Certified Paraoptometric Review Part 1

Transcription

1 Certified Paraoptometric Review Part 1 Stacie Layne Virden, O.D. Therapeutic Optometrist Glaucoma Specialist Eyecare Specialists and Ancillary Personnel Eyecare Specialists and Ancillary Personnel OPTOMETRIST Doctor of Optometry (O.D.) Undergraduate degree College of Optometry Optional residency Eyecare Specialists and Ancillary Personnel OPTOMETRIST diagnose and treat eye diseases diagnose and treat vision problems perform minor surgical procedures provide patients with pre- and post-op op care co-manage patients with other specialties Eyecare Specialists and Ancillary Personnel Ophthalmologist physician specializing in medical and surgical care of the eyes and visual system medical doctors (M.D.) or doctors of osteopathy (D.O.). Eyecare Specialists and Ancillary Personnel Ophthalmologists provide a full spectrum of care including: routine eye exams diagnosis and treatment of eye diseases prescriptions for glasses and contacts major and minor surgery management of eye problems that are caused by systemic illnesses. 1

2 Eyecare Specialists and Ancillary Personnel Paraoptometrics serve to enhance the profession of optometry assist in all areas of practice receive continuing education and training in order to fill this role must work with an optometrist to receive and maintain certification Eyecare Specialists and Ancillary Personnel Ophthalmic Medical Personnel (OMP) work with ophthalmologists supply important information to physicians assist in surgery and patient education many functions are the same as Paraoptometrics. Eyecare Specialists and Ancillary Personnel Opticians have an associate opticianry degree or have apprenticed for a required number of hours some states require opticians to be licensed candidates must pass an examination given by the American Board of Opticianry (ABO), and some states also require that candidates pass a state board exam can also take the National Contact Lens Examination (NCLE), which in certain states allows them to fit and dispense contact lenses. Eyecare Specialists and Ancillary Personnel Opticians fit eyeglasses and, in some states, contacts interpret prescriptions to determine which eyeglasses or contact lenses are best for the patient takes measurements to insure proper lens placement in the frame and verifies the accuracy of the finished product may also manufacture (grind) lenses from raw materials and cut them to fit into the frame Practice Management Practice Management Record Filing Systems Recalls Fee Presentation Collections Third Party Payments 2

3 The first things you see IRIS colored part of the eye controls light levels inside the eye similar to the aperture on a camera made of tiny muscles that dilate (widen) and constrict (narrow) the pupil PUPIL The pupil is the black, circular opening in the center of the iris regulates the amount of light entering the eye can be manipulated with pharmacological agents SCLERA "the white of the eye" serves as the eye's protective outer coat has NO blood vessels Conjunctiva thin, transparent tissue that covers the outer surface of the eye begins at the cornea, covers the visible part of the eye, and lines the inside of the eyelids nourished by nearly invisible blood vessels 3

4 Cornea transparent window covering the front of the eye powerful focus provides 2/3 of the eye's power note: contact lenses center on and cover the cornea Cornea no blood vessels in the cornea tiny vessels at the outermost edge of the cornea provide nourishment, along with the aqueous and tear film it is normally clear and has a shiny surface too much or too little fluid can make it look foggy extremely sensitive - there are more nerve endings in the cornea than anywhere else in the body only about 1/2 millimeter thick 5 layers of the cornea: Epithelium Bowman's membrane Stroma Descemet s s membrane Endothelium 5 layers of the cornea: Epithelium a layer of cells that cover the surface only about cell layers thick quickly regenerates when injured Bowman's membrane lies just beneath the epithelium very tough and difficult to penetrate 5 layers of the cornea: Stroma the thickest layer of the cornea composed of tiny collagen fibrils that run parallel to each other the special formation of the collagen fibrils gives the cornea its clarity if an injury penetrates more deeply into the corneal stroma,, it may leave a scar scars leave opaque areas, causing the corneal to lose its clarity and luster. 5 layers of the cornea: Descemet's membrane lies between the stroma and the endothelium Endothelium most internal layer only one cell layer thick pumps water from the cornea, keeping it clear. If damaged or disease, these cells will not regenerate. 4

