Last updated: 02/17/2009

Diagnosis

The clinical signs of congenital and infantile glaucoma may be detected within a few months after birth. They include an enlarged eye, called buphthalmos; corneal swelling; decreased vision; tearing; sensitivity to light; and blepharospasm, or uncontrolled twitching of the eyes. These signs, however, are usually absent in JOAG. As a result, glaucoma in the older child may go undetected until the child loses vision.

The examiner must take some measurements in order to confirm a diagnosis of glaucoma, including measurement of the corneal diameter and the axial length of the eye. The corneal diameter is usually less then 10 mm in an infant and only 11–12 mm in a one-year-old, but can be as large as 14 mm in a child with advanced glaucoma. The axial length is measured with an A-scan, which is a type of ultrasound. The doctor will also determine the intraocular pressure with either Schiotz tonometry or a TonoPen. An elevated intraocular pressure is not always present in congenital glaucoma; unless it is extremely high, it is only one factor in the diagnosis of glaucoma. Gonioscopy, a technique used to examine the interior structures of the eye, is performed by placing a special contact lens on the eye. This lens, used in combination with a biomicroscope, allows the surgeon to evaluate the structures of the anterior part of the eye. The condition of the optic nerve is also evaluated; photos or drawings may be taken for future comparison.

Since cooperation is difficult for infants and young children, these assessments may be done either under anesthesia or with the use of a sedative. Older children are examined in a manner similar to adults.

Preparation

Once the diagnosis of glaucoma is confirmed, goniotomy is often the first line of treatment. If goniotomy is determined to be the best procedure and there is a lot of corneal haze, the surgeon may treat the patient for several days pre-operatively with azetozolamide to lower the IOP and increase the clarity of the cornea. Or, he may elect to perform another procedure called a trabeculotomy, which is the preferred surgery if the corneal diameter is greater than 14 mm. The patient is given antibiotics for several days before surgery.

Obtaining the family's informed consent is another important part of preparing for a goniotomy. The surgeon tells the family that the child will need general anesthesia, and that several postoperative visits with anesthesia or sedation will be necessary after the goniotomy.