Ears, Eyes, Teeth Flashcards
Outer ear anatomy
a. Two parts
i. Pinna/auricle = projecting from the side of the head
ii. External acoustic meatus = canal leading inward
b. Auricle
i. Cartilage covered with skin
c. External acoustic meatus
i. Tube which transmits sound waves through to the tympanic membrane at the medial part of the outer ear
i. Meatus is partly cartilaginous (lateral 1/3 cartilaginous, medial 2/3 bony parts of temporal bone)
ii. Two nerve supplies to the meatus
1. Posterior and inferior = branches of vagus nerve
2. Superior and anterior = innervated by the auricular temporal nerve (branch of CNV 3)
b. Tympanic membrane = separates the external acoustic meatus from the middle ear
Middle ear anatomy
a. Space between tympanic membrane and petrous part of temporal bone
b. Eustachian tube = auditory tube = pharyngotympanic tube
i. Communicates between nasopharynx and tympanic cavity
ii. Auditory tube projects antero-inferiorly from wall of the middle ear
c. Ossicles
i. Malleus, incus, stapes
1. Malleus = lateral: tympanic membrane incus
2. Incus = medial: malleus stapes
3. Stapes = further medial: stapes oval window
ii. Together transmit energy of vibration (mechanical) via bones towards the inner ear
d. Two muscles = 1) tensor tympani (CNV) + 2) stapedius (CNVII)
Contraction = limit the amplitude of vibration produced by soundwaves -> controlled by reflexes
i. produced by loud sounds
Inner ear anatomy
c. Inner ear = series of cavities within the petrous part of the temporal bone between the middle ear laterally and the internal acoustic meatus medially
a. Overview
i. Bony labyrinth = vestibule + 3 semicircular canals + cochlea
ii. Membranous labyrinth = suspended within the perilymph is the membranous labyrinth
b. Function
i. Cochlea = hearing
ii. Vestibule + semicircular canal = head movement and equilibrium (vestibular apparatus)
Clinical manifestations of ear disorders
- Otalgia
- Purulent otorrhoea (otitis externa, otitis media with perf, first branchial cleft cyst)
- Hearing loss
a. Most common cause of hearing loss in children is otitis media - Swelling
- Vertigo
a. Uncommon complaint in children
b. Aetiology
i. Labyrinthitis
ii. Peri lymphatic fistula – due to trauma or congenital defect
iii. Cholesteatoma
iv. Vestibular neuronitis
v. BPPV
vi. Meniere disease
vii. Disease of CNS - Nystagmus
a. Vestibular in origin
b. Associated with vertigo - Tinnitus
a. Rarely described by children
b. Most common in those with eustachian tube-middle-ear disease or SNHL
Hearing assessments - ABR
= auditory brainstem response
a. Newborn screening test
b. Measures the summation of action potentials from the vestibulocochlear nerve in the inferior colliculus of the midbrain in response to a click stimulus
c. Tests 35 dB
d. “Pass” or “Refer” result
e. 50% referred have permanent hearing loss
Hearing assessments - otoacoustic emission test
a. Evaluates hearing from the middle ear to outer hair cells
b. Click or tone played to ear, measures vibrations of cochlear outer hair cells in response
c. Cannot detect auditory neuropathy
Hearing assessments - pure tone audiometry
a. Each ear tested individually
b. Test both air conduction (via headphones) and bone conduction (via oscillatory on mastoid)
c. Interpretation
i. Vertical axis = loudness in dB (logarithmic scale)
1. Conversation 45dB
ii. Horizontal axis = pitch in frequency (Hz)
iii. Right ear = round = red
iv. Left ear = cross = blue
v. < = bone conduction in right ear
vi. > = bone conduction in left ear
d. Results
i. Air = bone, R = L, normal amplitude = normal
ii. Air < bone = conductive hearing loss or mixed picture (bone conduction heard at lower decibel as bypasses middle ear)
iii. Air and bone both lost = sensorineural loss
Hearing assessments - acoustic reflectometry
a. Measures the reflection of sound from the tympanic membrane
b. Provides a measure of the difference in sound intensity from the incident and reflected sound waves around the frequency of maximal nullification
c. Normal TM = 50% of the incident sound is reflected back to the device
d. Fluid in ear = tympanic membrane is immobilized and the reflected sound is louder with a narrower spectrum