5 Lens focuses light onto the back of the eye the nucleus is the innermost part of the lens the cortex surrounds the nucleus and is a softer material the outer surface is a capsular-like like bag the entire lens is suspended within the eye by zonules. Vitreous gives the eye shape is mainly water comprises about 2/3 of the eye's volume a thick, transparent, jelly-like like substance that fills the eye Optic Nerve transmits electrical impulses from the eye to the brain connects at the back of the eye the fibers that make up the optic nerve branch out to line the eye and form a layer of the retina the visible portion of the optic nerve is called the optic disc Retina thin layer of tissue that lines the inside of the eye captures light rays that enter the eye the light impulses are then sent to the brain for processing, via the optic nerve. Macula most sensitive part of the retina used for detailed central vision allows us to appreciate detail the fovea is the very center of the macula located roughly in the center of the retina, temporal to the optic nerve Choroid lies between the retina and sclera composed of layers of blood vessels that nourish the back of the eye 5

6 anterior segment posterior segment Extraocular Muscles (EOMs) six tiny muscles surround the eye and control its movements the function of the four rectus muscles is to control the eye's movements from left to right and up and down the two oblique muscles move the eye rotate the eyes inward and outward Extraocular Muscles (EOMs) All six muscles work in together to move the eye As one contracts, the opposing muscle relaxes In addition to the muscles of one eye working together, the muscles of both eyes also work in unison so that the eyes are always aligned. Age-related macular degeneration (ARM) a degenerative condition of the macula (the central retina) the most common cause of vision loss in the United states in those 50 or older its prevalence increases with age ARM is caused by hardening of the arteries that nourish the retina Characterized by a loss of central vision Age-related macular degeneration (ARM) Varies widely in severity The worst cases cause a complete loss of central vision, making reading or driving impossible For others, it may only cause slight distortion. Macular degeneration does not cause total blindness since it does not affect the peripheral vision. ARM is classified as either wet (neovascular( neovascular) ) or dry (non-neovascular). neovascular). 6

7 Wet ARM occurs when new vessels form to improve the blood supply to oxygen-deprived retinal tissue the new vessels are very delicate and break easily causing bleeding and damage to surrounding tissue about 10% of ARM patients most severe loss is with this type Wet ARM Dry ARM occurs when vessels leak by-products into the retina, called exudates the exudates stretch the nerves of the macula, which causes distorted vision about 90% of ARM patients less severe loss with this type Cataract a clouding of the natural lens inside the eye as old cells die they become trapped within the capsule these cells accumulate over time causing the lens to cloud, making images look blurred or fuzzy for most people, cataracts are a natural result of aging. Cataract Eye injuries, certain medications, and diseases such as diabetes and alcoholism have also been known to cause cataracts. UV light also causes cataracts. Cataract 7

8 Glaucoma a disease thought to be caused by increased intraocular pressure (IOP) resulting either from a malformation or malfunction of the eye s s drainage structures untreated, high IOP causes irreversible damage the optic nerve and retinal nerve fibers a progressive, permanent loss of vision results early detection and treatment can slow, or even halt the progression of the disease. Average Optic Nerve Damaged Optic Nerve For years, we believed high IOP caused glaucoma: What causes glaucoma? WE REALLY DON T T KNOW!!! The eye produces aqueous fluid, the clear fluid that fills the anterior chamber (the space between the cornea and iris) The aqueous filters out of the anterior chamber through a complex drainage system The balance between the production and drainage of aqueous determines the eye s s intraocular pressure (IOP). Most people s s IOPs fall between 8 and 20. And if the IOP was too high, it damaged the nerves inside the eye. Research now shows that high IOP may just be risk factor for glaucoma, not a cause.*** Signs and Symptoms Glaucoma is an insidious disease because it rarely causes symptoms. Detection and prevention are only possible with routine eye examinations. 8

9 Other types of glaucoma Acute Angle Closure Glaucoma (emergency!!!) Sudden decrease of vision Extreme eye pain Headache Nausea and vomiting Glare and light sensitivity Other types of glaucoma Congenital Glaucoma Tearing Light sensitivity Enlargement of the cornea Keratoconus a degenerative disease of the cornea the cornea gradually thins and bulges into a cone-like shape light can no longer focus properly on the macula with time, the cone becomes more pronounced, causing distorted vision patients are usually very nearsighted and have a high degree of astigmatism that is not correctable with glasses Pinguecula Pinguecula a benign, yellowish growth that forms on the conjunctiva usually grow near the cornea on the nasal side, but can happen on both sides of the eye thought to be caused by ultraviolet light does not affect vision, but may cause irritation if it becomes elevated. Pterygium 9

