Eyes Flashcards
Developmental Aspects
- Development of vision is very age sensitive
- Like fresh plaster of Paris, you can mold it until it is set.
- Early detection is critical
- Untreated amblyopia causes more vision loss than any other disease in people under 40
- Failure of the eye to connect with the brain
NEED to assess eyes for 2 concepts
- RED LIGHT REFLEX –
- If there is no reflex = cataract
- In the first 6 weeks, light needs to reach cones and rods, otherwise = BLIND
- Exotropia - OUTWARD deviation
- Brain will turn off vision when you cannot see an object as one*
- Up to 6 years
Myopia
Occurs when the anterior-posterior diameter of the eye is too long relative to the refracting power of the cornea and lens
Eyes change at puberty
Hyperopia
- Hyperopic eye is too short relative to the refracting power of the eye
- The focal point of the image occurs posterior to the retina and the image that forms on the retina is blurred
Astigmatism
- Astigmatism is another type of refractive error that causes blurred vision
- Occurs because the optical system of the eye, partciularly the cornea, is not perfectly spherical
Strabismus
Occurs when the eyes do not move in synchronous pattern
Types of Strabismus
Esotropia
Convergent squint; inward deviation
Types of Strabismus: exotropia
Divergent squint; outward deviation
Types of Strabismus: Latent Strabismus
- Becomes apparent only on dissociation of the vision of the eyes (ex. on covering one eye) and is termed a phoria (exophoria, esophoria, hyperphoria)
- Can be more prominent with fatigue, illness, or with lack of attention
Types of Strabismus: Hypertropia
Condition of misalignment of the eyes (strabismus), whereby the visual axis of one eye is higher than the fellow fixating eye.
Types of Strabismus: Hypotropia
Similar condition, focus being on the eye with the visual axis lower than the fellow fixating eye
Tendency towards strabismus: Esophoria
Characterized by tendency toward inward deviation of the eye usually due to extraocular muscle imbalance with good fusion
Tendency towards strabismus: exophoria
Form of heterophoria in which there is a tendency of the eye to deviate outward.
Other ways to describe strabismus (2)
- Comitant strabismus
- Same deviation in all fields of gaze on EOM
- Incomitant strabismus
- Limited eye movements and size of deviation is different in different fields of gaze
- Occurs most commonly where there is paralysis of one or more extraocular muscles
- Paralysis of one or more EOM
Incomitant Strabismus (4)
**Need to find the cause**
- Neurological - due to lesions of 3rd, 4th, or 6th cranial nerves caused by:
- Trauma- Tumor – (Intracranial)
- Infection
- Raised Intra-Cranial Pressure (6th Nerve Palsy)
- Muscular – Direct involvement of the extraocular muscles by
- Trauma
- Tumor of the orbital or periorbital tissue
- Infection
- Muscular Anomaly – Dystrophy etc.
- Neuro Muscular – Myasthenia Gravis
- Congenital Conditions
Causes of Comitant Strabismus (4)
- Hereditary
- Familial predisposition
- Increased among siblings!
- Sensory Deprivation
- Accommodative
- Frequent excessive convergence (esotropia) in children who are hypermetropic i.e. because these children need to accommodate excessively to obtain clear vision they often break down and develop a convergent squint.
- Unknown
- No cause for the occurrence of strabismus will be
Testing for Strabismus (5)
- Hirschberg test or Corneal light reflex
- Some o’clock in both eyes
- Red reflex or Bruckner test
- Opthalmascope: Look at pupil
- Cover test
- Eye to eye with patient and cover and uncover eye; look for movement of eye (2x)
- Evaluate EOM
- DOUBLE H – up and down; vertical strabismus
- Binocular status
- Stereopsis Tests
Cranial nerve 6; abducens moves
Lateral rectus muscle
Trochlear CN 4 moves
Superior oblique
- Congential paresis is fairly common
- Head tilt
Oculomotor nerve CN 3
Superior rectus
Inferior oblique muscle
Medial rectus
Inferior rectus
Amblyopia
- Amblyopia is poor vision caused by abnormal visual development secondary to abnormal visual stimulation.
