Abstract: Apparatus and methods for converting continuous grey tone images into high resolution halftone images utilize an iterative, multi-level, multi-resolution error convergence process. The continuous grey tone image is first binarized. At each level of the process, the binarized image is compared with the grey tone image over a larger window of pixels. Within each window, selected binarized image pixels are tested for possible change in binary assignment. The binary assignment of a given test pixel is changed if the change would result in a lower average error over the entire window. By varying the selection of test pixels, the process can provide clustered dot patterns and dithering.

Abstract: A retinal blood flow velocimeter projects an illumination beam through a steering system onto a retinal vessel, and forms a separate tracking image back through the steering system. A fast tracking loop detects motion of the tracking image and moves the steering system to null image motion and keep the illumination beam centered on the vessel. The beam is reflected from the vessel, picked up by detectors at two fixed angles, and processed by spectral analysis. In one preferred embodiment the illumination beam and the steering system follow entirely separate paths through the steering system. Fiber optics translate the collected Doppler light without dispersion while preserving phase relationships, and absolute dimensions are determined from the image tracking electronics. A processor then computes volumetric blood flow which it compares with normative data.

Abstract: Disclosed is a method of inhibiting inositol metabolism in a cell. This method includes introducing into a cell a binding molecule which reduces inositol metabolism by reacting with A-protein or an A-protein containing complex. The binding molecule is an antibody which may be introduced into the cell via a liposome.

Abstract: An optical steering assembly includes first and second steering elements, such as orthogonally-oriented glavanometer mirrors, scanners or acousto-optical cells, for redirecting light in both forward and return optical paths without crosstalk or mixing. Input light traveling in the first direction is directed from the first side of the first element to the first side of the second element, undergoing two orthogonal steering deflections to a redirected output path. Return light along the same or a closely adjacent path is directed at the second side of one element, where an optical relay system tranlates it to the second side of the other element. The return light thus strikes the opposite sides of the same elements as the input light, and undergoes corresponding steering corrections while maintaining complete beam separation. The assembly is especially useful in instruments where low light levels, scan distortion, or crosstalk would otherwise limit performance.

Abstract: A method and apparatus for evaluating a human visual function employ a set of test objects that have viewing surfaces. One viewing surface bears no visually perceptible pattern and hence is visually homogeneous. Other viewing surfaces bear patterns of selected different coarseness corresponding to different visual acuities. The viewing surfaces preferably are otherwise visually identical and have selected luminosities. An examiner can readily evaluate a visual acuity function of a wide range of subjects, including infants, by observing the subject's eye motion to determine whether the subject distinguishes a perceptible pattern from the homogeneous pattern.

Abstract: The composition and method of using a non-steroidal antiinflammatory compound, such as indomethacin and/or a growth factor that causes a change in cell function when bound to specific cell surface receptor, such as epidermal growth factor (EGF), to enhance healing and restore function of the corneal endothelium. The compositions can be administered alone, in combination, or in sequence, before or after injury, for example, in an irrigation solution or in combination with a nutritive solution for storage of cornea prior to transplant.

Abstract: Method using a non-steroidal antiinflammatory compound, such as indomethacin and/or a growth factor that causes a change in cell function when bound to a specific cell surface receptor, such as epidermal growth factor (EGF), to enhance healing and restore function of the corneal endothelium. The compositions can be adminsitered alone, in combination, or in sequence, before or after injury, for example, in an irrigation solution or in combination with a nutritive solution for storage of a cornea prior to transplant.Examples of useful growth factors include, in addition to EGF and EGF-like compounds, fragments of EGF containing the receptor binding region, and EGF modified to improve stability, increase half-life, or enhance permeation into the eye. Examples of other non-steroidal antiinflammatories include aspirin, ibuprofen, and suprofen. The composition can be applied topically to the eye or delivered in a controlled fashion by means of a material such as a polymeric implant, gel, or liposomes.

Abstract: Method using a non-steroidal antiinflammatory compound, such as indomethacin and/or a growth factor that causes a change in cell function when bound to a specific cell surface receptor, such as epidermal growth factor (EGF), to enhance healing and restore function of the corneal endothelium. The compositions can be administered alone, in combination, or in sequence, before or after injury, for example, in an irrigation solution or in combination with a nutritive solution for storage of a cornea prior to transplant.Examples of useful growth factors include, in addition to EGF and EGF-like compounds, fragments of EGF containing the receptor binding region, and EGF modified to improve stability, increase half-life, or enhance permeation into the eye. Examples of other non-steroidal antiinflammatories include aspirin, ibuprofen, and suprofen. The composition can be applied topically to the eye or delivered in a controlled fashion by means of a material such as a polymeric implant, gel, or liposomes.

Abstract: Apparatus and methods for generating an image of an object utilize a scannable microlaser array to provide a flying spot light source. The microlaser array is scan-energized and imaged onto the object to illuminate the object. Light scattered, reflected, or transmitted from the object is collected and detected, and can be converted to a video-level signal for display on a monitor. The microlaser array can be raster-scanned, scanned in a random access mode, or have at least two laser elements energized simultaneously, to enhance contrast, provide multiplexing, and increase dynamic range. A confocal configuration utilizes a detector array that is scan-read synchronously with the laser excitation pattern.

Abstract: An instrument for imaging the vitreous of an eye wherein first and second windows in the iris plane accommodate a slit illumination or observation beam, and the two beams are synchronously scanned. Both beams pass through a common objective optical system, including an aspheric ophthalmic lens, and the observation beam is descanned by a mirror and spatially filtered by an observation slit conjugate to the slit which forms the illumination beam. Lateral position or width adjustment of a slit varies the axial extent or position of the focal region, to produce an image free of retinal reflection. Slit width may be increased to simulataneously image with good resolution and contrast all planes within a broad range of depths. In one binocular embodiment, the observation and illumination paths are alternately interchanged to produce a pair of stereo images formed along identical, but reversed, optical paths with a single set of optics.

