Optical Lab Instruments

New Eye Care Instrument

admin — Mon, 03 Sep 2007 02:02:05 +0000

Taking care of your eyes is an important part of your general health. Eye care is important for healthy eyes and is a very important part of your general health.

In this Article The eye care specialists have continuous search of ways to administered better care for the patients. Ameliorating more precise and efficient diagnostic tools is a significant element to this search. Hence, the UIC Eye Center-prides itself and has constant development and implemented a new optical lab instruemnts and techniques.

There are four new optical lab instruments that have greatly improved eye care and treatment of common eye condition:

1. Optical Coherence Tomographer Model 3000 (OCT3)

The UIC Eye center has acquired an Optical Coherence Tomography Model 3000 (OCT3) an extremely powerful tool that ophthalmologists use. Optical Coherence Tomography (OCT) uses light waves to create detailed images of underlying retinal structures. Using this scanner, doctors can more specifically diagnose, treat and manage glaucoma and retinal diseases including diabetic retinopathy and macular degeneration.

The OCT3 is considered as the state-of-the-art in optical lab instrument technology for cross-sectional imaging of the retinal tissue in living human eyes. This newest progression in imaging technology dramatically improves visualization of disease related abnormalities in the retinal structures. The UIC Eye Center clinicians and researches have visualized retinal abnormalities in patient who are suspected of having macular hole. Also, they would be able to image choroidal neovascularization in patients with age-related macular degeneration. The OCT3 could also be used to measure retinal nerve fiber layer in patients with diagnosed or suspected glaucoma and helped ophthalmologists to assess the progression of these diseases in an early stages and supervise treatment. The OCT is Food and Drug Administration (FDA) approved and it is a non-significant risk devise.

2. Core Imaging Facility

The NIH has supported Core Imaging Facility provided by the department investigators with state-of –the-art instrumentation for digital image acquisition, processing and analysis. Investigators used the facility extensively to augment their research capabilities and documentation. The facility support in 3D fluorescence microscopy techniques for laboratories in the Division of Basic Sciences.
High resolution images can be obtained by confocal microscopy or deconvolution. These facilities are highly automated, and the data are recorded digitally. Special expertise is available for assistance with deconvolution microscopy, as well as live cell imaging. The resulting multi-channel confocal imaging spectrophotometer extensively increases the flexibility and effectiveness of the detection system. The apparatus housed in the facility includes an imaging station comprised of an inverted microscope cooled high-resolution digital camera and a workstation with disconsolation and calcium ratio software.

3. The RetCam 120

The UIC Eye Center and the UIC Medical Center lately has purchased the RetCam 120, a digital imaging technology which has been hailed as a revolutionary tool in the diagnosis and management of pediatric retinal diseases. Massie Research Laboratories of Dublin, CA, who’s developed the RetCam 120, allows systematic photographic imaging of pediatric retinal diseases that disturbed the equator and periphery revealed new details about their natural history and response to treatment. Since its acquisition, ophthalmologists from the department have imaged many rare medical conditions together with meduloepithelioma, pre-term retinoblastoma, atypical retinopathy of prematurity, juvenile retinoschesis, posterior persistent fetal vasculature, and juvenile Coats’ disease. This device is particularly helpful according to the researcher, because it allows direct comparison of the pretreatment and post treatment for retinoblastoma and as well as monitoring the cause of this great diversity of maladies. As an unanticipated benefit, the RetCam 120 has increased the parents’ understanding and engagement since they could already visualize their child’s problem. Lastly, a physician has to share clinical information in meetings and over the internet mounting the access to information of these diseases.

4. Corneal Topography

Of all the optical lab instruments technology currently available, corneal topography provides the most detailed information about the curvature of the corneas. Researchers’ using a very sophisticated computer and software, thousands of measurements are taken and analyzed in just seconds. This equipment has the ability to see the contour of the cornea, the transparent portion of the outer coat of the eyeball, is an important tool in the identification of corneal disorders. The contour of the cornea has been traditionally measure by a keratometer, which has been around for more than 100 years. The Keratometer offers a limited evaluation of the cornea and is greatly enhanced by the cornea topography unit. The UIC Eye Center acquired a corneal topography unit several years ago. However, a new upgraded version has recently been obtained that is on the cutting edge of this new technology. The corneal topography unit projects a series of light rings onto the surface of the cornea. The separation between the rings is measured at many points by a computer and a colored-coded- map of the surface of the cornea presented.