- Classified by the presence of associated clinical findings.
- Strabismic amblyopia
- Anisometropic or refractive amblyopia
- Deprivational amblyopia
- When pt looked at world from deviating eye – eyes presented with two images; lose vision
Anisometropic Amblyopia
- Similar to strabismic amblyopia, the fovea in anisometropic amblyopia also are presented with different images
- Caused by unequal refractive error
Refractive amblyopia
Occurs most commonly in hyperopic patients but it may occur in patients with myopia or astigmatism
Deprivation Amblyopia
- Least common and most serious type of amblyopia
- Severe visual deprivation due to occlusion of the visual axis or severe distortion of the foveal image
Test for amblyopia
- Vision screen
- Using intrumentation in younger infants
- Optotypes in children starting at age 3
Changes in the AAP Table – Vision screen (3)
- Routine screening at age 18 has been changed to a risk assessment
- A visual acuity screen is recommended at ages 4 and 5 years, as well as in cooperative 3 year olds.
- Instrument based screening may be used to assess risk at ages 12 and 24 months, in addition to the well visits at 3 through 5 years of age.
History for Child Vision Screening
- Review the health records with vision screens as well as any prenatal/medical/genetic problems
- Discuss with child any visits to eye doctor
- Does child think she has a problem?
- When did the problem start?
- When does the child have more problem—look close or far away?
- Any signs of puberty?
- Eye length changes at puberty
- Any medical problems?
- Any medication?
- Any history of eye glasses or use of eye medications?
Assessment
- Watch the child reading
- Observe while child colors
- Put a small sticker on hand and watch them look at it
- External inspection of eyes and lids
- Ocular motility
- Pupil exam
- Vision
- Red Reflex
- Visual fields (after 6 years)
Vision screen from 0-6 months (6)
- Ocular history
- Vision assessment
- External inspection of the eyes and lids
- Ocular motility assessment
- Should fix and follow by 6 months
- Pupil examination
- Red reflex examination
- Refer infants with an abnormal red reflex or history of retinoblastoma in a parent or sibling.
Vision screening 6-12 months
- Ocular History
- External inspection
- Red reflex
- Testing
- Pupil Exam
- Ocular Motility
- Instrument based screen
- Visual acuity fixate & follow
- Refer infants with strabismus
- Refer infants with chronic tearing or discharge.
- Refer children who fail instrument based screen
Vision Screening
12 months to 3 years
- Ocular History
- External inspection
- Red reflex
- Testing
- Pupil Exam
- Ocular Motility
- Instrument based screen
- Visual acuity fixate & follow
- At age three, start vision screen using optotypes
- Refer children who cannot read at least 20/40 with either eye.
- Must be able to identify the majority of the optotypes on the 20/40 LINE
Vision screening 4-5 years
- Ocular history
- External inspection
- Red Reflex
- Testing
- Pupil exam
- Ocular motility
- Instrument based screen
- Vision screening using optotypes
Vision screening over 5 years old
- Ocular history
- Vision assessment
- External inspection of the eyes and lids
- Ocular motility assessment
- Pupil examination
- Red reflex examination
- Visual acuity testing
- Ophthalmoscopy
- Refer children who cannot read at least 20/32 with either eye. Must be able to identify the majority of the optotypes on the 20/32 line.
- Refer children not reading at grade level.
External Inspection (4)
- Look at orbits from above
- Lacrimal: tearing, epiphora (watery eye) and photophobia
- Lids: look at contour
- Head posturing:
- Torticollis
- Strabismus
- Refractive error
- Congenital nystagmus
- Tilting can also indicate astigmatism or hyperopia
- Posterior fossa brain tumor from tilting – we are concerned about a NEW head tilt
Anterior Part of Eye
- Look at lids and lashes
- Redness and swelling
- Discharge
- Foreign body
- Check cornea for clarity
- Large cornea can indicate glaucoma
Assess for Ocular Motility
- Stand or sit 3 to 6 feet in front of the child.
- Ask the patient to follow your finger with their eyes without moving their head.
- Check the movement of the eye in the six cardinal directions using a cross or double “H” pattern.
