Optho/ENT Flashcards
Name the derivation for each part of the eye below:
1. Retina
2. Vascular and sclerocorneal layers
3. Lens
- Neuroectoderm of the forebrain
- Mesoderm
- Surface ectoderm
Development of the eye begins in the 5th week of gestation
When does the pupil become reactive to light?
30 weeks but may not respond until 32 weeks, well developed by 1 month of age
eyelid closes in response to light at 30 weeks
When is optic nerve myelination complete?
2 years old
How does innervation control the pupillary reaction?
parasympathetic innervation –> constriction
sympathetic innervation –> dilation
What does the pupillary respons to light test for?
intact afferent and efferent pathways of cranial nerve III
suggests visual function of subcortex
What does a nonreactive UNILATERAL pupil with increased size suggest?
subdural hematoma or other unilateral mass
What does nonreactive BILATERAL pupils with increased size suggest?
Late signs of HIE, IVH, infantile botulism
What does the red reflex detect?
Retinal blood vessels
Demonstrates lack of obstruction between external corneal surface and retina
<28 weeks may not have red reflex- unclear corneas and vitreos
What is leukocoria and what does it suggest?
White reflex
Most commonly caused by cataracts
Other: retinoblastoma, coloboma, ROP, retinal detachment
What is hypotelorism associated with?
HIGHLY assoc with holoprosencephaly
Others: Meckel-Gruber, T13, Williams
What is hypertelorism associated with?
Apert, Cruzon, cat-eye, CHARGE, Cri du chat, DiGeorge, Holt-Oram, Noonan, Trisomy 8
Teratogentic effects of hydantoin, isoretinoin
Describe Ptosis
upper eyelid cannot rise to normal level
Usually caused by dysfunction of the levator palpebral muscle (CN III)
AD
Cranial nerve palsy in Horner’s syndrome
5 stages of ROP
- Distinct demarcation line separatin transition of vascularized posterior retina and avascular anterior retina
- Demarcation line is thickened and elevated
- Ridge with extraretinal neovascularization and retinal vessels enter vitreos space
- Partial retinal detachment
- Complete retinal detachment- severest from
Plus disease: dilated, tortuous vessels that demonstrate advanced vascular disease, always evident before retinal detachment
s
Threshold for treatment in ROP
stage 3 with plus disease in zone I and II + 5 contiguous clock hours or 8 total clock hours
50% progress to stage 5 ROP
Risk of retinal detachment decreased to 25% with treatment
Type I prethreshold ROP
Zone I: any ROP with plus disease; or stage 3+/- plus disease
Zone 2: stage 2 or 3 with plus disease
Treat
Type 2 prethreshold ROP
Zone 1: stage 1 or 2 without plus disease
Zone 2: stage 3 without plus disease
Close observation
15% progress to type I
Prognosis in ROP- infants are at risk for?
AMBLYOPIA, REFRACTIVE ERRORS (mostly MYOPIA with severe ROP), STRABISUMUS
If ROP as neonate, increased risk of retinal detachment during adulthood
Infectious causes of cataracts
Rubella, toxoplasmosis, HSV, varicella
**In utero radiation exposure can cause _____
Cataracts
Etiology of primary glaucoma
AR
Males>females
presents at birth
caused by structural abnormality
Epidemiology of hearing loss
~2% of all infants screened will refer
~15-20% of those will have confirmed hearing loss
Most common genetic cause of hearing loss
Mutation in the connexin 26 (Cx26) gene
Causes ~20-30% of congenital hearing loss
Etiology of hearing loss
50% genetic (Cx26 gene most common)
25% acquired (develops secondary to injury to the developing auditory system in intrapartum or perinatal period)
25% unknown
What is the most common cause of nonhereditary sensorineural hearing loss?
CMV!
10-15% of babies with congenital CMV are symptomatic
60% will have sensorineural hearing loss
5-10% of asymptomatic babies develop sensorineural hearing loss
In utero infections associated with hearing loss
CMV
Zika
Herpes
Rubella
Syphilis
Toxoplasmosis
Epidemiology of choanal atresia
1:8,000 births
2:1 females:males
More often unilateral (2/3) R>L
Differences between nasal encephalocele, glioma and meningocele
Encephalocele:
contiguous with CSF
lesion may be pulsatile, expand with crying or compression of jugular vein
Glioma:
connective tissue mass of CNS- NO CONNECTION WITH CNS
firm, noncompressible lesions
Meningocele:
contiguous with CNS, CONTAINS BRAIN TISSUE
lesion may be pulsatile, expand with crying or compression of jugular vein
Nasolacrimal duct obstruction
MC lacrimal abnormality in infants
incomplete canalization of nasal lacrimal duct system- nasal end at level of Hasner’s valve
Majority mild and resolve spontaneously
Distinguishing test to dx pyriform aperture stenosis
inability to pass #6 french catheter anteriorly through nares
manifestation of bony overgrowth of the nasal process of the anterior maxilla–> anterior narrowing of nasal airway
Describe a lingual thyroid
MC congenital mass
Posterior aspect of tongue
F>M (4:1)
mass of ectopic thyroid tissue- failure of normal thyroid tissue to descend to its usual cervical position
when present, only functioning thyroid tissuein 70%
Majority asymptomatic
Confirm by radionuclide scanning
Differences in mucoceles and ranulas
Mucoceles: develop from minor salivary glands, painless asymptomatic, acute smooth swelling, fluctuate in size, rupture spontaneously
Ranula: develop from major salivary glands, nontender, mobile, glistening, broad-based englargement with intact overlying mucosa, BLUISH HUE
Effects of edema on the neonatal airway
more profound effects because neonatal airway is small
1mm of local edema reduces the glottis to 35% of it’s initial size, reduces subglottic airway to 25% of initial size
with age, airway shape changes from conical to cylindrical
Which side is vocal cord paralysis more common?
LEFT- recurrent laryngeal nervs has longer/winding course, more susceptibel to trauma
2nd MC congenital laryngeal anomaly
Unilateral more common
Type of stridor in vocal cord paralysis
Inspiratory
may be biphasic
Type of stridor in laryngomalacia
INSPIRATORY
improves with prone positioning
worse with agitation
Type of stridor in tracheomalacia
EXPIRATORY
Disease associated with laryngomalacia
GE reflux
DD for preauricular lesions
Hemangioma
Venous malformation
DD for postauricular lesions
Branchial cleft cyst (I)
DD for submandibular lesions
Hemangioma
Ranula
DD for submental and midline neck lesions
Thyroglossal duct cyst
Dermoid cyst
Venous malformation
DD for anterior border of SCM muscle lesions
Branchial clef cyst (I, II, III)
Hemangioma
Laryngocele
DD for supraclavicular/paratracheal lesions
Thyroid mass
Parathyroid mass
Esophageal diverticulum
Lipoma
Dermoid cyst
DD for supraclavicular lesions
Lipoma
Bilateral leukocoria and hearing loss
Diagnosis?
Rubella!
CMV and toxo have hearing impairment but chorioretinitis not cataracts
when is retinal vascularization complete?
nasal side: 36 weeks
temporal side: 40 weeks
