What every physician should What every physician should know about the eyeknow about the eye

What every physician should What every physician should know about the eyeknow about the eye

Michael B. Gorin, MD PhDMichael B. Gorin, MD PhD

Professor of OphthalmologyProfessor of Ophthalmology

Jules Stein Eye Institute - UCLAJules Stein Eye Institute - UCLA

What every physician should What every physician should thinkthink about vision and the eye about vision and the eyeWhat every physician should What every physician should

thinkthink about vision and the eye about vision and the eye

Goals of this talkGoals of this talkGoals of this talkGoals of this talk

• What is blindness What is blindness • Understand basic concepts regarding Understand basic concepts regarding

vision and its assessmentvision and its assessment• How do we evaluate the eyeHow do we evaluate the eye• Appreciating the diversity of ocular Appreciating the diversity of ocular

diseasedisease• The eye with respect to general health The eye with respect to general health

and systemic diseaseand systemic disease• The “biggies”The “biggies”• What do you do with a patient with What do you do with a patient with

possible vision or eye problems.possible vision or eye problems.

““Non-goals” of this talkNon-goals” of this talk““Non-goals” of this talkNon-goals” of this talk

• Detailed discussion of ocular anatomy, Detailed discussion of ocular anatomy, physiology, biochemistry and geneticsphysiology, biochemistry and genetics• You should have already had this in prior You should have already had this in prior

sections sections • There is a website in your handout to review There is a website in your handout to review

this material and you will have a quiz on the this material and you will have a quiz on the morning of the first day to ensure that you have morning of the first day to ensure that you have the necessary information for the clerkship.the necessary information for the clerkship.

• Eye examination skills for the general Eye examination skills for the general physicianphysician• This was covered in the prior workshop (2This was covered in the prior workshop (2ndnd

year)year)

““Non-goals” of this talkNon-goals” of this talk““Non-goals” of this talkNon-goals” of this talk

• Recognition of the findings of different Recognition of the findings of different types of eye disorderstypes of eye disorders

• Management and treatment of major or Management and treatment of major or common eye conditionscommon eye conditions• These are the primary goals of this 3These are the primary goals of this 3rdrd year year

clinical clerkship experience.clinical clerkship experience.

• Convincing you that ophthalmology is the Convincing you that ophthalmology is the best specialty in medicinebest specialty in medicine

What is blindness?What is blindness?

• Blindness is a very indistinct term that has Blindness is a very indistinct term that has different meanings in different contexts.different meanings in different contexts.

1)1) A person whose vision is insufficient to A person whose vision is insufficient to carryout normal sighted tasks (ie color carryout normal sighted tasks (ie color blindness, night blindness)blindness, night blindness)

2) A person whose vision is restricted to 20/200 2) A person whose vision is restricted to 20/200 or worse in their better eye or with reduced or worse in their better eye or with reduced central visual fields of less than 20central visual fields of less than 20oo - Legal - Legal definition of blindnessdefinition of blindness

3) A person with no vision at all (no light 3) A person with no vision at all (no light perception) - actually relatively rareperception) - actually relatively rare

What is the definition of blindness?What is the definition of blindness?

20/10 - 20/25: Normal20/30 - 20/60: Near-normal20/70 - 20/160 : Moderate vision impairment - eligible for education assistance in US20/200 - 20/400: Severe vision impairment - legal blindness in US (visual field < 20 degrees)20/500 - 20/1000: profound vision impairment - WHO and several European countries definition of blindness (visual field < 10 degrees), CF < 3m< 20/1000: Near-total visual impairment: used by some developing countries as definition of blindness (visual field < 5 degrees), HM, LPNLP: Total visual impairment

Causes of Worldwide BlindnessCauses of Worldwide Blindness

• CataractCataract 17 million17 million• TrachomaTrachoma 6.0 million6.0 million• GlaucomaGlaucoma 3.0 million3.0 million• Xerophthalmia Xerophthalmia 0.5 million0.5 million• OnchocerciasisOnchocerciasis 0.5 million0.5 million• AMDAMD 1.0 million1.0 million• Diabetic retinopathyDiabetic retinopathy 0.25 million0.25 million• Leprosy Leprosy 0.25 million0.25 million• OthersOthers 2.5 million2.5 million

• 85% of blindness is in Africa and Asia85% of blindness is in Africa and Asia• 85% of cases are potentially treatable or preventable85% of cases are potentially treatable or preventable• Prevalence: Prevalence:

