Development and teratology of sensory organs
Anna Mac Gillavry Danylevska
9.5.2022

diencephalon
    3rd brain ventricle
Development of the eye
ectoderm
mesenchyme
 lens
 placode
   optic cup
         stalk of optic cup
     intraretinal space
     of optic cup

Development of optic cup and lens
      outer layer of cup
      intraretinal space
      inner layer of cup
 stalk of optic cup
lumen of stalk
of optic cup
lens vesicle
ectoderm
neuroectoderm
(wall of diencepalon)

      intraretinal space                                                    diencephalon wall
  lens vesicle
lumen of stalk
of optic cup

anterior epithelium
of lens
ectoderm
       eyelid
pigmented layer of retina
nervous layer of retina
intraretinal space
mesenchyme

+
retinal pigmented layer
retinal nervous layer
  camera oculi ant.
eyelid
ectoderm
conjunctival sac
mesenchyme

Eye abnormalities
•Coloboma – in most cases coloboma iridis, frequently associated with other eye abnormalities;
optic nerve coloboma is linked to PAX2 gene mutations – renal coloboma syndrome – autosomal
dominant
•Iridopupillary membrane
•Sclerocornea
•Peters anomaly
•Congenital cataracts – rubella virus!
•Persistent hyaloid artery (in 3 % of full term infants) – amblyopia, vitreous haemorrhage, retinal
detachment

•Microphtalmia – 1,5-1,9 in 10000, cytomegalovirus, toxoplasmosis
•Anophtalmia – 0,18-0,4 in 10000
•Congenital aphakia/aniridia – mutation in PAX6 results in aniridia; WAGR syndrome – microdeletion
in chromosome 11 (PAX6 and WT1)
•Cyclopia and synophtalmia (loss of midline tissue - holoprosencephaly) – alcohol, maternal
diabetes, mutations in SHH and abnormalities in cholesterol metabolism

Development of the inner ear
otic placode
mesenchyme
ectoderm
  otic pit
dorsal  aorta
    otic pit
wall of rhombencephalon
otocyst
the 1st
ectodermal
cleft

Development of membranous labyrinth
utricular part
of otocyst
saccular part
of otocyst
tubular process
of sacculus
T. W. Sadler, Langman’s medical embryology

*central regions of developing
semicircular canals
*these regions
perforate later
Development of semicircular canals
T. W. Sadler, Langman’s medical embryology

Development of middle ear
Meckel‘s
cartilage
   rhombencephalon
utriculus
sacculus
1st ectodermal
cleft
    middle ear
    ossicles
wall of inner ear
primitive
cavum tympani
wall of inner ear

Development of external ear
the 1st ectodermal cleft
basis
of eye
auricular
tubercles
T. W. Sadler, Langman’s medical embryology

External ear defects
•Anotia
•Microtia
•
•- (1 in 6000-12000) usually one ear is affected, the external accustic meatus is absent or
narrowed – conductive hearing loss
•Preauricular appendages and pits
•
•All of the most common chromosomal syndromes and most of the less common have ear anomalies in
their characteristics!!! (Langman’s medical embryology, T. W. Sadler, 12th edition, p. 328)
Anotia | Children's Hospital of Philadelphia (chop.edu)

Congenital hearing loss (sensory)
-Genetic factors
-Rubella virus, cytomegalovirus
-Isotretinoin!