10 Pterygium a wedge-shaped growth of the conjunctiva that spreads onto the cornea most common among those who live in the tropics or spend a lot of time in the sun symptoms may include irritation, redness, and tearing May grow quickly, or remain the same for years May alter vision by changing the shape of the cornea May be removed surgically Case History Demographic information Chief complaint The most important question to ask is Why are you here today? Elaborate with other questions Timing - when did it start? Location - one eye or both? Severity how bad is it? Does it happen all the time? If not, when? Case History Review of systems (eye and general health) Ask the patient for information about their vision history (Oc( Hx), health history (Med Hx), medications, and other background information. Visual Acuity the quantitative measure of the eye's ability to see an in-focus image at a certain distance the standard definition of normal visual acuity (20/20) is the ability to resolve a spatial pattern separated by a visual angle of one minute of arc. Usually measured using a Snellen Chart. Visual Acuity-Snellen Chart the Dutch ophthalmologist Hermann Snellen developed the chart in The traditional Snellen chart is printed with eleven lines of block letters. The first line consists of one very large letter, an "E." Subsequent rows have increasing numbers of letters that decrease in size. Patients taking the test cover one eye, and read aloud the letters on each row, beginning at the top. The smallest row that can be read accurately indicates the patient's visual acuity in that eye. 10

11 Visual Acuity-Snellen Chart Snellen Chart The letters are not from any ordinary typographer's font. They have a particular, simple geometry in which: 1. the thickness of the lines equals the thickness of the white spaces between lines and the thickness of the gap in the letter "C" 2. the height and width of the optotype (letter) is five times the thickness of the line. Keratometry measures the corneal curvature two curves are measured the steepest and the flattest gives information about the cornea s s curvature, focusing power, and whether astigmatism is present some of the uses of keratometry include calculating the intraocular lens power for cataract surgery, fitting contact lenses and monitoring the corneal curvature after surgery. Retinoscopy a technique that uses the eye's natural optics to help determine refractive error a light is shone into the patient's eye, and the "cat's eye" reflex is "neutralized" by the examiner using appropriate lens powers necessary to determine refractive error in many types of patients, such as small children or any non-verbal patient also via auto-refractor Manual Retinoscope Auto-Refractor 11

12 Subjective Refraction a refinement of lens combinations made based on the patient's choice of lens power comparisons "which is better, one or two done with each eye individually and then both together the instrument used in this part of the exam is called a phoropter. Binocular Vision Refers to both eyes working together as a team Each eye takes a "picture" and the two images are sent to the brain to merge With normal healthy eyes, the picture appears three- dimensional (stereo-vision) and gives you depth perception If the image is received from only one eye, or if one image is much poorer quality, the necessary two reference points are absent and binocular depth perception is altered Binocular Vision Several simple tests can evaluate binocular vision and depth perception Polarized vectograph plates are viewed through polarized glasses. The images appear to raise up off the page in 3D if stereo vision is present Commonly used tests are the Stereo Fly Test and Randot E test Biomicroscopy also known as the slit-lamp lamp examination, used to assess structures that are at the front of the eye (the anterior segment) the slit-lamp lamp is an instrument used with a high-intensity intensity light source that can be focused to shine as a slit. It is used with the biomicroscope (an optical instrument that is like a microscope with two eyepieces) the eyelid, the sclera, conjunctiva, iris,, natural crystalline lens, and the cornea are examined Ophthalmoscopy Biomicroscopy examination of the inside of the eye (fundus) may be performed dilated or undilated, with any of a series of equipment each tool allows for a different type of view these procedures are performed in a darkened room to allow for a better view inside the eye in all types, a beam of light is projected through the pupil, into the eye, in order to view the back of the eyeball 12