• 0.125-0.25% in Western world0.125-0.25% in Western world• 0.2-1.5% (av 0.75%) in Asia0.2-1.5% (av 0.75%) in Asia• 0.3-3.1% (av 1.2%) in Africa0.3-3.1% (av 1.2%) in Africa

Allen Foster in Clinical Ophthalmology - Duane, ed. (1991)Allen Foster in Clinical Ophthalmology - Duane, ed. (1991)

Aging and BlindnessAging and Blindness

• PrevalencePrevalence (in Germany)(in Germany) : :

• 15 % lose sight < 20 years old15 % lose sight < 20 years old• 51% lose sight >50 and <8051% lose sight >50 and <80• 15 % lose sight > 80 years old15 % lose sight > 80 years old

• IncidenceIncidence::

• 50% of new cases are people over 8050% of new cases are people over 80• ““ImbalanceImbalance” due to differences in life expectancy ” due to differences in life expectancy

and duration of blindness.and duration of blindness.• Blind < 10 years - 74%Blind < 10 years - 74%• Blind >10 years - 26%Blind >10 years - 26%• Blind > 20 years - 10%Blind > 20 years - 10%

Vision parametersVision parametersVision parametersVision parameters

• Central visual acuity Central visual acuity • Contrast sensitivityContrast sensitivity• ColorColor• AdaptationAdaptation• Peripheral visionPeripheral vision• Binocularity and stereopsisBinocularity and stereopsis• Central ProcessingCentral Processing• Confounders - nightblindness, Confounders - nightblindness,

photopsias, photophobia, scotomas, photopsias, photophobia, scotomas, distortions, glaredistortions, glare

Central visual acuityCentral visual acuityCentral visual acuityCentral visual acuity

• • Derives from the central 250 microns of the Derives from the central 250 microns of the retina retina

• • Beyond 250 microns, central acuity declines Beyond 250 microns, central acuity declines rapidlyrapidly

• • Measured by Snellen chart or ETDRSMeasured by Snellen chart or ETDRS Note: high contrast, high luminance Note: high contrast, high luminance conditionsconditions

• • Requires proper central (brain) developmentRequires proper central (brain) developmentEarly vision impairment can prevent good Early vision impairment can prevent good central vision even if problem is corrected - central vision even if problem is corrected - amblyopiaamblyopia

• • Uncorrected and Uncorrected and correctedcorrected

• • Refractive error Refractive error MyopiaMyopia HyperopiaHyperopia AstigmatismAstigmatism PresbyopiaPresbyopia• • Snellen chart, Snellen chart, near card, and the near card, and the ETDRS chartETDRS chart

ETDRS Chart Back-illuminated, High luminance, High contrast

Central Central visual acuityvisual acuity

Normal View

Central loss with paracentral blurringFixation on head

Central loss with paracentral blurringFixation on paper

Contrast sensitivityContrast sensitivityContrast sensitivityContrast sensitivity

• Variations in vision with Variations in vision with different lighting conditions different lighting conditions

• Different testsDifferent tests• Pelli Robison, othersPelli Robison, others

• Important to consider how Important to consider how different lighting conditions different lighting conditions can affect functional acuitycan affect functional acuity

Normal contrast

Reduced contrast Pelli-Robison Chart

ColorColor

• Most common vision deficiency other Most common vision deficiency other than refractive error. than refractive error.

• Most screening tests are for red-green Most screening tests are for red-green congenital colorblindnesscongenital colorblindness

• Color deficiencies are also seen in Color deficiencies are also seen in progressive conditions such as cone and progressive conditions such as cone and cone-rod dystrophiescone-rod dystrophies

• Testing (CRT, plates and chips)Testing (CRT, plates and chips)

Ishihara Color plates

Left - Normal

Right - Red green deficiency

Farnsworth D-85 Color Testing

1: Normal2: Red-green3: Complete color deficiency

12

3

AdaptationAdaptation

• Adjustment to lighting changesAdjustment to lighting changes• Nightblindness (such as with RP, Nightblindness (such as with RP,

Diabetics)Diabetics)• Delayed recovery from photostress testDelayed recovery from photostress test• (macular dystrophies, some stationary (macular dystrophies, some stationary

conditions (fundus albipunctatus)conditions (fundus albipunctatus)

• Goldman Weekers adaptometer, Goldman Weekers adaptometer, qualitative macular stress testqualitative macular stress test

