Lecture 7 Oct 6th

Opthalmology for Naturopathy

Fall 2006

(CLS201) Dr Peter Shaw O.D. Scarborough Low Vision Centre 3030 Lawrence Avenue , suite 206, Scarborough 416 438 3525 5915 Leslie Street, suite 205, Willowdale 416 4394 3050 NOTES: • My notes are in blue. • The order of the lecturer’s notes was rearranged slightly to reflect the order of presentation. • The sections without any additional notes were not discussed in class. I’m assuming we are still responsible for them… –GF Review of Eye Physiology Knowing anatomy of eye helps differentiate pathologies. Eye = Digital video camera. Blur/fog is a problem with light transduction. Blind spot may be a neural problem. Lens/Cornea = Lens system. Retina = CCD/Film + Image compression sofware! Retina is part of brain: functions as cortical tissue. Sends multiplexed signal to brain. Optic nerve and tract = USB Cable Visual Cortex = Image decoding software and Magic! Brain receives decoded picture. Visual cortex: perception of vision. Always be thinking laterally with eye disorders: What else is wrong? Look for associated disease. The eye is not separate from the rest of the body. Pathologies/Disorders Inherited Infective organism Age related • Most children are born slightly far-sighted. Uncorrected farsightedness in children: accommodation, associated convergence, child’s eyes turn in. “Lazy eye” can occur. Children should be examined before age 3. Environmental • People from tropical countries tend to need reading glasses 4-5 years earlier. May be due to the amount of sunlight they are exposed to. • Flicker of old-school computer screens is not good for the eye/brain. The eye likes stable, high contrast (books). New computer screens are better: light doesn’t flicker. This is the

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only time when not wearing glasses causes harm. Flickering can trigger epileptic episode in susceptible people. Diet Trauma Secondary to other disease Physiological/Physical Iatrogenic (treatment, medication side effects) Combination of any/all Symptoms/Signs Blurred Vision Redness Swelling Pain Discomfort Diplopia (double vision) Refractive Errors Myopia Can see close, can’t see far. Nearsighted. Optical focus of eye isn’t correct. Disorder of growth. More common in larger eyes. Light rays focus in front of retina, patient can see well at near but distance blurred Corrected with concave spectacle lenses or contact lenses Usual age of onset 8 – 20 usually stable after age 20 Causative factors: genetic, environmental? diet (if severe malnourishment) Hyperopia More common in smaller eyes: point of focus is behind retina. Light rays focus behind retina when accommodation relaxed (cilliary muscle = accommodation. As we age, we can no longer accommodate: lens becomes more dense.) Age of onset birth after 40 Accommodation can compensate in younger patient Far Sightedness (Near vision poorer than distance) Eyeglasses contact lenses If left uncorrected amblyopia and strabismus may be a result All children should be screened for this, a chief cause of reading/learning dysfunction Astigmatism Refracting surface is not spherical, but egg-shaped. Pointless vision. Very common Cornea has a cylindrical profile (like the side of an egg) Changes through-out life Spectacles /contact lenses Age of onset: 0-all

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Affect reading and distance vision (blur at all distances) Symptoms include headaches, poor reading skills, squinting Genetics/age/trauma Presbyopia This happens with every person: inability of eye to focus with age. Normal physiological changes in crystalline lens preventing accommodation Lens proteins coagulate = higher density --- decreased elasticity Cannot adjust to focus at near or adjust for hyperopia Corrected with reading glasses (convex) or multi-focal lenses Age of onset 40-50 stable at 60 Accelerated by UV exposure (earlier onset in those from tropical climates Binocular vision anomalies Can cause eye strain/problems. Strabismus= Manifest (visible) deviation The eyes don’t line up to look at the same thing at the same time. Can be corrected at a young age: neural pathways are plastic until age 4. If 1 eye is turning in different direction, the brain turns the eye “off” to avoid confusion. Esodiviation: 1 eye is turned in. Find out if this is the result of hyperopia. Phorias=: Latent (hidden) deviation. Latent strabismus. Patient compensates by using muscles, but this creates strain in muscles. If a child isn’t doing well in school, check their eyes and other senses. If they can’t see properly, they can’t take in the information, and can’t concentrate. They get distracted, don’t focus, don’t do well. Periodic either Near or Far only Correction with exercises Correction with surgery Amelioration with prism In = eso tropia / phoria Out = exo tropia / phoria, Up = hyper tropia / phoria Phoria Typically a lower deviation than a strabismus Able to compensate Binocular vision therapy may be applicable Exophoria is most treatable Symptoms are subtle but may cause blur and diplopia Esophoria treated with bifocals in juveniles Primary cause of distraction with children Strabismus Esotropia: first rule out accommodative esotropia All children should be assessed by age of 3 years preferably at 6 months by an optometrist or ophthalmologist If untreated will most likely lead to amblyopia Amblyopia