- Check convergence by moving your finger toward the bridge of the patient’s nose
Hirschberg Test
- If both reflexes are located 0.5 mm nasal to the center of the pupil, the Hirschberg test is negative, and no strabismus is present
- If one reflex is located in a position other than 0.5 mm nasal, the Hirschberg test is positive, and strabismus is suspected.
Cover Test pearls
- Watch for small, or “flick”, movements of the eye.
- A small angle strabismus is often not cosmetically visible and is difficult to detect with the corneal light reflex test.
- A small flick can be detected with the coveruncover test.
Red Reflex or Bruckner Test
How to assess
- Darken the room as much as possible.
- Adjust the ophthalmoscope so that the light is no brighter than necessary.
- Adjust the aperture to a plain white circle.
- Set the diopter dial to zero unless you have determined a better setting for your eyes.
- Use your left hand and left eye to examine the patient’s left eye.
- Use your right hand and right eye to examine the patient’s right eye.
- Ask the patient to stare at a point on the wall or corner of the room.
Red Reflex or Bruckner
Testing for
- Identify strabismus as well as asymmetric refractive errors
- Isometropic refractive errors=retinal reflexes are similar in appearance and brightness.
- If unequal refractive errors exist, the retinal reflexes will differ in brightness.
If retinal reflexes are not symmetric with the Bruckner test, what is expected?
anisometropia is expected
Strabismus can also result in…
Asymmetry of the retinal reflexes
White bottom in a Red reflex test
Myopia
Black in red reflex test
Mass, cataract
Visual acuity testing
Lea symbols = 18 months
Ototypes alphabet are the best
Titmus vision screener – cannot see if patient is squinting or tilting
Testing monocular vision
- Make sure the child cannot peek around the patch
- Get them used to a patch by working with the child up close
Pinhole Test for Vision Screening
- Put a several small pinhole in a 3X5 inch card
- If the patient visual acuity improves with viewing through a pinhole, refractive error is cause of decreased vision
- A pinhole can improve vision to 20/30 even when there is large refractive error
- Useful when patient comes without glasses.
Fixation methods to evaluate vision (5)
- Gross assessment of visual ability
- Bright or colorful object is placed in front of the child
- Fixation on the object is noted
- Move object slowly across the patient’s visual field
- Note whether or not the patient follows the object as it moves
Central Fixation to Evaluate Vision
- Patient looks directly at the target
- Child does not look off center
- Follows target smoothly accurately
- With poor vision, difficulty with locking in on target
- Poor fixation and poor vision
Instruments for Vision screening
Photorefractive screening
Autorefraction
Visual evoked potentials
Photorefractive Screening
- Photorefractive screening is a vision screening technique used to screen for amblyogenic factors, such as strabismus, media opacities, and significant refractive errors, in 1 or both eyes in children
- Ex. MTI photo screener
Autorefraction
- Can help confirm difficult or unusual refractions, as well as to refract nonverbal or uncooperative patients.
- Cannot prescribe on this alone due to accuracy issues
PUPILS integrity
Integrity depends on intact iris, cranial nerve 2 & 3, and sympathetic nerves innervating the eye
Hippus
- Normal pupil is in continuous motion dilating in and out by contracting a small amount
- More prominent in pediatric patients exposed to bright light
Normal light pupillary reflex
- Consensual reaction
- Flash a light in one eye and other pupil reactions
- Direct reaction
- Ipsilateral pupillary constriction
Assessing Pupils
- Fixate on target at far end of room
- Bring object near: pupils become smaller (accommodate)
- Child of 8 has 2.5 times more accommodative power than needed but may not be able to use it accurately or appropriately
Anisocoria
- Simple
- .4mm or more difference in size of right and left pupil
- Not due to drugs, ocular injury, or ocular inflammation
- PATHOLOGY when the anisorcoria is not the same in a lighted room vs. a darker one
Pupillary checks using the pen light
- Dim the room lights as necessary.
- Ask the patient to look into the distance.
- Shine a bright light obliquely into each pupil in turn.
- Record pupil size in mm and any asymmetry or irregularity.