Hearing assessments - tympanometry
a. Use = assess middle ear function to evaluate membrane compliance
b. Measure of:
i. Compliance of middle ear (ear drum movement)
ii. Ear canal volume
iii. Middle ear pressure
c. Abnormal if:
i. Fluid
ii. Ossicular dysfunction
iii. Eustachian tube abnormalities
d. Interpretation
i. X axis = pressure
ii. Y axis = volume
Hearing assessments - Weber and Rinne
a. Weber test
i. Tuning fork to forehead
ii. Sensorineural hearing loss = sound heard in unaffected ear
iii. Conductive hearing loss = sound heard in affected ear
b. Rinne test
i. Normally air conduction > bone (positive test- also the case in SNHL)
ii. Bone conduction > air in conductive hearing loss
Hearing loss - general bg
- Key points
a. Prevalence 1/1000 >40dB at birth
b. Doubles up to 9 years age (not screened, false negatives, acquired cases)
c. Hearing loss in the first few years of life - impacts on speech, language and cognitive deficit
d. Early identification of hearing loss is critical - Classification
a. Central
i. An auditory defect originating along the central auditory nervous system pathways from distal CNVIII to the cerebral cortex
ii. Rare in children
b. Peripheral
i. Conductive = dysfunction in the transmission of sound through the external or middle ear - Most common cause of hearing loss in children
ii. Sensorineural = involving inner ear, cochlea or the auditory nerve
c. Mixed - Severity
a. Mild = 20-30 dB
b. Moderate = 30-50 dB
c. Severe = 50-70 dB
d. Profound = >70 dB - Aetiology
a. Congenital
i. Genetic = 50% - Syndromic = 1/3
- Non-syndromic = 2/3 (Connexin 26 most common)
b. Acquired
i. Prenatal
ii. Perinatal
iii. Postnatal
Hearing loss - newborn screening
Screening detects hearing loss >35 decibels, and is reliable in children <3mo.
a. Screened for hearing loss
i. Auditory brainstem response: sensors on baby forehead, clicking sounds played whilst baby asleep -> responses to noise with movement recorded
ii. Pass/repeat/refer
iii. Refer after two failed screens
b. Referred for further testing (0.7%)
i. Half then found to be normal
ii. Half abnormal -> then audiologist
c. Audiologist
i. Auditory brainstem response: gives information on softest sounds a bub can hear
ii. Auditory steady state response
iii. Otoacoustic emissions: sounds given off by the inner ear when the cochlea is stimulated by sound
iv. Tympanometry
Hearing loss - assessment
a. History
b. Examination – biometrics, developmental assessment, dysmorphism (face/ears), digits/neck, eyes, skin for hypo/hyperpigmented lesions, neurological
c. Characterise with – pure tone audiometry + tympanometry
i. Family and sibling audiograms
d. Vestibular function testing (30-40% with bilateral severe-profound loss have areflexia - idea of cause)
e. Ophthalmology – 40-60% have visual deficiencies, and to detect associations (Usher)
f. Genetic testing – Connexin 26, others
g. CMV testing – asymptomatic/symptomatic infection
h. ECG – in those with FHx long QT or developmental delay
i. Urinalysis – microscopic haematuria for Alport’s syndrome
j. Imaging – MRI best for cochlear (most common cochlear dysplasia), CT for outer ear
k. Other tests – only if indicated
i. TORCH serology
ii. FBE and UEC
iii. Autoimmune screen
iv. Metabolic screen
v. Renal US
vi. Further genetic testing
vii. Clinical photography
SNHL - congenital causes
a. Infection = classified as congenital OR acquired depending on resource
b. Malformations
c. Perilymph fistula
d. Genetic
i. Occurs in 1/2000 births
ii. Accounts for 50% of sensorineural hearing loss = 1/3 syndromic, 2/3 non-syndromic
iii. Non-syndromic
1. Autosomal recessive – 80%
a. >80 distinct loci
b. GJB2 gene encoding connexin 26***
i. Mutations in on chromosome 13
ii. 50% of all bilateral moderate to profound congenital hearing loss in non-syndromic children
iii. Connexins are proteins essential for potassium ion metabolism in the cochlear
i. Syndromic
1. Down’s syndrome
2. Autosomal dominant
a. Waardenburg syndrome type 1 and 2
b. Branchio-oto-renal syndrome
c. Treacher Collins
d. CHARGE
3. Autosomal recessive
a. Pendred syndrome (SNHL+goitre)