• Not routinely testedNot routinely tested

Goldman WeekersAdaptometer

Central panel: poor light adaptation, nightblindness

Peripheral visionPeripheral vision

• Tested with visual fields Tested with visual fields • Abnormal in RP, glaucoma as well as Abnormal in RP, glaucoma as well as

other conditionsother conditions• When loss is gradual, patients adapt very When loss is gradual, patients adapt very

well until advanced diseasewell until advanced disease• Important to understand how the brain Important to understand how the brain

builds a picture of the world. builds a picture of the world. • A constricted visual field is like painting a A constricted visual field is like painting a

large wall with a small brush. It takes more large wall with a small brush. It takes more time and effort. Harder for a person to time and effort. Harder for a person to perceive a sudden change. perceive a sudden change.

Normal Glaucoma

Visual Field TestAutomated Perimetry

http://my-vision-simulator.com/http://my-vision-simulator.com/

Web site to play with simulations of Web site to play with simulations of vision loss for different conditionsvision loss for different conditions

glaucoma, macular degeneration, glaucoma, macular degeneration, cataracts, retinitis pigmentosa, cataracts, retinitis pigmentosa, diabetic retinopathy, myopia, diabetic retinopathy, myopia, astigmatism, hyperopiaastigmatism, hyperopia

Fun to useFun to useNot very accurateNot very accurateOnly shows limited aspects of vision lossOnly shows limited aspects of vision loss

Binocularity and Stereopsis - 1Binocularity and Stereopsis - 1

• Binocularity refers to the use of both eyes Binocularity refers to the use of both eyes to obtain a merged view of the world. to obtain a merged view of the world. • One can have binocular vision without One can have binocular vision without

stereopsis.stereopsis.

• Stereopsis is the perception of depth based Stereopsis is the perception of depth based upon image disparities perceived by the upon image disparities perceived by the brain from the input from both eyes. brain from the input from both eyes. • One cannot have stereopsis without binocular One cannot have stereopsis without binocular

vision.vision.• One can have binocular vision without One can have binocular vision without

stereopsis.stereopsis.

Binocularity and Stereopsis - 2Binocularity and Stereopsis - 2

• Depth perception is the awareness that objects Depth perception is the awareness that objects are closer or farther from the subject and the are closer or farther from the subject and the position of objects with respect to each other. position of objects with respect to each other. • One can have depth perception without stereopsis.One can have depth perception without stereopsis.

• Often lost in strabismus and amblyopiaOften lost in strabismus and amblyopia• May be diminished with poor central visionMay be diminished with poor central vision• Can be lost over time if person loses too much Can be lost over time if person loses too much

vision to allow for fusionvision to allow for fusion• Generally not critical to distance perception. Generally not critical to distance perception. • Not essential for driving and most tasksNot essential for driving and most tasks• Testing is done with polarizing glasses or special Testing is done with polarizing glasses or special

examination devices. examination devices.

Central processingCentral processing

• Cognitive perception of visionCognitive perception of vision• Usually not tested by ophthalmologistsUsually not tested by ophthalmologists• Seen with dyslexias, vision-deprivation Seen with dyslexias, vision-deprivation

amblyopiasamblyopias• May be evident as problems with May be evident as problems with

certain tasks such as reading or certain tasks such as reading or recognition of imagesrecognition of images

• Can be abnormal in patients with Can be abnormal in patients with dementias who claim that they can’t dementias who claim that they can’t read but have “20/20” acuitiesread but have “20/20” acuities

Confounders of visionConfounders of vision

• Distortion Distortion • May affect acuity or the ability to have May affect acuity or the ability to have

stereopsisstereopsis

• PhotophobiaPhotophobia• Perception of pain under normal lighting Perception of pain under normal lighting

conditionsconditions• Seen in a variety of conditions, especially Seen in a variety of conditions, especially

cone dystrophies and albinism.cone dystrophies and albinism.• Can be disabling for some peopleCan be disabling for some people

• Glare Glare • Certain cataract and corneal opacities will Certain cataract and corneal opacities will

scatter light, creating distracting imagesscatter light, creating distracting images

Confounders of visionConfounders of vision

• Photopsias - flashing lights Photopsias - flashing lights • May be a minor symptom but can vary and be May be a minor symptom but can vary and be

very troublesome in some individuals. very troublesome in some individuals. • Can occasionally worsen with stress or Can occasionally worsen with stress or

fatiguefatigue• Different patterns for retinal degenerations as Different patterns for retinal degenerations as

compared to migrainescompared to migraines• Blind infants will often press on their eyes to Blind infants will often press on their eyes to

trigger photopsias to provide stimulation to trigger photopsias to provide stimulation to the visual pathways.the visual pathways.