Normal Swinging Flashlight Test
- Swings flashlight back and forth from eye to eye
- Rhythmic and timing same for each eye
- Hold it over the pupil for 1-2 seconds, slightly below the horizon axis
- Both pupils will constrict strongly when light is shining into the eye
Relative Afferent Pupillary defect
MARCUS GUNN PUPIL
Most common pupil problems
An RAPD generally occurs with significant optic nerve or retinal disease, when there is a difference in the disease process between the two eyes
Afferent eye does not respond so the consensual eye doesn’t either
Abnormal Pupillary Reaction
Technique
Abnormal Rxn
- Technique
- Swings flashlight back and forth from eye to eye
- Rhythm and timing same for each eye
- Hold it over the pupil for 1-2 seconds, slightly below the horizon axis
- Abnormal Reaction
- In Marcus Gunn pupil, the pupil where the light is shined will constrict strongly when light is shining into the eye but as light moves to illuminate the abnormal eye, both pupils dilate (react as though the light was dimmer)
- The eye that dilates when the light is shown on it, is the abnormal or Marcus Gunn Pupil
Pupillary check – Iris coloboma
Iris coloboma
Isolated iris coloboma does not interfere with vision
Pupillary check
Aniridia
Aniridia
Absence of iris l 1/3 with have associated Wilms tumor
Stereopsis Testing
- Random dot stereogram Test distance =40 cm
- Perform binocularly with polarized glasses on Must locate stereo E on 4 of 5 presentations
- Tests child’s ability to identify the location of the stereo E
How to ask with a red eye complaint
- What is the mechanism of injury?
- When did it start and what was done after the injury?
- Are one or both eyes involved?
- What are the symptoms?
- Any discharge or crusting
- Blurred vision or any changes
- Pain
- Photophobia means corneal involved
- Halos or rainbows means edema of cornea
- Systemic problems like JIA
PAINFUL eye indicates
Glaucoma, injury, corneal abrasion
Hx red eye
(5)
- Trauma? (remember kids may not tell the whole story…)
- Blunt?
- Sharp?
- Chemical exposure?
- Conjunctivitis?
- Red eye contact?
- Upper respiratory infection?
- Fever?
- Purulent drainage?
- Allergy
- Itchy?
- Contact lens wearer? Extended wear?
- Use of eye drops?
- Use or abuse of OTC eye meds
- Use of any eye meds?
Eye Hx
6 Questions
- Past ocular history—what are the results of the last vision screen?
- Any preexisting eye disorder?
- Drug allergies?
- When did the child last eat?
- Prior tetanus immunization?
- Preexisting medical problems?
- Any use of contact lens?
Assessment of the Red Eye
- External inspection of eyes and lids
- Suspect orbital injury if the eye is red at the limbus (the area where the iris meets the sclera)
- ciliary injection and is a sign of corneal injury in a painful eye
- Ocular motility
- Pupil exam
- Vision screen
Ciliary Injection
- Injection at the limbus
- Lessens as it moves to the palpebral conjunctiva
- Seen in
- Uveitis
- Keratitis
- Acute angle glaucoma
- Lead to BLINDNESS
Chemosis
- Swelling of the conjunctiva
- Found in acute allergic conjunctivitis and in sick children with pharyngoconjunctival fever (adenoviral infection)
Red Eye Exam (2)
Visual acuity; external exam
- Check Visual acuity
- One eye at a time
- Distance vision, Near card vision is also good
- Use their specs!
- External exam
- Eyelids, pull down the lid to inspect the conjunctiva (lines the inside of the eye lid)
- Globe
Subconjunctival Hemorrhage
- Blood under the conjunctiva
- Causes
- Trauma
- Sudden increase of pressure in the chest; sneeze, cough, vomiting, strangulation
S&S of subconjunctival Hemorrhage
- May be associated with aching if history of trauma
- Hemorrhage itself does not cause pain generally
If subconjunctival hemorrhage is mild and no other signs of ocular injury…
- Is benign, and will disappear in a week
- No tx necessary
- Likely no need to refer
Causes and S&S of corneal abrasion
- Cause
- Trauma, foreign body or chemical exposure
- Signs and symptoms (OUCH!)