b. Usher syndrome (SNHL+visual loss)
c. Jervell and Lange Neilsen syndrome (Long QT + SNHL)
d. Alport syndrome (eyes, ears, kidney)
4. Other
a. Goldenhar Syndrome (conductive, SNHL, mixed)
b. Hereditary motor-sensory neuropathies – E.g. Charcot Marie Tooth, Friedreich ataxia etc, neurofibromatosis
c. Mitochondrial diseases = multisystem
i. Infants – progressive deterioration
ii. Adults – diabetes + SNHL
iii. Associated with increased susceptibility to aminoglycoside ototoxicity
SNHL - acquired causes
a. Prenatal
i. Intra-uterine infections
1. CMV = leading infectious cause, occurs in symptomatic + asymptomatic individuals, and can be progressive/delayed onset, and unilateral or bilateral
2. Toxoplasmosis, rubella, syphilis
ii. Ototoxic medication give to mother during pregnancy
b. Perinatal
i. Hypoxia – mechanical ventilation
ii. Prematurity, Low BW <1500g
iv. Hyperbilirubinaemia
v. ECMO
vi. Bacterial meningitis
vii. Ototoxic drugs
c. Postnatal
i. Infections
1. Complications of OM
2. Viral labyrinthitis
3. Meningitis
ii. Ototoxic drugs
1. Aminoglycosides
2. Other antibiotics = macrolides, vancomycin, tetracyclines
3. Chemotherapy
a. Cisplatin – hearing loss in 10-25% of children
b. Other – 5FU, bleomycin
4. Salicyclates
iii. Trauma
iv. Metabolic diseases – bone diseases
v. Neoplastic disease – infiltration of the cochlear with leukaemia or other tumours
vi. Noise exposure
Congenital malformations of the ear - summary
- Pinna malformations
a. Isolated abnormalities occur in 1% of children
b. Pit-like depression in front of the helix and above the tragus
i. Common
ii. Unilateral or bilateral
iii. Surgical removal only if recurrent
c. Accessory skin tag
i. Incidence of 1-2/1,000 births
ii. Removed for cosmetic regions
d. Microtia = subtle abnormalities of the size, shape and location of the pinna and ear canal, OR major abnormalities
e. Anotia = absence of pinna and ear canal - Congenital stenosis or atresia of the external auditory canal
a. Occurs in association with malformation of the auricle and middle ear
b. Isolation or as part of genetic syndrome – T21, brachio-oculofacial syndrome
c. Reconstructive surgery required - Congenital middle-ear malformations
a. Usually associated conductive hearing loss
b. Most malformations involve the ossicles – incus most commonly affected - Congenital inner ear malformations
- Congenital cholesteatoma
Otitis external - general
- Key points
a. Inflammatory condition of the external auditory canal - Risk factors
a. Excessive wetness = swimming, bathing, humidity
b. Dryness
c. Presence of other skin pathogens
d. Trauma - Aetiology
a. Infectious
i. Bacteria - P. aeruginosa***
- Other GP and GN organisms
ii. Fungi = Candida, Aspergillus
b. Non infectious
i. Atopic dermatitis
ii. Psoriasis
iii. Seborrheic dermatitis
iv. Acne - Clinical manifestations
a. Ear canal + erythema
b. Thick, clumpy otorrhoea - Diagnosis = clinical
- Treatment
a. Topical antibiotics
b. IV antibiotics - Complication = necrotising otitis externa
a. Can result in facial paralysis, CN abnormalities, vertigo and SNHL
b. Usually due to Pseudomonas
c. Rare in children
d. Usually associated with immunocompromise or severe malnourishment
e. IN adults associated with DM
Otitis media - bg
- Key points
a. Peak incidence and prevalence first 2 years of life
b. 50% children by 12 months
c. 70% children by 3 years - Spectrum
a. Acute otitis media
b. Chronic otitis media with effusion
c. Atelectasis of the tympanic membrane
d. Chronic adhesive otitis media
e. Chronic suppurative otitis media
i. Tubotympanic (safe)
ii. Atticoantral (unsafe) = cholesteatoma - Risk factors
a. Child
i. Younger age 6-12months
ii. Genetics/Atopy
iii. Cleft palate
iv. Immune deficiency
v. Indigenous (more severe disease)
b. Environment
i. Family member with AOM (strongest)
ii. Daycare exposure (second)
iii. Siblings (more)
iv. Household smoking
v. Bottle feeding/dummies
c. Protective factors
i. Breastfeeding for at least 3 moths - Microbiology
a. 25% viral
b. 35% strep pneumoniae
c. 25% non-typeable Haemophilus
d. 15% Moraxella
e. Other
i. A streptococcus, Staphylococcus aureus, Gram-negative organisms.