This new technology permits earlier diagnosis of many corneal diseases, provides
vital information to eye surgeons for preoperative and post-operative decision
making and provides helpful information for the fitting of the contact lenses.

5. Home Tonometer (Portable Eye Pressure Monitor)

Glaucoma is an eye disease that causes damage to the optic nerve and may result in blindness. High intraocular pressure (IOP) is a dominant risk factor in the development of glaucoma. Eye doctors must keep a constant record of their glaucoma patients’ IOP to indemnify that they receive the most effective treatment. However, an accurate assessment of a glaucoma patient’s eye pressure is difficult establish because eye pressure may fluctuate during the day and go on undetected. A patient with presumably normal eye pressure during a doctor visit may have periods of increased eye pressure at other times during the day. To control this problem, a portable instrument called the Home Tonometer has been developed at the UIC Eye Center. The Home Tonometer slows the p[patient to monitor aye pressure vat home or work. With the eye also to the instrument, that patient pushes a lever in the eye pressure measurement is taken comfortably an easily in abut two seconds.

In this Article we must be aware that monitoring of IOP provides the eyes specialist with important information to determine proper treatment and prevent further loss vision.

6. Retina thickness Analyzer

Muscular edema (thickening of the retina) is a major contribution to 5000 new cases of diabetes-related blindness yearly in the U.S. This condition is caused by leakage of fluid from the blood vessels’ into the retina, the light-sensitive layer of the eye. The accumulation of fluid causes retinal thickening and deterioration of vision. This condition can often be treated with lesser treatment. A new technique has been developed at the UIC Eye Center to assess and document the degree of retinal thickening. The procedure takes less than 30 minutes and is similar to an eye exam. A week, harmless lesser beam is projected on the retina while the patient is asked to look in different directions. An image of the retina is recorded in photographic film or video tape. A computer than processes and analyzes the images to determine the degree of thickening. Measurements are obtained at various locations on the retina to generate a thickness map for each eye.

The new technique of measuring retinal thickening sensitively monitors the degree of thickening for evaluating progression and treatment of muscular edema.

DRIVING ASSESSMENT SYSTEM

Certain eye conditions can cause severe peripheral or side-vision loss. This question becomes even more difficult in some older patients who may additionally have reflexes that have naturally slowed with age. Therefore, specialists conduct the driving assessment system, which currently being tested at the UIC Eye Center , objectively measures a number of driving skills using three-screen, interactive driving simulator. A Patient’s driving ability is assessed through the recording of a patient’s responses during an eight-minute session on a simulated driving test course. The driving session tests patients on crossing lane boundaries, braking response and the rate of the deceleration. Head and eye movements made during driving are also measured. Additionally, the driver is presented with a number of challenges on the simulator to test hand-eye coordination and response time.

Studies show that performance on the simulator is highly representative of real-world performance. Upon the completion of the driving test, patients and their physicians are given a “driving performance profile”, which is a report of how the patient performed. The driving assessment system helps eye care specialists make this difficult decision.

As new technologies are developed, the ability to diagnose and treat eye conditions will continue to improve, as will the overall quality of eye care.

Devising Nano Vision for an Optical Microscope

admin — Mon, 16 Jul 2007 05:55:57 +0000

The topic from this link is released to public to inform us about the Devising Nano Vision for an optical microscope. This article was released by the National Institute of Standards and Technology’s (NIST) Tech Beat journal, dated last February 10, 2005 by a member of their media named Mark Bello. This link also provides another links related to some of the topics that were featured here.
Nanometer is defined as a tiny fraction of the wavelength of the lights that are visible. The National Institute of Standards and Technology (NIST), suggests that an optical microscope has a hybrid version that might be able to view and measure features smaller than 10 nanometers. This is because of the advanced technology into the small realm of molecules and atoms may not be out of sight for the venerable optical microscope, after all.
There was a preliminary testing for the embryonic technique that has been made by the National Institute of Standards and Technology (NIST) scientists as reported. They used violet light with a measure in wavelength of 436 nanometers based on the article to image features as small as 40 nanometers, and equated for about five times smaller than possible with a conventional optical microscope. Actually, it has been specified that such an achievement is not easy. But if given an opportunity to make it successfully developed, the imaging technology could be readily incorporated into chip-making and other scale for commercial processes for making parts and products with scale dimensions that measure in nanometer.
In this article it has been stated that in the visible part of the spectrum the wavelengths of light greatly exceed nanoscale dimensions. The explanation said that the resolution of conventional light-based imaging methods is only limited to about 200 nanometers. It means that it is too large in resolving details of nanotechnology, in which they are no more than half that size, according to the definition from the first paragraph. There is a newly begun research of the National Institute of Standards and Technology NIST for five years already suggesting that a novel combination of illumination, computing and detection technologies can circumvent this limitation. Success would be extended for such technology for 400-year-long record as an essential imaging and measurement instrument well into the realm expansion of nanotechnology.
This article also featured topic on the computer-intensive technique under the development at the National Institute of Standards and Technology (NIST) that uses a set of dynamically engineered light waves optimized tools for particular properties. They are called phase-sensitive, scatter-field optical imaging, such as angular orientation and polarization, as well. This structured illumination field was engineered differently to highlight the geometry particularly of each and every type of the specimen and how they scattered, after striking the target can reveal the tiniest of details. According to the physicist named Rick Silver, of the National Institute of Standards and Technology (NIST) Precision Engineering Division, “The scattering patterns are extremely sensitive to small changes in the shape and size of the scattering feature,” Read more on this article

