Ocular Jeopardy. The major refractive portion of the eye 5/12/2015. Presented by Jill J Luebbert, CPOT, ABOC. Watch This Refractive optios

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1 Ocular Jeopardy Presented by Jill J Luebbert, CPOT, ABOC In the beginning anterior Way back Visual Pathway Say What? terminolog y Watch This Refractive optios Posterior Segment The major refractive portion of the eye 1

2 The muscle that controls dilation of the pupil The third layer of the tear film The glands that produce the oily layer of the tear film. 2

3 The direction sphincter muscles move The point of intersection of the optic nerves Projected on the right side of the retina 3

4 Where electrical impulses are converted to radiation Vision is achieved at this point A blockage at point will cause a homonymous hemianopsia. 4

5 The two generic types of contact lenses. The distance across the contact lens. The posterior curve. 5

6 The instrument used to measure base curves. The relaxing curves on the posterior on the contact lens. The colored part of the eye. 6

7 The major refracting surface on the eye. They control the movement of the eye. Covers the interior 5/6 of the eye. 7

8 The area consisting only of cones. One of the most important procedures in any eye examination. The distance between the eyes. 8

9 The measurement of the finest detail of vision. The instrument used to measure the central 3mm of the cornea The evaluation of the patient s perception to color. 9

10 Use to evaluate the patient s pursuit skills. Cornea Image courtesy of National Eye Institute Layers of the cornea Epithelium Bowman s Membrane Stroma Descement s Membrane Endothelium 10

11 Levator palpebrae superioris Eyelids Seven layers of tissue Skin Subcutaneous areolar layer Orbicularis oculi muscle Submuscular areolar layer Levator palpebrae superioris Tarsal plate Meibomian glands Skin layer Outer most layer Thinnest skin of the entire body Contains sweat glands and hair Nasal portion smoother & greasier Begins at gray line 11

12 Subcutaneous areolar layer Loose connective tissue Contains no fat Demonstrates edema (puffy) Orbicularis Oculi Runs the entire length of the eyelid Responsible for lid closure Controlled by Cranial Nerve VII Submuscular areolar Loose connective tissue Contains majority of nervous and circulatory supply 12

13 Levator palpebrae superioris Occupies the entire width of lid Is the major muscle responsible for lid opening Tarsal Plate Located in upper & lower lid Made of dense & elastic connective tissue Contains Meibomian glands Produces oil layer of tears Mucous Layer 13

14 Tear Layers Oily Water Mucous Meibomian Glands 14

15 Hordeolum (Sty) Chalazion Circular 15

16 Optic Chiasm The crossroads of vision 16

17 Left Visual Fields Left Visual Fields Left Visual Fields Visual Cortex 17

18 Vision is using our eyes and our brain Visual Cortex Lateral Geniculate Body 18

19 Lateral Geniculate Body Post Chiasmal Optic Tract 19

20 Hard and Soft Soft Contact Lens Introduced in 1972 Silicon / Hydrogel Soft and flexible Easier to adjust to wearing Soft Contact Lens Daily wear Flexible wear Disposable 20

21 Rigid Contact Lens Hard Gas Permeable (RGP) Hard Contact Lens Materials 1940 s, 50 s, 60 s Polymethylmethacrylate (PMMA) 1970 s Rigid Gas-permeable (RGP) Silicone Acrylate Fluoro- Silicone Acrylate Fluorine known for its nonstick properties in Teflon Enhanced surface wettability Silicon adds higher oxygen permeability Permeable The ability to allow oxygen to pass through it Referred to Dk DK/t (t = thickness) 21

22 Overall Diameter Overall Diameter (OAD) Measurement from edge to edge of contact lens Overall Lens Diameter 22

23 Base Curve Base Curve Measurement of the back surface of the lens Power Refractive power needed on the eye is different than the refractive power in ophthalmic lenses which are in front of the eye Example: Ophthalmic Prescription x 180 Contact lens prescription may be