• Charles Bonnett phenomenon Charles Bonnett phenomenon • visual hallucinations in people with acquired visual hallucinations in people with acquired

blindnessblindness

Each visually-impaired child or adult, Each visually-impaired child or adult, regardless of their condition, has a regardless of their condition, has a

unique set of vision challenges unique set of vision challenges

• Even if a condition predominantly affects a Even if a condition predominantly affects a particular aspect of sight, one must appreciate particular aspect of sight, one must appreciate individual variation in other components. individual variation in other components.

• Vision loss in an infant is not the same in an Vision loss in an infant is not the same in an older individual, even if central acuities are the older individual, even if central acuities are the same. same.

• The rate of vision loss has a major impact on a The rate of vision loss has a major impact on a person’s ability to modify their vision-based person’s ability to modify their vision-based behavior. A child with Stargardt disease and loss behavior. A child with Stargardt disease and loss of central vision is not the same as an elderly of central vision is not the same as an elderly individual with age-related macular degeneration.individual with age-related macular degeneration.

• SymptomsSymptoms •pain, itching, light sensitivity pain, itching, light sensitivity (photophobia)(photophobia)

• FunctionFunction•changes in visual functionchanges in visual function•blurring, peripheral loss, distortions, blurring, peripheral loss, distortions, flashing lights, afferent pupillary defect, eye flashing lights, afferent pupillary defect, eye movementsmovements

• AppearanceAppearance •redness, distension/swelling of tissues, redness, distension/swelling of tissues, clouding of the cornea or lens, loss of red clouding of the cornea or lens, loss of red reflex, lid ptosis, assymetry between the reflex, lid ptosis, assymetry between the eyes, optic nerve changeseyes, optic nerve changes

Evaluating the eye - 1Evaluating the eye - 1

• DiagnosticsDiagnostics•FunctionalFunctional

•Acuity (pinhole, refraction) Acuity (pinhole, refraction) •Visual fields (confrontation, quantitative) Visual fields (confrontation, quantitative) •Color tests (red desaturation, screening, Color tests (red desaturation, screening, quantitative)quantitative)

•Structural/AnatomicStructural/Anatomic•Slit lamp, fundus imagingSlit lamp, fundus imaging•Angiography (Fluorescein/ ICG)Angiography (Fluorescein/ ICG)•Optical coherence tomography (OCT) Optical coherence tomography (OCT) •UltrasonographyUltrasonography

•ElectrophysiologicElectrophysiologic•VEP, ERG, mfERG, EOGVEP, ERG, mfERG, EOG

Evaluating the eye - 2Evaluating the eye - 2

The Eye as a microcosm of the rest of health The Eye as a microcosm of the rest of health (systemic examples and ocular examples (systemic examples and ocular examples not exact counterparts)not exact counterparts)

InfectionInfectionURIURI ConjunctivitisConjunctivitissepsissepsis Endophthalmitis, Endophthalmitis,

Orbital cellulitisOrbital cellulitisMalignancyMalignancy

Lung CaLung Ca MelanomaMelanomaPediatric leukemiaPediatric leukemia RetinoblastomaRetinoblastoma

ImmunologyImmunologyAsthmaAsthma Allergic conjunctivitisAllergic conjunctivitisLupusLupus Uveitis, ScleritisUveitis, Scleritis

GeneticGeneticMuscular dystrophyMuscular dystrophy Retinitis pigmentosaRetinitis pigmentosa

AgingAgingBPHBPH CataractCataractAtherosclerosisAtherosclerosis Macular DegenerationMacular Degeneration

Vascular diseaseVascular diseaseCAD/StrokeCAD/Stroke Transient Ischemic AttacksTransient Ischemic Attacks

Vein or Arteriolar occlusionsVein or Arteriolar occlusionsPulmonary embolusPulmonary embolus Retinal artery embolusRetinal artery embolus

The Eye as a microcosm of the rest of health The Eye as a microcosm of the rest of health (systemic examples and ocular examples (systemic examples and ocular examples not exact counterparts)not exact counterparts)

NeurologicNeurologicDementiaDementia Retinal degenerationRetinal degeneration

Optic atrophyOptic atrophyNeuromuscular Neuromuscular StrabismusStrabismusMigrainesMigraines Visual migrainesVisual migraines