What is a Slit lamp?

admin — Wed, 06 Jun 2007 16:12:11 +0000

A slit lamp microscope is used by ophthalmologists to directly examine the eyes of a patient below the magnification of a binocular microscope by creating a stereoscopic, erect image. The slit lamp microscope produces a narrow beam of strong light that can illuminate the patient’s cornea, aqueous humor, crystalline lens, anterior vitreous layer, or other see-through ocular tissue. A form of oblique microscopy, the slit lamp microscope uses an imaging method similar to optical sectioning. Identical paired 10x and 15x eyepieces fit the binocular tubes of the Microscope. Thus, the ophthalmologist controls the magnification during an eye examination. Objectives for the slit lamp microscope are relatively low-powered 1.0x and 1.6x lenses, which merge with the eyepieces for total magnifications ranging from 10x to 24x. The numerical aperture of 0.04 for the lower power objective and 0.07 for the 1.6x lens are particularly very low to ensure maximum illumination and infiltration into the eye tissues, with a more concentrated beam of light. A relatively long working distance of 101.5 millimeters is provided for the patient’s comfort and to make easy accurate diagnoses, even for the deeper eye layers.
A 6-volt, 30-watt tungsten-halogen bulb provides the light for the slit lamp illumination system that features a brightness adjustment dial. The slit adjusts from 0.0 to 9 millimeters in width and ranges from 0.2 to 9 millimeters in length, depending on the setting of the five-position rise. Utmost rotation of the slit from the first vertical position is 90 degrees in either direction via the slit rotating lever, which is mounted above the lamp housing. Green and cobalt blue filters are provided as accessories for the illumination and can be bring into the optical path by moving the filter change-over lever. The gelatin green filter blocks red light, which aids observation of the blood vessels in the sclera and conjunctiva membranes.
Serving of the blue filter, when coupled with an applanation-tonometer, facilitates the measurement of intraocular pressure and the finding of glaucoma. To position the lamp, the focusing rod is erected and it is adjusted until the black surface faces the operator. For the fine motion of the slit image, a lever that resembles a video game joystick is tilted and for common motions, the lever is moved in the desired direction. The lamp housing is adjusted vertically and is centered until the image of the slit is projected onto the black surface and there is even illumination crosswise in the field of view.
The slit lamp microscope is mounted on a flat metal base plate for steadiness. The entire visual diagnostic apparatus is raised or lowered by two foot pedal switches mounted on a grouping power control unit and telescoping instrument base. The table adds stability and helps control unwanted vibrations during eye exams. For finer vertical adjustments to match the patient’s height and eye position, the level adjustments for the instrument body and the jaw rest are moved up or down, until the slit image is projected on the patient’s eye correctly. Once the patient’s head is set in opposition to the forehead and jaw rest, the width of the slit is adjusted by turning the slit-width change knob that is mounted on top of the joystick lever, and which is located nearby the ophthalmologist on the microscope base. A fascination lamp enables the patient to focus the eye in a standard direction and distance, while a reference line on the post allows the doctor to examine the patient in a usual or standardized position. The lens, when placed in front of the patient’s eye, allows the doctor to focus from the rear inner part region of the eye.