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Can be caused by hyperopia, ,strabismus. “Lazy Eye”: the RESULT of strabismus. Result of brain turning off the eye. Typically due to one eye not receiving a clear image prior to age 4 Visual cortex actively supresses a blurred eye or one causing double vision Screen < age 4 for anisometropia (unequal refractive error), hyperopia and strabismus Treatment consists of correcting the underlying disorder and possible patching/exercises Treatment to be initiated as early as possible Efficacy rapidly decreases after age 4 Lay term= Lazy Eye, Common Disorders of the Eyelids Eyelashes • Can grow inwards and scratch the cornea. Scratch leads to abrasion, can cause corneal ulcer. Potential entry point for bacteria. • Haziness from ulcer prevents clear vision. The cornea is avascular: we have trouble clearing it. • Cornea is very sensitive, so patient will likely seek help for discomfort caused by scratching eyelashes • Primary treatment for all eyelash disorders: HYGIENE! • Diet also an important factor. Epidermis of the eye is affected by the same conditions that affect the rest of the skin. Good to help patients manage their diets. • #1 pathogen of eyelids is staph. Opportunistic bacteria. It is everywhere, but will be problematic if immune system is compromised. Trichiasis: Misdirection of the eyelashes often resulting in corneal trauma and abrasion potential causing a corneal ulcer Phthiriasis palbebrarum: Lice of the eyelashes Madarosis: Missing lashes, Alopacia, prosiasis, chronis margin disease Allergic Disorders Atopic Dermatitis:(Excema of the eyelids), associated with asthma and hay fever Acute allergic edema,: unilateral or bilateral puffy lids without pain Contact dermatitis:localised erythema and crusting Chronic marginal Blepharitis: • Can be treated by lid cleansing (there are products on market for cleaning lids, maintaining good hygiene.) Staphyloccocal infection and Seborrhhea play a major role Due to the positionexpect secondary corneal pathology Treatment through lid hygiene (lid cleansing) and artificial tears Antibiotics may be useful as a kick start but not chronically. Antibiotics may not be necessary: can lead to more serious reactions. Steroids are often prescribed too: may also be unnecessary! Steroids may be used to treat associated complications Watch for symptoms of staph exotoxins (injected conjunctiva, mild keratitis) Tear film instability DDX LECTURE 7, OCTOBER 6TH – PAGE 4

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Glands in eyelids secrete mucin, water, oil to protect cornea. Eyelids maintain the integrity of the cornea. Lid Nodules and Cysts • Determine if condition is acute or chronic Chalazion: meibomian gland cyst, chronic lipo-granulomatous inflammatory lesion caused by a blocked meibomian gland. • A gland that becomes hard. Gets plugged • Benign condition, but can be cut out if the patient desires. • Lacrimal glands (above eye) flush stuff away, produce “crying” tears. Different from mucin produced by meibomian glands in eyelids. Tears wash away mucin, leave the eye feeling dry after crying. Mucin (water, oil) keeps eyes “wet” • B6 may be good for encouraging the production of mucin (we will learn more about this in other classes). There may be other systemic supplements that can help with this. Internal Hordeolum: small abscess caused by acute staph. infection of meibomian gland. A STYE. Can turn into chalazion if infection (staph) is chronic. Gradual transition from hordeolum to chalazion. External Hordeolum: acute abscess of lash follicle or Xanthelasma: common in aged, yellow subcutaneous plaques of cholesterol and lipid Lid Tumours: Non healing , pigmented, localised unilateral, Mechanical Disorders of the lids Ptosis: unilateral upper lid droop Neurogenic: Third nerve palsy, oculo-sympathetic palsy Horner’s syndrome, Mercus-Gunn jaw winking syndrome Myogenic: Levator muscle Congenital, myasthenia gravis Ectropian: Lower lid away from cornea, tissue dries dry eye Surgery, lubricant gels Entropian Lower lid turn in, lashes abrade cornea,Treat with surgery/ soft contact lens Potential for corneal ulcer (a bad thing) • Caveat with laser surgery: patient must have no lid disorders! Need good mucin, especially in immediate post-operative stage. Cornea has to be kept clean and moist for proper healing. Conjunctivitis • When using contact lenses, FOLLOW THE RULES! Dispose of solution and lenses when you are supposed to. • #1 cause of conjunctivitis is allergy. • Also called “red eye” (not “pink eye”) Allergic - Viral – Bacterial –Toxic – Trauma • If allergic: clear stuff will come out of the eye. Could indicate presence of toxin, foreign body. • If discharge is stringy, mucous-y, or possibly clear, this is viral. • If discharge is yellow-green: this is a bacterial infection. Patients may be given antibiotics, but this may not help at all. (not sure why…) DDX LECTURE 7, OCTOBER 6TH – PAGE 5