13 Direct Ophthalmoscopy Direct Ophthalmoscopy performed using a handheld, direct ophthalmoscope an ophthalmoscope is about the size of a flashlight, with a light source and a disk of rotating lenses magnification is obtained because the eye itself is a simple magnifier the rotating lenses in the instrument are used to correct the focusing error of the examiner or the patient being examined very high magnification, smallest field of view Slit-lamp lamp Ophthalmoscopy the patient is seated at the same instrument used in examining the front part of the eye an additional magnifying lens will be held close to the eye to enable the doctor to see the fundus this technique has the advantage of giving a three- dimensional view in addition to magnification ophthalmoscopy the view gives moderate magnification and a moderate field of view Indirect Ophthalmoscopy the patient may sit or be reclined in the exam chair the doctor uses an instrument resembling a miner's light (BIO) using a hand-held held magnifier, or condensing lens, the examiner shines a bright light into the eye to view the fundus some pressure may be applied to the eyeball using a small, blunt instrument, and the patient will be asked to look in various directions Indirect Ophthalmoscopy Indirect Ophthalmoscopy this examination takes between 5 and 10 minutes. the light may be uncomfortable, but the test is not painful this examination requires more skill and time than the other forms of ophthalmoscopy, but has the advantage of allowing the doctor to see the entire retina. 13

14 Tonometry Tonometry tests measure intraocular pressure (IOP) This test is used to help detect glaucoma Tonometry measures IOP by determining the resistance of your cornea to indentation Eye drops to numb the surface of your eye are used with most of the methods used to measure IOP. Applanation (Goldmann) tonometry uses a special probe in combination with the slit lamp to flatten part of your cornea to measure eye pressure IOP determined by how much weight it takes to flatten the cornea very accurate, but requires anesthetic drops may be used to verify IOP after a simple screening test (such as air-puff tonometry) detects increased IOP, or may be the primary method used considered the standard against which all other IOP tests are compared Non-contact tonometry (pneumotonometry or NCT) the NCT does not touch the eye but uses a puff of air to flatten the cornea is the least accurate way to measure intraocular pressure used as a simple way to screen for high IOP and is the easiest way to test children also used for people who have had recent laser-assisted assisted in-situ keratomileusis (LASIK) surgery NCT requires no eye drops Indentation (Schiotz) tonometry uses a plunger to indent the cornea the IOP within your eye is determined by measuring how much your cornea is indented by a given weight less accurate than other tests, and rarely used today other doctors, such as family medicine doctors or urgent care doctors, may still use this test. Electronic indentation tonometry electronic tonometry is being used more frequently although very accurate, electronic tonometry can be more variable than applanation tonometry the doctor carefully places the rounded tip of a small, pen-like instrument directly on your cornea the IOP reading is then digitally displayed on a liquid crystal display (LCD) panel A commonly encountered brand is the Tonopen Visual Fields The visual field is the total area in which objects can be seen in the peripheral vision while the eye is focused on a central point. 14

15 Confrontation Visual Fields a quick and basic evaluation of the visual field done during preliminary testing the examiner sits directly in front of the patient with one eye covered, the patient is asked to look at the examiner's eye and tell when you can see the examiners hand, often counting fingers Automated Perimetry the patient sits in front of a concave dome and stares at a central fixation target within the dome a computer-driven program flashes small lights at different locations within the dome's surface, and the patient is instructed to press a button whenever the small lights are seen in the periphery responses are mapped and compared to age-matched controls to determine the presence of defects within the visual field Automated perimeter Tangent screen or Goldmann field exam the patient sits about 3 feet from a screen with a target in the center the patient stares at the central fixation target and lets the examiner know when an object brought into the peripheral vision is visible the extent of the peripheral vision is mapped. Fundus Photography Fundus means the bottom or base of anything. In medicine, it is a general term for the inner lining of a hollow organ. The ocular fundus is the inner lining of the eye made up of the Sensory Retina,, the Retinal Pigment Epithelium, Bruch's Membrane,, and the Choroid. Fundus Photography pictures are sometimes necessary to document the health of the optic nerve, vitreous, macula, retina and its blood vessels the photographs are used for comparison, documentation, and sometimes to diagnose certain eye conditions requires a customized camera that is mounted to a microscope with intricate lenses and mirrors 15

