to cones. In this approach, gene delivery is limited to cells that contact the local "bleb" of injected fluid. Furthermore, retinal detachment that occurs during subretinal injections is a concern in eyes with retinal degeneration. Here, the inventors establish several new vector-promoter combinations to overcome the limitations associated with AAV-mediated cone transduction in the fovea with supporting studies in mouse models, human induced pluripotent stem cell-derived organoids, post-mortem human retinal explants and living macaques. They show that an AAV9variant provides efficient foveal cone transduction when injected into the subretinal space several millimeters away from the fovea, without detaching this delicate region. The delivery modality relies on a cone-specific promoter and result in high-level transgene expression compatible with optogenetic vision restoration. Accordingly, the present invention relates to method of expressing a polynucleotide of interest in the cone photoreceptors of a subject comprising subretinal delivery of a therapeutically effective amount of a recombinant AAV9-derived vector comprising a VP1 capsid protein asset forth in SEQ ID NO: 11 and the polynucleotide of interest under the control of the pR1.7 promoter as set forth in SEQ ID NO: 12.

The invention discloses a bionic visual image target recognition method fusing dot-line memory information, and the method comprises the steps of constructing a grid cell set based on visual drive, constructing a distance cell model, and calculating a displacement vector between the positions coded by a grid cell group vector; calculating the response of all sensory neurons to each central concavepixel k through a Gaussian kernel, wherein the response is used for target recognition; calculating the fovea centralis of the current target image by using Gaussian nuclear sensory cells, taking thefeature tag unit with the strongest response as the next jump point, and accumulating the corresponding stimulated identity cells; selecting a next-hop viewpoint, and updating a foveal displacement vector through a distance cell model; and circularly repeating the calculation of the current position during the target identification process, selecting the next-hop viewpoint, and carrying out the vector calculation until the accumulation of a certain stimulated identity cell reaches a threshold value 0.9, and considering the stimulated identity as the finally identified target. The method provided by the invention has a relatively higher recognition rate for the position change, zooming and shielded images.

Wide angle fovea lens and a camera design using the lens are described. The lens has three lens groups and includes a single aspherical lens element. The lenses have higher magnification on the optical axis than at angles off the optical axis.

An intraocular lens system comprising a single lens comprising two optical surfaces selected to maintain image quality at the foveal centre whilst reducing image aberration at preferred retinal locus locations outside of the fovea region.

Provides neuroprotective therapy for glaucoma, including the generation of micropulsed laser beams with parameters and characteristics, including pulse length, power, and duty cycle, selected to produce a therapeutic effect without visually visible laser lesions or damage to the retina tissue damage. Laser beams are applied to the retinal tissue and / or foveal tissue of eyes with or at risk of glaucoma to produce therapeutic effects on the retinal tissue and / or foveal tissue exposed to the laser beam without destroying or permanently Damage retinal tissue and / or foveal tissue, and improve the function or condition of the optic nerve cells and / or retinal ganglion cells of the eye.

The invention relates to the field of fundus image processing, in particular to a pre-processing method for fundus image quantitative analysis and storage equipment. The pre-processing method for fundus image quantitative analysis comprises the following steps: acquiring a fundus image to be processed; carrying out optic disc positioning on the fundus image to be processed; carrying out macular fovea centralis positioning on the fundus image to be processed; and calculating quantification parameters of the temporal side edge of the optic disc and the macular fovea. Through the method, the obtained data is converted from an absolute representation mode to a relative representation mode, and through normalization processing, meaningful and comparable quantitative analysis data between people, between different people and even between inspection results of different instruments is formed. And meaningful and comparable quantitative indexes can be formed for fundus images from different sources.

Wide angle fovea lens and a camera design using the lens are described. The lens has three lens groups and includes a single aspherical lens element. The lenses have higher magnification on the optical axis than at angles off the optical axis.