ii. S. aureus and GN = most commonly in neonates and very young infants who are hospitalized
Otitis media - sx, dx
- Clinical manifestations
a. Ear pain
b. Fever
c. Anorexia
d. Vomiting
e. Lethargy - Examination
a. Haemorrhagic, injected or cloudy appearance of TM
b. Bulging TM – most specific finding of AOM (97%) but has lower sensitivity (51%)
c. Many febrile or crying children have red TMs. A red TM alone is not AOM - Diagnosis
a. History of acute onset symptoms + signs (otalgia, ear pulling, otorrhoea, fever, anorexia, vomiting)
b. Demonstratable middle ear effusion characterised by
i. Bulging of TM
ii. Limited or absent movement
iii. Air-fluid level
iv. Perforation of TM with otorrhoea
c. Signs and symptoms of middle ear inflammation – characterised by redness of TM - Natural history
a. 80% resolve in 7-14days (without treatment)
b. NNT antibiotics is 7 (good improvement without treatment)
c. Between 2-7 days antibiotic therapy reduces pain in 40% - Recurrent AOM
a. 3 episodes in 6 months or 4 in 12 months
Otitis media - rx, cx
- Treatment
a. Analgesia
i. Topical lignocaine
ii. Paracetamol/neurofen
b. Antibiotics
i. Consider none in the first 48 hours
ii. If no improvement – amoxicillin 30-45 mg/kg/dose BD for 5 days
iii. Other indications - <12 months
- Immunocomprimised
- Indigenous
- Unwell
- Severe pain
- Suppurative complication - perforation, bilateral OM
- Single ear
- Cochlear implant
iv. If recurrent acute or no improvement – augmentin - Complications
a. Otologic
i. TM perforation
ii. Chronic suppurative OM
iii. Ossicular necrosis
iv. Cholesteatoma
v. Persistent effusion (often leading to hearing loss) – most common cause of hearing loss in children
b. CNS
i. Meningitis
ii. Brain abscess
iii. Facial nerve paralysis
c. Other
i. Mastoiditis
ii. Labyrinthitis
iii. Sigmoid sinus thrombophlebitis
Otitis media with effusion - general
a. Middle ear effusion without acute symptoms + signs
b. 70% will have effusion at 2 weeks
c. Diagnosed by pneumotoscopy +/- tympanometry (flat)
d. No acute symptoms
e. Often causes mild conductive hearing loss
f. 60% resolve 1 month, 90% 3 months
g. Risk factors = parental smoking, dummies
h. Management
i. Observe for 3-6months if no speech or language delays
ii. Refer ENT for ventilation tubes if associated with hearing loss >25dB
i. Long term effects on development unclear
Chronic middle ear effusion - general
a. >2 months
b. Affects 90% of children <2 years
c. Treatment
i. Otovent = no significant improvement, useful short term treatment
ii. Grommets recommended if 4-6 months of bilateral OM with effusion and hearing loss
1. Factors that favour surgery
a. Bilateral
b. >3months
c. Multiple drug allergies
d. Comorbidities – cleft, craniofacial abnormalities, Down’s
e. Risk factors present – Group day care, frequent smoke exposure
f. Symptomatic – recurrent AOM, ear pain, tugging, TM retraction
g. Complicated – Bilateral conductive hearing loss, speech delay, misarticulation, abnormal behavior, poor school performance
h. At risk children – suspected or diagnosed speech + language delay, ASD, blindness or uncorrectable visual impairment
d. Outcomes
i. No evidence to suggest difference in language/speech/learning outcomes with insertion of grommets
ii. Provides short term symptomatic improvement
