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RD, Coloboma , NLD obstruction
Beginning of the fourth week-optic groves
appear in the neural folds at the cranial end
of the embryo
As the neural folds fuse, the optic grooves evaginate to form hollow diverticula-optic vesicles
As the optic vesicle enlarge, their connection with forebrain narrow to form optic stalks
The surface ectoderm adjacent to optic vesicles thicken to form lens placodes
These placodes invaginate and sink deep to the surface ectoderm, forming lens pits
Figure 17-2 Photomicrograph of a sagittal section of the eye of an embryo (×200) at approximately 32 days. Observe the primordium of the lens (invaginated lens
placode), the walls of the optic cup (primordium of the retina), and the optic stalk (primordium of the optic nerve). (From Moore KL, Persaud TVN, Shiota K: Color
Atlas of Clinical Embryology, 2nd ed. Philadelphia, WB Saunders, 2000.)
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© 2005 Elsevier
The edges of the lens pits approach each other and
fuse to form spherical lens vesicles which soon lose
their connection with surface ectoderm
As the lens vesicle develop, the optic vesicles
invaginate to form double-walled optic cups
Optic fissures- develop on the ventral surface of the
optic cup and along optic stalks
It contain vascular mesenchyme which hyloid blood
vessels develop
The hyaloid artery supplies the inner layer of the
optic cup, the lens vesicles and the mesenchyme of
optic cup
The closure of optic fissure occurs at around 6th-7th
week
Retina outer layer of optic cup –retinal pigment epithelium Inner layer of optic cup- neural retina
Ciliary body Wedge shape extension of choroid
Ciliary muscle develop from the mesenchyme located at the edge of the optic cup
Iris Develop from rim of the optic cup
The dilator and sphincter pupillae muscles of the iris derived from neuroectoderm of the optic cup
Lens Lens vesicle-surface ectoderm
Supplied by distal part of hyaloid artery - later in fetal period it will degenerate
Anterior wall of lens vesicle become the subcapsular lens epithelium
Posterior wall of lens vesicle undergo dissolution and lengthen to form primary lens fiber
The rim of the lens is known as equatorial zone-the cell are cuboidal; as the elongate, they lose their nuclei and become secondary lens fiber
Lens capsule represent greatly thickened basement membrane
Aqueous Chambers Anterior chamber develop from cleftlike space that form in
the mesenchyme between lens and cornea
Posterior chamber develops from space in the mesenchyme posterior to the developing iris and anterior to developing lens
Cornea External corneal epithelium- surface ectoderm
Corneal endothelium and stroma – neural crest cell
Choroid and sclera The mesenchyme around optic cup differentiate to vascular
layer - the choroid – and fibrous layer – the sclera
Eyelid Develop during 6th week from the mesenchyme and two folds
of skin that grow over cornea
Adhere to one another at 10th week and remain so until 26th-28th week
Eyelash and glands derives from surface ectoderm
Tarsal plate derived from mesenchyme
Figure 17-5 Sagittal sections of the eye, showing the successive developmental stages of the lens, retina, iris, and cornea. A, At 5 weeks. B, At 6 weeks. C, At 20
weeks. D, Newborn infant. Note that the layers of the optic cup fuse to form the retinal pigment epithelium and the neural retina and that they extend anteriorly as
the double epithelium of the ciliary body and its iris.
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Congenital retinal detachment
Coloboma of the retina
Coloboma of the iris
NDL obstruction.
Retinoblastoma .
Congenital retinal detachment
occurs when the inner and outer layers of the optic cup
do not fuse during the fetal period to form the retina
and obliterate the intraretinal space
separation of the neural and the pigmented layers may
be partial or complete
A gap in part of the structures of eye
The gap can be large or small and is normally in the inferior part of the eye
A typical coloboma results from defective closure of the retinal fissure
occurs in about 1 in 10,000 births.
can affect one eye (unilateral) or both eyes (bilateral).
It can affect the iris, lens, choroid, retina, optic disc and eyelid
The present of coloboma can be related to certain syndrome – CHARGE syndrome and patau syndrome
Presentasion
Keyhole-like shape of the pupil – iris coloboma
Leukocoria – retinal coloboma
The affect on vision depend on which part of the
eye is affected and how big the gap is.
