Dr Nidhi Thaker

CHILDHOOD GLAUCOMA

DEFINITION 0CGRN/WGA 20130Based on national criteria; Glaucoma in

children less than 18 yrs of age(USA): < 16 yrs of age(UK,Europe)0Noted by Hippocrates0First recognised by Von Muralt in 1869

CLASSIFICATION OF CHILDHOOD GLAUCOMA

CONGENITAL GLAUCOMA0Primary congenital glaucoma/ primary infantile

glaucoma/ primary congenital open angle glaucoma

0Definition: Glaucoma in children less than 2yrs of age that can be primary infantile or secondary infantile associated with ocular or systemic syndromes and with surgical aphakia.

Definition of glaucoma 2 or more required1) IOP > 21 mm Hg2) Optic disc cupping:0 progressive in CDR0 asymmetry of cup: >0.2 0 focal rim thinning3) cornea;l findings: 0Haab striae0 Increase diameter of cornea4) Progressive myopia/ myopic shift:5)Reproducible visual field defect consistant with glaucomatous optic neuropathy

Definition of glaucoma suspect Atleast 1 required1) IOP > 21 mm Hg on 2 separate occasions2) Suspicious optic disc cupping:0 progressive in CDR0 asymmetry of cup: >0.2 0 focal rim thinning3) Increase diameter of cornea and increase axial length 4) suspicious visual field defect

PRIMARY INFANTILE GLAUCOMA

EPIDEMIOLOGY AND GENETICSPrimary congenital glaucoma –

50-70-% of the congenital glaucomasOccurs less frequent than primary adult glaucomaRare – 1:10,000 birthsM:F ; 3:2b/l in 65-80%

Of pediatric glaucoma cases -

20% diagnosed as newborn60% - diagnosed by the age of 6 months80% within the 1st year of life

EPIDEMIOLOGY AND GENETICS0Sporadic 90%0Only 10% familial

Autosomal recessive pattern with incomplete or variable penetrance and possibly multifactorial inheritance

3 major loci of recessively inherited primary congenital galucoma GLC3A - on chromosome 2

(2p21), CYP1B1 gene GLC3B -on chromosome 1

(1p36) GLC3C – on chromosome 14

(14q24.3) LTBP2 gene

• Genetic counselling- for parents of child w/ pediatric glaucoma & adults w/ childhood onset glaucoma

Development of Angle structures

At 5 months' gestation, a continuous layer of endothelium (e) creates a closed cavity of the anterior chamber (according to most studies), and the anterior surface of the iris (i) inserts in front of the primordial trabecular meshwork (tm).

In the 3rd trimester,endothelial layer progressively disappears from the pupillary membrane (pm) and iris and cavitates over

the anterior chamber angle (aca), possibly becoming incorporated in the trabecular meshwork. At the same time,

the peripheral uveal tissue begins to slide posteriorly in relation to the chamber angle structures

C: Development of the trabecular lamellae and

intertrabecular spacebegins in the inner,

posterior aspect of the primordial tissue and progresses toward the

Schlemm canal (Sc) and Schwalbe line (Sl)

D: The normal anterior chamber angle is not fully developed until 1 year of

age.

PATHOPHYSIOLOGY1. Mann: Retention of an abnormal mesodermal

tissue due to imcomplete atrophy2. Barken : incomplete resorption of mesodermal

cells which forms a membrane across the TM (barken’s membrane)

3. Allen: incomplete cleavage of mesoderm to form AC structures

4. Worst: combined theory of atrophy and resorption

5. Maumenee:0 abnormal anterior insertion of cilliary

musculature into TM0 absence of schlemm’s canal in histologic

specimen6. Anderson :0Premature or excessive formation of

collagenous beams in TM preventing posterior sliding of CB and peripheral iris

7. Kupfer at all : 0Faulty migration or differentiation of neural

crest cells

summary0Primary congenital glaucoma is due to failure or

abnormal development of the trabecular meshwork .0Maldevelopment of trabeculum including the

iridotrabecular junction (trabeculodysgenesis) is responsible for impaired aqueous outflow resulting in raised IOP.