iii. Usually fall out 9-18months later
Chronic suppurative otitis media - general
a. Chronic discharge from the ear from perforation of TM
i. Tubotympanic = safe – central perforation +/- hearing loss
ii. Atticoantral = unsafe – marginal perforation, granulation tissue which destroys structures and develops into cholesteatoma
b. Management
i. Ear cleaning – dry mopping and betadine washouts
ii. Topical antibiotics E.g. ciprofloxacin ear drops until discharge resolves
Cholesteatoma - general
Key
- abnormal growth of squamous epithelium in the middle ear and mastoid
- may progress to destroy ossicles -> conductive hearing loss
- average age 5 years, usually unilateral
Exam
- white mass behind TM
- granulation tissue on TM
- new hearing loss
Treatment
- surgery
Mastoiditis - general
- Classification
a. Acute mastoiditis
i. Complication of AOM with retroauricular inflammation & protrusion of auricle
ii. Patients are younger
iii. Inflammation of post-auricular area, with displacement of the pinna inferiorly and anteriorly
iv. Strep pneumoniae and strep pyogenes
v. Diagnosis – CT of temporal bones
b. Chronic mastoiditis
i. Extensive history of OM, including grommets
ii. Patients are older
iii. Less than 50% have retroauricular swelling
iv. Most likely cause is pseudomonas aeruginosa - Treatment
a. Myringotomy
b. Mastoidectomy
c. IV antibiotics - Complications
a. Petrositis – temporal bone involvement where eye pain prominent symptom due to irritation of ophthalmic branch CN5
b. Gradenigo syndrome – triad suppurative OM, paralysis external rectus and eye pain on same side
BPPV - general
= Benign paroxysmal positional vertigo
a. Disorder of early childhood manifested by recurrent episodes of brief disequilibrium
i. A family history of migraine headaches is frequently present
b. Pathogenesis
i. Particles form in the semicircular canals (most often posterior)
c. Clinical manifestations
i. During the attacks, the child appears frightened and off balance
ii. Associated with nystagmus, diaphoresis, nausea, and vomiting
iii. Vertigo or dizziness
iv. Episodes usually last less than a minute and are not associated with an altered consciousness
d. Natural history
i. Episodes recur in clusters, occurring daily for several days in a row, then remitting for several weeks, and recurring again
ii. Spontaneously remits by age 5
iii. Many patients subsequently develop typical migraine headaches
e. Treatment = Hallpike manoeuvre
Tonsils and Adenoids - general
- Function + anatomy
a. Immunologically reactive tissue at the entrance to the aerodigestive tract
b. Framework of fibrous tissue and lymphocytes, covered by epithelium
c. Waldeyer’s ring – circle of lymphoid tissue
i. Lingual, Palatine, Pharyngeal, Lateral pharyngeal
d. Role in immunity from exposure to both inhaled + ingested antigens
e. Composed of mainly B lymphocytes
f. Exposure to Ag produces secretory Ab + lymphokines
g. Removal does NOT produce significant immunological problems - Indications for T + A
a. Recurrent tonsillitis
i. 7 infections in one year
ii. 5 infections/year for 2 consecutive years
iii. 3 infections/year for 3 consecutive years
iv. >2 weeks missed school
b. Recurrent quinsy
c. OSA
i. Severity NOT proportional to tonsil size
ii. Combination of anatomical + neuromotor factors
