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Disclosure Ocular Anatomy and Motility
Jenean Carlton BA, ABOC, NCLC
9President, Carlton & Associates, LLC – Carlton and Associates, 6 Course #214 Monterey Symposium LLC provides communications and educational materials for the optical industry
9Contributing Editor for Refractive Eyecare magazine. 6 Jenean Carlton BA, ABOC, NCLC 9Contributing Author Eyecare Business magazine.
9Communications Committee member OWA.
9Has been in the optical industry for 30 years with more than half of this time working in practices.
9Vision Monday’s Most Influential Women Award in Optical 2005 1
Ocular Anatomy Overview The Human Vision System
9 The eye is an amazing organ that works like a camera.
9 Think of the cornea and crystalline lens as the lenses of a camera, the iris as the shutter, and the retina as the photographic film.
The Human Vision System Lids and Lacrimal System Vision takes place in the occipital lobe of The tear film has 3 layers: the brain Outer: the lipid layer (meibomian 9The brain can be glands in lids) is the oil layer. thought of as the
development Middle: the aqueous layer center because it (lacrimal glands) is mainly water and provides oxygen converts and nutrients. electrical signals from the retina Inner: the mucin layer (goblet cells in conjunctiva) helps the tears into vision. adhere to the cornea. It is the mucus layer.
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Dry Eye Syndrome Lid Disorders
What causes dry eyes? Ectropion= Out
Treatments
Entropion= In
Ptosis- a drooping of the lid. Lids can have other problems too like turning out, in.
Lids Disorders Lid Disorders
Blepharitis is a chronic Hordeolum (stye) - inflammation- not an acute inflammation of a infection. sebaceous gland.
Treatments are lid scrubs, warm compresses, antibiotics and anti-inflammatories.
Image source: http://www.bascomoptometry.com/eyedisorders.html
Lid Disorders Conjunctiva and Sclera Disorders Chalazion-Chronic inflammation of a Subconjunctival meibomian gland - hemorrhage - result of a not an infection. broken blood vessel. Results in blockage Spontaneous – benign of the gland. The Traumatic – ruptured first symptoms globe until proven resemble those of otherwise. styles.
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Conjunctiva and Sclera Disorders Conjunctiva and Sclera Disorders Conjunctivitis – “pink eye”
Pinguecula - elevated growth Pterygium - a membrane that grows of the conjunctiva. across the cornea
Viral = clear Allergic = giant Bacterial= discharge, papillary, itch green/yellow contagious discharge, antibiotics Both caused by excessive UV exposure, and dusty, windy environments.
Image: http://www.pterygium.us/images/pinguecula.jpg
Cornea- 5 Layers Corneal Disorders
Outer layer The cornea is the Abrasions- This could be an abrasion from a window of the eye and has five layers. foreign body caught in the upper lid.
The cornea has 45 diopters of power Inner and is avascular. layer
Corneal Disorders Corneal Disorders
9 Foreign Bodies Corneal Ulcer is an infection developed after a break of the epithelium layer. 9 Symptoms and removal
Image 1: opt.pacificu.edu
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Corneal Disorders Pupil and Iris
Keratoconus- progressive thinning of the central cornea.
The iris controls the size of the pupil and light passing through the eye.
Image 1: http://www.eyeconx.com/patient/article.asp?itemtype=publicarticle&itemid=CADC1677B4957B1807E1024FBBE0ED36
Image 2: http://commons.wikimedia.org/wiki/Image:Keratoconus_eye.jpg
Crystalline Lens Accommodation Retina
Near objects 9The retina has photoreceptor cells called rods and cones.
Far objects
Presbyopia – loss of focusing ability with age
Retinal Problems Optic Nerve Problems - Glaucoma
Normal fundus
Retinal detachment
Image*: http://www.houstonretina.com/tear.html
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How the Eye Works How the Eye Works 1) Light enters the eye through the ______. 2) Light travels through the _____ and is focused by the ______.
The ____ is the colored muscular ring that surrounds the _____ and functions like a camera shutter.
How the Eye Works How the Eye Works
3) Light exits the ______and travels through a jelly- like substance in the middle of the eye ______. Images are focused onto the ______. 5) Signals travel from the retina to the brain through the ______. The ______of the brain then translates light into vision.
Vision in humans takes place in the _____- not the eye.
Rapid Fire Review Normal Eye and Refraction 3. 2.
4.
5.
1.
Through Cornea To 8. focus Light travels from on Retina 7. distant object 6.
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Myopia- Nearsighted Eye Spectacle Correction of Myopia
A “minus” lens causes light rays to diverge...... the eye is longer
...to focus further back in the eye, on the retina
Hyperopic- Farsighted Eye Hyperopic- Farsighted Eye
…or Cornea is too “flat” ...the eye is shorter causing light to be out of focus
Astigmatism Astigmatism
Astigmatism - In one plane, light focuses on retina …but does not in another plane
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Astigmatism Presbyopia Causing light in both planes to focus on the retina Normally, when a close object is viewed...
