Basics
Description
- Elevation of intraocular pressure (IOP) due to congenital anomalies that prevent outflow of aqueous humor, leading to damage to the optic nerve
- Neonatal primary congenital glaucoma (PCG), presents at birth
- Depending on the degree of the malformation, presentation can occur even later in life.
- About 80% of childhood glaucoma presents in the 1st year of life. Secondary congenital glaucoma is associated with systemic conditions.
Epidemiology
- PCG accounts for ~1/2 of all cases of childhood glaucoma.
- 1:10,000 births (ranging from 1:2,500 in Saudi Arabia to 1:38,000 in Spain)
- Male > female (3:2)
- ~70% bilaterally affected
Pathophysiology
- PCG is caused by immature anatomic relationship between the iris, trabecular meshwork, and cornea.
- Secondary glaucoma is mostly due to damage or alteration of the trabecular meshwork.
Genetics
- Most are sporadic, but 10-40% are familial.
- Autosomal recessive is most common.
- PCG is associated with mutations in cytogenic locations 2p22.2 (GLC3A), 1p36.2-p36.1 (GLC3B), 14q24.3 (GLC3C), and 14q24.2-q24.3 (GLC3D).
Etiology
- Aqueous humor, a clear fluid produced by the ciliary body at the posterior base of the iris, passes through the pupil and exits through the trabecular meshwork and Schlemm canal, which are located at the junction of the cornea and iris.
- Outflow blockage of aqueous humor causes pressure to build in eye.
- The blockage may be microscopic (open-angle glaucoma) or due to obstruction of the outflow by the iris (angle-closure glaucoma).
- High IOP in young children leads to enlargement of eye and destruction of fibers of the optic nerve.
Commonly Associated Conditions
- Sturge-Weber syndrome
- Neurofibromatosis type 1
- Oculocerebrorenal (Lowe) syndrome
- Marfan syndrome
- Rubinstein-Taybi syndrome
- Stickler syndrome
- Walker-Warburg syndrome
- Hepatocerebrorenal syndrome (Zellweger)
- Pierre Robin syndrome
- Homocystinuria
- Rubella
- Trisomy 13
- Trisomy 21 (Down syndrome)
- Axenfeld-Rieger syndrome
- Ocular Anomalies
- Aniridia
- Peters anomaly
- Sclerocornea
- Congenital iris ectropion syndrome
- Congenital cataract
Alert
Intraocular neoplasms such as retinoblastoma can cause glaucoma. Other causes of secondary glaucoma include trauma and chronic uveitis. �
Diagnosis
History
- Classic triad of symptoms that develop from corneal edema caused by increased IOP
- Epiphora (excessive tearing)
- Blepharospasm (squeezing of eyelids)
- Photophobia (light sensitivity)
- Cloudy corneas
- Red eyes (can be mistaken for conjunctivitis)
- Fussiness
- Large eyes
Physical Exam
- Unlike adult glaucoma, PCG presents with physical changes due to high pressure.
- Buphthalmos (ocular enlargement) due to stretching of immature collagen in infants
- Corneal asymmetry or enlargement (diameter >11 mm at birth or >12 mm in the 1st year of life)
- Corneal haze from edema and/or scarring
- Myopic shift in refractive error
- Rapid changes in IOP present with redness and pain but usually painless without redness from gradual change in pressure.
- Optic nerve cupping develops rapidly in infants but may be reversible with control of glaucoma in very young children.
- Nystagmus may be present if there is early sensory deficit.
- Common to develop amblyopia and strabismus from insult on developing visual system
- General signs of many systemic syndromes associated with glaucoma (neurofibromatosis, Sturge-Weber syndrome)
Imaging
Ultrasound: axial length using A-scan �
- Eye is usually abnormally long for age.
- Longitudinal data are very useful in determining progression of glaucoma.
Diagnostic Procedures/Other
- IOP measurement
- An awake child is ideal; use bottle or breast to quiet, along with low lighting.
- If examination under anesthesia is needed, check IOP as soon as possible after induction, as IOP decreases with anesthetic agents.
- Corneal inspection
- Diameter measured with calipers
- Normal newborn: 10-10.5 mm
- >11.0 mm suspicious
- Watch for asymmetry.
- Clarity: Haze may be due to edema or breaks in the Descemet membrane (Haab striae).
- Optic disc evaluation
- Increase in cupping of the optic nerve head is early sign.
- May reverse with good IOP control in the very young
- Refractive error
- Myopic shift from enlargement of the eye
- Anisometropia (difference in refractive error between the two eyes)
- Astigmatism from change in ocular shape or corneal scar
- Early signs of glaucoma and useful office test for monitoring control of glaucoma
- Gonioscopy: evaluation of anterior chamber angle (between iris and cornea)
- In trabeculodysgenesis, insertion of iris into corneoscleral angle often flat or concave
- Iris defects may suggest type of abnormality causing glaucoma.
- Abnormal iris vessels may influence surgical plan.
- In angle-closure glaucoma: diagnostic apposition of iris on cornea
- Pachymetry: measurement of corneal thickness to assess corneal edema as an indicator of pressure control
Differential Diagnosis
- Excessive tearing: commonly due to nasolacrimal duct obstruction in neonates
- Megalocornea
- May be associated with high myopia
- Contralateral microphthalmia
- Corneal haze
- Birth trauma, forceps
- Congenital corneal dystrophies
- Mucopolysaccharidoses
- Cystinosis
- Intrauterine inflammation (rubella, syphilis)
- Photophobia
- Uveitis
- Retinal cone dystrophy
- Enlarged optic nerve cupping
- Physiologic cupping
- Optic atrophy from hydrocephalus can look similar to glaucomatous damage.