iii. Present in 2% of young children – peak 2-8 years
iv. Most common groups - Marked tonsil + adenoid hypertrophy without obesity
- Obesity with milder upper airway lymphoid hyperplasia
- Craniofacial + neuromuscular disorders – Crouzon and Apert, T21, CP
d. Suspected malignancy (Fanconi anaemia)
Tracheostomy - general
- Indications
a. Airway obstruction
b. Prolonged ventilation
c. Airway toileting
d. Airway surgery - Complications
a. Early
i. Stomal/tracheal granuloma
ii. Obstructed tube
iii. Haemorrhage
iv. Pneumothorax
v. Pneumomediastinum
vi. Infection
b. Late
i. Stoma/tracheal granuloma
ii. Tracheal stenosis
iii. TOF
iv. Erosion into vessels
v. Tracheocutaneous fistula
Normal vision development - birth to 5 years
Birth • Brief fixation on face, light, object • No contrast, no colour differentiation • Hyperopic (farsighted) • VA 20/400 • May have imperfect coordination of eye movements + alignment during early days and weeks • Test = visual evoked potential
6 weeks
• Maintain fixation on face, object or light and follow through 90 degrees
• Smiling and visual response (especially to a face)
• Test = fix and follow using bright objects (180 degrees)
6 months
• Reach for small object
• Actively follow object
• Proper eye coordination – if noted >6 months should b referred
• Test = identify and pick up small object
One year
• Vision similar to adult
• Test = Reach for a tiny object (eg. 100 and 1000s)
2-3 years
• VA 20/40
• Test = Picture matching (Kay picture test)
3-4 years
• VA 20/30
• Test = Letter matching (Sheridan Gardiner test), Tumbling E test, HOV test (modified Snellen)
5 years
• VA 20/20
• Test = Snellen acuity, LogMAR/STYCAR tests, Tumbling E test
- When to refer
a. Suspect poor or subnormal vision
b. Visual acuity of 6/12 or worse
c. Nystagmus at 8-12 weeks of age can be a sign of poor vision
Amblyopia
- Key points
a. Decrease in visual acuity (unilateral or bilateral) that occurs in visually immature children
b. Occurs due to a lack of a clear image projecting onto the retina
c. Amblyopia occurs ONLY during the critical period of development before the cortex is visually mature – within the first decade of life
d. The younger the child, the more susceptible to amblyopia - Pathogenesis
a. Developmental of visual acuity normally proceeds rapidly in infancy + early childhood
b. Anything that interferes with the formation of a clear retinal image during this time can produce amblyopia - Aetiology + classification
a. Strabismic (50%)
i. Due to a deviated eye
ii. Abnormal interaction between two foveas -> different + unfusable images
iii. Visual cortex suppresses the image from one eye
b. Refractive/ ametropic (15-20%)
i. Unequal refractive errors -> one eye not focused on the fovea
c. Anisometropic - unequal need for vision correction
d. Derivational (<5%)
i. Congenital cataracts
ii. Vitreous haemorrhage
iii. Severe refractory error
e. 15-20% is combined - Treatment
a. Remove media opacity
b. Glasses
c. Good eye is covered (occlusion therapy) or blurred with glasses (fogging) or drops – stimulates the proper visual development of the more affected eye
Relative afferent pupillary defect
Sensitive measure of retinal and/or optic nerve dysfunction.
Direct pupil dilates when light shined in that eye.
