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Congenital Glaucoma

5,124 views • Published on 11/03/2018 in Peds and Strabismus

(Data acquisition - Description of abnormalities)

This is an external photo of the child’s eyes.  My attention is immediately drawn to how cloudy this infant’s cornea are.  Both globes also appear to be enlarged.  It is difficult to discern iris details due to the cloudiness of the corneas.

(Data acquisition - History to obtain)

I would begin by asking the mother about a complete obstetric and family history.  Specifically, I would ask the mother if there was a history of gestationally acquired rubella infection or previous vaginal or cervical herpes simplex infection.  I would ask if there was any genetic diseases, systemic or ocular, that run through the family.  I would ask if there was any birth trauma during the delivery of the child.  I would ask the mother if the child has any systemic abnormalities.  I would ask the mother if the child seems to have any light sensitivity, blepharospasm, tearing, and whether the cloudiness was noticed at birth.
 
(Data acquisition - Exam data to seek out)

Initially, I would try my best to perform a comprehensive exam of both eyes in the office.  In particular, I would note the presence of any nystagmus and attempt retinoscopy to estimate the child’s refractive error.  I would counsel the mother than an examination under anesthesia (EUA) would be necessary to obtain a comprehensive eye exam.

I would measure the intraocular pressures of both eyes, making sure to measure the IOPs as quickly as possible after general anesthesia was induced.  During the EUA, I would perform a biomicroscopic examination of the cornea and anterior segment using a handheld slit lamp.  I would note the density and the depth of the corneal edema.  I would note the presence of tears in Descemet’s membrane and the orientation of such tears.  I would try to examine the other parts of the anterior segment looking for iris abnormalities, such as iridocorneal adhesions, and cataract formation.  I would dilate the infant’s pupils and attempt a fundus exam paying particular attention to the extent of optic disc cupping and any retinal abnormalities.

During the EUA, I would measure the horizontal and vertical diameters of the infant’s corneas using calipers. 

You are told that the infant’s horizontal corneal diameters are 13.0 mm in both eyes and the intraocular pressures are 30 mmHg OU.

A horizontal corneal diameter of 13.0 mm is grossly large since the normal infant horizontal corneal diameter measures 10.0-10.5 mm.  The intraocular pressures are also elevated since the normal IOP in an infant under anesthesia typically ranges from 10 to 15 mmHg.

Are there any other tests during the EUA you would like to perform?

I would also perform an A scan, B scan, and high-frequency ultrasound biomicroscopy (UBM).  The A-scan allows me to measure the axial length of the eye as well as the position of the iris and lens.  An even more detailed analysis of the anterior segment structures can be obtained with the UBM.  Since these corneas seem very cloudy, a B scan would help determine the presence of any gross retinal pathology such as retinal detachment.

You are told that the axial length of both eyes measures approximately 24 mm.

The normal axial length of a newborn is approximately 16-17 mm.  The axial length gradually increases to an average of 19.5 mm in infants.  An axial length of 24 mm is grossly enlarged and thus abnormal.

Is there any other test you would perform during the EUA?

I would also perform gonioscopy using a direct goniolens like the Koeppe lens.  Gonioscopy would allow me to view the anterior segment structures and help determine whether a procedure, like a goniotomy, would be possible.

(Diagnosis -- Focused differential diagnosis)

My focused differential diagnosis of cloudy corneas in infant include:
  • Sclerocornea
  • Tears in Descemet’s membrane (for example, from congenital glaucoma or birth trauma)
  • Infectious ulcer (for example, bacterial, herpes simplex virus, neurotrophic)
  • Metabolic causes (for example, the mucopolysaccharidoses)
  • Posterior corneal defects (for example, Peter’s anomaly)
  • Endothelial dystrophies (for example, CHED, PPMD, CSCD); and dermoid.  
Since this child appears to have corneal edema, elevated intraocular pressure, enlarged horizontal corneal diameters, and an enlarged axial length, the most likely diagnosis is congenital glaucoma.  Primary congenital glaucoma is the most important diagnosis to rule-in or rule-out in the differential diagnosis of congenital corneal clouding since early treatment can lead to preservation of vision and delayed treatment can lead to irreversible vision loss.

(Management -- appropriate plan for medical or surgical management of condition)

For primary congenital glaucoma, medications have limited long-term value in most cases and are primarily used to acutely lower intraocular pressure prior to surgery.  This acute lowering of intraocular pressure can reduce corneal edema to improve visualization.  I would never use an alpha-2-adrenergic agonist in an infant because these medications can cause apnea.  

The initial procedures of choice are goniotomy or trabeculotomy ab interno if there is adequate view of the angle structures or trabeculotomy ab externo if there is too poor of a view.  If the initial angle surgery fails, then a second angle surgery (either another goniotomy or trabeculotomy) can be performed.  If a second angle surgery fails to control intraocular pressure, then a filtering or tube shunt operation can be performed.

(Management -- prognosis and/or therapeutic complications)

The prognosis of primary congenital glaucoma is better for patients who are asymptomatic at birth and present with symptoms before 24 months of age.  The prognosis is more guarded if the disease is diagnosed after 24 months of age.  I would counsel the mother that even if intraocular pressure is controlled, the child’s visual prognosis can be negatively affected by corneal scarring, amblyopia, strabismus, anisometropia, cataract, lens dislocation, susceptibility to trauma, and recurrent elevation in intraocular pressure many years later.  Thus, I would counsel the mother that the infant would need to be closely monitored during her entire childhood.