Treatment
General Measures
- Surgery is considered definitive therapy.
- Medical treatment for glaucoma in children is usually a temporizing measure or adjunctive therapy.
- In other types of pediatric glaucoma, medical treatment involves use of the same medications as those used in adults such as β-blockers, adrenergic agents, and carbonic anhydrase inhibitors. In general, miotics are not used because they may cause a paradoxical rise in IOP in children.
Medication
Alert
Topical α-adrenergic agonists are contraindicated in infants and young children, as they can cause CNS suppression leading to apnea, sedation, and fatigue. �
First Line
- Carbonic anhydrase inhibitors: Side effects include metabolic acidosis, growth retardation, loss of appetite, paresthesias, polyuria, diarrhea, and nausea.
- Systemic
- Acetazolamide (10 mg/kg/24 h PO divided t.i.d.)
- Methazolamide
- Topical
- β-Blockers, topical: Side effects include bronchospasm, apnea, and bradycardia.
- Timolol
- Betaxolol
- Levobunolol
- Metipranolol
- Carteolol
- Prostaglandins, topical: Side effects include iris and eyelid pigmentation and growth of lashes.
- Latanoprost
- Bimatoprost
- Travoprost
Surgery/Other Procedures
- Goniotomy/trabeculotomy: Both procedures open portions of Schlemm canal into anterior chamber, allowing easier outflow of aqueous humor (goniotomy approaches the Schlemm canal from inside the eye and trabeculotomy from the outside).
- Trabeculectomy: creates a sclerotomy covered with a partial-thickness scleral flap to create a controlled outflow that bypasses the Schlemm canal and trabecular meshwork. Fluid drains in the sub-Tenon space.
- Seton procedures: various drainage devices placed in subconjunctival space with tube inserted into the anterior chamber, allowing free flow of aqueous humor from eye
- Cyclodestructive procedures: procedures involving destruction of the ciliary body, which produces aqueous humor
- Iridectomy: If the mechanism of glaucoma is angle closure (limited outflow of aqueous humor due to anatomic blockage with iris), then creating a window in the iris allows bypass for aqueous humor to access the anterior chamber.
Ongoing Care
Follow-up Recommendations
Early postoperative �
- Postoperative steroids and cycloplegic drops to decrease pain and prevent adhesions due to inflammation
- Corneal edema clears slowly, but IOP falls quickly if surgery is successful.
- Adjusting pressure-lowering medications based on the success of the surgery
Longer term �
- Follow-up is needed throughout life.
- Examination under anesthesia may be required frequently during the first 3-4 years of life to ensure adequate control of IOP.
- Contact social services for children suspected of having visual impairment.
Patient Education
Children and parents must understand that glaucoma may recur at any point and that continued, long-term surveillance is essential. �
Prognosis
Guarded; even if pressure is well controlled and amblyopia treatment undertaken rigorously, child is still at high risk for visual impairment. Must be carefully followed for the following: �
- Amblyopia
- Abnormal refractive errors
- Recurrence of glaucoma
Complications
- Severe visual impairment or blindness due to optic nerve damage, amblyopia, and corneal scarring likely if glaucoma is undetected or uncontrollable
- Corneal edema and decompensation requiring corneal transplant especially from Seton procedures
- Development of cataract
- If glaucoma is controlled, the following are relatively common:
- Unrecognized and untreated amblyopia (most serious threat to child's vision)
- High degrees of myopia
- Anisometropia (difference in refractive error between fellow eyes)
- Buphthalmos and corneal scarring
Additional Reading
- Beck �AD. Diagnosis and management of pediatric glaucoma. Ophthalmol Clin North Am. 2001;14(3):501-512. �[View Abstract]
- Bejjani �B, Edward �D. Primary congenital glaucoma. In: Pagon �RA, Adam �MP, Ardinger �HH, et al, eds. Gene Reviews [Internet]. Seattle, WA: University of Washington, Seattle; 2007.
- De Silva �DJ, Khaw �PT, Brookes �JL. Long-term outcome of primary congenital glaucoma. J AAPOS. 2011;15(2):148-152. �[View Abstract]
- Kipp �MA. Childhood glaucoma. Pediatr Clin North Am. 2003;50(1):89-104. �[View Abstract]
- Mandal �AK, Gothwal �VK, Bagga �H, et al. Outcome of surgery on infants younger than 1 month with congenital glaucoma. Ophthalmology. 2003;110(10):1909-1915. �[View Abstract]
- Papadopoulos �M, Khaw �PT. Advances in the management of paediatric glaucoma. Eye. 2007;21(10):1319-1325. �[View Abstract]
- Yeung �HH, Walton �DS. Clinical classification of childhood glaucomas. Arch Ophthalmol. 2010;128(6):680-684. �[View Abstract]
Codes
ICD09
- 743.20 Buphthalmos, unspecified
ICD10
- Q15.0 Congenital glaucoma
SNOMED
- 415176004 Primary congenital glaucoma
FAQ
- Q: Can glaucoma be painful?
- A: If the ocular pressure rises quickly (hours), pain occurs frequently. Very high IOPs may be present without pain if they occur slowly (months to years). However, most patients with glaucoma are asymptomatic until they have advanced vision loss.
- Q: Can glaucoma occur after eye trauma?
- A: Yes. This is a very common cause of glaucoma and may be asymptomatic, thus requiring periodic follow-up ophthalmic examinations for early detection and treatment.
- Q: Can infantile glaucoma be inherited?
- A: Yes. Both primary infantile glaucoma and glaucoma related to systemic or ocular syndromes may be inherited. Siblings and children of affected individuals should be examined for glaucoma.