Injected vessels Palpebral – Inner lid Bulbar – on the eyeball • No yellow-green discharge, no pain? No problem. • Eg. “Pink Eye”: common in daycares (epidemic). Contagious, but not treatable. Spreads through rubbing eyes, through shared towels. No cure for pink eye: treat with hygiene. Sub Conjunctival Hemorrhage Solid red appearance to eye. Bleeding under conjunctiva. Burst blood vessel that leaks into space between conjuctiva and sclera. Can’t see dilated blood vessels as you wood in conjunctivitis. Causes? Hypertension, also look for systemic bleeding disorders. Usually benign Check Blood pressure Resolves in two weeks Possible blood dyscrazia Giant Papillary Conjunctivitis Papillae under the upper lid Soiled soft contact lenses the primary cause Disposable lenses advocated Treatment = change contacts or discontinue Tears and secretions An even tear film = clear vision Watery eyes = blur 2nd Most common cause of blurred vision after refractive errors Causes: marginal blepharitis,lid disorders, dry eye, allergic conjunctivitis, viral conjunctivitis. Cause changes in the tear film Age, Envirionment, Allergies, Other diseases Corneal Ulcer • Some benign pathologies in other parts of body limit function in the eye: more serious consequences in the eye. Ulcer on lip? Ok. Ulcer on eye? Painful, red eyes, excessive tearing, blurring. • Could be due to herpes simplex infection. Have to refer for antibiotic treatment. Corneal ulcer or abrasion characterised by a white spot on the cornea Herpes simplex, pseudomonas, opportunistic pathogens Painful Eye red, excessive tearing, blurred, Refer immediately for treatment Often associated with soft contact lens wear or injury abrasion • The problem isn’t the virus, but the inflammation that the body creates as a response to the virus. • Associated with unhygienic soft contact use. Pingueculitis DDX LECTURE 7, OCTOBER 6TH – PAGE 6

Mild inflammation of pinguecula • “snow blindness”. Due to UV burn on eye. Treat with sunglasses May be due to excess uv exposure Lubricants can be used to treat if it causes irritation. • Pinguecula is a small pterygium Red Eye: Pterygium • Response to UV exposure. Seen especially in rural areas, farmers, fisherman. Can start in corner of eye. Has to be removed as it grows over pupil. fibrovascular tissue • Fibrous: can’t see through it as it grows. Pulls on cornea and deforms it. UVA UVB Common near the equator Surgical excision when large Cataract • Light is bent by cornea and lens. Lens is made of proteins Homogenous in clear lens Random sizes in cataract UV energy may cause proteins to “clump together” • With age, proteins start to change and become opaque. Non-homogenous proteins in lens. Like an egg white as it cooks: goes white and opaque. Typical onset >65 Rarely <50 More common in sunny countries and outdoor lifestyle (UV component) Congenital with rubella Treat with surgical removal Cataract surgery: Indicated when patients vision is less than they desire and cataract is the cause. Surgery only needed when it bothers the patient. “Ripe” is an antiquated term No stitches (small incision through cornea) Lens is replaced with a plastic one. 20 minutes, local anaesthesia, out patient • Possible correlation with free-radicals. • Cornea doesn’t change with age. Anterior Chamber Haze: Uveitis: Inflammation of anterior structures releasing inflammatory cells into AC Uveitis Associated with other inflammatory conditions Arthritis, Cholitis etc Be aware, your patients may be pre-disposed. (lupus, IBS, Chron’s, etc)

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