Paedatric ophtalmology - PowerPoint Presentation

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Paedatric ophtalmology

RD,

Coloboma

, NLD obstruction

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Embryology

Beginning of the

fourth

week-optic groves appear in the neural folds at the cranial end of the embryo

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Embryology

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 stalksThe surface ectoderm adjacent to optic vesicles thicken to form lens placodes

These

placodes

invaginate and sink deep to the surface ectoderm, forming lens pits

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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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Embryology

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Embryology

The edges of the lens pits approach each other and fuse to form spherical

lens vesicles

which

soon lose their connection with surface ectodermAs the lens vesicle develop, the optic vesicles invaginate to form double-walled optic cups

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Optic fissures- develop on the ventral surface of the optic cup and along optic stalks

It contain vascular mesenchyme which

hyloid

blood vessels developThe 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

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Retina

outer layer of optic cup –retinal pigment epithelium

Inner layer of optic cup- neural retina

Ciliary body

Wedge shape extension of choroidCiliary muscle develop from the mesenchyme located at the edge of the optic cupIrisDevelop from rim of the optic cup

The dilator and sphincter

pupillae

muscles of the iris derived from neuroectoderm of the optic cupLens

Lens vesicle-surface ectodermSupplied by distal part of hyaloid artery - later in fetal period it will degenerateAnterior wall of lens vesicle become the subcapsular lens epitheliumPosterior 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

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Aqueous Chambers

Anterior chamber develop from

cleftlike

space that form in the mesenchyme between lens and corneaPosterior chamber develops from space in the mesenchyme posterior to the developing iris and anterior to developing lensCornea

External corneal epithelium- surface ectodermCorneal endothelium and stroma – neural crest cellChoroid 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 weekEyelash and glands derives from surface ectodermTarsal plate derived from mesenchyme

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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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Lens Formation

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Congenital Anomalies of the eye

Congenital retinal detachment

Coloboma

of the retinaColoboma of the

irisNDL obstruction.Retinoblastoma .

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Congenital retinal detachmentoccurs

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

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Coloboma

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 fissureoccurs 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 eyelidThe present of coloboma can be related to certain syndrome – CHARGE syndrome and

patau

syndrome

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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.ManagementNo 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

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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

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Congenital Ptosis

drooping eyelid is called ptosis

or

blepharoptosiscan affect one eye or both

eyesCongenital ptosis - droopy eyelid is present at birth or within the first year of lifeUsually does not affect the vision

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Congenital Ptosis

Pathophysiology

 results from a localized myogenic

dysgenesisfibrous and adipose tissues are present in the muscle belly, diminishing the ability of the levator

to contract and relaxcan also occur when the innervation to the levator is interrupted through neurologic or neuromuscular junction dysfunction

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Congenital Ptosis

Causes

Idiopathic

AD

inheritenceBlepharophimosis syndrome

Third cranial nerve

palsy

Horner

syndromeMarcus Gunn jaw-winking syndromeBirth traumaMyotonic dystrophy

Blepharochalasis

Pseudotumor

of the

orbitPseudoptosis

Duane syndromeKearns-Sayre syndrome

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Management

Mild case – observation for sign of

amblyopia, strabismus and abnormal head posture

If the ptosis worsen – surgical intervention may be needed

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NASOLACRIMAL SYSTEM DEFECT

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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 conjunctivitisNo redness or itching to the eye

can have reflux of

mucopurulent

material from lacrimal punctum

when pressure is applied overlacrimal sacTreatmentmassage 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)

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Probing

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Retinoblastoma

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Retinoblastoma

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.

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History and symptoms

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 .

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cont

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.

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prognosis

Overall mortality is 15%.

50% of children with germinal mutation will develop a second primary tumor. Ex. Osteosarcoma of the femur.

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DDx of leucocoria

Cataract.

Retinoblastoma

.

Toxocariasis.

Coat´s disease.

ROP (RETINOPATHY OF PREMATURITY ).

PHPV (Persistent hyperplastic primary vitreous ).

Retinal detachment.

Coloboma.

Retinal dysplasia.

Norrie´s disease

.

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OPHTALMIA NEONATARUM

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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 virusgonococcal

infection is the most serious threat to sight as it can rapidly penetrate

corneal epithelium

, causing corneal ulceration

diagnose using stains and culturesTreatmentsystemic antibiotics with possible hospitalization if infectious etiologytopical prophylaxis, most commonly with erythromycin (or silver nitrate), is required by law at birth

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