Abstract: A method and preparation for the stimulation of tear secretion. The method involves topically applying a phosphodiesterase inhibitor and/or cyclic nucleotide analogue to the ocular surface. Inhibition of phosphodiesterase and cyclic nucleotide analogues increase cyclic nucleotide levels in lacrimal gland tissue, thereby stimulating tear secretion. The preparation contains a phosphodiesterase inhibitor or a cyclic nucleotide analogue and a vehicle for the phosphodiesterase inhibitor or cyclic nucleotide analogue, and may contain an ophthalmic preservative.

Abstract: A multidose liquid dispenser for maintaining the sterility of solutions without a preservative has been developed. The dispenser includes a filter assembly having a hydrophobic filter and a hydrophilic filter in tandem with the hydrophobic filter located near the dispensing tip. The use of the hydrophobic exterior filter and the hydrophilic interior filter permits excellent liquid flow while precluding the growth of bacteria on the filter. The inability of the bacteria to attach to the exterior hydrophobic filter prevents clogging of the pores.

Abstract: An ophthalmic preparation and a method for preparing the ophthalmic preparation is described. The ophthalmic preparation has an enhanced ability to permit essentially normal maintenance of ocular surface mucus-containing goblet cells while present in the eye.

Abstract: An apparatus and method for correcting cross scan error in a two coordinate optical scanning system where the two scanners are spaced apart in the optical system. An anamorphic lens is positioned between the scanner which is introducing the cross scan error and the second scanner, with the lens being formed and positioned so that the focal length on the coordinate of scan from the first scanner is different from its focal length on the coordinate of scan orthogonal to it. An object lens is placed between the second scanner and the object being scanned. This lens in an ophtalmoscope is the lens of the eye.

Abstract: A solid-state laser system for producing a frequency-doubled CW laser output beam having a stabilized output. The laser system includes within a three-mirror resonator cavity, a Nd: YAG laser rod operating at an output wavelength of 1.064 .mu.m in the TEMoo transverse mode, and a KTP frequency-doubling crystal. At one end of the laser cavity the beam is reflected from a folding mirror through the frequency-doubling crystal to another reflecting mirror which reflects both the fundamental wavelength of the output beam from the laser rod, and also the doubled frequency beam at a wavelength of 0.532 .mu.m back through the frequency-doubling crystal onto the folding reflector. The folding reflector is coated to reflect light at the longer wavelength but transmits substantially all of the light incident upon it at the 0.532 .mu.m wavelength.

Abstract: A method and preparation for the stimulation of tear secretion. The method involves topically applying to the ocular surface melanocyte stimulating hormones, and their active precursors, derivatives, and fragments which activate melanotropin receptors of lacrimal gland tissue. The preparation contains a melanocyte stimulating hormone, and a vehicle for a melanocyte stimulating hormone and may also contain an ophthalmic preservative.

Abstract: An endophotocoagulation probe has a probe tip adapted for insertion into the eye of a subject, and includes an optical fiber for carrying light, and a lens for focusing the light from the end of the fiber onto target tissue at a desired working distance. The lens forms a convergent beam with the waist of the beam providing a spot of maximum power density whose size is independent of the ocular medium. In a preferred embodiment a positioner provides selective variation of the spacing between the lens and the fiber to select a desired spot size. Preferably the lens is a selfocal or rod lens. A step-positioning handle selects one of a plurality of determined spacings, so as to achieve plural different spot sizes, each having a predetermined power density. Examples of probes having variable spot sizes in ranges from 50 to 500 microns are described with particular fibers and selfocal lens elements. A microprocessor may control lens position and light input power in accordance with the selected spot size.

Abstract: An eye movement tracker for stabilizing in two dimensions a diagnostic, treatment or other ophthalmic illumination on the fundus has a laser source which produces a narrow directed tracking beam, an optical steering assembly for controllably directing the beam to illuminate a region of the fundus, and an optical imaging assembly for imaging the illuminated region on a spatially-distributed photodetecting element. A tracking circuit scans the detecting element to detect motion of a spatially variant intensity feature and controls the optical steering assembly to redirect the optical path and maintain the feature in a fixed position. This repositions the diagnostic or other illumination, maintaining it in a fixed position on the fundus during eye movement. Scanning rates many times those of conventional systems are achieved, effectively stabilizing even very rapid eye movements. A viewing port provides an operator with a 30 degree field of the subject's eye fundus.

Abstract: An ophthalmic preparation and a method for preparing the ophthalmic preparation is described. The ophthalmic preparation has an enhanced ability to permit essentially normal maintenance of ocular surface mucus-containing goblet cells while present in the eye.

Abstract: An optical apparatus for providing a two-dimensional output representation of reflection characteristics of an eye fundus in which a laser beam is passed through an anamorphic optical element to produce an output beam focused on a first axis and dispersed on a second axis normal to the first axis forming a line. The line of the output beam is directed onto a scanning element which moves the beam along the first axis and a focusing element directing the output beam from the scanning element through the pupil of the eye onto the fundus, the size of the beam being such that it has a small cross sectional area at the pupillary plane of the eye compared to the diameter of the pupil. The light from the fundus is reflected back through an exit aperture which is large compared to the cross sectional dimension of the input beam at the pupillary plane. The device includes a detector which extends along the non-scanning coordinate of the scanned area.