The diagnosis and management of children with glaucoma differs greatly from adults, said Anya Trumler, MD.
A comprehensive medical history and careful ophthalmic exam are required, as is a full physical assessment to determine other systemic or organ system involvement.
"There's a lot about pediatric glaucoma that isn't the same as that in adults," said Dr. Trumler, assistant professor of ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore. "We like to think of kids as little adults, but they should be addressed differently."
Unfortunately, research in the arena of pediatric glaucoma is moving relatively slow, she said.
Because of the slow pace, however, a new research group known as the Congenital Glaucoma Research Network (CGRN) was recently formed, and is now establishing a database with information on children with pediatric glaucoma, Dr. Trumler said.
Pediatric glaucoma does not yet have a solid universally applied definition, and one of the goals of the CGRN is to create one for research purposes.
As it stands, pediatric glaucoma is defined as being present in children with IOP greater than 21 mm Hg, Dr. Trumler said.
"A child [suspected of having glaucoma] is the one with pressure greater than 21 mm Hg on two separate occasions, suspicious optic nerve, visual field defect, or a change in corneal diameter or axial length," she said.
DIAGNOSING CHILDREN WITH GLAUCOMA
A thorough history is critical for children in whom glaucoma is suspected, Dr. Trumler said.
* Look for glaucoma in a sibling or parent in infancy or childhood.
* Look all siblings of a child with a glaucoma diagnosis, because about 10% of all cases of childhood glaucoma worldwide originate from autosomal recessive inheritance.
* Check for glaucoma in all children who have demonstrated large myopic shifts during infancy and in those with a history of cataract, ocular abnormalities, uveitis, trauma, or intraocular neoplasms.
"Many secondary childhood glaucomas can occur when ocular abnormalities and systemic diseases or conditions are present, or after pediatric surgery," she said.
Ophthalmologists should also:
* Look for joint laxity.
* Palpate the liver.
* Assess for decreased hearing/tone.
* Look for Rieger's anomaly.
* Check the umbilicus.
* Look for cleft palate.
* Examine hands and toes for extra digits and broad hands and feet.
* Test for cardiac defects.
* Review any renal abnormalities.
Pediatric glaucoma may also occur following cataract surgery, Dr. Trumler said.
The incidence is about 12.2% in those who have a cataract removal at less than 4 months old at 1-year follow-up. Over 10 years, this increases to 58.7%, she said.
During the ocular exam, take note of and document any optic nerve hypoplasia or asymmetry, increased corneal diameter, age, myopia, coupled with an increase in corneal diameter, axial length, or mean reducible visual field defects.
IOP measurements can be challenging in this population, Dr. Trumler said.
Historically, the Perkins handheld applanation tonometer, or Tono-Pen, have been used, but a newer device, the rebound tonometer by Icare, is preferred, Dr. Trumler said.
Studies have shown it to be more accurate and effective in children, she said.
Clemens, et al. showed measurements with the Icare to be within 3 mm of Goldmann applanation in 63% of children, and greater than Coldmann in 75%.
Pachymetry should not be relied on too much in children, she said.
"Kids have different corneas," Dr. Trumler said. "Pachymetry is significantly higher in children. Whether they have glaucoma or not, their corneas will be thicker."
Though patients' gender and age are not risk factors for variations in pachymetry, ethnicity can be, she said.
Children of Hispanic descent have the thickest corneas, followed by Caucasians, whereas children of African-American descent have the thinnest corneas.
Optical coherence tomography (OCT) imaging and photographs are also good tools to use in the pediatric population, according to Dr. Trumler.
"While OCT is a great baseline tool, it is not always as helpful in pediatric glaucoma because there is no normative data," Dr. Trumler explained. "Photographs are very helpful in children, because you will get glimpses of the optic nerve.
"Don't just pass off children who are [suspected to have] glaucoma, document these children," she said. "Get OCT images with optic nerve head photos, and give these to the children and their parents so they can carry these with them for the rest of their lives."
* There are many differences between adults and children which should be kept in mind when recognizing and treating glaucoma.
ANYA TRUMLER, MD
Dr. Trumler has no financial disclosures.
By Liz Meszaros; Reviewed by Norman B. Medow, MD, FACS