TraumaTraumaUV Skin damage UV Skin damage PtyergiumPtyergiumPost CA reconstructionPost CA reconstruction Lid reconstruction Lid reconstruction

after cancer resectionafter cancer resectionAbnormal growthAbnormal growth

GH deficiency or excessGH deficiency or excess hyperopia or myopiahyperopia or myopia

Toxic (acute versus chronic)Toxic (acute versus chronic)Lead poisoningLead poisoning Ferrous toxicityFerrous toxicityDigoxinDigoxin Plaquinil retinopathyPlaquinil retinopathy

Ethambutol optic neuropathyEthambutol optic neuropathyLoss of homeostasisLoss of homeostasis

Hypertension Hypertension GlaucomaGlaucoma

• HTN, vascular disease, arrhythmiasHTN, vascular disease, arrhythmias

• • DiabetesDiabetes

• • Metabolic disordersMetabolic disorders

• • Genetic syndromes (VHL, NF, myotonic Genetic syndromes (VHL, NF, myotonic

dystrophy, lysosomal storage diseases)dystrophy, lysosomal storage diseases)

• • Autoimmune conditionsAutoimmune conditions

• • Infection (emboli to the eye, bacterial, Infection (emboli to the eye, bacterial,

fungal, viral)fungal, viral)

• • Cancer (metastatic disease)Cancer (metastatic disease)

• • Neurologic – papilledema, migraines, Neurologic – papilledema, migraines,

abnormal eye movementsabnormal eye movements

The Eye as a portal of general healthThe Eye as a portal of general health what we can see (when we know how to look)what we can see (when we know how to look)

Infants:Infants: Amblyopia Amblyopia Strabismus Strabismus Loss of the red reflexLoss of the red reflex

Children and Young adults:Children and Young adults:Refractive error Refractive error Infections Infections Trauma Trauma Inherited disordersInherited disorders

Older adults:Older adults: Cataract, Glaucoma, Diabetic Retinopathy, Cataract, Glaucoma, Diabetic Retinopathy, Macular Degeneration, Vascular diseaseMacular Degeneration, Vascular disease

What are the “biggies”What are the “biggies”

Is this person’s visual function normal?Is this person’s visual function normal?If not, can it be accounted for by my knowledge If not, can it be accounted for by my knowledge of prior conditions (including refractive error)?of prior conditions (including refractive error)?

Does this person have new or recent symptoms that Does this person have new or recent symptoms that may be eye-related? – e.g. pain, blurred vision, may be eye-related? – e.g. pain, blurred vision, flashing lightsflashing lights

Based on my examination skills – can I confidently Based on my examination skills – can I confidently establish what features are normal and what are not.establish what features are normal and what are not.

Are the symptoms and findings serious? Do they Are the symptoms and findings serious? Do they require urgent attention?require urgent attention?

What do you need to know when presented What do you need to know when presented with an “eye” patient (or any patient)with an “eye” patient (or any patient)

OpticiansOpticians fit glasses (they do not provide the prescription for the fit glasses (they do not provide the prescription for the lenses, they do fitting)lenses, they do fitting)

OptometristsOptometrists can handle glasses and contact lenses, can make can handle glasses and contact lenses, can make basic diagnoses and are legally allowed to prescribe eye basic diagnoses and are legally allowed to prescribe eye medications. Training is 4 years after college. A small percentage do medications. Training is 4 years after college. A small percentage do postgraduate training. The majority of their clinical training exposure postgraduate training. The majority of their clinical training exposure is to normal people.is to normal people.

OphthalmologistsOphthalmologists are physicians and complete 4 years of medical are physicians and complete 4 years of medical school an internship and three-year residency. They are trained in school an internship and three-year residency. They are trained in both medical and surgical care. The majority of their training both medical and surgical care. The majority of their training exposure is to patients with significant eye pathology. Many of them exposure is to patients with significant eye pathology. Many of them do 1-2 year subspecialty fellowships: do 1-2 year subspecialty fellowships: pediatric ophth., neuro-ophth., pediatric ophth., neuro-ophth., medical retina, vitreo-retinal surgery (including medical retina), medical retina, vitreo-retinal surgery (including medical retina), oculoplastics, glaucoma, cornea and external disease, refractive, oculoplastics, glaucoma, cornea and external disease, refractive, ocular oncology, ocular immunology. ocular oncology, ocular immunology.

Who should care for my patient’s Who should care for my patient’s eye and/or vision problemseye and/or vision problems