24 Radiuscope Radiuscope Instrument used for measuring the radius of curvature of the surfaces of a contact lens. It is based on the Drysdale method. Also known as optical microspherometer. 24

25 Peripheral Curves Peripheral Curves Steps to flatten the contact lens and improve fit Iris 25

26 Iris Colored portion Dilates and constricts Contains only brown pigment CAN THAT BE TRUE????? Image courtesy of National Eye Institute Constriction and Dilation 26

27 Cornea Cornea 27

28 Cornea Works as the eye s windshield Is about 12 mm in diameter Accounts for approximately 42 diopters of the eye s total power of 60 diopters Has NO blood vessels Has 5 layers Primary Eyecare Network Cornea Primary Eyecare Network 28

29 Limbus Extraocular Muscles 29

30 Retina Nervous Tunic Retina 30

31 Retina Converts light energy into electrical impulses Consists of 10 layers Covers 65% of the interior surface of the eye Retina Begins at Ora Serrata Generally divided into two general sections Outer layer (RPE) Inner layer (Retina) 31

32 10 layers Retina Pigment Epithilium (RPE) Neural Retina (rods and cones) External limiting membrane Outer nuclear layer Outer plexiform layer Inner nuclear layerr Inner plexiform layerr Ganglion cell layer Nerve fiber layer Internal limiting membrane Retina Contains photoreceptors Macula Fovea Optic nerve head Image Courtesy of National Eye Institute Optic Nerve Cable network Communication center to the brain 32

33 Fovea Macula Contains cones Fovea used to see finest details of vision Image Courtesy of National Eye Institute Photoreceptors Used for motion and vision in low illumination Short cone shaped cells Responsible for pattern detection and fine details 33

34 Case History Case History Image Courtesy of National Eye Institute Investigation What brings you here today? Record in patients own words Sets the foundation for the examination process 34

35 Documentation is the key History of Present Illness Where When Duration History of Present Illness (HPI) Location (where) Quality (sharp, dull, hazy) Severity (mild, severe, bothersome) Duration (constant, off & on) Timing ( mornings, mid day) Context (driving, reading) Modifying Factors (bright light, close eyes) Associated Signs & Symptoms(itch, headache) 35

36 Pupillary Distance (PD) INTERPUPILLARY DISTANCE MEASUREMENT Distance and near PD measuring ruler Pupillometer Monocular PD measurement PD Measurement 36

37 Prentice s Rule The rule that states induced prism is equal to the lens power multiplied by the displacement in centimeters of the lens optical centers from the patient's PD. Vision Acuity 37

38 Vision Acuity Measurement of the finest detail the eye can detect Snellen Chart What is normal vision? Clarity of Cornea Aqueous Humor Crystalline Lens Vitreous Humor Foveal Fixation Optic Nerve Health Visual Cortex Function 38

39 Snellen Fraction 20/20 Numerator / Denominator Numerator = Test Distance Denominator = Distance at which letter is standardized to be read What is legal blind? Legal blindness is defined as visual acuity of 20/200 or worse in the best seeing eye. A visual field that is limited to only 20 degrees. 39

40 Keratometer Keratometer Determines amount of power in each meridian of the cornea Measures Central 3 mm SPECIALTY TESTING Keratometry Vertical and horizontal meridians Keratometers; Ophthalmometers Mires; plus and minus signs 40

41 Manual Keratometry Starting Point End Point + + Readings Example: x 90 / Topography 41

42 Topography Color Test Color Testing Normal Color Color Perception Protanope red sensitive dichromat 42

43 Pseudoisochromatic Plates Farnsworth D 15 Dichotomous Test Broad H 43

44 EXTRA OCULAR MUSCLE TESTING EOM S Pursuits Movement of the eyes while following a moving target Saccades Jumping movements from one target to another BROAD H LSR RIO RMR LLR LIR RSO RSR LIO RLR LMR SIR LSO 44