Uses of slit lamp in ophthalmologic examination

admin — Wed, 06 Jun 2007 16:04:59 +0000

Eye Examinations
Slit-lamp examination: A slit lamp focuses the height and width of a beam of light for a accurate stereoscopic view of the eyelids, conjunctivae, cornea, anterior chamber, iris, lens, and anterior vitreous. It is especially useful for identifying corneal foreign bodies and abrasions and for measuring the depth of and identifying inflammation or cells in the frontal chamber.
Visual acuteness: The first step is to record visual acuity. Patients who require remedial lenses should wear them during trying. On the other hand, testing by using slit lamp microscope can be performed in patients who are not wearing or who do not require corrective lenses by having them look throughout a pinhole device a paddle with multiple pinholes or an index card with an array of 18-gauge needle punctures; these holes focus light rays and recompense for refractive error. Visual acuity in each eye is tested as the opposite eye is covered. Vision is tested by having the patient look at an eye chart 20 ft 6 m away. Be prompt that the least letter that can be read by someone with normal vision at 40 ft has to be.
Eyelid conjunctival examination: Eyelid limitations and subcutaneous tissues are examined under a focal light and enlargement, of slit lamp microscope provided by loupe, , or focused at the examiner’s working distance. In cases of suspected retinal disease, diagnostic attempt is made to express any inside all the way through the following eyelid and bulbar conjunctivae can be inspected for foreign bodies, signs of inflammation , follicular hypertrophy, hyperemia, edema, or other abnormalities.
Corneal examination: Uncertain or blurred edges of the corneal light reflex reflection of light from the cornea when illuminated, suggest the corneal surface is not intact, as occurs with a corneal abrasion. Before staining, a drop of topical anesthetic , may be supplementary to facilitate examination if the patient is in pain or if it will be needed to touch the cornea or conjunctiva.
Pupil examination: The accumulation and shape of the pupils are distinguished, and pupil reaction to light is tested by rapidly moving a penlight back and forth by each eye swinging flashlight test. Normal response under illumination of slit lamp microscope is pupil enlargement without consensual limitation is a sign of afferent pupillary defect , signifying optic nerve dysfunction or widespread retinal disease.
Extra ocular muscles: The examiner guides the patient to look in 8 directions up, up and right, right, down and right, down, down and left, left, left and up with a moving finger, observing for gaze deviation, limitation of progress, scattered gaze consistent with cranial nerve palsy, orbital disease, or other abnormalities that limit movement.
Ophthalmoscopy: Ophthalmoscopy can be performed directly using a handheld ophthalmoscope or not directly using a head-mounted ophthalmoscope with a handheld lens.. The view of the retina is inadequate with a handheld ophthalmoscope; indirect ophthalmoscopy gives a 3-dimensional view and is better for visualizing the peripheral retina, where retinal lack of involvement most commonly occurs. Ophthalmoscopy can detect lens or vitreous opacities, assess the optic cup-to-disk ratio, and recognize retinal and vascular changes.
Visual field testing: Visual fields may be impaired by lesions anywhere in the neural visual pathways from the optic nerves to the occipital lobes: Higher visual pathways—lesion sites and matching visual field defects. Glaucoma causes loss of peripheral vision. Fields can be assessed by direct confrontation testing or more formal methods. In direct argument, the patient maintains a fixed gaze at the examiner’s eye or nose. The examiner brings a little target from the patient’s visual periphery into each of the 4 visual quadrants and asks the patient to point out when he first sees the object. Each eye is tested separately. Abnormalities in target detection should prompt formal testing with slit lamp microscope instruments.

Recommended Slit Lamp Examination Procedure

admin — Wed, 06 Jun 2007 16:03:09 +0000

1.) By means of a broad beam or better a 2 to 4 mm wide Parallel Type Illumination, Magnification 10-16x, Illumination on low at 45 Degrees, Examine both the upper and lower lids and lashes. The patient’s eyes are open and the illumination source is moved at the midline of the lid.

2.) Include the patient look to their left, light source to your left at approximately 45 degrees. The slit lamp microscope is set straight ahead.

3.) Have the patient look to their right, light starting place to your right at approximately 45 degrees. The microscope is set straight ahead.

4.) Have the patient look up, retract the lower lid, examining the lower bulbar, conjunctiva and inferior cornea. The light source should be moved across to the opposite side at the midline of the eye. The microscope is set directly ahead.

5.) Have the patient look down, retract the upper lid, examine the upper bulbar conjunctiva and superior cornea. The light source should be moved across to the reverse side at the midline of the eye. The slit lamp microscope is set straight ahead.

6.) Employ a Parallelepiped, 16X magnification, light source at 45 degrees and the microscope set straight ahead. Scan and examine the cornea. The light starting place should be stimulated across at the midline of the cornea.

