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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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