0Trabeculodysgenesis is characterized by absence of the angle recess with iris having a flat or concave direct insertion into the surface.

0The iris may not completely separate from the cornea that the angle remains closed by persistent embryonic tissue.

Pathogenesis of Glaucomatous Ocular Damage

Main Theories are:1 Mechanical changes due to the rise of

intraocular pressure; and2 Vascular perfusion of the optic nerve head3 Defective autoregulation

CLINICAL FEATURES 1. Photophobia,blepharospasm,lacrimatio

n: are often occur together. o caused by irritation of corneal nerves, which

occurs as a result of the elevated IOP. o Photophobia is usually the initial sign, but is not

enough by itself to arouse suspicion in most cases.2 others: cloudy cornea , enlarged cornea or eye, red

eye , irritability , poor vision & pain

EXTERNAL EXAMINATION Corneal signs : Corneal haze is the first signCorneal oedema – Epithelial and stromal edema Sec to raised IOPclears with normalization of the pressureSevere cases: acute hydrops

Corneal enlargement- It occurs along with enlargement of globe-buphthalmos especially when the onset is before the age of 3yrs.

0The healthy newborn's cornea has a horizontal

diameter ranging from 9.5 to 10.5 mm, which enlarges about 0.5 to 1.0 mm in the first year of life .

0A corneal diameter larger than 12 mm in the first year of life is a highly suspect finding.

0Tears and break in Descement’s membrane(Haab’s straie)-These occur because Descement’s membrane is less elastic than the corneal stroma.0Breaks in Descement’s membrane0Migration of endothelial cells overthere0Lay down new basement membrane0Ridges develop along the sepersted edges0Horizontal straie

3. Sclera becomes thin and appears blue due to underlying uveal tissue.

4. Anterior Chamber becomes deep.

5. Iris may show iridodonesis and atrophic patches due to stromal hypoplasia and loss of crypts

6. Lens becomes flat due to stretching of zonules and may even subluxate.

7. Optic disc may show variable cupping and atrophy especially after third year.

8. IOP is raised which is neither marked nor acute

9. Axial myopia may occur because of increase in axial length which may give rise to anisometropic ambylopia.

Buphthalmos • Hydrophthalmia• enlargement of the eye that may occur with this

condition , these terms should not be used as synonyms for PCG because enlargement of the globe is seen with other childhood glaucomas if they occur early enough in life.

Refractive Error

0The enlargement of the globe with elevated IOP in the first 3 years of life

0 myopic shift anisometropia amblyopia

0presence of Haab striae often produces significant astigmatism, which also contributes to amblyopia, especially in unilateral or asymmetric cases.

0Children between 3 and 10 years of age: refractive changes have been attributed to continued scleral stretching .

Tonometry

0Perkins applanation tonometer

0Tono-Pen (i.e., a handheld Mackay-Marg-type tonometer)

0Goldmann applanation tonometry: children as young as 3 or

4 years of age can often cooperate

0Icare tonometer

0The normal IOP in childhood :10 to 22 mm Hg

0Infants with PCG : 30 to 40 mm Hg with unanesthetized

IOPs

0falsely elevated in a struggling patient and is often

unpredictably altered by systemic sedatives and anesthetics

Fundoscopy0Done with anesthetized or

sedated child,using a direct ophthalmoscope with a Koeppe gonioscopy lens on the cornea

0Normally: pink , but slight pallor physiological cupping0 In PCG: loss of neuronal tissue

in vertical poles0Enlarged scleral canal in

horizontal meridian0Cupping is rapid but reversible

Above is shown a typical nerve appearance with damage from glaucoma.  Note that the center of the nerve has an excavated or "scooped out" appearance.

ULTRASONOGRAPHY

0documenting progression of infantile glaucoma by recording changes in the axial length

0 axial length may decrease by as much as 0.8 mm after surgical reduction of the IOP

0helpful when glaucoma drainage-device surgery is being contemplated

0After such surgery, helpful in confirming the presence of fluid around the device's reservoir, especially in patients in whom the bleb cannot easily be visualized

THANK

YOU