- Intense sensitivity to light, extreme pain, trouble even opening the eye
- Copious tearing
- Foreign body sensation
Stroma
The cornea is compromised of 1 layer of epithelium and 50 layers of stroma
Corneal Abrasion
Defect in which layer?
Defect in the epithelial layer only
Typically the rest of the cornea is not damaged
VERY painful because of so many nerve endings in the cornea
Corneal abrasion Dx
Area of corneal epithelial defect stains with fluorescein dye and “lights up” with a blue light
Linear abrasion – look for FB under upper lid
Corneal abrasion supplies
Anesthetic drops
Fluorescent dye papers
Penlight with blue filter cap
Foreign bodies
Hammering a nail could get metal on eye!
Hyphema
- Blood in the anterior chamber (space in between iris and cornea)
- Causes
- Trauma, blunt or penetrating
- May be associated with other eye injury
- Corneal abrasion
- Open globe
- Extensive subconjunctival hemorrhage
- Peaked pupil
Types of Conjunctivitis
- Bacterial
- H. influenza
- Staph
- Chlamydia (very uncommon now)
- Viral
- Allergic
- Toxicity from eye drops
- Contact lens related
S and S of bacterial conjunctivitis
- Conjunctiva red (eyeball and inside lid)
- Purulent discharge (THE hallmark)
- Eye lid swelling
- One or both eyes
One important exception to the rule that any antibiotic drop cures all bacterial conjunctivitis…. EXCEPT
Gonococcal Conjunctivitis
- If excessive purulent discharge, suspect Gonorrhea and send to ER
- IV antibiotics required
- GC can infect the cornea, so sight-threatening
Viral Conjunctivitis
- Causes
- Adenovirus
- HSV
- HZV
- Molluscum Contagiosum
Viral Conjuctivitis – signs and symptoms
- Irritation, mild light sensitivity, mild FB sensation, swollen lids
- Mild conjunctival hyperemia to intense hyperemia with subconjunctival hemorrhages
Exam findings for VC
- Discharge is watery, possibly some mucous, not purulent
- This helps distinguish viral from bacterial
- Often an enlarged tender lymph node is present in front of the ear (preauricular node)
Signs and Symptoms of Herpes
- Can get any of the following
- Skin vesicles (if present helps with diagnosis)
- Conjunctivitis (no characteristics to help make diagnosis)
- Corneal infection with classic “dendrite” (the Hallmark of this condition)
Allergic Conjunctivitis
Cause
S&S
- Usually environmental allergen
- May be seasonal, associated with sneezing and congestion, or isolated
- Signs and symptoms
- Itchy
- The Hallmark of an allergy
Physical Assessment of Allergic Conjunctivitis
- Diffuse milky conjunctival hyperemia
- Swollen conjunctiva
- Tearing, maybe slight mucoid discharge
- Usually bilateral
- Occasionally “bumps” on tarsal conjunctiva – called follicles, another hallmark of allergy
Blepharitis
- Defined as eyelid inflammation/infection
- Typical cause of blepharitis (is a combo of):
- Staphylococcal infection at lash bases and
- Skin oil glands of the eyelid (meibomian glands) being inflamed
Chalazion
- Obstructed meibomian gland
- Causes an acute mass in lid
- Like a pimple
- Initially tender, then not
- Often associated w blepharitis
- Causes an acute mass in lid
Another cause of Blepharitis
Phthiriasis palpebra – LICE
Usually cause is public lice, rarely head or body lice
The louse hangs to two neighboring lashes or public hairs
Nits and Louse
Differentiating Blepharitis
HINT - crust in lashes is red brown – not white or clear like typical blepharitis
Why? The lice live off blood so their feces (the crust) is red-brown in color
Hyphema
Layering of blood in the anterior segment
Hypopyon
Pus in the anterior segment
Iridocyclitis
Inflammation of the iris
Iridodonesis
Quivering of the iris when the patient moves the eye.
Synechia
Adhesion between the iris and the cornea.