7.) Make use of a full length Optic Section, magnification 16X, light source at 60 degrees and the microscope set straight ahead. Evaluate and grade the temporal and nasal angles.

8.) Apply a narrow Parallelepiped, 16X Magnification, light source at 45 degrees and the microscope set straight ahead. Examine the iris, crystalline lens and the anterior vitreous body.

For all time, pull the slit lamp back, shut off the instrument, and lock it down at the end of any process.
The above is only proposed as a schematic and students are encouraged to develop any order with which they feel comfortable. It should be pointed out that all steps in the representation are relevant and should be part of the method

Positioning The Patient In The Slit Lamp

admin — Wed, 06 Jun 2007 16:01:07 +0000

1.) Procedure:
Let the patient what you are going to do and why. For Example: This is slit lamp microscope and I’ll be examining the general health of the patient eye.

2.) Head Position:
A.) Inform the patient what you want them to do: chin in the chin rest and forehead up beside the headrest. For specialized and hygienic reasons always place a facial tissue on the slit lamp’s chin rest. You should have already cleaned the head and chin rest with an alcohol swab. This is always done between every patient. This not only helps remain things more antiseptic, but also makes the slit lamp microscope smell clean and more professional.

B.) Make sure the patient not only looks at ease but is comfortable. Their forehead tight against the headrest, chin firmly down on the chin rest and their outer corner aligned with the black marker on the slit lamp post. At this point it is a good idea to reach around and gently pull their head a little forward against the headrest.

3.) Fixation Instructions:
The patient must be given interesting instructions, where you want them to look. This might be the fascination light, part of the slit lamp or just past your ear.
4.) Pre-Alignment And Focusing:
Inform your patient to close their eyes and calm down while you get things aligned. Turn the slit lamp microscope on and focus the light source on the patient’s lid. The eyelid is only about 1 mm thick, so, when you instructed the patient to open their eyes you should almost be in focus on the tear film of the cornea.

Eye Surgery

admin — Wed, 06 Jun 2007 15:58:37 +0000

Our bodies as we grow older mature and change naturally. Within the aging eye, these changes often develop into conditions that impact the quality of your vision. But if you are experiencing age-related visual problems, with successful treatment, it may be possible to have clearer, brighter and sharper vision than you’ve had for a long, long time. As the crystalline lens ages, it becomes harder and less flexible, and less able to change shape for near vision or accommodation. This process becomes clinically apparent at about age 40 and continues until accommodation is lost, typically by age 65. Loss of accommodation of the lens is a normal aging process, known as presbyopia. Stronger reading glasses are necessary to compensate for the loss of ability to focus up close. A cataract is a change in the clarity, or a clouding of the lens in your eye. The crystalline lens, which is made mostly of protein and water, can become clouded enough to prevent light and images from reaching the retina. A cataract can be the reason sharp images become blurred and seeing things at night becomes more difficult. More than half of all Americans age 65 and older have a cataract and cataracts are the leading cause of treatable blindness. In cataract surgery is an outpatient procedure that will only take a few hours. Then the eyes may be treated with eye drops and anesthetic to minimize any discomfort during the operation. Giving cataract patients their best chance to live free of glasses, there is a breakthrough in vision surgery. Throughout this vision routine operation, a small incision is made in the eye. The surgeon will use a tiny instrument about the size of a pen tip, to remove your clouded lens. This can be done with either an aqua laser device, which uses gentle pulses of fluid to wash away your cloudy lens, or an ultrasonic instrument that breaks up and gently removes your cloudy lens called the phacoemulsification. Once this is accomplished, surgeon will insert an artificial intraocular lens into your eye. After the procedure, patient will be given a short time to rest. Then, the very same day, patient can go home. Within the next 24 hours, the doctor will probably want to see you for an evaluation. Drops will be prescribed to guard against infection and to help your eyes heal. For a few days, you may need to wear a clear shield, especially at night, to prevent you from rubbing your eye. A number of attempts have been made to design a functional bifocal or multifocal/defractive intraocular lens. Unfortunately, the multifocal and defractive properties of these lenses produce significant visual aberrations and the technology has not become popular with patients and cataract surgeons. But with multifocal or defractive lens designs, crystalens, offers a whole new dimension in vision restoration after cataract extraction. At the heart of the system is a unique intraocular accommodative lens design called crystalens. The crystalens reacts to the eyes natural accommodative response by providing a single point of focus that moves more anterior for intermediate and near vision, and posterior for distance vision. The patient perceives a true sense of accommodation throughout a full range of vision.