16 Fundus Photography Terms Fundus Oculi interior posterior surface of the eyeball Posterior Pole refers to the retina between the optic nerve and macular area Arcades normal pattern of retinal blood vessels as they leave the optic nerve head and arch around the macula Fundus Photography Terms Cup-to to-disc ratio numerical expression indicating percentage of disc occupied by the optic cup Exudates protein or fatty fluid that leaks from blood vessels into retinal tissue (hard is less fluid, more dense) (soft fluffy looking also called cotton wool spots) Fundus Photography Terms Cotton Wool Spots fluffy looking white deposits resembling small tufts of cotton within the retinal nerve fiber layer that represent small patched of retina that have lost their blood supply from vessel obstruction Nevus small, flat, and usually pigmented area, found in skin and eye tissue. Often labeled a benign tumor. Fluoresciene Angiography is a procedure where dye is injected into a patient s s arm and is used to examine the circulatory system of the eye Fundus Photography some cameras require that the pupils be dilated (otherwise, they would automatically constrict from the bright light of the camera flash) the patient is asked to stare at a fixation device so the eyes are still while the photographer is taking the pictures, the patient will see a series of bright flashes the entire process usually takes approximately five to ten minutes Fundus Photography Fundus Photography 16

17 Fundus Photography Fundus Photography Fundus Photography Fundus Photography Optical Coherence Tomography Provides diagnostic information never before available Non-contact, non-invasive scan is obtained in just a few seconds Similar to an MRI or CT scan Optical Coherence Tomography Cross-sectional sectional scan of living tissue Reveals underlying structure not directly observable by any other means Imaging of ocular tissue at micron-resolution resolution Provides detail 10 times superior to Ultrasound B-scanB Automated nerve fiber layer/retinal thickness Allows precise monitoring for treatment and management of disease Shows living histology with minimal discomfort to the patient No injections or exposure to painful high-intensity intensity light Increased patient comfort and safety, reduced photophobia 17

18 Optical Coherence Tomography Optical Coherence Tomography Marks a major advancement in the diagnosis and management of retinal conditions Doctors can more specifically diagnose, treat and manage vitreoretinal diseases and glaucoma with detailed, quantifiable images of underlying retinal structures. Refractive Status Refractive Status Emmetropia ideal state of the eye with no refractive error present the focus of the eye is set for distance vision without the need for glasses or contact lenses emmetropia occurs when the curvature of the cornea, the shape of the lens and their distances from each other and the retina are at ideal distances the cornea and lens are able to focus the incoming rays of light from an object perfectly on the retina, creating a sharp image Refractive Status Emmetropia Refractive Status Myopia (nearsightedness) a condition in which a person can see near objects more clearly than distant objects usually the result of a longer than normal eye in the myopic eye, light rays from distant objects focus before they reach the retina; the result is blurred vision a tendency for myopia may be inherited; frequent or prolonged near work may influence its progression typically detected in school-age children, may worsen during adolescence, and generally stabilizes between the ages of 20 and 40 years of age. 18

19 Refractive Status Refractive Status Myopia Hyperopia (farsightedness) a condition in which a person can see distant objects more clearly than near objects usually occurs when an eyeball is smaller than normal light rays from near objects do not focus properly on the retina at the back of the eye babies and young children tend to be slightly hyperopic. As the eye grows and becomes longer, hyperopia can lessen presbyopia,, a condition with similar symptoms, has an entirely different cause that is related to aging. Refractive Status Refractive Status Hyperopia Astigmatism a condition in which objects, both near and distant, appear blurred red the cornea and lens should be round like a basketball, or spherical; with astigmatism, the eye has more power in one direction than the t other and the optics take on a toric shape, like a football This uneven curvature prevents light rays entering the eye from focusing to a single point on the retina, blurring the visual image somewhat like a funhouse mirror at an amusement park Astigmatism often occurs in combination with myopia and hyperopia. Refractive Status Astigmatism Refractive Status Presbyopia After 40 years of age, most people find it increasingly difficult to read or see clearly at close range This is a normal part of aging It develops as the lens of the eye becomes less flexible and loses its ability to focus on near objects Presbyopia should not be confused with hyperopia or farsightedness, which relates to the eyeball being too short, a feature that is present from birth 19

20 Refractive Status Presbyopia Refractive Status Accommodation the eye s s way of changing its focus as the lens thickens, it increases the ability to focus at near; as it thins, it allows for distance vision A young person s s ability to accommodate allows him or her to see clearly far away and up close At about the age of 40, the lens becomes less flexible and accommodation is gradually lost, making close- range work increasingly difficult. This is known as presbyopia. QUESTIONS? drvirden@wacovision.com website: 20