Management
No treatment at present
The child will need regular follow up to access
the effect of coloboma on his vision.
They also have increase risk of glaucoma and
retinal detachment
Figure 17-6 Bilateral coloboma of the right iris. Observe the defect in the inferior part of the iris (at the 6 o'clock position). The defect is in the area of closure of the retinal
fissure. (Courtesy of A.E. Chudley, MD, Section of Genetics and Metabolism, Department of Pediatrics and Child Health, Children's Hospital, University of Manitoba,
Winnipeg, Manitoba, Canada.)
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Coloboma of the Iris
drooping eyelid is called ptosis or blepharoptosis
can affect one eye or both eyes
Congenital ptosis - droopy eyelid is present at birth or
within the first year of life
Usually does not affect the vision
Pathophysiology
results from a localized myogenic dysgenesis
fibrous and adipose tissues are present in the
muscle belly, diminishing the ability of the
levator to contract and relax
can also occur when the innervation to the
levator is interrupted through neurologic or
neuromuscular junction dysfunction
Causes
1. Idiopathic
2. AD inheritence
3. Blepharophimosis syndrome
4. Third cranial nerve palsy
5. Horner syndrome
6. Marcus Gunn jaw-winking syndrome
7. Birth trauma
8. Myotonic dystrophy
9. Blepharochalasis
10. Pseudotumor of the orbit
11. Pseudoptosis
12. Duane syndrome
13. Kearns-Sayre syndrome
Management
Mild case – observation for sign of amblyopia,
strabismus and abnormal head posture
If the ptosis worsen – surgical intervention may
be needed
congenital obstruction of the nasolacrimal duct (failure of canalization), usually occurs at 1-2 months of age
most commonly a membranous obstruction at the valve of Hasner at the distal end of the nasolacrimal duct.
epiphora, crusting, discharge, recurrent conjunctivitis
No redness or itching to the eye
can have reflux of mucopurulent material from lacrimal punctum when pressure is applied overlacrimal sac
Treatment
massage over lacrimal sac at medial corner of eyelid
vast majority spontaneously resolve in 9-12 months, otherwise consider referral for duct probing(via punctum thru nasolacrimal duct to perforate the occluding membrane)
Probing
Commonest malignant tumor of the eye in
childhood.
May be inherited as autosomal dominant but most
cases are sporadic.
If inherited it will be bilateral.
Signs :
Whitish-pink mass protruding from the retina into the
vitreous cavity.
Present at mean age of 8 months to 25 months (if
sporadic).
Most cases present at the age of two.
White pupillary reflex (leucocoria) , A white pupillary
reflex (leukocoria) due to a pale elevated tumour at the
posterior pole of the eye. Sometimes the tumour is bilateral on
Presentation.
A squint due to reduce vision.
Painful red eye .
Investigations:
Usually clinical diagnosis
CSF and the bone marrow must be examined for
metastasis.
Treatment:
Removal of the eye is performed in advanced cases.
Radiotherapy , cryotherapy and photocoagulation.
Chemotherapy for metastasis.
Overall mortality is 15%.
50% of children with germinal mutation will
develop a second primary tumor. Ex. Osteosarcoma
of the femur.
Cataract. Retinoblastoma.
Toxocariasis.
Coat´s disease.
ROP (RETINOPATHY OF PREMATURITY ).
PHPV (Persistent hyperplastic primary vitreous ).
Retinal detachment.
Coloboma.
Retinal dysplasia.
Norrie´s disease.
OPHTALMIA
NEONATARUM
newborn conjunctivitis in first month of life
due to maternal vaginal infection.
Causes
toxic: silver nitrate, erythromycin
infectious: bacterial (e.g. Neisseria gonorrhoeae- most common, Chlamydia trachomatis), herpes simplex virus
gonococcal infection is the most serious threat to sight as it can rapidly penetrate corneal epithelium, causing corneal ulceration
diagnose using stains and cultures
Treatment
systemic antibiotics with possible hospitalization if infectious etiology
topical prophylaxis, most commonly with erythromycin (or silver nitrate), is required by law at birth