Friday, June 02, 2006

Section 4-E: Childhood Glaucoma

Although glaucoma occurs mostly in adults, children can get glaucoma as well. Glaucoma that is present at birth or within the first years of life is called congenital or infantile glaucoma. Congenital glaucoma occurs in 1 of 10,000 live births, so it is a rare condition. It may be inherited or can occur spontaneously without family history. It tends to occur more often in males and does not appear to have racial predilection.

As in adult glaucoma, an elevated IOP leads to glaucomatous optic nerve damage. The clinical presentation, however, is much different. Since infants have eyes which are still growing, elevated IOP can cause an increase in the size of their eyes unlike adult glaucoma. The enlargement of the eye from high pressure in infants is called buphthalmos (meaning “ox eye”; figure 4-10). The high IOP can also cause their corneas to become cloudy or hazy, which can cause tearing and sensitivity to light (“photophobia”). One or both eyes may be affected.
Typical findings of congenital glaucoma include buphthalmos (enlarged eye), sensitivity to light, and tearing from the cloudy cornea. The elevated IOP also causes the posterior layer of the cornea to be torn, in addition to optic nerve cupping and visual loss. In addition, these children are at high risk for developing “lazy eye” or amblyopia because the impaired vision secondary to cloudy cornea.

Figure 4-10. The left eye of this congenital glaucoma patient is noticeably larger than the right eye. The patient has buphthalmos of the left eye

The examination for children with suspected glaucoma includes measurements of the eye length and cornea, IOP, gonioscopy, as well as dilated examination for evaluation of the optic nerve. This may require that the infant be sedated (or put under general anesthesia) for examination. (figure 4-11) Ultrasound is used for measurements of the eye length. Serial measurements may be made to determine if the eye is stable or becoming too large from high IOPs. Unfortunately, infants cannot verbalize their vision or perform visual field testing so their glaucoma is often followed with careful eye exams without visual field documentation.

Figure 4-11. Children with congenital glaucoma often require examinations under anesthesia (EUA) for the best measurements of their eyes.

Congenital glaucoma is caused by an abnormal insertion of the iris which leads to decreased outflow of aqueous fluid from the eye. Since this developmental abnormality is the cause of the high IOP, the treatment is aimed towards relieving this abnormality. The treatment is surgical incision of this abnormality which allows better outflow of aqueous fluid from the eye. This is in contrast to adult glaucoma where surgery is often the last line of treatment for glaucoma. In addition, once surgery relieves the elevated IOP, the optic nerve damage (or cupping) may be more reversible in contrast to irreversible nature of optic nerve damage in adult glaucoma.
Despite treatment with surgery to relieve the anatomic abnormality, patients who have had congenital or infantile glaucoma need to be followed chronically for the progression of their disease. This means that they will still require periodic evaluation into adulthood. Childhood Glaucoma will be covered in more depth in Chapter 10.

Chapter 4: References
Alward WLM. Glaucoma: The Requisites in Ophthalmology. St Louis: Mosby, 2000.

Shields MB, Allingham RR, et al. Shields' textbook of glaucoma, 5th ed. Philadelphia: Lippincott Willliams & Wilkins, 2005.

Collaborative Normal-Tension Glaucoma Study Group. The effectiveness of intraocular pressure reduction in the treatment of normal-tension glaucoma. Am J Ophthalmol. 1998;126(4):498-505.

Gordon MO, Beiser JA, Brandt JD, Heuer DK, Higginbotham EJ, Johnson CA, Keltner JL, Miller JP, Parrish RK 2nd, Wilson MR, Kass MA. The Ocular Hypertension Treatment Study: baseline factors that predict the onset of primary open-angle glaucoma. Arch Ophthalmol. 2002;120(6):714-30.

Robin AL, Pollack IP. Argon laser peripheral iridotomies in the treatment of primary angle closure glaucoma. Long-term follow-up. Arch Ophthalmol. 1982;100(6):919-23.

Previous ~ Chapter 5


Post a Comment

Links to this post:

Create a Link

<< Home