Hyperopia
= farsightedness [can see far]
o Parallel rays of light come to focus posterior to the retina
o Results from short AP diameter of eye or lower refractive power of cornea or lens
o Majority of children hyperopic at birth
o Manifests as eye strain, headaches or fatigue
o Results in great accommodative effort
o If not treated can result in bilateral amblyopia (ametropic amblyopia) or esotropia
Myopia
= near sightedness [can see near]
o Parallel rays of light come to focus anterior to the retina
o Results from long AP diameter of the eye or higher refractive power of the cornea or lens
o Tend to squint – as results in improved VA (pinhole effect)
o Infrequent in infants and preschool aged children
o More common in infants with retinopathy of prematurity
o Hereditary tendency
o Degree of myopia increases with age
Astigamatism
= refractive powers of the various meridians of the eye differ
o Most cases due to irregularity in the curvature of the cornea
o Mild cases do not require treatment and are asymptomatic
o With greater degrees can result in visual distortion
o May require glasses
Causes consistent blurred vision both near and far (but as above often mild/asymptomatic)
Anisometropia
= differences in refractive state of each eye
o If uncorrected can develop amblyopia due to constantly being out of focus
Accommodation disorders
o Accommodation = ciliary muscle contracts, the suspensory fibers of the lens relax, and the lens assumes a more rounded shape increasing the lens power
o Amplitude of accommodation is greatest in childhood and gradually decreases with age (= presbyopia)
o Disorders in accommodation is relatively rare
Blindness - general
- Definitions
a. Vision impaired = VA 20/70 – 20/200
i. Prevalence 1/500 school aged children
b. Blindness = VA >20/200 - Epidemiology
a. Severe visual impairment (corrected vision poorer than 6/60) and blindness in children is uncommon
b. Incidence 2.5 per 100,000 children
c. Incidence highest in developing countries, LBW infants and in first year of life - Aetiology
a. Mild-moderate
i. Usually refractory errors - Most commonly myopia near sighted
b. Blindness/severe impairment
i. Most common is retinopathy of prematurity
ii. Cataracts
iii. Albinism
iv. Congenital infection
v. HIE
vi. Hydrocephalus
Key Question – Is there nystagmus? • If no o Cortical visual impairment o Delayed visual development o COMA – oculomotor apraxia; abnormality in enervation of saccades, cannot generate rapid eye movements; blink end fixation • If yes o Anterior – cataract, aniridia, albinism, cornea o Posterior segment pathology
Diplopia - general
• Generally, results from misalignment of the visual axes
• Binocular
o Occluding either eye relieves the diplopia if it is binocular in effect
o Affected eye commonly squint, cover one eye with a hand, or assume abnormal head tilt
o Onset of diplopia requires full evaluation
o DDX
Increased ICP/ brain tumour
Infection
Migraine
GBS
Orbital mass
• Monocular
o Monocular diplopia results from dislocation of the lens, cataract, dry eyes or defect in media or macula
o Covering the non-diplopic eye will not relieve symptoms
o May be psychological
Nyctalopia
= night blindness
• Vision that is defective in reduced illumination • Aetiology o Inherited – AD, AR, X linked o Vitamin A deficiency o Drugs – quinine
Amaurosis - general
- Amaurosis = partial or total loss of vision; describes profound impairment, blindness or near blindness
- Aetiology
a. Congenital (neurological, developmental malformation, infection, hypoxia, trauma)
b. Acquired
i. Ocular disease - Cataract
- Chorioretinitis
- Retinoblastoma
- Retinitis pigmentosa
ii. Rapid onset - Infectious process
- Vasculitis
- Migraine
- Leukaemia
- Demyelination
- Clinical manifestations
a. Nystagmus or strabismus
b. Timidity, clumsiness, behavioural change - Investigations
a. Complete ophthal assessment
b. Imaging
Cortical visual impairment
• Visual impairment caused by a brain problem rather than eye problem
• Aetiology o Hypoxia o Developmental brain abnormality o Head injury o Infections – meningitis, encephalitis
Delayed visual maturation
• Describes infants who do not exhibit the ability to fix or follow objects in the environment
o Child appears blind – unable to focus attention, fixate or follow
• Normal ocular and neurological examination
• Improves by age of 6 months without treatment
• Pathophysiology unknown
Aniridia
a. Hypoplastic iris tissue
b. May be associated with other eye abnormalities – macular and optic nerve hypoplasia
c. Bilateral in 98% of cases
d. Aetiology = genetic
i. 2/3 of cases AD
ii. 1/3 of cases sporadic
e. Consequences
i. Glaucoma – develops in 75%
ii. Wilm’s tumour – develops in 20% of individuals with sporadic aniridia
1. Gene for aniridia close to the Wilm’s tumour gene
f. Management
i. Screening using renal USS 3-6/12 until 5 years of age if there is an 11p13 region deletion
Coloboma
a. Developmental defect of the iris – defect of a sector, hole or notch in the pupillary margin
b. May be associated with other abnormalities
c. Always located inferiorly
d. AD in most cases
Congenital mydriasis
a. Pupils appear dilated and do not constrict significantly to light or near gaze
b. Respond minimally to miotic agents
c. Iris is otherwise normal
d. Affected individuals usually healthy