The lens will change shape…Accommodation
Presbyopia Presbyopia
…to focus light on the retina With Presbyopia, the lens will not sufficiently reshape...
Presbyopia
...and glasses may be required for close viewing
Ocular Motility: the movement of our eyes to place images on the fovea of each eye.
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Ocular Motility Ocular Motility
6 Convergence 6 Binocular Vision 6 Divergence 6 Fixation
6 Eyes that move together in perfect harmony have stereo vision.
Image source: http://www.ebicom.net/~rsf1/fun/3d-not.htm
Ocular Motility
3 Cranial Nerves control
ocular movement 3LRSO6 4
9 CNIII‐ Oculomotor Nerve
9 CN IV‐Trochlear Nerve
9 CN VI‐ Abducens Nerve
Image source:http://library.thinkquest.org/11965/html/cyber- http://www.uniteforsight.org/course/im anatomy_ner692.html age/eyemuscle3.jpg
Binocular Vision Binocular Vision
Binocular Vision- A single image is gained by the Depth Perception blending of retinal 6 Allows us to travel about safely in our world. signals from both eyes. 6 Without it our ability to judge distances or estimate the size of objects is limited. 6 However, everyone ‐ even monocular patients, have some level of depth perception.
Image source: http://www.hhmi.org/senses/popups/images/b410_1p.gif
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Ocular Motility Ocular Motility problems
6 Monocular patients estimate depth perception______6 Diplopia is double vision or 6 Magnification 2 images. 6 Parallel lines 6 Shadows 6 Monocular or binocular? 6 Strabismus is a misalignment of the eyes.
Image source: http://www.honda- tech.com/zerothread?id=1246218&postid=16525201
Strabismus Strabismus
Strabismus: Strabismus can be subtle or obvious, intermittent or Failure of the two eyes constant. to simultaneously direct their gaze at the same 6 It can affect one eye only or shift between object due to an the eyes. imbalance in the activity of the EOM’s. 6 Usually presents early in life. 6 If left untreated strabismus can result in the brain suppressing the image from one eye, this is called amblyopia. Image source: http://www.fairview.org/healthlibrary/content/ea_strabism_art.htm
Diagnosing Strabismus Strabismus
6 Amblyopia: Cover Test 6 Loss of vision due to muscle imbalance, anisometropia, or cataract.
6 Sometimes referred to as “lazy eye”.
6 Can occur in children up to teenage years.
6 The amblyopic eye is the weaker eye.
http://www.ssc.education.ed.ac.uk/courses/Pictures/jskill15.jpg
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Diagnosing Strabismus Diagnosing Strabismus
6 Krimsky’s Test Hirschberg Reflex Test
9 The strength of the prism 6 A screening test for the recognition of strabismus is the required to center the corneal Hirschberg Reflex test. Light reflexes ______in reflection in the eye with strabismus is equal to the the same place for each eye. amount of ______. OD: Note that light reflex falls on center of pupil.
OS: Light reflex falls on temporal Image source: http://eyelearn.med.utoronto.ca/Lectures04- margin of pupil. 05/Paediatric/03Strabismus.htm
Strabismus Treatment Strabismus Treatment
6 Prisms displace images towards the ______of the prism. Strabismus Treatment: 9 1. Prism
9 2. Patching/Atropine drops 9 3. Vision Training/Orthoptics 9 4. Botox injections
9 5. Surgery Image source:http://science.howstuffworks.com/lens3.htm
Strabismus Treatment Strabismus Treatment
6 Botox: Patching the ______forces the brain to use 6 a toxin developed from Clostridium the problem eye. botulinium, a common______.
Patching= occlusion. What about drops?
Image source: http://eyelearn.med.utoronto.ca/Lectures04- Image source: 05/Paediatric/03Strabismus.htm http://www.ophthalmic.hyperguides.com/tutorials/pediatric/botulinum/tuto rial.asp
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Strabismus Treatment Rapid Fire Review
6 Strabismus surgery is done to straighten the eye. With Resection 9 Eyes that don’t move perfectly together resection______don’t______. ______.
9 Binocular vision is______.
6 If the muscle is too strong it is made weak Recession 9 What is amblyopia and what causes it? by______. 9 Horizontal movements are made by these 2 muscles______. Image source: http://www.myeyeworld.com/files/squint.htm
Rapid Fire Review Thank You!!
9 Diplopia is______.
6 Please contact me: [email protected] 9 Strabismus is______.
9 Occluding the good eye forces______.
9 There are 5 methods of treating strabismus. They are ______.
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