Glaucoma–Congenital

Descriptive text is not available for this imageBASICS

DESCRIPTION

  • Patient with childhood glaucoma has two or more of the following:
    • Intraocular pressure (IOP) >21 mm Hg
    • Visual field deficits consistent with glaucomatous optic neuropathy
    • Axial length demonstrating progressive nearsightedness (myopia)
    • Cornea with enlargement greater than expected by age or Haab striae (pressure-induced breaks in the inner layer of to the cornea)
    • Optic nerve with progressive increase in cup-to-disc ratio or >0.2 asymmetry in cup-to-disc ratio
  • Can be classified as (i) primary congenital glaucoma (PCG), (ii) glaucoma following cataract surgery, (iii) glaucoma associated with nonacquired systemic disease or syndrome, (iv) glaucoma associated with nonacquired ocular abnormalities, and (v) glaucoma associated with acquired conditions
  • PCG can present at birth or before age of 1 month (neonatal), before age of 2 years (infantile), or after age of 2 years (late onset or late recognized).
  • PCG can occur in isolation or in association with systemic disorders and other anterior segment anomalies.
  • Juvenile open angle glaucoma (JOAG) can present between ages of 4 and 30 years and is usually not associated with ocular enlargement.
  • >75% of primary childhood glaucoma presents in the 1st year of life.

EPIDEMIOLOGY

  • PCG accounts for ~1/2 of all cases of childhood glaucoma.
  • 1:10,000 births in the United States (ranging from 1:1,250 in Slovakian Romas to 1:18,500 in Great Britain)
  • Consanguinity increases risk
  • Male > female (3:2)
  • ~80% bilaterally affected

RISK FACTORS

  • Most PCG is sporadic, but 10–40% are familial.
  • Autosomal recessive with variable penetrance is the most common.
  • Three identified genes for PCG include CYP1B1 (cytochrome P-450), LTBP2 (transforming growth factor), and TEK (angiopoietin).
ALERT

PCG is a rare disease; secondary glaucomas are far more common. Genetic testing should be considered for children who presents with glaucoma at birth or in infancy.

PATHOPHYSIOLOGY

  • PCG is caused by development anomaly of the anterior chamber angle (junction of iris and cornea) resulting in increased outflow resistance through the trabecular meshwork, the primary location through which aqueous humor flows out of the eye.
  • High IOP in young children leads to permanent destruction of the nerve fibers of the optic nerve and enlargement of the eye.
  • Secondary glaucoma is mostly due to damage or alteration of the trabecular meshwork, increasing resistant to outflow.
  • The blockage may be microscopic (open-angle glaucoma) or due to obstruction of the outflow by the apposition of the iris on the cornea (angle-closure glaucoma).

COMMONLY ASSOCIATED CONDITIONS

  • Glaucoma associated with nonacquired systemic conditions
    • Sturge-Weber syndrome
    • Neurofibromatosis type 1
    • Oculocerebrorenal (Lowe) syndrome
    • Marfan syndrome
    • Rubinstein-Taybi syndrome
    • Stickler syndrome
    • Walker-Warburg syndrome
    • Cerebro-hepato-renal syndrome (Zellweger)
    • Pierre Robin syndrome
    • Homocystinuria
    • Intrauterine inflammation (rubella, syphilis)
    • Mucopolysaccharidoses, cystinosis, sphingolipidoses
    • Trisomy 13 (Patau syndrome)
    • Trisomy 21 (Down syndrome)
  • Glaucoma associated with nonacquired ocular abnormalities
    • Aniridia
    • Axenfeld-Rieger syndrome
    • Congenital ectropion uvea
    • Iris hypoplasia
    • Microphthalmia
    • Oculodermal melanocytosis
    • Corneal malformations (sclerocornea, Peters anomaly, corneal dystrophies)
    • Persistent fetal vasculature
    • Posterior polymorphous dystrophy
    • Ectopia lentis
  • Glaucoma associated with acquired conditions
    • Trauma or chemical injury
    • Postsurgical
    • Tumors
    • Uveitis
    • Steroid induced
    • Retinopathy of prematurity

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